Karyosystematics ofVeronica sect.Beccabunga (Scrophulariaceae) with special reference to the taxa in Turkey

The chromosome numbers ofVeronica beccabunga subsp.abscondita (2n=18),V. anagallis-aquatica subsp.lysimachioides (2n=18),V. anagallis-aquatica subsp.michauxii (2n=36), and of a presumable hybridV. poljensis × V. anagalloides (2n=36) are new for the relevant taxa. — A new number was found forV. anagalloides subsp.heureka (2n=18). The other counts, ofV. scardica (2n=18),V. anagalloides subsp.anagalloides (2n=18), andV. anagallis-aquatica subsp.oxycarpa (2n=36) agree with earlier findings.—Data from the literature have been critically evaluated, in some cases the relevant vouchers have been checked and, where needed, the original determinations have been revised. For several taxa, comments concerning their systematics and remarks on their distribution in Turkey are given.     

Die Chromosomenzahlen von tschechoslowakischen Arten der GattungKnautia L. (Dipsacaceae)

Die Chromosomenzahlen von den tschechoslowakischen Sippen der GattungKnautia L. sind angegeben:K. drymeia Heuffel subsp.drymeia—2n = 40 (41,42),K. slovaca ?těpánek— 2n = 20,K. arvensis (L.)Coulter subsp.arvensis—2n = 20, 40 (39, 41),K. arvensis (L.)Coulter s. 1.—2n = 20,K. kitaibelii (Schult.) Borbás—2n = 20 (39, 41),K. dipsacifolia Kreutzer subsp.dipsacifolia—2n = 60,K. dipsacifolia agg.—2n = 40, 50, 60. Keine taxonomisch wertvolle morphologische Unterschiede zwischen diploiden und tetraploiden Zytotypen vonK. arvensis subsp.arvensis wurden gefunden. Für die Populationen von Pflanzen, deren Morphologierauf Kreuzung oder Introgression zwischen tetraploiden Sippen (K. arvensis subsp.arvensis—4x,K. drymeia subsp.drymeia, K. kitaibelii undK. dipsacifolia agg.) zeigt, wurden ím Einklang mit dieser Voraussetzung die tetraploiden Chromosomenzahlen—2n = 40 (39, 41)— festgestellt. Einige ungelöste taxonomische Fragen hauptsächlich über die diploiden Populationen vonK. arvensis s. l. in Böhmen und überK. dipsacifolia agg. in den Westkarpaten werden diskutiert.     

A high polyploidEleocharis uniglumis S.L. (Cyperaceae) from Central and Southeastern Europe

Chromosome counts and morphological measurements were carried out onEleocharis uniglumis s. 1. samples from nine populations in Slovakia, Hungary, Austria and Croatia. A high polyploidEleocharis uniglumis s.l. (2n=71–88) was found on halophilous sites: in western Slovakia (Svätojurský ?úr near Bratislava; 2n=71–78), on the Hungarian and Austrian shores of Lake Neusiedlersee (Hungary: Hidegség; Austria: Tadten, St. Andrä am Zicksee; 2n=71–82), and on the Croatian island of Krk, (shores of Lake Jezero and Lake Ponikve; 2n=80–88). These high polyploid populations have the same ploidy level asE. uniglumis subsp.sterneri, described as endemic to the islands of Öland and Gotland. Morphological similarities between the high polyploids and subsp.sterneri were found both in quantitative features correlated with ploidy level (stomatal length, anther length and fertile glume length) and in other characters (number of perianth bristles, broad sterile glume margins). Differences were detected in the receptacle density and in the length of perianth bristles compared to the length of the achene. Intermediate somatic chromosome numbers 2n=60–70, corresponding to Scandinavian hybrids betweenE. uniglumis subsp.uniglumis andE. uniglumis subsp.sterneri, were found near Neusiedlersee (Austria: Apetlon, Tadten; Hungary: Hidegség, Hegykö). These (karyologically intermediate) plants have intermediate stomatal lengths. In other features they are similar to the Central European high polyploids.Eleocharis uniglumis subsp.uniglumis (2n=46) was found here as well (Hungary: Fert?rákos).     

