Natural and directed biosynthesis of communesin alkaloids

A role for tryptophan, acetate, mevalonate and methionine in the biosynthesis of communesins A and B, novel structurally-related and biologically-active Penicillium metabolites, has been established by isotopic labelling techniques. The incorporation of (14)C-tryptamine has also been demonstrated. dl-2-(13)C-tryptophan specifically enriched two carbon atoms in the (13)C NMR spectrum, thereby defining the intra-molecular arrangement of the two tryptophan-derived moieties. Feeding differentially labelled precursors during communesin production showed that tryptophan and methionine are involved early in the biosynthesis and that mevalonate provides an isoprene which is added later. A biosynthetic pathway involving an early precursor based on tryptophan is proposed. Indole-N-((13)C-methyl) tryptophan was not incorporated into communesins implying that N-methylation of tryptophan is not the first step of the communesin biosynthetic pathway. During deamination of indole-N-((13)C-methyl) tryptophan to 1-(13)C-methylindole-3-carboxylic acid communesin biosynthesis was inhibited. Of several halogenated indoles tested for directed biosynthesis, only dl-6-fluoro-tryptophan and 6-fluoro-tryptamine caused accumulation of the corresponding monofluoro-analogues of communesins A and B.     

An experimental strategy towards optimising directed biosynthesis of communesin analogues by Penicillium marinum in submerged fermentation

It was previously demonstrated that a fungus producing communesin alkaloids, subsequently identified as Penicillium marinum, could also accept 6-fluoro analogues of tryptophan or tryptamine to form mono-fluoro-communesin analogues in addition to communesins. A strategy to increase the relative yield of analogues by mutation to impair decarboxylation of tryptophan has been studied. Four mutants with much reduced activity of tryptophan decarboxylase, and other phenotypic change, were selected from 1500 colonies from spores that survived a 99 % kill treatment with N-methyl N-nitro N-nitrosoguanidine. Tlc assessment of cell-associated products from standard submerged fermentations showed that one non-sporing mutant apparently produced little or no communesins, but productivity was restored when grown in a medium supplemented with glutamine. However, more sensitive mass spectrometric analysis detected both communesins A and B in mycelium grown on a rich, yeast extract–sucrose agar, showing that deletion of communesin biosynthesis was not absolute. It was concluded that mutagenesis had generally achieved its objective, but that new literature on a putative role of aurantioclavine in communesin biosynthesis presented an additional challenge to integrate the prenylation of tryptophan before its decarboxylation, which is a characteristic of ergot alkaloid biosynthesis.     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.     

Potential Compounds for Oral Cancer Treatment: Resveratrol,Nimbolide, Lovastatin,Bortezomib, Vorinostat,Berberine, Pterostilbene,Deguelin, Andrographolide,and Colchicine

Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.     

Ostracoda (Crustacea) from Lizard Island,northern Great Barrier Reef,Australia. I. Families: Cytherellidae,Loxoconchidae, Cytherideidae,Cytheruridae, Paracytherideidae,Pectocytheridae, Krithidae,Cytheromatiidae, Bythocytheridae,Cytheridae

This paper deals with the taxonomy of the ostracod families Cytherellidae, Cytheridae, Cytheromatidae, Cytherideidae, Krithidae, Loxoconchidae, Paracytherideidae, Cytheruridae, Pectocytheridae and Bythocytheridae from the coral reefs around Lizard Island, northern Great Barrier Reef, Australia. 22 species belonging to these families were found. 7 species had been described from Australian coasts, 1 from the Red Sea and 1 with Indopacific-Westatlantic distribution. 9 species are newly described and 4 species remain in open nomenclature.     

Synthesis,tautomerism, and antimicrobial,anti-HCV,anti-SSPE,antioxidant, and antitumor activities of arylazobenzosuberones

2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3a–i. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3a–i were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities.     

Treatment-resistant depression: definition,prevalence, detection,management, and investigational interventions

