Oocysts of Isospora ernsti n. sp. and Isospora blagburni n. sp. (Apicomplexa: Eimeriidae) from the black-capped bulbul,Pycnonotus xanthopygos

Oocysts of Isospora ernsti n. sp. and Isospora blagburni n. sp. are described from the black-capped bulbul Pycnonotus xanthopygos from Lincoln Park Zoo, Chicago, Illinois. The bird came from southwestern Africa seven years earlier. I. ernsti oocysts are ellipsoidal to bluntly ovoid, 28–38 × 23–31m (mean 34 × 28 m) and have a single-layered oocyst wall. Micropyle, oocyst residuum and polar granules are absent. Sporocysts are elongate ovoid, 24–30 × 11–16 m (mean 27×13 m). Stieda and substiedal bodies and sporocyst residuum are present. I. blagburni oocysts are spherical to subspherical. 21–28 × 19–26 m (mean 25 × 23 m) and have a single oocyst wall. Sporocysts are ovoid and 17–23 × 10–13 m (mean 20 × 12 m). Stieda and substiedal bodies and sporocyst residuum are present.     

Choline Administration Reverses Hypotension In Spinal Cord Transected Rats: The Involvement of Vasopressin

Intracerebroventricular (i.c.v.) choline (50–150 g) increased blood pressure and decreased heart rate in spinal cord transected, hypotensive rats. Choline administered intraperitoneally (60 mg/kg), also, increased blood pressure, but to a lesser extent. The pressor response to i.c.v. choline was associated with an increase in plasma vasopressin. Mecamylamine pretreatment (50 g; i.c.v.) blocked the pressor, bradycardic and vasopressin responses to choline (150 g). Atropine pretreatment (10 g; i.c.v.) abolished the bradycardia but failed to alter pressor and vasopressin responses. Hemicholinium-3 [HC-3 (20 g; i.c.v.)] pretreatment attenuated both bradycardia and pressor responses to choline. The vasopressin V1 receptor antagonist, (-mercapto-, -cyclopenta-methylenepropionyl¹, O-Me-Tyr², Arg⁸)-vasopressin (10 g/kg) administered intravenously 5 min after choline abolished the pressor response and attenuated the bradycardia-induced by choline. These data show that choline restores hypotension effectively by activating central nicotinic receptors via presynaptic mechanisms, in spinal shock. Choline-induced bradycardia is mediated by central nicotinic and muscarinic receptors. Increase in plasma vasopressin is involved in cardiovascular effects of choline.     

Uptake and Retention of Selenite and Selenomethionine in cultured K-562 cells

The selenium uptake and retention have been studied in K-562 cells exposed to selenite or selenomethionine. In the uptake experiments the cells were exposed to two doses of selenite (5 or 50 M) or selenomethionine (10 or 50 M). In the retention study the cells were treated for 2 h with the above mentioned doses of the selenocompounds before being observed at different times. The selenium uptake in cells exposed to selenite 5 M began to saturate at 8 h, but increased again between 48 and 96 h. In cells exposed to selenite 50 M the selenium uptake never reached a maximum, however, at 48 and 96 h the cell viability decreased strongly. The two doses of selenite showed different retention patterns, with a relatively small cellular decrease of selenium after treatment with selenite 5 M compared to treatment with 50 M of selenite. The selenium uptake in cells exposed to selenomethionine 10 M or selenomethionine 50 M began to saturate at 24 h and 48 h, respectively. The retention patterns were similar for both selenomethionine doses with a continuous decrease of the selenium concentration during the whole observation period. The results indicated a more controlled uptake and retention pattern of selenomethionine compared to selenite.     