Can enemy release explain the invasion success of the diploid <Emphasis Type="Italic">Leucanthemum vulgare</Emphasis> in North America?

Enemy release is a commonly accepted mechanism to explain plant invasions. Both the diploid Leucanthemum vulgare and the morphologically very similar tetraploid Leucanthemum ircutianum have been introduced into North America. To verify which species is more prevalent in North America we sampled 98 Leucanthemum populations and determined their ploidy level. Although polyploidy has repeatedly been proposed to be associated with increased invasiveness in plants, only two of the populations surveyed in North America were the tetraploid L. ircutianum. We tested the enemy release hypothesis by first comparing 20 populations of L. vulgare and 27 populations of L. ircutianum in their native range in Europe, and then comparing the European L. vulgare populations with 31 L. vulgare populations sampled in North America. Characteristics of the site and associated vegetation, plant performance and invertebrate herbivory were recorded. In Europe, plant height and density of the two species were similar but L. vulgare produced more flower heads than L. ircutianum. Leucanthemum vulgare in North America was 17 % taller, produced twice as many flower heads and grew much denser compared to L. vulgare in Europe. Attack rates by root- and leaf-feeding herbivores on L. vulgare in Europe (34 and 75 %) was comparable to that on L. ircutianum (26 and 71 %) but higher than that on L. vulgare in North America (10 and 3 %). However, herbivore load and leaf damage were low in Europe. Cover and height of the co-occurring vegetation was higher in L. vulgare populations in the native than in the introduced range, suggesting that a shift in plant competition may more easily explain the invasion success of L. vulgare than escape from herbivory.     

Significant Attenuation of Stimulated Cortisol In Early Graves Disease Without Adrenal Autoimmunity

ObjectiveTo investigate cortisol responses to adreno corticotropic hormone during thyrotoxic (G1) and euthyroid (G2) phases in patients with Graves disease (GD) who were without adrenal autoimmunity.MethodsFifteen patients with GD, who were thyrotropin receptor antibody positive and 21-hydroxylase antibody negative, were recruited to this prospective pilot study. A modified short Synacthen test (SST) was per formed, in which cortisol was measured every 30 minutes for 2 hours during G1 and G2.ResultsThe median times to SST were 3 weeks (G1) and 27 weeks (G2) after diagnosis of GD. Integrated stimulated cortisol levels were significantly lower at G1 in comparison with G2: mean ± standard error of the mean for area under the curve was 78,091.6 ± 4,462.1 nmol/L (G1) versus 89,055 ± 4,434 nmol/L at 120 minutes (G2), P = .017; and for delta area under the curve was 36,309.9 ± 3,526 nmol/L (G1) versus 44,041.7 ± 2,147 nmol/L at 120 minutes (G2), P = .039. Mean cortisol levels were significantly lower for G1 versus G2 at 60, 90, and 120 minutes of the SST (P = .001 to .013). The cortisol level was abnormal in 2 patients (13%) at 30 minutes during G1 but in none during G2. There was no correlation of inte grated cortisol with free thyroxine or thyrotropin receptor antibody. There was no significant difference in median adrenocorticotropic hormone level (17 versus 20.4 ng/mL at G1 and G2, respectively; P = .14).ConclusionSignificant attenuation of stimulated cortisol occurs in the early thyrotoxic phase in comparison with the euthyroid phase in patients with GD without adrenal autoimmunity. Clinicians treating patients with GD should have a low threshold for investigating symptoms suggestive of hypoadrenalism at times of “stress.” (Endocr Pract. 2012;18:924-930)     

Chromosome counts of some MongolianPotentilla species

Chromosome numbers are reported for 26 collections representing 12 MongolianPotentilla taxa. The first chromosome records are reported forP.[x]agrimonioides Bieb. (2n = 42, 49–50),P. [x]chionea Soják (2n = 64, 74+1B, 84–86, 86),P. [x]stepposa Soják (2n = 62) andP. supina, L. subsp.costata Soják (2n = 42). Tetraploid and pentaploid populations ofP. sericea L. (2n = 28, 34, 35) and hexaploid populations ofP. omithopoda Tausch (2n = 42) were found in Mongolia. Chromosome numbers of the following species were confirmed:P. longifolia Willd. exSchlecht. (2n = 14),P. multifida L. (2n = 28),P. sanguisorba Willd. exSchlecht. (2n = 28),P. sericea L. (2n = 42),P. supina L. subsp.paradoxa (Nutt.) Soják (2n = 28 China) andP. tanacetifolia Willd. exSchlecht. (2n = 28). Taxonomic observations are briefly discussed.     

