bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE ANATOMY OF CHAROPHYTA: II. THE AXIAL NODAL COMPLEX—AN APPROACH TO THE TAXONOMY OF LAMPROTHAMNIUM12
Authors: Frame Paul , Sawa Takashi
Published: August 2007

The present investigation on the axial nodes of 32 taxa belonging to the genera Chara, Lamprothamnium, Nitellopsis, Nitella and Tolypella confirms previous reports that within a given taxonomic group the structure of the main axial nodal complex is highly consistent. Besides the genera Nitella and Tolypella of the tribe Nitelleae, Lamprothamnium of the tribe Chareae is the only genus in which the central cells of the main axial nodal complex subdivide. This anatomical feature of the main axial nodal complex thus clearly separates the genus Lamprothamnium from the other genera of the tribe chareae. In 2 controversial species of the genus Chara, C. hornemannii and C. buckellii, the present study reveals that the central cells of their main axial nodal complexes do not subdivide. The transfer of these two species to the genus Lamprothamnium by Daily (1) may not be appropriate.
A RHIZOPLAST IN CARTERIA RADIOSA (CHLOROPHYCEAE)12
Authors: Lembi Carole A.
Published: August 2007

A rhizoplast or rhizoplast‐like structure was observed with the electron microscope in Carteria radiosa. The cross‐banded structure extends from the proximal end of each of at least 2 of the basal bodies and extends toward, although does not make contact with, the nucleus. The rhizoplast terminates in a ribosome‐free area composed of fine granules and microfibrils. This is the first ultrastructural verification of a rhizoplast in a volvocalean alga.
D‐LACTATE UTILIZATION BY GONIUM (CHLOROPHYCEAE)1
Authors: Saito Shôichi
Published: August 2007

Acetate, glucose, pyruvate, and lactate utilization as Carbon sources have been investigated in 3 strains of Gonium multicoccum, 2 of G. octonarium, and 1 of G. quadratum. In all strains, growth was supported with acetate, pyruvate and dl‐lactate in continuous light. These species commonly utilized d‐lactate for growth as a carbon source in the light, but there was no effect in the dark. However, they could not utilize l‐lactate for growth in light or darkness.
SEXUAL REPRODUCTION OF PERIDINUM CINCTUM F. OVOPLANUM (DINOPHYCEAE)1,2
Authors: Pfiester Lois A.
Published: August 2007

Sexual reproduction is induced in the dinoflagelate Peridinium cinctum f. ovoplanum Lindemann when exponentially growing cells are inoculated into nitrogen deficient medium. Small, naked vegetative cells, produced by division of the thecate cells, then act as gametes. The zygote remains motile for 12–13 days during which time it enlarges and the theca which it forms becomes warty. Thirteen to 14 day s following plasmogamy the zygote is nonmotile, the protoplast contracts, a large red oil droplet appears, the wall thickens and becomes chitinized. This hypnozygote germinates within 7–8 weeks at 20 c producing 1 post‐zygotic cell retaining the large red oil droplet. The presence of 4 nuclei in these post‐zygotic cells may be demonstrated by staining them with acetocarmine. Two of these nuclei are smaller than the other two and probably abort. One may infer that meiosis occurs immediately prior to or at the germinartion of the hypnozygote. This post‐zygotic cell divides within 24 h into 2 daughter cells each with a promment red oil droplet. These daughter cells divide after 2–3 days into ordinary vegetative cells.

Attempts to induce sexual reproduction by changes in temperature or light and by inoculation of cells into media deficient in a number of basic elements were unsuccessful.
MORPHOLOGICAL VARIATION OFACHNANTHES HAUCKIANA(BACILLARIOPYCEAE) IN THE RIELD1
Authors: Tropper Caroline B.
Published: August 2007

Samples of 2 populations of the diatom,Achnanthes hauckiana Grun.,collected from Sippewissett Marsh, Massachusetts, were measured. Regression analyses of the measurements were calculated. The length/width ratio of both samples decreased almost linearly with decreasing length. The length/width ratio of the rostrate ends also decreased almost linearly with decreasing length. The number of striae per 10 μm showed a slight tendency to increase with decreasing length. Some of the specimens collected, which fit the descriptions ofA. hauckianavar.ellipticaor ver.rostrata,appear to be morphological variants of the nominate variety. The change in shape with size fits Geitler's rule of proportionally greater decrease in the apical axis than the decrease in the transapical axis.

The regression lines of change in shape with size might be used as taxonomic characteristics and contain more information than the usual descriptions of limits of size and shape of a species.
EFFECT OF PHOSPHORUS DEFICIENCY ON TWO ALGAE GROWING IN CHEMOSTATS1
Authors: Healey F. P. , Hendzel L. L.
Published: August 2007

phosphorus‐limited chemostats were used to study the effect of degree of phosphorus deficiency on several aspects of the composition and metabolism of Anabaena variabilis Kütz. and Scenedesmus quadricauda (Turp.) Bréb. The changes as a function of the dilution rate could be placed into 3 patterns. Most aspects of the composition showed it progressive change with dilution rate. The carbohydrate content generally increased while cellular P and nitrogen, protein, nucleic acid and chlorophyll contents generally decreased over the entire range of increasing deficiency studied. The changes in metabolism fell into a second pattern, showing great sensitivity to the onset of P deficiency. The ability to take up phosphate and the alkaline phosphatase activity increased most markedly with increasing deficiency at the higher dilution rates. The third pattern was confined to the, lipid content of S. quadricauda, which increased with deficiency only at the lowest dilution rates.
EFFECT OF WATER POTENTIAL ON A MICROCOLEUS (CYANOPHYCEAE) FROM A DESERT CRUST1
Authors: Brock Thomas D.
Published: August 2007

