The life cycle of an introduced caddisfly,Cheumatopsyche pettiti (Banks) (Trichoptera: Hydropsychidae) in Waikolu Stream,Molokai, Hawaii

Hawaiian streams contain some of the most unique species of aquaticinvertebrates known. In the 1960's a North American net spinningcaddisfly, Cheumatopsyche pettiti was inadvertentlyintroduced and is found in most perennial streams on Oahu, Maui,Molokai and Kauai. We investigated the life cycle of thistemperately evolved caddisfly in Waikolu Stream, Molokai. The lifecycle of C. pettiti was interpreted as probably multivoltinewith continuous recruitment throughout the year. At all samplingdates, instars I–V were present as well as pupae and adults.Detritus accounted for >50% of the gut contents of all larvae.Diatoms and other algae accounted for the remaining 50% of thediet. Cheumatopsyche pettiti has also apparently adapted toextremes in stream flows by building smaller capture nets andrudimentary retreats, usually on bedrock or firmly embeddedcobble.     

Identification of Unique Type II Polyketide Synthase Genes in Soil

Many bacteria, particularly actinomycetes, are known to produce secondary metabolites synthesized by polyketide synthases (PKS). Bacterial polyketides are a particularly rich source of bioactive molecules, many of which are of potential pharmaceutical relevance. To directly access PKS gene diversity from soil, we developed degenerate PCR primers for actinomycete type II KS_α (ketosynthase) genes. Twenty-one soil samples were collected from diverse sources in New Jersey, and their bacterial communities were compared by terminal restriction fragment length polymorphism (TRFLP) analysis of PCR products generated using bacterial 16S rRNA gene primers (27F and 1525R) as well as an actinomycete-specific forward primer. The distribution of actinomycetes was highly variable but correlated with the overall bacterial species composition as determined by TRFLP. Two samples were identified to contain a particularly rich and unique actinomycete community based on their TRFLP patterns. The same samples also contained the greatest diversity of KS_α genes as determined by TRFLP analysis of KS_α PCR products. KS_α PCR products from these and three additional samples with interesting TRFLP pattern were cloned, and seven novel clades of KS_α genes were identified. Greatest sequence diversity was observed in a sample containing a moderate number of peaks in its KS_α TRFLP. The nucleotide sequences were between 74 and 81% identical to known sequences in GenBank. One cluster of sequences was most similar to the KS_α involved in ardacin (glycopeptide antibiotic) production by Kibdelosporangium aridum. The remaining sequences showed greatest similarity to the KS_α genes in pathways producing the angucycline-derived antibiotics simocyclinone, pradimicin, and jasomycin.     

Effect of natural b-carotene supplementation in children exposed to radiation from the Chernobyl accident

Attempts were made to evaluate 709 children (324 boys and 385 girls) who had been exposed long-term to different doses of radiation during and after the Chernobyl accident and had moved to Israel between 1990 and 1994. Upon arrival, all of them underwent a check-up for most common clinical disorders and were then divided into three groups according to their residences (distance from the reactor) and the level of irradiation exposure: no radiation, <5 Ci/m², and >5 Ci/m², respectively. Blood serum analyses for total carotenoids, retinol, α-tocopherol and oxidized conjugated dienes in 262 of the children showed increased HPLC levels of conjugated dienes, indicating increased levels of oxidation of in vivo blood lipids in children from the contaminated areas. The levels were higher in girls than in boys. Some 57 boys and 42 girls were given a basal diet with a diurnal supplementation of 40 mg natural 9-cis and all-trans equal isomer mixture β-carotene in a capsulated powder form of the alga Dunaliella bardawil, for a period of 3 months. Blood serum analyses were regularly conducted before supplementation to determine the baseline effect of radiation exposure to the children, after 1 and 3 months of natural β-carotene supplementation. After supplementation, the levels of the oxidized conjugated dienes decreased in the children's sera without any significant changes in the level of total carotenoids, retinol or α-tocopherol. Other common blood biochemicals were within the normal range for all tests and no statistical differences before or after supplementation of β-carotene were noted. High pressure liquid chromatography (HPLC) analyses for carotenoids in the blood detected mainly oxycarotenoids, and to a lesser extent, all-trans β-carotene, α-carotene, but not 9-cis β-carotene. The results suggest that irradiation increases the susceptibility of lipids to oxidation in the Chernobyl children and that natural β-carotene may act as an in vivo lipophilic antioxidant or radioprotector. Received: 20 March 1998 / Accepted in revised form: 1 August 1998     

The serotyping of Azospirillum spp. by cell-gold immunoblotting

Ten Azospirillum strains were serotyped using the method of cell-gold immunoblotting (dot-blot immune-overlay assay). Colloidal gold-protein A conjugate was used. Antibodies raised against the whole cells showed strain specificity and interacted mainly with carbohydrate antigens on the cell surface. Immunological identity for A. brasilense Sp 245 and Sp 107 strains was found. Cell-gold immunoblotting can be recommended for serotyping of a wide variety of bacterial strains.     