Phytochemical diversity of Origanum vulgare L. subsp. vulgare (Lamiaceae) from Austria

This investigation was aiming at the phytochemical characterisation of Origanum vulgare subsp. vulgare from Austria. To study the qualitative and quantitative composition of essential oil compounds 374 individual plants were analysed via GC. The volatiles of Austrian O. vulgare subsp. vulgare were found to be complex mixtures of 53 mono- and sesquiterpenes. Among the sesquiterpenes β-caryophyllene, germacrene D, E-E-α-farnesene, germacrene D-4-ol and caryophyllene oxide were frequently present in higher amounts. The monoterpenes were mainly made up of sabinyl-compounds [mainly sabinene (up to 48.4%) and cis-sabinene hydrate (up to 57.8%)] and/or cymyl-compounds [mainly p-cymene (up to 49.7%), γ-terpinene (up to 21.5%) and carvacrol (up to 32.9%)] that were accompanied by usually smaller amounts of bornyl-compounds and acyclic compounds. Some exceptional (in O. vulgare rare) chemotypes were detected. The essential oil content of Austrian O. vulgare subsp. vulgare ranged between 0.1 and 1.8%. The content of rosmarinic acid was analysed by HPLC and ranged from 0.6 mg/g dry mass up to 37.2 mg/g dry mass. No arbutin could be detected in the analysed populations.     

Karyo-taxonomic study of the genus<Emphasis Type="Italic">Pseudolysimachion</Emphasis> (<Emphasis Type="Italic">Scrophulariaceae</Emphasis>) in the Czech Republic and Slovakia

Flow cytometry was used to determine ploidy levels in the Czech and Slovak taxa of the genusPseudolysimachion (W.D.J. Koch)Opiz (=Veronica auct. p.p.,Scrophulariaceae). In total, 123 populations from the Czech Republic, Slovakia, Ukraine (one locality), Austria (one locality) and Hungary (one locality) were analyzed. InP. maritimum (L.)Á. Löve etD. Löve andP. spicatum (L.)Opiz, two cytotypes were found: diploid (2n=2x=34) and tetraploid (2n=4x=68). In both species the tetraploid cytotype predominated (P. maritimum: 41 tetraploid populations out of 45;P. spicatum: 57 tetraploid populations out of 58). The two cytotypes ofP. maritimum have no taxonomic significance because ploidy level is not obviously correlated with morphology, distribution pattern or ecology. Tetraploid populations ofP. spicatum belong to two morphologically different subspecies, subsp.spicatum and subsp.fischeri Trávní?ek. The diploid cytotype (one population only) should be provisionally classified as a third subspecies ofP. spicatum, which is morphologically similar to the Asian subsp.porphyrianum (Pavlov)Trávní?ek. Only diploid plants (2n=2x=34) ofP. orchideum (Crantz)Wraber were found; all 13 populations that were analyzed belong toP. orchideum s.str. One diploid population sample ofP. spurium subsp.foliosum (Waldst. etKit.)Holub (2n=2x=34) and one tetraploid sample ofP. incanum subsp.pallens (Host)Trávní?ek (2n=4x=68) were also analyzed. In addition, three tetraploid populations of hybrid origin were investigated:P. maritimum ×P. spicatum subsp.spicatum (one population) andP. maritimum ×P. spurium subsp.foliosum (two populations). While hybrid plants ofP. maritimum ×P. spicatum arose from tetraploid parental species, plants ofP. maritimum ×P. spurium probably resulted from a cross between tetraploidP. maritimum and diploidP. spurium. The putative origin and evolutionary importance of polyploids in thePseudolysimachion are discussed.     