Treatment-resistant depression (TRD) is common and associated with multiple serious public health implications. A consensus definition of TRD with demonstrated predictive utility in terms of clinical decision-making and health outcomes does not currently exist. Instead, a plethora of definitions have been proposed, which vary significantly in their conceptual framework. The absence of a consensus definition hampers precise estimates of the prevalence of TRD, and also belies efforts to identify risk factors, prevention opportunities, and effective interventions. In addition, it results in heterogeneity in clinical practice decision-making, adversely affecting quality of care. The US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have adopted the most used definition of TRD (i.e., inadequate response to a minimum of two antidepressants despite adequacy of the treatment trial and adherence to treatment). It is currently estimated that at least 30% of persons with depression meet this definition. A significant percentage of persons with TRD are actually pseudo-resistant (e.g., due to inadequacy of treatment trials or non-adherence to treatment). Although multiple sociodemographic, clinical, treatment and contextual factors are known to negatively moderate response in persons with depression, very few factors are regarded as predictive of non-response across multiple modalities of treatment. Intravenous ketamine and intranasal esketamine (co-administered with an antidepressant) are established as efficacious in the management of TRD. Some second-generation antipsychotics (e.g., aripiprazole, brexpiprazole, cariprazine, quetiapine XR) are proven effective as adjunctive treatments to antidepressants in partial responders, but only the olanzapine-fluoxetine combination has been studied in FDA-defined TRD. Repetitive transcranial magnetic stimulation (TMS) is established as effective and FDA-approved for individuals with TRD, with accelerated theta-burst TMS also recently showing efficacy. Electroconvulsive therapy is regarded as an effective acute and maintenance intervention in TRD, with preliminary evidence suggesting non-inferiority to acute intravenous ketamine. Evidence for extending antidepressant trial, medication switching and combining antidepressants is mixed. Manual-based psychotherapies are not established as efficacious on their own in TRD, but offer significant symptomatic relief when added to conventional antidepressants. Digital therapeutics are under study and represent a potential future clinical vista in this population.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Comparative floral structure and systematics in Crossosomatales (Crossosomataceae, Stachyuraceae, Staphyleaceae, Aphloiaceae, Geissolomataceae, Ixerbaceae, Strasburgeriaceae)

Floral structure of all putative families of Crossosomatales as suggested by molecular studies was comparatively studied. The seven comprise Crossosomataceae, Stachyuraceae, Staphyleaceae, Aphloiaceae, Geissolomataceae, Ixerbaceae, and Strasburgeriaceae. The entire clade (1) is highly supported by floral structure, also the clades (in sequence of diminishing structural support): Ixerbaceae/Strasburgeriaceae (2), Geissolomataceae/Ixerbaceae/Strasburgeriaceae (3), Aphloiaceae/Geissolomataceae/Ixerbaceae/Strasburgeriaceae (4), and Crossosomataceae/Stachyuraceae/Staphyleaceae (5). Among the prominent floral features of Crossosomatales (1) are solitary flowers, presence of a floral cup, imbricate sepals with outermost smaller than inner, pollen grains with horizontally extended endoapertures, shortly stalked gynoecium, postgenitally united carpel tips forming a compitum, stigmatic papillae two‐ or more‐cellular, ovary locules tapering upwards, long integuments forming zigzag micropyles, cell clusters with bundles of long yellow crystals, mucilage cells, seeds with smooth, sclerified testa and without a differentiated tegmen. Clade (2) is characterized by large flowers, petals forming a tight, pointed cone in bud, stamens with long, stout filaments and sagittate anthers, streamlined, conical gynoecium, antitropous ovules, rudimentary aril, lignified, unicellular, T‐shaped hairs and idioblasts with striate mucilaginous cell walls. Clade (3) is characterized by alternisepalous carpels, punctiform stigma formed by postgenitally united and twisted carpel tips, synascidiate ovary, only one or two pendant ovules per carpel, nectary recesses between androecium and gynoecium. Clade (4) is characterized by pronounced ‘pollen buds’. Clade (5) is characterized by polygamous or functionally unisexual flowers, x‐shaped anthers, free and follicular carpels (not in Stachyuraceae). Crossosomataceae and Aphloiaceae, although not retrieved as a clade in molecular studies, share several special floral features: polystemonous androecium; basifixed anthers without a connective protrusion; stigma with two more or less decurrent crests; camplyotropous ovules and reniform seeds; simple, disc‐shaped nectaries and absence of hairs. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147 , 1–46.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Electromagnetic fields: mechanism,cell signaling,other bioprocesses,toxicity, radicals,antioxidants and beneficial effects

Electromagnetic fields (EMFs) played a role in the initiation of living systems, as well as subsequent evolution. The more recent literature on electrochemistry is documented, as well as magnetism. The large numbers of reports on interaction with living systems and the consequences are presented. An important aspect is involvement with cell signaling and resultant effects in which numerous signaling pathways participate. Much research has been devoted to the influence of man-made EMFs, e.g., from cell phones and electrical lines, on human health. The degree of seriousness is unresolved at present. The relationship of EMFs to reactive oxygen species (ROS) and oxidative stress (OS) is discussed. There is evidence that indicates a relationship involving EMFs, ROS, and OS with toxic effects. Various articles deal with the beneficial aspects of antioxidants (AOs) in countering the harmful influence from ROS-OS associated with EMFs. EMFs are useful in medicine, as indicated by healing bone fractures. Beneficial effects are recorded from electrical treatment of patients with Parkinson’s disease, depression, and cancer.     