The occurrence of HT-2 toxin and other trichothecenes in Norwegian cereals

A total of 449 grain samples, 102 barley, 169 wheat and 178 oat samples were collected from different regions of Norway from 1996–1998 crops, mainly from grain loads and silos. The samples were analysed for type A and B trichothecenes, the largest groups of mycotoxins produced by the Fusarium species, by gas chromatography with mass spectrometric detection (GC-MS). Factors affecting the presence of the different trichothecenes are discussed. Deoxynivalenol (DON) and HT-2 toxin were the trichothecenes most frequently detected, followed by T-2 toxin, nivalenol, and scirpentriol, scirpentriol being detected only in seven samples (>20 g/kg).Oats were the grain species most heavily contaminated with an incidence(% >20 g/kg) and mean concentration of positive samples of 70%(115 g/kg) for HT-2 toxin, 30% (60 g/kg) for T-2 toxin, 57%(104 g/kg) for DON, and 10% (56 g/kg) for nivalenol. The corresponding values for barley were 22% (73 g/kg), 5% (85 g/kg),17% (155 g/kg) and 6% (30 g/kg), and for wheat 1.2% (20 g/kg),0.6% (20 g/kg), 14% (53 g/kg) and 0% for HT-2, T-2, DON and nivalenol, respectively. Norwegian oats were found to contain HT-2 and T-2 toxin in concentrations that might be at threat to human health for high consumers of oats. The amount of DON was significantly lower than in the crop from previous years.This revised version was published online in October 2005 with corrections to the Cover Date.     

Promotion of flowering in apple trees with gibberellin A4 and C-3 epi-gibberellin A4

The proportion of spurs flowering on apple trees (Malus domestica Borkh. cv Golden Delicious) displaying a high degree of alternate-year flowering was increased in the off year by gibberellin A₄ (GA₄) and C-3 epi-GA₄ applied in the previous year. When applied 4.5 weeks after anthesis amounts of GA₄ ranging from 3 to 300 g per spur and 25 or 50 g of C-3 epi-GA₄ per spur were effective. Treatments with GA₄ made seven weeks after anthesis were less effective. A combination of 30 g GA₄ and 30 g zeatin (6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine) promoted flowering at both treatment times, and tended to be more effective than GA₄ alone.Abbreviation GA gibberellin or gibberellin-like substance Contribution No. 618     

Problems in estimating growth rates of marine phytoplankton from short-term14C assays

Growth rate estimates () of phytoplankton populations that were sampled from nitrogen-limited continuous cultures and then incubated for short durations in batch culture with added¹⁴C-HCO₃ ^– were significantly different than steady-state growth rates () for 3 of 5 marine phytoplankton species. Two diatoms,Thalassiosira weissflogii andChaetoceros simplex, displayed virtually identical growth rates (=) over a wide range of, whereas for a third diatom,Phaeodactylum tricornutum, was overestimated by an average of 40% compared to. In contrast, was underestimated by the¹⁴C technique for the two remaining species: up to 40% at a steady-state of 1.0 day^–1 for the chlorophyteDunaliella tertiolecta and up to 100% at of 1.4 day^–1 for the haptophytePavlova lutheri. For the latter two species the divergence between and appeared to increase with increasing steady-state. A simple model of labeled and total carbon flow between the aqueous phase and cellular biomass was constructed to demonstrate that respiration was negligible when=, but was significant when>. In the cases in which<, a rapid physiological alteration presumably took place once the steady state was disturbed and cells were placed in the incubation chambers, which perhaps was related to the nutritional state of the cultures at the time of sampling. Questions thus are raised regarding our ability to measure accurately primary productivity from shipboard experiments with confined samples of phytoplankton from nutrient-impoverished waters that probably are less hardy than the laboratory cultures used in these studies.     

Micropropagation and ecorestoration of Vanda spathulata,an exquisite orchid

Node explants collected from flowering plants of Vanda spathulata, an endemic and exquisite orchid of Peninsular India and Sri Lanka, were cultured in Mitra medium with combinations of 4.4–88.8 m 6-benzyl adenine (BA) and 0.0–114.2 m indole-3-acetic acid (IAA). Combinations of 44.4 m BA with 17.1 or 28.5 m IAA and 66.6 mM BA with 28.5 or 40.0 m IAA induced maximum formation of 12.6 and 12.1 shoots / node, respectively, in a 6-month period. Subcultured nodal explants produced maximum of 6.1 shoots at combinations of 22.2–44.4 m 21 BA and 5.7–28.5 m IAA. Rooting of shoots occurred in medium containing 75 g l^–1 banana pulp and 5.7 m IAA within 3–9 weeks. Plantlets of 2–5 cm length possessing two to five roots established easily in community pots at 80–90% rates without hardening. Community potted plants introduced into forest segments at Ponmudi and Palode in Southern Western Ghats of India established at a rate of 50–70%.     