Chromosome numbers and DNA ploidy levels of selected species ofHieracium s.str. (Asteraceae)

Chromosome numbers and /or ploidy levels are reported for 44 species and subspecies ofHieracium s.str. from the following European countries: Andorra, Austria, Bulgaria, Czech Republic, France, Italy, Montenegro, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland and Ukraine. The chromosome numbers/DNA ploidy levels ofH. bocconei (2n ～ 4x),H. bupleuroides subsp.leviceps (2n = 27),H. caesioides subsp.caesioides (2n = 27),H. basifolium (H. caesium agg., 2n = 36),H. plumbeum (H. caesium agg., 2n = 36),H. glaucum subsp.nipholepium (2n= 27),H.gouanii (2n = 18),H. gymnocerinthe (2n = 27),H. ramondii (2n = 27),H. recoderi (2n = 18),H. stelligerum (2n = 18), andH. tomentosum (2n = 18, 2n ～ 2x, 2n ～ 3x) were determined for the first time. New ploidy levels are reported forH. cerinthoides s.str. (2n = 27),H. humile (2n = 36), andH. tommasinianum (2n = 27).     

Comparison of Basal Insulin Regimens on Glycemic Variability in Noncritically Ill Patients with Type 2 Diabetes

Objective: To evaluate the impact of different subcutaneous basal insulin regimens on glycemic variability (GV) and hospital complications in non-intensive care unit (ICU) patients with type 2 diabetes (T2D).Methods: This study is a post hoc analysis of 279 general medicine and surgery patients treated with either a “Basal Bolus” insulin regimen using glargine once daily and glulisine before meals or a “Basal Plus” regimen using glargine once daily plus correction doses of glulisine before meals for glucose >140 mg/dL. GV was calculated as mean delta (Δ) daily glucose, mean SD, and mean amplitude of glycemic excursions (MAGE).Results: Treatment with Basal Bolus and Basal Plus regimens resulted in similar mean daily glucose, hypoglycemia, length of stay (LOS), and hospital complications (all P>.05). There were no differences in GV between treatment groups by Δ change (72.5 ± 36 vs. 69.3 ± 34 mg/dL), SD (38.5 ± 18 vs. 37.1 ± 16 mg/dL) and MAGE (67.5 ± 34 vs. 66.1 ± 39 mg/dL) (all P>.05). Surgery patients treated with Basal Bolus had higher GV compared to those treated with Basal Plus (Δ daily glucose and SD: P = .02, MAGE: P = .009), but no difference in GV was found between treatment groups for the general medicine patients (P>.05). Patients with hypoglycemia events had higher GV compared to subjects without hypoglycemia (P<.05), but no association was found between GV and hospital complications (P>.05).Conclusion: Treating hospitalized, non-ICU, diabetic patients with Basal Plus insulin regimen resulted in similar glucose control and GV compared to the standard Basal Bolus insulin regimen. Higher GV was not associated with hospital complications.Abbreviations:BG = blood glucoseCV= coefficient of variationGV= glycemic variabilityICU = intensive care unitLOS = length of stayMAGE = mean amplitude of glycemic excursionsSSI = sliding scale insulinT2D = type 2 diabetesTDD =total daily dose     

Genetic differentiation in theAedes atropalpus complex. I. Isozyme variability and genetic distances betweenAe. atropalpus andAe. epactius

During the course of their evolution,Ae. atropalpus andAe. epactius have undergone considerable genetic differentiation. The average genetic distance between the two species was 0.458 ±0.05. The average genetic distance between populations ofAe. atropalpus was 0.019 ± 0.01 while the average distance between populations ofAe. epactius was 0.075 ±0.02. The GREEN population, representing the new “form” ofatropalpus found breeding in discarded tires, exhibited electromorph frequencies characteristic of the “typical”atropalpus populations. Of the enzymatic loci examined, ADK2 was species diagnostic, and PGi was species discriminating. The electrophoretic results from the populations examined have provided additional support for the present taxonomic status of the two species.     