Super-motifs and evolution of tandem leucine-rich repeats within the small proteoglycans--biglycan, decorin, lumican, fibromodulin, PRELP, keratocan, osteoadherin, epiphycan, and osteoglycin

Leucine-rich repeats (LRRs) with 20-30 amino acids in unit length are present in many proteins from prokaryotes to eukaryotes. The LRR-containing proteins include a family of nine small proteoglycans, forming three distinct subfamilies: class I contains biglycan/PG-I and decorin/PG-II; class II: lumican, fibromodulin, PRELP, keratocan, and osteoadherin; and class III: epiphycan/PG-Lb and osteoglycin or osteoinductive factor. Comparative sequence analysis of the 34 available protein sequences reveals that these proteoglycans have two types of LRRs, which we call S and T. The type S LRR is 21 residues long and has the consensus sequence of xxaPzxLPxxLxxLxLxxNxI. The type T LRR has 26 residues; its consensus sequence is zzxxaxxxxFxxaxxLxxLxLxxNxL. In both "x" indicates variable residue; "z" is frequently a gap; "a" is Val, Leu, or Ile; and I is Ile or Leu. These type S and TLRRs are ordered into two super-motifs--STT with about 73 residues in classes I and II and ST with about 47 residues in class III. The 12 LRRs in the small proteoglycans of I and II are best represented as (STT)4; the seven LRRs of class III as (ST)T(ST)2. Our analyses indicate that classes I/II and III evolved along different paths after the establishment of the precursor ST, and classes I and II also diverged after the establishment of the precursor (STT)4.     

Phylogeny,classification, and biogeography of Afrotrichloris,Apochiton, Coelachyrum,Dinebra, Eleusine,Leptochloa, Schoenefeldia,and a new genus,Schoenefeldiella (Poaceae: Chloridoideae: Cynodonteae: Eleusininae)

To investigate the evolutionary relationships among species of Afrotrichloris, Apochiton, Coelachyrum, Dinebra, Eleusine, Leptochloa, and Schoenefeldia of subtribe Eleusininae, a phylogeny based on DNA sequences from nine gene regions (ITS, rps16-trnK, rps3, rps16, rpoC2, rpl32-trnL, ndhF, ndhA, ccsA) is presented. Previous molecular phylogenies indicated that Coelachyrum was polyphyletic and Schoenefeldia was paraphyletic, with Afrotrichloris embedded within it. Apochiton burttii was embedded in the Coelachyrum clade paired with C. longiglume, Coelachyrumpoiflorum was placed outside of Coelachyrum and sister to Eleusine, and Schoenefeldia is paraphyletic, with its two species forming a grade sister to Afrotrichoris. Our molecular phylogeny supports recognition of a new genus, Schoenefeldiella, and a new combination, Schoenfeldiella transiens. In addition, we provide generic emendations for Coelachyrum, which now includes five species including a new combination proposed here, Coelachyrum burttii, and Eleusine, which now includes 11 species.     

A method for concurrent measurement of picomole quantities of acetylcholine, choline, dopamine, norepinephrine, serotonin, 5-hydroxytryptophan, 5-hydroxyindoleacetic acid, tryptophan, tyrosine, glycine, aspartate, glutamate, alanine, and gamma-aminobutyric acid in single tissue samples from different areas of rat central nervous system.

A rapid and sensitive method for separation and concurrent assay of 14 compounds at the picomole level in individual rat brain parts is described. The putative amino acid neurotransmitters (aspartate, γ-aminobutyric acid, glutamate, and glycine) are extracted from a 20–30 mg portion of the tissue with 5% TCA and assayed as their respective DNP-amino acid methyl ester derivatives by glc. Four other putative neurotransmitters (acetylcholine, dopamine, norepinephrine, and serotonin) and some of their precursors and metabolites (choline, tryptophan, 5-hydroxytryptophan, 5-hydroxyindoleacetic acid, and tyrosine) are extracted in 1n formic acid-acetone (v/v:15/85) from the remaining tissue. The lipids are removed with a heptane-chloroform (v/v:8/1) wash and the aqueous phase is dried at 37°C under N₂. The dried extract is dissolved in water (pH 4). With one portion of this solution, acetylcholine and choline are assayed using a radioenzymatic method whereas with the rest, dopamine, norepinephrine, serotonin, 5-hydroxyindoleacetic acid, 5-hydroxytryptophan, tryptophan, and tyrosine are separated with three ion exchange resins arranged in tandem. These compounds are assayed fluorometrically with modified microadaptations of previously reported methods.     