Developmental aspects of long-term callus culture ofVicia faba L.

Summary Vicia faba callus line (VFS 1), isolated from expiants of immature embryo, grew satisfactorily onMurashige andSkoog complete medium with 1.38 M 2,4-D, or with 0.92 M 2,4-D to which 1.0 M kinetin was added. It also grew well on the B 5 modified medium containing 2.3 M 2,4-D and 25.0 M kinetin. On the last of these media the cultures grew more uniformly and without necrosis. They also showed diminishing variation in polyploidy in favour of diploids and corresponding aneuploids (hypodiploids).After being cultured for nearly three years on MS containing 1.38 M 2,4-D, 8–33% of cultures of VFS 1 were able to regenerate roots when transferred to either MS half strength with 5.37 M NAA, or to a medium without 2,4-D, or else to media with the addition of kinetin only (in various concentrations).     

Coccidia of Brazilian edentates: Eimeria cyclopei n.sp. from the silky anteater,Cyclopes didactylus (Linn.) and Eimeria choloepi n.sp. from the two-toed sloth,Choloepus didactylus (Linn.)

Summary Eimeria cyclopei n.sp. is described from the silky anteater, Cyclopes didactylus, from Pará State, north Brazil. Undifferentiated oocysts, passed in the faeces, complete sporulation in seven days at 26 to 28°C. Oocysts are ellipsoidal to sub-spherical, with a mean size of 28.1 × 23.6 m: the wall is 1.5 to 2.0 m thick, apparently with an outer thin, colourless membrane and two inner, thicker, striated and yellowish layers. There is no micropyle, oocyst residuum or polar body. The mean measurements of sporocysts are 19.0 × 9.0 m, and they are slightly asymmetrical, elongate pear-shape, with a plug-shaped Steida body projecting beyond the end of the sporocyst. Sporozoites are as long as or longer than the sporocysts: The sporocyst residuum is scattered between sporozoites in younger specimens and becomes condensed into rounded mass in older ones. The endogenous stages occur in the epithelial cells of the ileum, on the lumenal side of the host-cell nucleus. Uninucleate meront, microgamont and macrogamont precursors are recognizable morphologically. Mature meronts are 20.0 × 15.7 m some produce 12 to 20 merozoites which are 8.7 × 2.0 m, and others 10 to 26 merozoites which are 11.4 × 2.0 to 15.0 × 3.0 m. Mature microgamonts which are 27.5 × 24.1 m, produce from 150 to 170 microgametes of 7.1 × 1.0 m: microgametes have two flagella of unequal length. Mature macrogamonts are 28.4 × 24.5 m Eimeria choloepi n.sp. is recorded from the two-toed sloth, Choloepus didactylus, from the same area of Brazil. Undifferentiated oocysts, passed in the faeces, complete sporulation in 23 days at 26 to 28°C. Oocysts with a mean size of 23.0 × 20.3 m, have a wall 2.0 to 2.5 m thick which is composed of two thick, yellowish and striated outer layers and a delicate, colourless inner one. There is no micropyle, oocyst residuum or polar granule. Mature sporocysts with a mean size of 11.3 × 7.1 m, are ellipsoidal to egg-shaped and have a poorly developed Steida body. The sporocyst residuum is composed of a small number of large globules: The sporozoites are longer than the sporocyst and strongly recurved. The endogenous stages occur in epithelial cells of the ileum, on the lumenal side of the host-cell nucleus. Dimorphic meronts produce 8 to 18 merozoites which are either 13.0 × 2.0 m or 13.0 × 3.0 m. Microgamonts produce 50 to 80 microgametes of 8.0 × 1.0 m. Mature macrogamonts are 18.3 × 17.9 m. ac]19820212     

In vitro meristem cloning of Eucalyptus tereticornis Sm.