The effect of water potential, on the growth and photosynthesis of a species of Microcoleus forming a desert crust was determined, using both osmotic and matric variations in water potential. The alga was quite sensitive to moisture stress, partial inhibition of growth being observed at ‐7 bars, and complete inhibition at ‐18 bars. Photosynthesis was markedly inhibited at ‐18 bars, and virtually completely at, ‐28 bars (water potential of seawater) and lower. The alga was more sensitive to matric reduction in water potential than osmotic. By comparisons of these results with those obtained with other algae, it is concluded that this desert crust alga is not especially adapted to grow and photosynthesize at low water potentials, although it shows considerable ability to survive severe drought conditions.
MERCURY ACCUMULATION IN PEDIASTRUM BORYANUM (CHLOROPHYCEAE)1,2,3
Authors: Richardson Thomas R. , Millington William F. , Miles Harry M.
Published: August 2007

Laboratory grown cultures of the green alga Pediastrum boryanum (Turp.) Meneg. concentrate mercury in amounts greater than the concentration in the culture medium. The concentration effect proceeds rapidly during colony formation and is directly dependent upon the materials of the outer layer of the cell wall known to include silica and sporopollenin. The alga displays exceptional tolerance to the rather high levels of mercury used.
NITRATE UPTAKE IN MARINE PHYTOPLANKTON: (NITRATE, CHILORIDE)‐ACTIVATED ADENOSINE TRIPHOSPHATASE FROMSKELETONEMA COSTATUM(BACILLARIOPHYCEAE)1,2
Authors: Falkowski Paul G.
Published: August 2007

A membrane‐bound (nitrate, chloride)‐activated AT Pase was found in the neritie diatom,Skeletonema costatum(Grev.) Cleve. The enzyme is suggested to translocate NO3−across the plasmalemma, against a concentration gradient. TheKmof the enzyme with respect to NO3−isca.0.9 × 10−6M, and is in close agreement with the reportedK8for NO3−uptake by the whole cell.
THE EFFECT OF INTERTIDAL STRESS ON PADINA SANCTAE‐CRUCIS (PHAEOPHYTA)1
Authors: Liddle Larry B.
Published: August 2007

The hypothesis is that plants growing in the intertidal region display developmental and morphological differences from subtidal plants of the same species. Intertidal and subtidal populations of Padina sanctae‐crucis Börg. Were compared, emphasizing morphological and developmental features. Plant size in relation to number of reproductive bands, vegetative cell sizes and the rate of spore development were analyzed to evaluate the hypothesis. The results indicate that environmental stress tends to dwarf intertidal plants through reduction in cell size. Spores from both intertidal and subtidal populations were cultured in the laboratory under standard conditions. No significant differences were found between the growth rates. The results may be interpreted to mean that cell enlargement is inhibited by intertidal stress.
UNIPARENTAL INHERITANCE IN CHLAMYDOMONAS EUGAMETOS (CHLOROPHYCEAE)1,2
Authors: McBride A. Charles , McBride Judy C.
Published: August 2007

The gene sr‐2 conferring resistance to 500 μ/ml streplomycin exhibits uniparental inheritance in Chlamydomonas eugametos Moewus. The mutation to neamine dependence (nd) is probably of the same type. All meiotic progeny from crosses involving these mutant genes have the phenotype of the historically designated male parent. Unlike C. reinhardtii Dang., no exceptional zygotes have been observed.
SODIUM: SOME EFFECTS ON BLUEGREEN ALGAL GROWTH1
Authors: Ward Amelia K. , Wetzel Robert G.
Published: August 2007

The growth of heterocystous bluegreen algae in various concentrations of sodium, was examined in axenic culture as well as in situ studies. Anabaena cylindrica Lemm. with no Na+ added, suffered from decreased rates of acetylene reduction, 14C, assimilation, excretion of organic C as well as lower concentrations of chlorophyll a and particulate organic C compared to cultures supplied with 5, 10, and 50 mg Na+·l−1 Sodium deficient algae released, extracellularly a higher percentage of previously fixed C as organic C. No differences in any parameter measured were demonstrable among cultures grown with 5, 10, and 50 mg Na+·l−1 High nitrate concentrations (20 mg NO3−·l−1) resulted in decreased rates of acetylene reduction and heterocyst numbers in. Na sufficient, and Na deficient cultures: however, decreased, cellular Na content at high NO3− levels occurred only in N deficient, cultures. Higher percentages of excreted organic C occurred with increasing NO3− concentrations in Na deficient cultures. Sodium enrichment of natural bluegreen populations with the addition of 50, 100, and 200 mg Na+·l−1 elicited neither a stimulatory nor an inhibitory response in photosynthetic C fixation. In contrast, the addition of small amounts of Na+ (5 mg·l−) resulted in increased C fixation. However, since the Na. concentration of the lake water, at ca. 5 mg Na+·l−1, was sufficient for growth of the bluegreens present, sodium, is not assumed to be limiting under most natural conditions. No increase in in situ acetylene reduction rates occurred with additions of sodium.
EFFECTS OF LOW NITROGEN LEVELS AND VARIOUS NITROGEN SOURCES ON GROWTH AND WHORL DEVELOPMENT IN ACETABULARIA (CHLOROPHYTA)1
Authors: Adamich Marina , Gibor Aharon , Sweeney Beatrice M.
Published: August 2007

Nitrate, ammonia, urea, and glycine were compared as nitrogen sources for Acetabularia mediterranea. Cells grew normally in media containing nitrate or urea, while cells did not grow at all when the same amount of N was supplied as ammonium ion. The utilization of glycine remains questionable. Cells in medium without added N (NDM) increased in length and some formed reproductive caps.

The whorls of vegetative cells showed considerable hypertrophy in NDM and in glycine. This hypertrophy was due to the elongation of only the first‐(a1) and second‐ (a2) order articles. When cut, the basal portion of cells without added N regenerated new apices with whorls. The development of these whorls was inversely proportional to the NO2 concentration.