Correlation of viral load of Hepatitis B with the gestation period and the development of diabetes mellitus

ObjectiveTo elaborate how the viral load of HBV affects the gestational diabetes mellitus (GDM).MethodsWe enrolled 196 chronic HBV-infected pregnant patients in this hospital between January 2012 and December 2017 for delivery in this study. According to the viral load of HBV-DNA, these patients were divided into the HBV-DNA negative group (n = 107, <1 × 10³ copies/mL) and HBV-DNA positive group (n = 89, ≥1 × 10³ copies/mL). Simultaneously, 100 HBV-free pregnant women who were admitted to the hospital for delivery were included in the control group. Before delivery, fasting venous blood was drawn from the pregnant women to perform the HBV-DNA quantification through qRT-PCR; from the 24th to 28th gestation week, all pregnant women underwent OGTT, with the third-trimester-of-pregnancy as the endpoint. Besides, we also measured the FBG, 2hPG and hemoglobin A1c (HbAIc).ResultsAmong 168 pregnant patients carrying chronic HBV, viral load of 107 patients was less than 1 × 10³ copies/mL (54.6%), and 89 not less than 1 × 10³ copies/mL (45.4%). The incidence rates of GDM in the HBV-DNA negative group and HBV-DNA positive group were 18.7% and 19.1%, respectively, significantly higher than that in the control group (p < 0.05), while the difference of the incidence rates of GDM between two HBV-DNA groups were not significant (p > 0.05). In HBV-DNA negative group and HBV-DNA positive group, FBGs, 2hPGs and HbAIcs were respectively (6.96 ± 0.36) mmol/L and (7.04 ± 0.37) mmol/L, (10.26 ± 1.29) mmol/L and (10.16 ± 1.12) mmol/L, and (8.66 ± 0.97) % and (8.91 ± 0.90) %, significantly higher than (4.57 ± 0.34) mmol/L, (6.16 ± 0.86) mmol/L and (5.13 ± 0.57) % (p < 0.05); however, between two HBV-DNA groups, comparisons of the FBG, 2hPG and HbAIc suggested no significant differences (p > 0.05). In 196 patients carrying chronic HBV, positive correlations were identified between the viral load of HBV-DNA, and FBG, 2hPG and HbAIc (p < 0.01).ConclusionHBV infection can increase the incidence rate of GDM, and the viral load of HBV-DNA is correlated with the glucose level of pregnant patients.     

Animal protein-free OptiXcell and shortened equilibration periods can replace egg yolk-based extender and slow cooling for rhinoceros semen cryopreservation

OptiXcell (OP) was tested as an animal protein-free alternative to an egg yolk-based extender for rhinoceros semen cryopreservation and shorter chilling/equilibration periods were evaluated. Semen was collected from three rhinoceros species: black (Diceros bicornis; n = 2), white (Ceratotherium simum; n = 2), and greater one-horned (GOH; Rhinoceros unicornis; n = 3). Controls were diluted with equine extender (EQ) or OP and equilibrated for 1 h. Treatments were diluted with extender and cooled for 15 min (fast: FEQ; FOP) or not cooled (immediate: IEQ; IOP), prior to cryopreservation. Motility decreased post-thaw (EQ: 50.7 ± 5.2%; OP: 52.9 ± 3.4%) from fresh (82.9 ± 2.9%), was higher in OP than IOP (38.6 ± 4.9%; P ≤ 0.05) and decreased over time (P ≤ 0.05). Post-thaw acrosomal integrity was lower in EQ, FEQ, and IEQ (56.9 ± 0.7; 56.6 ± 4.5; 54.9 ± 2.9%) than OP, FOP, IOP (71.8 ± 4.7; 71.9 ± 3.8; 69.9 ± 4.5%) and fresh (72.6 ± 1.4%; P ≤ 0.05). Progression and viability were lower in EQ (2.8 ± 0.2; 61.9 ± 7.4%) and OP (3.1 ± 0.2; 53.4 ± 6.9%) than fresh (3.7 ± 0.2; 87.2 ± 1.3%), decreased over time (P ≤ 0.05) but not different among treatments (P > 0.05). Morphology did not differ between fresh (75.0 ± 4.9% normal) and any treatment group (70.0–77.8%) or over time (P > 0.05). OptiXcell is comparable to egg yolk-based EQ when used for rhinoceros semen cryopreservation. Furthermore, chilling/equilibration can be reduced with little impact on sperm characteristics.     