Standardized,systemic phenotypic analysis of Slc12a1I299F mutant mice

Background

Type I Bartter syndrome is a recessive human nephropathy caused by loss-of-function mutations in the SLC12A1 gene coding for the Na⁺-K⁺-2Cl⁻ cotransporter NKCC2. We recently established the mutant mouse line Slc12a1^I299F exhibiting kidney defects highly similar to the late-onset manifestation of this hereditary human disease. Besides the kidney defects, low blood pressure and osteopenia were revealed in the homozygous mutant mice which were also described in humans. Beside its strong expression in the kidney, NKCC2 has been also shown to be expressed in other tissues in rodents i.e. the gastrointestinal tract, pancreatic beta cells, and specific compartments of the ear, nasal tissue and eye.

Results

To examine if, besides kidney defects, further organ systems and/or metabolic pathways are affected by the Slc12a1^I299F mutation as primary or secondary effects, we describe a standardized, systemic phenotypic analysis of the mutant mouse line Slc12a1^I299F in the German Mouse Clinic. Slc12a1^I299F homozygous mutant mice and Slc12a1^I299F heterozygous mutant littermates as controls were tested at the age of 4–6 months. Beside the already published changes in blood pressure and bone metabolism, a significantly lower body weight and fat content were found as new phenotypes for Slc12a1^I299F homozygous mutant mice. Small additional effects included a mild erythropenic anemia in homozygous mutant males as well as a slight hyperalgesia in homozygous mutant females. For other functions, such as immunology, lung function and neurology, no distinct alterations were observed.

Conclusions

In this systemic analysis no clear primary effects of the Slc12a1^I299F mutation appeared for the organs other than the kidneys where Slc12a1 expression has been described. On the other hand, long-term effects additional and/or secondary to the kidney lesions might also appear in humans harboring SLC12A1 mutations.     

Iodine-129 measurements in soil samples from Dolon village near the Semipalatinsk nuclear test site

Dolon village, located about 60 km from the border of the Semipalatinsk nuclear test site, is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly (131)I). Iodine-129 in soil was measured by using the technique of accelerator mass spectrometry. The (129)I/(127)I atom ratios measured were in the range from 3.3 x 10(-9) to 3.3 x 10(-7). These values were within the range of the current background level ( approximately 10(-9) to 10(-7)) in the environment, including contributions from the global fallout of atmospheric nuclear tests and local fallout of nuclear facilities. The (129)I atom accumulated level in soil ranged from 1.28 x 10(13) to 1.59 x 10(14) atoms m(-2), the average (8.0 x 10(13)) of which was higher than the background level of (2-5) x 10(13). From the relationship between (129)I and( 137)Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of (129)I and the (129)I/(137)Cs ratio around Dolon were estimated to be (6.4 +/- 0.4) x 10(13) atoms m(-2) and 0.25 +/- 0.16, respectively. This (129)I/(137)Cs ratio is almost similar to the fission yield ratio for (239)Pu fast fission (0.24).     

NON-TOXIC GOITER TREATMENT WITH I-TRIIODOTHYRONINE AND I-THYROXINE

Twenty-one patients with goiters—four diffuse and 17 nodular—were treated with I-triiodothyronine and I-thyroxine in doses to tolerance. The four diffuse goiters were barely palpable at the end of the treatment. The average dose of I-triiodothyronine required was 100 mcg. per day. The average dose of I-thyroxine was 0.3 mg. per day. Of the 17 multinodular goiters, 11 showed at least a 50 per cent reduction in size. The average dose of I-triiodothyronine used was 125 mcg. In six cases the gland did not change in size; in three of the six the lesion was diagnosed, at operation, as microfollicular and macrofollicular colloid goiter.Hypermetabolic symptoms may occur when doses of 100 mcg. or more of I-triiodothyronine are used.Results indicated that suppressive therapy with thyroid hormone to tolerance is effective in diffuse goiters. It is only partially effective in the treatment of multinodular goiters. In the cases in which operation was done, no change in the basic histological goiter structure was observed.     

Mechanism of chaperone-like activity. Suppression of thermal aggregation of betaL-crystallin by alpha-crystallin

Thermal denaturation and aggregation of beta(L)-crystallin from bovine lens have been studied using differential scanning calorimetry (DSC) and dynamic light scattering (DLS). According to the DLS data, the distribution of the beta(L)-crystallin aggregates by their hydrodynamic radius (R(h)) remains monomodal to the point of precipitating aggregates (sodium phosphate, pH 6.8; 100 mM NaCl; 60 degrees C). The size of the start aggregates (R(h,0)) and duration of the latent stage (t(0)) leading to the formation of the start aggregates have been determined from the light scattering intensity versus the hydrodynamic radius plots and the dependences of R(h) on time. The R(h,0) value remains constant at variation of the beta(L)-crystallin concentration, whereas the t(0) value increases with diminishing beta(L)-crystallin concentration. The suppression of beta(L)-crystallin aggregation by alpha-crystallin is connected with the decrease in the R(h,0) value and increase in the t(0) value. In the presence of alpha-crystallin the aggregate population is split into two components. The first component is represented by stable aggregates whose size remains constant in time. The aggregates of the other kind grow until they reach the size characteristic of aggregates prone to precipitation. The DSC data show that alpha-crystallin has no appreciable influence on thermal denaturation of beta(L)-crystallin.