Analyses showed that the intracellular nitrogen pool in young cells and regenerating bases was very small, about 1/10 of that of fully grown cells. Therefore we suggest that trace amounts of N contaminants in the medium supported growth and development, the uptake of which was facilitated by the hypertrophied whorls, under N‐limited conditions.
CHLOROPLAST PIGMENT PATTERNS IN DINOFLAGELLATES1
Authors: Jeffrey S. W. , Sielicki Margarete , Haxo F. T.
Published: August 2007

The chlorophylls and carotenoids of 22 species of dinoflagellates were analysed by thin layer chromatography, using 2‐dimensional sucrose plates, and 1‐dimensional polyethylene plates for chlorophylls c1and c2. Peridinin was the major carotenoid in 19 of the species, while fucoxanthin was the major carotenoid in 3. In the peridinin‐containing species, 5 carotenoid fractions, constituting more than 95% of the total carotenoids, were always present. These were peridinin (± neo‐peridinin), averaging 64% of the total carotenoid, diadinoxanthin, dinoxanthin, β‐carotene and a polar, unidentified pink xanthophyll. Six other carotenoid fractions occurred in minor or trace quantities among the species, but were not identified. Two of these had, a wide distribution; the other 4 were restricted to one or 2 species. The chlorophyll content of the dinoflagellate cultures ranged from 1–141 μg chlorophyll a + c/106cells, a pattern which was broadly correlated with cell size. In the peridinin‐containing species the ratio of chlorophyll a to c on a molar basis was approximately 2 (range 1.60–4.39); in the fucoxanthin‐containing species this ratio was approximately 4 (range 2.65–5.73). Both chlorophylls c1and c2occurred in the fucoxanthin‐containing dinoflagellates, and only chlorophyll c2(one exception) occurred in the peridinin‐containing dinoflagellates. These patterns of chlorophyll c and major carotenoid correspond to patterns previously observed in the Pyrrhophyta and the Chrysophyta, suggesting different phylogenetic origins for the “dinoflagellate” chloroplasts.
NORTH CAROLINA MARINE ALGAE. VI. SOME CERAMIALES (RHODOPHYTA), INCLUDING A NEW SPECIES OF DIPTEROSIPHONIA1
Authors: Schneider Craig W.
Published: August 2007

Six members of the Ceramiales are added to the flora of North Carolina. Two of these, Acrosorium uncinatum (Turner) Kylin and, Rhododictyon bermudensis Taylor, are also reported from South Carolina for the first time. One species, Mesothamnion boergeseni Joly, was previously known only from Brazil and another, Dipterosiphonia reversa sp. nov., is added to the algal literature for the first time. Evidence is presented for the reassignment of R. bermudensis from the Dasyaceae to the Ceramiaceae.
KINETICS OF SILICON‐LIMITED GROWTH IN THE FRESHWATER DIATOM ASTERIONELLA FORMOSA1,2
Authors: Kilham Susan Soltan
Published: August 2007

Growth rates of two clones of the freshwater planktonic diatom Asterionella formosa Hass. were measured under conditions in which external silicon concentrations controlled growth. Clone AfOH2 from Lake Ohrid, Yugoslavia, had a higher maximum growth rate (μmax= 1.11 doublings/day) and apparent half‐saturation constant (Ksi] + Sio= 1.93 μM Si) than clone L262 from Lake Windermere, England. (μmax= 0.61 doublings/day; Ksi+ Sio= 1.09 μM Si). Klim, the silicon concentration at μ= 0.9 μmax, is 13.8 μM Si for clone AfOH2 and 6.5 μM Si for clone L262. These values agree well with published field observations showing A. formosa populations decreasing below 0.5 mg/l SiO2 (= 8.4 μM Si). Calculations of yield gave a range of 0.5–1.5 μM Si/106 cells for clone AfOH2 and 0.6–1.9 μM Si/106 cells for clone L262.
A SENSITIVE ALGAL ASSAY: AN IMPROVED METHOD FOR ANALYSIS OF FRESHWATERS1
Authors: Klotz R. L. , Cain J. R. , Trainor F. R.
Published: August 2007

An algal assay capable of detecting the carrying capacity of nutrient‐poor rivers was developed. In order to eliminate carry‐over of nutrients, thus masking the true nutrient condition of the water tested, a new growth medium was developed. This maintenance medium contained less than 4 mg · 1−1 total inorganic salts. With an inoculum of 104 cells‐ml−1 the test organism Selenastrum capricornutum Printz was grown in sterile‐filtered, river water and transferred daily with a 1:1 dilution. The assay was carried out for 4 or 5 days, at which time cell number was calculated, and the doublings per day were determined. Comparisons are made with similar but less sensitive assays, on the basis of both daily and 5‐day readings.
EFFECTS OF ENVIRONMENTAL FACTORS ON PHOTOSYNTHESIS PATTERNS INPHAEODACTYLUM TRICORNUTUM(BACILLARIOPHYCEAE). I. EFFECT OF NITROGEN DEFICIENCY AND LIGHT INTENSITY1
Authors: Glover Hilary , Beardall John , Morris Ian
Published: August 2007