New chromosome numbers for plant taxa endemic to the Balearic Islands

Mitotic chromosome numbers are reported from 25 vascular plant taxa, endemic to the Balearic Islands that are poorly known cytogenetically. The chromosome numbers ofAnthyllis vulneraria subsp.balearica (2n=12),Cymbalaria fragilis (2n=56), andPolygonum romanum subsp.balearicum (2n=40) were determined for the first time. A new chromosome number was found in several populations ofAnthyllis hystrix (2n=70) suggesting that this species is decaploid, in contrast to an earlier work reporting a higher ploidy level (2n=12x=84). The new chromosome number 2n=32 was reported inHypericum hircinum subsp.cambessedesii. It is suggested that the previous count (2n=40) could be explained by the presence of anomalous pentaploid cells in some tissues, contrating with the presence of a regular tetraploid complement (2n=32). Cytogenetic observations suggest thatSibthorpia africana has a diploid chromosome complement of 2n=18, with 0–2 accessory chromosomes. Accessory chromosomes are also reported forPhlomis italica, being the first record of B chromosomes in this genus. Chromosomal instability was found inGalium crespianum andG. friedichii species, with three numbers 2n=44, 55 and 66. Two cytotypes differing in ploidy level were documented within single plants. It is suggested that both species share a regular complement of 2n=44 and that the past hybridization events and formation of regenerating roots from the typical rootstock ofG. crespianum andG. friedrichii could be involved in the genesis of chromosome variants through partial endopolyploidy and concomitant somatic segregation.     

Comparative karyotype analysis of populations in the Alstroemeria presliana Herbert (Alstroemeriaceae) complex in Chile

Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28–38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered “endangered” and 10 as “vulnerable”). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27′ S, Region of Maule) to Antuco, (37°25′ S, Region of Bío-Bío), and is also found in Neuquén, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CV_CL vs. M_CA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level.     

OIL FLOWERS AND OIL BEES: FURTHER EVIDENCE FOR POLLINATOR ADAPTATION

We examined foreleg length and body size variation in two species of oil-collecting bees (Rediviva; Melittidae) in southern Africa. Oil-collecting bees harvest oil from host flowers by rubbing their forelegs against oil-secreting trichomes. Significant differences in foreleg length occur among populations of both species. Rediviva “pallidula” populations vary significantly in mean foreleg length (11.34 ± 0.42 mm to 12.67 ± 0.36 mm), but not in body length (10.59 ± 0.74 to 10.80 ± 0.64), and foreleg length and body size are not significantly correlated. Instead, foreleg variation appears to be a function of host plant spur length. Ninety-two percent of the variance in foreleg length of R. “pallidula” is explained by mean Diascia spur length. Rediviva rufocincta populations vary significantly in mean foreleg length (10.12 ± 0.70 mm to 12.34 ± 0.68 mm) and in body length (9.03 ± 0.26 mm to 10.56 ± 0.24 mm). Foreleg length scales allometrically with body size in this species as 90.5% of the variance in foreleg length can be explained as a function of body length. Body size appears to be constrained by the morphology of the oil-secreting host plant. Both bees collect floral oil with specially modified setae on the tarsi of their forelegs. The length of the disti- + mediotarsus (refered to here as “tarsus”) in relation to the entire foreleg is shorter in R. rufocincta and does not increase as rapidly with increasing foreleg length as for R. “pallidula.” These differences in variation can be attributed to differences in position of oil within the flowers of the respective host plants. Rediviva “pallidula” collects oil from Diascia species that have the oil deeply situated in narrow floral spurs of varying length, while R. rufocincta collects oil from the broadly saccate flowers of Bowkeria verticillata and B. citrina.     