Multi-element analysis of the rat hippocampus by proton induced X-ray emission spectroscopy (phosphorus, sulphur, chlorine, potassium, calcium, iron, zinc, copper, lead, bromine, and rubidium).

A technique for multi-element analysis of brain tissue by proton induced X-ray emission spectroscopy (PIXE) is described and data from analysis of fixed and unfixed samples from rat hippocampus, neocortex, amygdala, and spinal cord is presented and commented on. The atoms present in the tissue are bombarded with protons which causes the ejection of electrons from the inner shells. When the "holes" are refilled with electrons from outer shells, X-ray quanta characteristic for each element are emitted. Using a high resolution energy dispersive detector a complete X-ray spectrum of the specimen can be recorded in a single measurement. Detection limits less than or approximately 5 p.p.m. of dry matter are obtained for most elements with atomic number greater than 14 (silicon). Around 13 elements were found in concentrations above the detection limits. The grand means for non-fixed hippocampi were e.g. for Zn - 120 p.p.m.; Rb - 20 p.p.m.; Fe - 150 p.p.m.; Pb - 3 p.p.m; Ni - 5 p.p.m.     

An adapid primate,sinoadapis, from lufeng,latest miocene,Yunnan, China

The paper deals with a new form ofSinoadapis from the Lufeng hominoid Locality, assigned toSinoadapis shihuibaensis sp. nov. Holotype PA 882 A fragment of right mandible with C,−M₃. Other materials. PA 903 A fragment of left maxilla with P³−M³. PA 959 Left lower tooth row with I₁−P², P₄. PA 902 Right upper tooth row with C′−P³. PA 964 An isolated left I¹. PA 907 An isolated right I³. PA 972 An isolated right M³.     

Competitive inhibition and selectivity enhancement by Ca in the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, Hf) by carrot (Daucus carota cv. U.S. harumakigosun)

We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.     

Novel, fluorescent, magnetic, polysaccharide-based microsphere for orientation, tracing, and anticoagulation: preparation and characterization

A fluorescent, magnetic composite poly(styrene-maleic anhydride) microsphere, suitable for conjugation with polysaccharide, was synthesized using magnetite/europium phthalate particles as seeds by copolymerization of styrene and maleic anhydride. The magnetite/europium phthalate particles were wrapped up by poly(ethylene glycol), which improved the affinity between the seed particles and the monomers. The composite microspheres obtained, with a diameter of 0.15-0.7 microm, contain 586-1013 microg of magnetite/g of microsphere and 0.5-16 mmol surface anhydride groups/g of microsphere. Heparin was conjugated with the reactive surface anhydride groups on the surface of the microspheres by covalent binding to obtain a fluorescent, magnetic, polysaccharide-based microsphere. The microspheres not only retain their bioactivities but also provide magnetic susceptibility and fluorescence. They can be used as a carrier with magnetic orientation and fluorescence tracer for potent drug targeting. The orientation, tracer, and anticoagulation of the fluorescence, magnetic, polysaccharide-based microspheres were studied. The anticoagulant activity of the microspheres and heparin binding capacity reached 54,212.8 U and 607.1 mg/g of dry microspheres. The activity recovery was 50.2%. The anticoagulant activity of the microspheres increases with the increase of the conjugated heparin on the surface of the microspheres and the decrease of the microsphere size. Furthermore, The fluorescent, magnetic, polysaccharide-based microspheres can be easily transported to a given position in a magnetic field and traced via their fluorescence.     

Whales,lifespan, phospholipids,and cataracts

This study addresses the question: why do rats get cataracts at 2 years, dogs at 8 years, and whales do not develop cataracts for 200 years? Whale lens lipid phase transitions were compared with the phase transitions of other species that were recalculated. The major phospholipids of the whale lens were sphingolipids, mostly dihydrosphingomyelins with an average molar cholesterol/phospholipid ratio of 10. There was a linear correlation between the percentage of lens sphingolipid and lens lipid hydrocarbon chain order until about 60% sphingolipid. The percentage of lens sphingolipid correlated with the lens lipid phase transition temperature. The lifespan of the bowhead whale was the longest of the species measured and the percentage of whale lens sphingolipid fit well in the correlation between the percentage of lens sphingolipid and lifespan for many species. In conclusion, bowhead whale lens membranes have a high sphingolipid content that confers resistance to oxidation, allowing these lenses to stay clear relatively longer than many other species. The strong correlation between sphingolipid and lifespan may form a basis for future studies, which are needed because correlations do not infer cause. One could hope that if human lenses could be made to have a lipid composition similar to whales, like the bowhead, humans would not develop age-related cataracts for over 100 years.