Cultures of the marine diatomPhaeodactylum tricornutumBohlin incorporated, a large proportion of the total fixed carbon (50% or more) into amino acids and amides during short periods of photo‐assimilation of14C‐labelled carbon dioxide. Although increasing nitrogen limitation in a nitrate‐limited chemostat had little significant effect on the proportion of C incorporated into amino acids and amides combined, it did affect the distribution of radioactivity within individual compounds of this group. In particular, increasing degrees of N deficiency reduced the proportion incorporated into amides to almost undetectable levels, reduced the proportion in alanine and increased the proportion in glutamic acid. Also, increasing N limitation decreased the relative synthesis of sugar phosphates and increased the proportion of C assimilated into intermediates of the tricarboxylic acid cycle. Reduced light intensity did not have any significant effect on the proportion of C incorporated into the total amino acids and amides, but did cause a decrease in the radioactivity
EFFECTS OF ENVIRONMENTAL FACTORS ON PHOTOSYNTHESIS PATTERNS IN PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE). II. EFFECT OF OXYGEN1
Authors: Beardall John , Morris Ian
Published: August 2007

Oxygen inhibited the rate of light‐saturated photosynthesis of the marine diatom Phaeodactylum tricornutum Bohlin. However, inhibition could only be detected with O2 concentrations approaching 100%. Atmospheric concentrations of O2 (21%) had little effect on photosynthesis. In this, Phaeodactylum more closely resembles the so‐called C‐4 plants which show low rates of photorespiration. The results presented here agree with others in showing increased O2 inhibition at reduced bicarbonate concentrations. The biochemical mechanism of photorespiration in Phaeodactylum appears to be similar to that reported for other photosynthetic systems.

The activity of ribulose‐1,5 diphosphate (RuDP) carboxylase in cell‐free extracts was also inhibited, by oxygen. Inhibition by O2 was optimal at pH 9.2 as was the RuDP‐dependent O2 uptake. RuDP carboxylase/oxygenase ratios decreased with increasing pH and were greater in cells grown at lower light intensities. Carboxylase levels were less affected by the light intensity for growth than were the levels of the oxygenase.

Short‐term incorporation of NaHCO3‐14C by cells grown at high light intensities showed increased labelling of glycolate and glycine plus serine under O2 compared with nitrogen. There was a concomitant decrease in the radioactivity found in phosphoglyeric acid (PGA) and sugar phosphates in the presence of O2. The effects of O2 on the short‐term pattern of photosynthesis were less marked when the alga was previously grown at low light intensities.
EFFECT OF AMMONIA ON PHOTOSYNTHETIC RATE AND PHOTOSYNTHATE RELEASE BY AMPHIDINIUM CARTERAE (DINOPHYCEAE)1
Authors: Byerrum R. U. , Benson A. A.
Published: August 2007

Ammonia concentration between 10–300 μM in 75% seawater in which Amphidinium carterae Hulb, was allowed to photosynthesize caused an increased rate of photosynthesis. In addition, these same concentrations caused the dinoflagellate to release to the medium up to 50% of the carbon fixed during the 30 min period of photosynthesis used in the experiments.
LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS ON MOTILE CELLS OFPORPHYRIDIUM PURPUREUM(RHODOPHYTA)1,2
Authors: Lin Hsiu‐ping , Sommerfeld Milton R. , Swafford James R.
Published: August 2007

Motile cells of the unicellular red alga,Porphyridium purpureum(Bory) Drew & Ross were studied using light, interference, and electron microscopy. In liquid culture, moving cells possessed a mucilaginous stalk which extended from one end of the cell and tapered to a point. On tin agar surface, distinct trails were left by moving cells. With interference microscopy, the trails appeared to be shallow grooves. Microscopy of shadowed replicas confirmed that moving cells produced a shallow groove as they moved across agar. Ultrastructure observations revealed that cells moving on agar exhibited morphological polarity. Large vesicular elements containing fibrillar material similar to that in the cellular sheath was associated with the posterior area of the motile cells.
PRODUCTS OF PHOTOSYNTHESIS IN CAULERPA SIMPLICIUSCULA (CHLOROPHYCEAE)1
Authors: Howard Russell J. , Gayler Ken R. , Grant Bruce R.
Published: August 2007

The kinetics of carbon flow through various metabolites of Caulerpa simpliciuscula C. Ag., a siphonaceous green alga, are described. The pattern of C fixation in this alga differs from those observed in higher plants and other green algae in a number of respects. After 40 min incubation, soluble β‐linked polyglucans are the most important labelled carbohydrates. Sucrose, although delectable, is never a major recipient of label and does not label until after other oligosaccharide fractions. The sugar monophosphates contain a large proportion of the 14C assimilated even after 40 min and behave not only as metabolic intermediates, but also as storage pools. The pattern of ammo acid labelling resembles that reported for other species of green algae in that alanine becomes labelled most rapidly, followed by glycine, and much later by glutamate, glutamine and asparagine. These labelling patterns are discussed in the light, of what is known of patterns of C flow in other algae.
Knockdown of clock genes in the suprachiasmatic nucleus blocks prolactin surges and alters FRA expression in the locus coeruleus of female rats
Authors: Poletini Maristela O. , McKee De'Nise T. , Kennett Jessica E. , Doster Jamie , Freeman Marc E.
Published: August 2007

The nature of the circadian signal from the suprachiasmatic nucleus (SCN) required for prolactin (PRL) surges is unknown. Because the SCN neuronal circadian rhythm is determined by a feedback loop of Period (Per) 1, Per2, and circadian locomotor output cycles kaput ( Clock) gene expressions, we investigated the effect of SCN rhythmicity on PRL surges by disrupting this loop. Because lesion of the locus coeruleus (LC) abolishes PRL surges and these neurons receive SCN projections, we investigated the role of SCN rhythmicity in the LC neuronal circadian rhythm as a possible component of the circadian mechanism regulating PRL surges. Cycling rats on proestrous day and estradiol-treated ovariectomized rats received injections of antisense or random-sequence deoxyoligonucleotide cocktails for clock genes ( Per1, Per2, and Clock) in the SCN, and blood samples were taken for PRL measurements. The percentage of tyrosine hydroxylase-positive neurons immunoreactive to Fos-related antigen (FRA) was determined in ovariectomized rats submitted to the cocktail injections and in a 12:12-h light:dark (LD) or constant dark (DD) environment. The antisense cocktail abolished both the proestrous and the estradiol-induced PRL surges observed in the afternoon and the increase of FRA expression in the LC neurons at Zeitgeber time 14 in LD and at circadian time 14 in DD. Because SCN afferents and efferents were probably preserved, the SCN rhythmicity is essential for the magnitude of daily PRL surges in female rats as well as for LC neuronal circadian rhythm. SCN neurons therefore determine PRL secretory surges, possibly by modulating LC circadian neuronal activity.
Application of menthol to the skin of whole trunk in mice induces autonomic and behavioral heat-gain responses
Authors: Tajino Koji , Matsumura Kiyoshi , Kosada Kaori , Shibakusa Tetsuro , Inoue Kazuo , Fushiki Tohru , Hosokawa Hiroshi , Kobayashi Shigeo
Published: August 2007