Rapid multiplication of axillary meristems and direct shoot development occurred from nodal explants of mature Eucalyptus tereticornis Sm. with 5.3 M NAA, 1.1 M IAA and 4.4 M BA in Murashige-Skoog medium. Repeated subcultures of the second generation shoot cultures into low cytokinin-auxin containing media (0.44–0.88 M BA+0.1 M NAA) yielded axillary microshoots in large numbers. Half-strength MS liquid medium with 4.9 M IBA, 5.5 M IAA and 5.3 M NAA for four days, half-strength semi-solid hormonefree MS medium with charcoal, and MS liquid medium without charcoal and hormones, in sequence, induced rooting of shoots in the dark. This system is suitable for the mass propagation of this difficult-to-root eucalypt.Abbreviations BA 6-benzyladenine - IAA indole-3-acetic acid - IBA -indole-3-butyric acid - 2-iP isopentyl adenine - Kn kinetin - MS Murashige-Skoog - NAA -naphthalene acetic acid - PVP polyvinylpyrrolidone     

Effects of lead and cadmium on chemical composition and total water content of the pupal parasitoid, Pimpla turionellae

The parasitoid Pimpla turionellae L. (Hymenoptera, Ichneumonidae) was fed on Cd, Pb and Cd+Pb-contaminated food (33g Cd, 82g Pb and 33g Cd+82g Pb per gram food fresh weight, respectively). Significant decrease in the total lipid and protein content was found along with an increase in the water content particularly in Cd-contaminated parasitoids.     

Somatic embryogenesis and plant regeneration in wild cotton (Gossypium klotzschianum)

A simple and efficient method for high frequency somatic embryogenesis and plant regeneration from hypocotyl-derived cultures and suspension cultures of Gossypium klotzschianum Anderss, a wild, diploid species of cotton is described here. Embryogenic cultures were induced from hypocotyl sections on MSB medium with 0.9 M 2,4-D and 2.32 M kinetin. MSB medium containing 0.045 M 2,4-D, 0.93 M kinetin, 2.46 M IBA promoted embryogenic culture proliferation and embryo development. Suspension cultures with 0.23 M 2,4-D and 0.93 M kinetin also produced many embryos. Somatic embryos cultured on MSB medium with PGRs produced secondary embryos, and embryos developed into normal plantlets on PGR-free MSB medium. Regenerated plantlets were transferred onto the quarter-strength MSB medium with 0.5% active charcoal to avoid recallusing. Hypocotyls were better than cotyledons for culture induction and plant regeneration. 2,4-D and kinetin were essential for culture induction and maintenance.     

In vitro clonal propagation of tea (Camellia sinensis (L.) O. Kuntze)

A system for in vitro clonal propagation has been developed in tea plants. Shoots obtained from primary explants were induced from terminal buds and axillary buds of mature field-grown plants. Cultures were initiated from both types of explants on Murashige and Skoog (MS) medium supplemented with 10% coconut milk (CM), 200 mg l^-1 of yeast extract (YE), 1.4 M indoleacetic acid (IAA) and 17.8 M benzyladenine (BA). The shoot tips were multiplied on 1/2 strength MS medium containing 10% CM, 2.9 M IAA and 17.8 M BA. The larger shoots were separated after multiplication and rooted on 1/2 MS medium supplemented with 11.4 M ascorbic acid and 34.5 M indolebutyric acid (IBA). A pretreatment of the plants with an aqueous solution of 493 M IBA greatly increased the frequency of rooting. More than 60% of the rooted plants have been transferred to soil successfully.Abbreviations BA benzyladenine - IAA indoleacetic acid - IBA indolebutyric acid - YE yeast extract - CM coconut milk - MS Murashige and Skoog medium (1962)     

The effect of monoterpenes on astaxanthin production by a mutant ofPhaffia rhodozyma

Summary The total pigment and astaxanthin content ofPhaffia rhodozyma increased with increasing concentrations -pinene up to 500 l -pinene/l. Above this concentration the total pigment and astaxanthin content as well as the biomass production decreased. The addition of 500 l -pinene/l increased the total pigment content from 1652 g/g to 2201 g/g and the astaxanthin content from 1554 g/g to 1883 g/g. A sharp decrease in maximum specific growth rate occurred above 150 l -pinene/l.     