TLC screening of thraustochytrid strains for squalene production

Screenings of thraustochytrids (Labyrinthulomycetes) have been conducted for 176 strains isolated from various sites in the Asian region to investigate what type of species and strains accumulate high levels of squalene. Thin layer chromatography (TLC) screening for squalene production revealed that 38 strains were rated as “+” (high), 29 as “±” (medium), and 109 as “?” (low). Further, high performance liquid chromatography analysis strongly supported the TLC screening results. Besides the 18W-13a strain of Aurantiochytrium sp., which was previously recognized as a squalene-rich strain, several strains produced squalene at approximately 1 g L^?1 of culture volume. Squalene production was strongly related to locality, colony color, and phylogenetic clade. Most strains with “+” squalene spots were isolated from Okinawa, a subtropical region of Japan, while the strains with “±” and “?” squalene spots were isolated from wide geographical regions from tropical to subarctic. Approximately half the strains with orange colonies on GTY medium plates produced a high amount of squalene, whereas the other strains with different colors showed less or no squalene spots on TLC. All the squalene-rich strains were assigned to the Aurantiochytrium clade. Overall, our results suggest that (1) the thraustochytrids show tendentious locality in terms of squalene production, (2) a relationship exists between the metabolic synthesis of carotenoid pigments and squalene production, and (3) the Aurantiochytrium clade may have evolved to accumulate squalene.     

Cytogenetic studies on natural intergeneric hybridization inAster alliances

In addition to various types of natural hybrids betweenAster ageratoides subsp.ovatus andKalimeris incisa reported earlier, a new backcross type has been discovered. This new type, characterized by the chromosomes of 2n=27L+54S, was most probably produced through fertilization of a normally-reduced gamete of the F₁ plant (2n=72=18L+54S) and an unreduced gamete of subsp.ovatus (2n=36=18L+18S).     

Basal and Stimulated Plasma Leptin in Diabetic Subjects

LIU, JIANMEI, HASAN ASKARI, AND SAMUEL DAGOGO-JACK. Basal and stimulated plasma leptin in diabetic subjects. Obes Res. Objective: To determine whether leptin secretion is impaired in diabetes, we compared basal and stimulated plasma leptin levels in diabetic subjects and healthy controls. Research Methods and Procedures: Blood samples for assay of leptin and other hormones were obtained at baseline in 54 diabetic patients and 65 controls, and 8 hours, 16 hours, and 40 hours following ingestion of dexamethasone (4 mg) in 6 healthy and 12 controls. C-peptide status was defined as “negative” if ≤0.1 ng/mL or “positive” if ≥0.3 ng/mL, in fasting plasma. Results: Basal plasma leptin levels were 19. 7±2. 2 ng/mL in nondiabetic subjects, 13. 4±1. 5 ng/ml in C-peptide negative (n = 28) and 26. 1±23. 7 ng/mL in C-peptide positive (n = 26, p = 0. 001) diabetic patients. Dexamethasone increased leptin levels of controls (n = 6) to 145±17% of baseline values at 8 hours (p = O. O3), 224±18% at 16 hours (p = 0. 01), and 134218% at 40 hours (p = 0. 05). The corresponding changes were 108±13%, 126±23%, and 98±16% in C-peptide negative (n = 6), and 121±10%, 144±16% (p = 0. 03), and 147±23% (p = 0. 11) in C-peptide positive (n = 6) diabetic patients, respectively. The peak stimulated leptin levels were lower in the diabetic patients, compared with controls. Plasma insulin increased (p = 0. 02) in controls, but not in the diabetic patients, following dexamethasone. Discussion: Although diabetic patients have normal plasma leptin levels under basal conditions, their leptin responses to glucocorticoid are impaired, probably because of the concomitant insulin secretory defect. A subnormal leptin secretory response could worsen obesity and insulin resistance in diabetes.     

Cytotaxonomic study ofChelidonium majus L. s. l.

The present paper deals with cytotaxonomy ofChelidonium majus L. s. 1. taxa and their hybrids. Based on results of hybridization experiments, cytology and reproductive isolation, a new combination,Ch. asiaticum (Hara) Krahulcová, is proposed. The structure of the aggregate is as follows:Ch. majus L. subsp.Majus (2n=12, distributed in Europe),Ch. majus L. subsp.grandiflorum (DC.)Printz (2n=12, S. Siberia, China) andCh. asisaticum (2n=10, E. Asia). Karyotypes ofCh. m. subsp.grandiflorum andCh. asiaticum are compared in detail.