When ambient temperature is decreased in mammals, autonomic and behavioral heat-gain responses occur to maintain their core temperatures. However, what molecules in cutaneous sensory nerve endings mediate cooling-induced responses is unclear. Recently, transient receptor potential melastatin-8 (TRPM8) has been identified in cell bodies of sensory neurons as low-temperature and menthol-activated cation channel. We hypothesized that TRPM8 mediates cooling-induced autonomic and behavioral heat-gain responses. To activate TRPM8 specifically, we applied 1–10% menthol to the skin of whole trunk in mice instead of cooling and measured core temperatures and autonomic and behavioral heat-gain responses. Solvent of menthol (100% ethanol) was used as control. Significant elevation of core temperatures was observed between 20 and 120 min after menthol application. Pretreatment with diclofenac sodium, an antipyretic drug, did not affect this hyperthermia, indicating that the menthol-induced hyperthermia is not fever. Menthol application induced a rise in oxygen consumption, shivering-like muscle activity, tail skin vasoconstriction (autonomic responses), and heat-seeking behavior. All of them are typical heat-gain responses. These results support the hypothesis that TRPM8 mediates cooling-induced autonomic and behavioral heat-gain responses.
Mitochondrial proton leak in obesity-resistant and obesity-prone mice
Authors: Fink Brian D. , Herlein Judy A. , Almind Katrine , Cinti Saverio , Kahn C. Ronald , Sivitz William I.
Published: August 2007

We quantified uncoupling proteins (UCPs) in molar amounts and assessed proton conductance in mitochondria isolated from interscapular brown adipose tissue (IBAT) and hindlimb muscle [known from prior work to contain ectopic brown adipose tissue (BAT) interspersed between muscle fibers] of obesity-resistant 129S6/SvEvTac (129) and obesity-prone C57BL/6 (B6) mice under conditions of low (LF) and high-fat (HF) feeding. With usual feeding, IBAT mitochondrial UCP1 content and proton conductance were greater in 129 mice than B6. However, with HF feeding, UCP1 and proton conductance increased more in B6 mice. Moreover, with HF feeding GDP-inhibitable proton conductance, specific for UCP1, equaled that seen in the 129 strain. UCP1 expression was substantial in mitochondria from hindlimb muscle tissue (ectopic BAT) of 129 mice as opposed to B6 but did not increase with HF feeding in either strain. As expected, muscle UCP3 expression increased with HF feeding in both strains but did not differ by strain. Moreover, the proton conductance of mitochondria isolated from hindlimb muscle tissue did not differ by strain or diet. Our data uncover a response to weight gain in obesity-prone (compared to resistant) mice unrecognized in prior studies that examined only UCP1 mRNA. Obesity-prone mice have the capacity to increase both IBAT UCP1 protein and mitochondrial proton conductance as much or more than obesity-resistant mice. But, this is only achieved only at a higher body mass and, therefore, may be adaptive rather than preventative. Neither obesity-prone nor resistant mice respond to HF feeding by expressing more UCP1 in ectopic BAT within muscle tissue.
Synchronization among mechanisms of renal autoregulation is reduced in hypertensive rats
Authors: Sosnovtseva Olga V. , Pavlov Alexey N. , Mosekilde Erik , Yip Kay-Pong , Holstein-Rathlou Niels-Henrik , Marsh Donald J.
Published: August 2007

We searched for synchronization among autoregulation mechanisms using wavelet transforms applied to tubular pressure recordings in nephron pairs from the surface of rat kidneys. Nephrons have two oscillatory modes in the regulation of their pressures and flows: a faster (100–200 mHz) myogenic mode, and a slower (20–40 mHz) oscillation in tubuloglomerular feedback (TGF). These mechanisms interact; the TGF mode modulates both the amplitude and the frequency of the myogenic mode. Nephrons also communicate with each other using vascular signals triggered by membrane events in arteriolar smooth muscle cells. In addition, the TGF oscillation changes in hypertension to an irregular fluctuation with characteristics of deterministic chaos. The analysis shows that, within single nephrons of normotensive rats, the myogenic mode and TGF are synchronized at discrete frequency ratios, with 5:1 most common. There is no distinct synchronization ratio in spontaneously hypertensive rats (SHR). In normotensive rats, full synchronization of both TGF and myogenic modes is the most probable state for pairs of nephrons originating in a common cortical radial artery. For SHR, full synchronization is less probable; most common in SHR is a state of partial synchronization with entrainment between neighboring nephrons for only one of the modes. Modulation of the myogenic mode by the TGF mode is much stronger in hypertensive than in normotensive rats. Synchronization among nephrons forms the basis for an integrated reaction to blood pressure fluctuations. Reduced synchronization in SHR suggests that the effectiveness of the coordinated response is impaired in hypertension.
Time course of neuroanatomical and functional recovery after bilateral pudendal nerve injury in female rats
Authors: Damaser Margot S. , Samplaski Mary K. , Parikh Mansi , Lin Dan Li , Rao Soujanya , Kerns James M.
Published: August 2007