Rabbit heavy chain haplotypes — Allotypic determinants expressed byVH-CH recombinants

This report summarizes our current understanding of the heavy chain haplotypes found in our laboratories' rabbits. Independently derived data from several laboratories have been synthesized into a consistent picture of the linked inheritance of allotypic markers found on the different heavy chain classes and subclasses of rabbit immunoglobulins in pedigreed rabbits, including the families of three apparentVH-CH recombinants. In one recombinant, the entire group ofCH markers (C, C, and C) recombined with the set ofVH. Although in the other two recombinants all CH markers may also have recombined as a group, in one of these only IgG and IgACH genes were informative; in the other recombinant, only the IgG allotypes were informative. Some allotypic determinants found on IgM molecules (conformational) appear only when a specific variable region allotype (VHa) is combined with a specific constant region allotype (C). New combinations ofVHa and C allotypes were generated in two of the genetic recombinants and led to new conformational determinants. The gains and losses observed lend support to the hypothesis that the determinants result from conformations generated by the combination of allotype-specificVH and C protein sequences. Conceivably, DNA events that joinVH to diversity (D)- and joining (J)-coding sequences or mRNA processing events that splice J to C could be involved in generating the sequences that form allotype-specific determinants.     

Penicillinase activity in three strains ofClostridium butyricum

Three strains ofClostridium butyricum exhibited elevated minimal inhibitory concentrations (MICs) to penicillin (64–1,024 g/ml), ampicillin (32–256 g/ml), carbenicillin (128–1,024 g/ml), and oxacillin (32–64 g/ml). Cephalosporin/cephamycin agents were more active than penicillin drugs. All isolates were found to possess a -lactamase. The -lactamases were primarily cell associated during the logarithmic phase of growth. Stationary-phase cells released most of the enzyme into the culture medium. Cephalothin supplementation of broth cultures with concentrations equivalent to one-eighth of the MIC significantly increased the quantity of -lactamase synthesized. The -lactamases produced by these three isolates exhibited greatest activity with penicillin followed by ampicillin>cephaloridine>carbenicillin and oxacillin. No enzymatic activity was observed using cephalothin, cephalexin, cefazolin, cefoxitin, or cephamandole substrates. The -lactamases were inhibited by clavulanic acid and para-chloromurcuribenzoate and not inhibited by cloxacillin. Each enzyme exhibited an isoelectric point of 4.2.     

Coral growth in high-nutrient,low-pH seawater: a case study of corals cultured at the Waikiki Aquarium,Honolulu, Hawaii

Fifty-seven species of hermatypic corals have been maintained and grown in high-nutrient seawater at the Waikiki Aquarium, Honolulu, Hawaii. In this study we document the chemical conditions of aquarium water in terms of dissolved nutrients and carbon. Aquarium water is characterized by concentrations of inorganic nutrients that are high relative to most natural reef ecosystems: SiO₃ 200 M; PO₄ 0.6 M; NO₃ 5 M; NH₄ 2 M. In contrast, concentrations of organic nutrients are lower than most tropical surface ocean waters: DOP 0.1 M and DON 4 M. The incoming well-water servicing the facility has low pH, crating over-saturation of carbon dioxide. The coral communities in aquaria took up inorganic nutrients and released organic nutrients. Rates of nutrient uptake into aquaria coral communities were similar to nutrient uptake by natural reef communities. Coral growth rates were near the upper rates reported from the field, demonstrating corals can and do flourish in relatively high-nutrient water. The growth of corals does not appear to be inhibited at concentrations of nitrogen up to 5 M. Statements implying that corals can only grow in low nutrient oligotrophic seawater are therefore oversimplifications of processes that govern growth of these organisms. Some basic guidelines are given for maintenance of coral communities in aquaria.     

