Calmodulin-binding drugs affect responses to cytokinin, auxin, and gibberellic Acid

Trifluoperazine, a phenothiazine tranquilizer, and tetracaine, a local anesthetic, have been found to inhibit a variety of plant hormone responses at concentrations compatible with their known inhibition of Ca²⁺-calmod-ulin-dependent enzyme activities. Among these responses are cytokinin-dependent betacyanin synthesis and increase in fresh weight in Amaranthus tricolor cotyledons, auxin-dependent increase in length of wheat coleoptile segments and gibberellic acid-dependent induction of α-amylase synthesis in barley aleurone layers. The reversibility of some of these inhibitory effects has been demonstrated, indicating that, up to a point, a generalized membrane destruction can be ruled out. The evidence, taken in conjunction with numerous examples from the literature showing calcium involvement in the action of all of the plant hormones, support a unifying theory of hormone action.     

Glucose Tolerance and Serum Insulin in Identical Twins of Diabetics

Glucose tolerance with serum insulin assay has been carried out in 24 apparently unaffected identical twins of diabetics. Glucose values were significantly higher and insulin values significantly lower than in control subjects, but there was considerable individual variation and in half the cases glucose tolerance was normal. There was no case of increased insulin response. In these twins glucose tolerance and insulin response were not correlated with weight, family history of diabetes, age at diagnosis of diabetes in the affected twin, time since that diagnosis, nor with age at testing the unaffected twin. On retesting 12 of the twins after two years no significant differences were found from the first testing.We conclude that not all these twins are likely to develop diabetes, that the assumption that identical twins of diabetics are necessarily “prediabetic” is probably erroneous, and that factors other than genetic ones are important in the aetiology of diabetes.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

Sex chromosome complement and developmental diversity in pre-and post-hatching porcine embryos

To examine sex and development relationships in porcine embryos in early gestation, 10 gilts were killed on Day 4, 5, or 6 post mating (first day of standing estrus = Day 0). Embryos recovered immediately after slaughter were cultured in Medium 199 with colcemid (0.05mug/ml), fixed on slides, and stained with 4% Giemsa. The number of cells in each specimen was counted from the slides, and, whenever cell dispersion allowed, sex was determined by presence or absence of the Y-chromosome in at least 2 spreads from each embryo. Three gilts slaughtered on Day 4 yielded 2- and 4-cell stage embryos (n = 38), but no data on sex could be obtained due to lack of mitosis or readable metaphase spreads. Three Day 5 litters had individual specimens ranging from 8 to 14 cells (n = 8), 32 to 64 cells (n = 10), and 13 to 31 cells (n = 11), with the sex determined in 15 of these. Cell numbers ranged from 18 to 165 (n = 14), 16 to 32 (n = 9), 36 to 82 (n = 12), and 16 to 30 (n = 9) in the 4 gilts slaughtered on Day 6, with the sex determined in 26 of these. Embryos within each litter were divided into low, medium and high cell numbers by 3 equal divisions of the range of cell numbers. Three Day-5 embryos and 1 Day-6 embryo were lost during preparation; neither the cell numbers nor the sex could be determined in 4 Day-5 and in 3 Day-6 embryos. The overall sex ratio approximated 1:1, but on Day 5, the ratios for males to females were 0:5, 1:3 and 6:0 for the low, medium and high cell number groups, respectively. Embryos of undetermined sex in these same groups numbered 3, 1 and 3, respectively. On Day 6 the distribution was 1:11, 4:2 and 8:0 in favor of the males, while embryos of undetermined sex in the low, medium and high cell number groups numbered 5, 7 and 2, respectively. Chi-square analysis of the combined Day-5 and Day-6 results indicated the presence of significantly more females among embryos with low cell numbers and more males in the high cell number group (P < 0.01).     

Effects of methyldopa on prolactin and growth hormone.

The effects of administration of methyldopa on serum prolactin and growth hormone (GH) concentrations in hypertensive patients were studied. Single doses of methyldopa (750 or 1000 mg) significantly increased serum prolactin levels, peak concentrations occurring four to six hours after drug administrations. Long-term methyldopa treatment was associated with threefold to fourfold increases in basal prolactin levels compared with those in normal subjects. In patients treated with methyldopa for two to three weeks the GH response to insulin hypoglycaemia was significantly greater than in normal subjects and untreated hypertensive patients. In contrast, patients treated for prolonged periods (mean 13-4 months) had a GH reponse indistinguishable from normal.     

Trends in tuna carbon isotopes suggest global changes in pelagic phytoplankton communities

Considerable uncertainty remains over how increasing atmospheric CO₂ and anthropogenic climate changes are affecting open‐ocean marine ecosystems from phytoplankton to top predators. Biological time series data are thus urgently needed for the world's oceans. Here, we use the carbon stable isotope composition of tuna to provide a first insight into the existence of global trends in complex ecosystem dynamics and changes in the oceanic carbon cycle. From 2000 to 2015, considerable declines in δ¹³C values of 0.8‰–2.5‰ were observed across three tuna species sampled globally, with more substantial changes in the Pacific Ocean compared to the Atlantic and Indian Oceans. Tuna recorded not only the Suess effect, that is, fossil fuel‐derived and isotopically light carbon being incorporated into marine ecosystems, but also recorded profound changes at the base of marine food webs. We suggest a global shift in phytoplankton community structure, for example, a reduction in ¹³C‐rich phytoplankton such as diatoms, and/or a change in phytoplankton physiology during this period, although this does not rule out other concomitant changes at higher levels in the food webs. Our study establishes tuna δ¹³C values as a candidate essential ocean variable to assess complex ecosystem responses to climate change at regional to global scales and over decadal timescales. Finally, this time series will be invaluable in calibrating and validating global earth system models to project changes in marine biota.     