The pudendal nerve innervates the external urethral sphincter (EUS) and is among the tissues injured during childbirth, which may lead to symptoms of stress urinary incontinence (SUI). To understand the mechanisms of injury and repair, urethral leak-point pressure (LPP) was measured 4 days, 2 wk, or 6 wk after bilateral pudendal nerve crush. Morphometric changes in the distal nerve and EUS were examined by light and electron microscopy. To determine whether recovery resulted from pudendal neuroregeneration, LPP was measured before and after pudendal nerve transection 2 wk after nerve crush. LPP was significantly decreased 4 days after pudendal nerve crush compared with sham-injured animals as well as 2 or 6 wk after nerve crush. LPP was not significantly different 2 or 6 wk after nerve crush compared with sham-injured animals, suggesting that urethral function had returned to normal. Four days after pudendal nerve crush, the EUS branch of the pudendal nerve distal to the injury site showed evidence of nerve degeneration and the EUS appeared disrupted. Two weeks after nerve crush, the distal nerve and EUS both showed evidence of both nerve degeneration and recovery. Two weeks after nerve crush, LPP was significantly decreased after nerve transection. Six weeks after nerve injury, evidence of neuroregeneration was observed in the pudendal nerve and the EUS. This study has demonstrated that functional recovery and neuroregeneration are significant 2 wk after nerve crush, although by anatomical assessment, recovery appears incomplete, suggesting that 2 wk represents an early time point of initial neuroregeneration.
Commissural Mirror-Symmetric Excitation and Reciprocal Inhibition Between the Two Superior Colliculi and Their Roles in Vertical and Horizontal Eye Movements
Authors: Takahashi M. , Sugiuchi Y. , Shinoda Y.
Published: August 2007

The functional roles of commissural excitation and inhibition between the two superior colliculi (SCs) are not yet well understood. We previously showed the existence of strong excitatory commissural connections between the rostral SCs, although commissural connections had been considered to be mainly inhibitory. In this study, by recording intracellular potentials, we examined the topographical distribution of commissural monosynaptic excitation and inhibition from the contralateral medial and lateral SC to tectoreticular neurons (TRNs) in the medial or lateral SC of anesthetized cats. About 85% of TRNs examined projected to both the ipsilateral Forel's field H and the contralateral inhibitory burst neuron region where the respective premotor neurons for vertical and horizontal saccades reside. Medial TRNs received strong commissural excitation from the medial part of the opposite SC, whereas lateral TRNs received excitation mainly from its lateral part. Injection of wheat germ agglutinin–horseradish peroxidase into the lateral or medial SC retrogradely labeled many larger neurons in the lateral or medial part of the contralateral SC, respectively. These results indicated that excitatory commissural connections exist between the medial and medial parts and between the lateral and lateral parts of the rostral SCs. These may play an important role in reinforcing the conjugacy of upward and downward saccades, respectively. In contrast, medial SC projections to lateral SC TRNs and lateral SC projections to medial TRNs mainly produce strong inhibition. This shows that regions representing upward saccades inhibit contralateral regions representing downward saccades and vice versa.
Global expression profiles from C57BL/6J and DBA/2J mouse lungs to determine aging-related genes
Authors: Misra Vikas , Lee Hannah , Singh Anju , Huang Kewu , Thimmulappa Rajesh K. , Mitzner Wayne , Biswal Shyam , Tankersley Clarke G.
Published: August 2007

This study identified gene expression profiles that provided evidence for genomic mechanisms underlying the pathophysiology of aging lung. Aging lungs from C57BL/6 (B6) and DBA/2 (D2) mouse strains differ in physiology and morphometry. Lungs were harvested from B6 mice at 2, 18, and 26 mo and from D2 mice at 2 and 18 mo of age. Purified RNA was subjected to oligonucleotide microarray analyses, and differential expression analyses were performed for comparison of various data sets. A significant majority of differentially expressed genes were upregulated with aging in both strains. Aging D2 lungs uniquely exhibited upregulation in stress-response genes including xenobiotic detoxification cascades. In contrast, aging B6 lungs showed downregulation of heat shock-response genes. Age-dependent downregulation of genes common to both B6 and D2 strains included several collagen genes (e.g., Col1a1 and Col3a1). There was a greater elastin gene ( Eln) expression in D2 mice at 2 mo, and Eln was uniquely downregulated with age in this strain. The matrix metalloproteinase 14 gene ( Mmp14), critical to alveolar structural integrity, was also downregulated with aging in D2 mice only. Several polymorphisms in the regulatory and untranslated regions of Mmp14 were identified between strains, suggesting that variation in Mmp14 gene regulation contributes to accelerated aging of lungs in D2 mice. In summary, lungs of B6 and D2 mice age with variable rates at the gene expression level, and these quantifiable genomic differences provide a template for understanding the variability in age-dependent changes in lung structure and function.
Assessment of Central Serous Chorioretinopathy by Optical Coherence Tomography and Multifocal Electroretinography
Authors: Moschos Marilita , Brouzas Dimitrios , Koutsandrea Chrysanthi , Stefanos Baltatzis , Loukianou Heleni , Papantonis Fotis , Moschos Michael
Published: August 2007