Antioxidant Properties of New Chalcogenides Against Lipid Peroxidation in Rat Brain

Ebselen (2-phenyl- 1,2-benzisoselenazole-3 (2H)-one) is a seleno-organic compound with antioxidant properties, and anti-inflammatory actions. Recently, ebselen improved the outcome of acute ischemic stroke in humans. In the present study, the potential antioxidant capacity of organochalcogenide compounds diphenyl diselenide (PhSe)₂, diphenyl ditelluride (PhTe)₂, diphenyl disulfide (PhS)₂, p-Cl-diphenyl diselenide (pCl-PhSe)₂, bis-[S-4-isopropyl 2-phenyl oxazoline] diselenide (AA-Se)₂, bis-[S-4-isopropyl 2-phenyl oxazoline] ditelluride (AA-Te)₂ and bis-[S-4-isopropyl 2-phenyl oxazoline] disulfide (AA-S)₂ was compared with that of ebselen (a classical antioxidant). Spontaneous and quinolinic acid (QA)- (2 mM) and sodium nitroprusside (SNP)- (5 M)-induced thiobarbituric reactive species (TBARS) production by rat brain homogenates was determined colorimetrically. TBARS formation was reduced by ebselen, (PhSe)₂, (PhTe)₂, (AA-Se)₂, (AA-S)₂ and (pCl- PhSe)₂ to basal rates. The concentrations of these compounds needed to inhibit TBARS formation by 50% (lC₅₀) are 1.71 M, 3.73 M, 1.63 M, 9.85 M, > 33.3 M, 23.2 M and 4.83 M, respectively for QA. For TBARS production induced by SNP the lC₅₀ was 2.02 M, 12.5 M, 2.80 M, > 33.3 M, 24.5 M and 7.55 M, respectively. The compounds (AA-Te)₂ and (PhS)₂ have no antioxidant activity and pro-oxidant activity, respectively. These results suggest that (AA-Se)₂ and (AA-S)₂ can be considered as potential pharmaceutical antioxidant agents.     

In vitro somatic embryogenesis and plant regeneration in Acacia arabica

In vitro somatic embryogenesis and subsequent plant regeneration was achieved in callus cultures derived from immature zygotic embryos of Acacia arabica on semi-solid Murashige and Skoog (MS) basal salts and vitamins supplemented with 8.88 MBA, 6.78 M2,4-D and 30 g l^–1 (w/v) sucrose. Somatic embryos proliferated rapidly by secondary somatic embryogenesis after transfer to MS medium supplemented with 6.66 M BA, 6.78 M 2,4-D. The maximum number of somatic embryos per callus was 72.6 after 8 weeks of culture on medium containing 6.66 M BA and 6.78 M 2,4-D. The isolated somatic embryos germinated on half-strength basal MS salts and vitamins supplemented with 0.04 M BA, 0.94 M ABA and 2% (w/v) sucrose. The embryo-derived plantlets were acclimatized in the greenhouse and subsequently showed normal growth.     

The gibberellin synthesis inhibitors,ancymidol and flurprimidol,promote in vitro rooting of white pine microshoots

Summary Ancymidol and flurprimidol were tested for their ability to induce in vitro rooting on axillary proliferated shoots of white pine (Pinus strobus L.). Shoots were treated for 30 days (pulse) with growth regulators, then subcultured to 0.5X medium for conifer morphogenesis without growth regulators. A pulse treatment containing 5 M ancymidol and 0.54 M naphthaleneacetic acid resulted in 43% rooted shoots, whereas a pulse treatment with 0.54 M naphthaleneacetic acid alone resulted in 7% root formation. Flurprimidol also stimulated rooting of white pine shoots, but was less effective than ancymidol. No detrimental effects on shoot growth were observed with the gibberellin synthesis inhibitors at the 5 M concentration used. Some rooted shoots were successfully acclimatized to the greenhouse.Abbreviations ancymidol -cyclopropyl-(4-methoxyphenyl)-5-pyrimidinemethanol - flurprimidol -(1-methylethyl--[4-trifluromethoxy)phenyl]-5-pyridinemethanol - GA gibberellin - MCM medium for conifer morphogenesis - NAA 1-naphthaleneacetic acid