Multi‐generational long‐distance migration of insects: studying the painted lady butterfly in the Western Palaearctic

Long‐range, seasonal migration is a widespread phenomenon among insects, allowing them to track and exploit abundant but ephemeral resources over vast geographical areas. However, the basic patterns of how species shift across multiple locations and seasons are unknown in most cases, even though migrant species comprise an important component of the temperate‐zone biota. The painted lady butterfly Vanessa cardui is such an example; a cosmopolitan continuously‐brooded species which migrates each year between Africa and Europe, sometimes in enormous numbers. The migration of 2009 was one of the most impressive recorded, and thousands of observations were collected through citizen science programmes and systematic entomological surveys, such as high altitude insect‐monitoring radar and ground‐based butterfly monitoring schemes. Here we use V. cardui as a model species to better understand insect migration in the Western Palaearctic, and we capitalise on the complementary data sources available for this iconic butterfly. The migratory cycle in this species involves six generations, encompassing a latitudinal shift of thousands of kilometres (up to 60 degrees of latitude). The cycle comprises an annual poleward advance of the populations in spring followed by an equatorward return movement in autumn, with returning individuals potentially flying thousands of kilometres. We show that many long‐distance migrants take advantage of favourable winds, moving downwind at high elevation (from some tens of metres from the ground to altitudes over 1000 m), pointing at strong similarities in the flight strategies used by V. cardui and other migrant Lepidoptera. Our results reveal the highly successful strategy that has evolved in these insects, and provide a useful framework for a better understanding of long‐distance seasonal migration in the temperate regions worldwide.     

吐鲁番市胃食管反流病发生相关危险因素分析（附280例报道）

目的：探讨280例胃食管反流病（GERD）的分布特点及危险因素。方法：对临床诊断和胃镜确诊的280例GERD患者进行临床和风险因子相关性分析。结果：不论汉族还是维族,男性患者比例均明显高于女性;汉族患者高发年龄段早于维族患者（z=-2．939,P=0．003,）;汉族和维族患者占反流性食管炎和Barrett食管比例分别为42．4％、81_3％及56．5％、18．8％,其中汉族患者Barrett食管比例较高（X2=14．358,P=0．000）;肥胖、习惯性便秘、重体力活动者、饮食习惯不良在维族患者中的比例较高（P〈0．001）。结论：GERD与性别、年龄密切相关,男性多于女性,汉族患者发病年龄高峰旱于维族患者;汉族患者Barrett食管发生比例高于维族患者;肥胖、习惯性便秘、重体力活动、饮食习惯不良可能是GERD尤其是维族人群GERD的危险因素。     

Successful immunotherapy with matrix metalloproteinase-derived peptides in adjuvant arthritis depends on the timing of peptide administration

We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.     

Characterization of terminal NeuNAcalpha2-3Galbeta1-4GlcNAc sequence in lipooligosaccharides of Neisseria meningitidis

Group B and C Neisseria meningitidis are the major cause of meningococcal disease in the United States and in Europe. N . meningitidis lipooligosaccharide (LOS), a major surface antigen, can be divided into 12 immunotypes of which L1 through L8 were found among Group B and C organisms. Groups B and C but not Group A may sialylate their LOSs with N-acetylneuraminic acid (NeuNAc) at the nonreducing end because they synthesize CMP-NeuNAc. Using sialic acid-galactose binding lectins as probes in an ELISA format, six of the eight LOS immunotypes (L2, L3, L4, L5, L7, and L8) in Groups B and C bound specifically to Maackia amurensis leukoagglutinin (MAL), which recognizes NeuNAcalpha2- 3Galbeta1-4GlcNAc/Glc sequence, but not to Sambucus nigra agglutinin, which binds NeuNAcalpha2-6Gal sequence. The combination of SDS-PAGE and MAL-blot analyses revealed that these six LOSs contained only the NeuNAcalpha2-3Galbeta1-4GlcNAc trisaccharide sequence in their 4.1 kDa LOS components, which have a common terminal lacto-N-neotetraose (LNnT, Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) structure when nonsialylated as shown by previous studies. The LOS-lectin binding was abolished when the LOSs were treated with Newcastle disease viral neuraminidase which cleaves alpha2-->3 linked sialic acid. Methylation analysis of a representative LOS (L2) confirmed that NeuNAc is 2-->3 linked to Gal. Thus, these LOSs structurally mimic certain glycolipids, i.e., paragloboside (LNnT-ceramide) and sialylparagloboside and some glycoproteins in having LNnT and N-acetyllactosamine sequences, respectively, with or without alpha2-->3 linked NeuNAc. The molecular mimicry of the LOSs may play a role in the pathogenesis of N.meningitidis by assisting the organism to evade host immune defenses in man.