Purpose: To evaluate central serous chorioretinopathy (CSCR) by means of optical coherence tomography (OCT) and multifocal electroretinogram (mf-ERG) at presentation and after resolution of the acute phase. Design: Prospective comparative observational case series with a normal sample. Patients and Method: Twenty-one eyes of 21 patients with unilateral CSCR were examined. Both eyes underwent complete ophthalmological examination, which included measurement of best-corrected visual acuity, fluorescein angiography, OCT and mf-ERG recording. Our results were compared with the corresponding findings of 33 normal volunteers of the same age. Results: At presentation, the averaged mean retinal thickness of the fovea, measured by OCT, was 303 µm in the affected eyes, 69.3% higher compared to the normal controls (p < 0.001). The averaged mean retinal response density of the mf-ERG of the affected eyes in area 1 was 11.29 nV/degree2, 50.8% lower compared to the normal controls (p < 0.001). After regression of CSCR, the averaged mean retinal thickness of the fovea was 213 µm in the affected eyes, 19.3% greater compared to the normal controls (p < 0.001). The averaged mean retinal response density of the mf-ERG of the affected eyes in area 1 was 16.05 nV/degree2, 30.1% lower compared to normal controls (p < 0.001). It is interesting that 6 of 21 fellow nonaffected eyes showed abnormal values, with an averaged mean retinal thickness of OCT (246 µm) and an averaged mean retinal response density of mf-ERG in area 1 (12 µV/degree2). In the remaining 15 eyes, the OCT and the mf-ERG values were within normal limits.
Analysis of Retinal Nerve Fiber Layer Thickness in Patients with Pseudoexfoliation Syndrome Using Optical Coherence Tomography
Authors: Yüksel Nurşen , Altıntaş Özgül , Çelik Mustafa , Özkan Berna , Çağlar Yusuf
Published: August 2007

Objective: To evaluate the retinal nerve fiber layer (RNFL) thickness in patients with unilateral pseudoexfoliation syndrome (PXS) without glaucoma by using optical coherence tomography (OCT). Methods: 22 patients with unilateral PXS were evaluated. Group 1 included the eyes with the pseudoexfoliation, group 2 included the fellow eyes; 18 age-matched normal control eyes were assessed in group 3. The mean and segmental RNFL thickness in eyes with pseudoexfoliation and their fellow eyes in patients with unilateral PXS was compared to age-matched control subject eyes. Results: The RNFL in patients with PXS were significantly thinner than controls in all quadrants except the nasal quadrant with regard to segmental analysis (p < 0.05). This RNFL loss was apparent at 7, 10 and 11 o’clock of the PXS eyes with regard to clock hour position (p < 0.05). In the fellow eyes, no significant difference in RNFL measurement was found except the temporal quadrant when compared with the controls. In the analysis with regard to clock hour position, no significant reduction in RNFL thickness was found except in the 11-o’clock segment. In PXS eyes, RNFL thicknesses at the inferior quadrant and the 1-, 2- and 5-o’clock segments were significantly lower than in non-PXS eyes (p < 0.05). Conclusions: This study suggests that PXS without glaucoma may be associated with a thinner RNFL compared with those of age-matched control subjects and non-PXS fellow eyes. Further studies are needed to clarify the relationship between the decrease in RNFL thickness and the development of glaucomatous damage in eyes with pseudoexfoliation.
The Use of Ultrasound Biomicroscopy in the Evaluation of Anterior Segment Tumors and Simulating Conditions
Authors: Gündüz Kaan , Hoşal Banu M. , Zilelioğlu Güler , Günalp İlhan
Published: August 2007

Purpose: To report the ultrasound biomicroscopy (UBM) findings of anterior segment tumors and simulating conditions. Methods: Thirty-five patients underwent UBM. Of those, 16 had histopathologically or cytopathologically diagnosed tumors, and 19 had clinically diagnosed lesions. Results: The study material comprised 13 iris pigment epithelial (IPE) cysts, 7 ciliary body melanomas, 4 iris melanomas, 4 iris nevi, 3 intraocular invasions of conjunctival squamous cell carcinoma, 2 ring melanomas of the anterior chamber angle, 1 medulloepithelioma and 1 pars plana cyst. On UBM, all IPE cysts presented as cystic lesions with a thin cyst wall and no solid components. All ciliary body melanomas showed low to medium reflectivity, with cavitation in one case and extraocular extension in another. Iris melanomas presented as anterior (stromal) iris lesions with medium to high internal reflectivity. There was irregularity and convex bowing of the posterior iris plane in iris melanomas, a feature not seen in iris nevi. Intraocular invasion of conjunctival squamous cell carcinoma was evidenced as areas of medium to high reflectivity in the ciliary body and iris, loss of the acute angle shape and highly reflective spots in the anterior chamber. Conclusions: UBM was particularly useful in the diagnosis of IPE cysts, in the visualization of small ciliary body melanomas, in the differentiation of iris melanomas from iris nevi and in the demonstration of intraocular invasion from conjunctival squamous cell carcinoma.
Systemic Adverse Events: A Comparison between Topical and Peribulbar Anaesthesia in Cataract Surgery
Authors: Stupp Tobias , Hassouna Ismail , Soppart Karin , Thanos Solon , Förster Werner
Published: August 2007

Aims: To evaluate the safety of topical anaesthesia (TA) versus peribulbar anaesthesia (PBA) in patients undergoing routine cataract surgery on the basis of systemic adverse events. Methods: In this retrospective study, a total of 2,020 consecutive cases of cataract surgery performed by one surgeon on 1,621 patients with PBA (n = 1,010; between 1998–1999) or TA (n = 1,010; between 1999–2001) were evaluated on the basis of intra-operative and early postoperative adverse events requiring medical intervention. Results: The rate of pre-existing risk factors in patients undergoing cataract surgery is high (97%). Complications are significantly less frequent in TA than in PBA in the intra-operative (p < 0.001) and postoperative (p = 0.022) courses. The incidence of intra-operative complications is higher in elderly patients (≧65 years of age) than in younger patients (p < 0.001). Conclusion: The results from the present study indicate that intra-operative complications are less likely in patients that receive TA, suggesting the use of TA for routine cataract surgery both in young patients and particularly in elderly patients when there are no contraindications in the individual case.
Clinicopathological Analysis of Periocular Sebaceous Gland Carcinoma
Authors: Yoon Jin Sook , Kim Se Hoon , Lee Christopher Seungkyu , Lew Helen , Lee Sang Yeul
Published: August 2007

Background: We analyzed the clinicopathological features and prognosis in patients with periocular sebaceous gland carcinoma. Methods: Retrospectively, we studied the records of 24 cases of sebaceous gland carcinoma treated in our clinic between 1999 and 2004. The reviewed data included demographic information, initial clinical and histopathological diagnosis, anatomic tumor location, details of treatment, tumor involvement of resection margin, and outcomes such as local recurrence, distant metastasis and survival. Results: Local recurrence developed in 6 cases (25%) at a median of 20 months from initial diagnosis. Only 2 patients (8.3%) died of systemic metastasis to brain and bone from primary lacrimal gland carcinoma. The local recurrence rate in the complete excision group (5.9%) was significantly lower compared with the incomplete excision with irradiation group (71.4%; Fisher’s exact test, p = 0.003). We observed a shorter duration of symptom, a higher rate of eventual exenteration and local recurrence, and a shorter time interval to local recurrence from initial management in poorly differentiated tumors compared with moderately differentiated tumors. Conclusion: It is critical to achieve a negative tumor margin in both frozen and permanent section to prevent local recurrence. Early aggressive management is required in sebaceous gland carcinoma of the lacrimal gland, as its mortality is much higher than that of eyelid origin.
Indolent Stage IE Non-Hodgkin’s Lymphoma of the Orbit: Results after Primary Radiotherapy
Authors: Bischof M. , Zierhut D. , Neuhof D. , Karagiozidis M. , Treiber M. , Roeder F. , Debus J. , Krempien R.
Published: August 2007

Aims: Primary non-Hodgkin’s lymphoma (NHL) of the orbit is uncommon, representing approximately 8% of extranodal NHLs. Twenty-two patients with indolent stage IE NHL were reviewed retrospectively to analyze the outcome and late effects of primary local radiotherapy. Materials and Methods: The median age at first diagnosis was 63.5 years (range 24–82 years). Extranodal mucosa-associated lymphoid tissue lymphoma (n = 15) was the most common histological subtype of NHL, followed by follicular (n = 6) and lymphoplasmacytic lymphoma (n = 1). Radiotherapy was performed using a linear accelerator. The median radiation dose was 40 Gy (range 30–46 Gy). None of the patients received chemotherapy before irradiation. The follow-up period was 62 months (range 8–136 months). Results:A complete response was achieved in all patients. The 5-year local control rate was 100%. Distant relapse occurred in 2 patients, resulting in a 5-year distant relapse-free survival rate of 88%. The 5-year overall survival rate was 89%; there were no lymphoma-related deaths. No serious acute complications (grade 3/4) were observed. Grade 1/2 late effects were documented in 44% of patients. Grade 3 complications (cataract: 2, dryness: 2) were observed in 4 patients (18%). Conclusions: Indolent early stage orbital NHL can be controlled with local radiotherapy. Morbidity is low. Regular follow-up examinations are necessary to detect rare cases of distant relapse.
Endovascular Treatment of Aortic Aneurysms: Techniques and Clinical Update
Authors: Chaer Rabih A. , Makaroun Michel S. , Chedrawy Edgar G. , Abdelhady Khaled , Lele Himalaya , Massad Malek G.
Published: August 2007

Open repair of abdominal and thoracic aortic aneurysms continues to be associated with considerable morbidity and mortality. Endovascular repair of abdominal and thoracic aortic aneurysms has evolved over the past few years and has significantly reduced the morbidity of aortic aneurysm repair compared with the standard open surgical procedures. Several devices have been approved for clinical use for this purpose. This has allowed the treatment of patients who are otherwise at high risk for open repair. This review paper aims to (1) describe the general principles of use for endovascular devices and review the radiographic features and clinical trials for the devices in current use, (2) present the results of the clinical trials that led to the approval and marketing of the current devices, and (3) review new techniques and approaches for the treatment of aortic aneurysms.
Methamphetamine-Associated Acute Left Ventricular Dysfunction: A Variant of Stress-Induced Cardiomyopathy
Authors: Srikanth Sundararajan , Barua Rajat , Ambrose John
Published: August 2007

This brief report describes a case of transient left ventricular dysfunction in a 42-year-old woman associated with methamphetamine abuse. Transient (stress-induced) left ventricular dysfunction has been described previously, usually in postmenopausal women following emotional stress and also severe medical illness. This is the first reported case associated with methamphetamine abuse.
Diet Quality of Pregnant Women Attending an Antenatal Clinic in Nakuru, Kenya
Authors: Kamau-Mbuthia Elizabeth , Elmadfa Ibrahim
Published: August 2007

Background/Aims: To determine diet quality and common food sources of various nutrients of pregnant Kenyan women. Methods: Cross-sectional study of 716 pregnant women attending the antenatal clinic at the Provincial General Hospital, Nakuru, Kenya. Nutrient intake was estimated using the 24-hour dietary recall method. Results: Inadequate nutrient intake was found for energy, total folic acid, calcium, iron and zinc. Adequate intake was found for protein, fat, PUFA, carbohydrate, dietary fiber, vitamins A and C. Diet quality was poor as evidenced from the food sources of various nutrients. Maize flour was the most common source of the following nutrients: energy, protein, total folic acid, iron and zinc. Young women and those of low socio-economic status were at risk of inadequate intake of some of the nutrients. Conclusion: The results of this study indicate poor-quality diets of pregnant women attending the antenatal clinic, low in multiple micronutrients. Nutrient education for dietary diversification and nutrient supplementation should be explored as interventions for improving nutrient intake among pregnant women.