Egg-cases and size at hatching of Sympterygia acuta in the south-western Atlantic

Ten egg-cases of Sympterygia acuta were collected from the surf line at Cassino Beach, Rio Grande do Sul, Brazil, and incubated in the laboratory. The egg-cases and neonates (77–84 mm total length) are described.     

Monitoring of HAB species in the Mediterranean Sea through molecular methods

A qualitative and semi-quantitative polymerase chain reaction(PCR)-based assay was developed for the detection of severalpotentially Harmful Algal Bloom (HAB) species and genera belongingto Dinophyceae, Bacillariophyceae and Raphydophyceae. Oligonucleotideprimers were designed based on Internal Transcribed Spacer (ITS)–5.8Sribosomal DNA (rDNA) sequences available in public databaseor identified in this study. The specificity and sensitivityof the PCR assay were validated using clonal cultures and thennatural seawater samples, as well as the known copy number ofplasmids containing the target ITS–5.8S rDNA regions.A filter system for collecting mixed phytoplankton cells coupledto a target species-specific PCR assay was performed on spatialand temporal series of net and surface seawater samples duringcoastal water monitoring carried out in several localities ofthe Mediterranean Sea. The application of PCR allowed a rapiddetection of various genera and species-specific potential HABtaxa in all examined natural samples. Qualitative and semi-quantitativePCR results obtained from field samples were compared with microscopic[light microscope (LM)] examinations. The two methods gave comparableresults, and the molecular assay was able to detect HAB targetcells at concentrations not detectable by microscopy or thoseof uncertain identity. The highest values of positive detectionof potential HAB taxon presence obtained by PCR assay comparedwith the microscopic examination ranged from 67 to 8.0%.     

Synthesis and biological evaluation of antifungal derivatives of enfumafungin as orally bioavailable inhibitors of β-1,3-glucan synthase

Orally bioavailable inhibitors of β-(1,3)-d-glucan synthase have been pursued as new, broad-spectrum fungicidal therapies suitable for treatment in immunocompromised patients. Toward this end, a collaborative medicinal chemistry program was established based on semisynthetic derivatization of the triterpenoid glycoside natural product enfumafungin in order to optimize in vivo antifungal activity and oral absorption properties. In the course of these studies, it was hypothesized that the pharmacokinetic properties of the semisynthetic enfumafungin analog 3 could be improved by tethering the alkyl groups proximal to the basic nitrogen of the C3-aminoether side chain into an azacyclic system, so as to preclude oxidative N-demethylation. The results of this research effort are disclosed herein.     

Reproductive characteristics and reproductive tract anatomy of the California butterfly ray Gymnura marmorata (Myliobatiformes: Gymnuridae)

The California butterfly ray Gymnura marmorata is frequently caught by artisanal fisheries in north-western Mexico (Baja California Sur; BCS). The aim of this study was to estimate reproductive characteristics and describe the micro and macroscopic reproductive structures of female and male G. marmorata. Sampling was carried out at two fisheries landing sites located on the west coast BCS, from 2008 to 2012. The largest disc width (W_D) ever recorded for this species was 131.0 cm and females were larger than males. The male sample was composed exclusively of adult specimens, with a median size at 50% maturity (W_D50) estimated at 44.9 cm W_D. For females, size at onset of maturity was estimated at 63.0 cm W_D; W_D50, at 64.7 cm W_D; and size at pregnancy at 80.1 cm W_D. Gonadal asymmetry was observed for the first time in this species. Indeed, in males only the left testis was functional (testicular asymmetry), while in females, only the left ovary was functional (ovarian asymmetry).     

Distribuzione del fitoplancton in un'area salmastra della Sicilia nord-orientale

Abstract

Phytoplankton distribution in a brackish area of North-Eastern Sicily -The abundance and taxonomic composition of the phytoplankton have been studied in relation to temperature, salinity and dissolved oxygen in the brackish pools of Oliveri-Tindari, a very restricted area on the Tyrrhenian coast of Sicily (Italy). The phytoplankton distribution in these pools has been subject to relatively few investigations. Although this area is not influenced by sewage and industrial effluents, some pools showed episodical high densities of phytoplankton, due to the influence of organic inputs (streams and water-bearings), and anoxic conditions.

The microalgal communities were generally characterized by chlorophyceans, although sometimes other taxa prevailed.     

Structural and biochemical characterization of the yeast exosome component Rrp40

The exosome is a protein complex that is important in both degradation and 3'-processing of eukaryotic RNAs. We present the crystal structure of the Rrp40 exosome subunit from Saccharomyces cerevisiae at a resolution of 2.2 A. The structure comprises an S1 domain and an unusual KH (K homology) domain. Close packing of the S1 and KH domains is stabilized by a GxNG sequence, which is uniquely conserved in exosome KH domains. Nuclear magnetic resonance data reveal the presence of a manganese-binding site at the interface of the two domains. Isothermal titration calorimetry shows that Rrp40 and archaeal Rrp4 alone have very low intrinsic affinity for RNA. The affinity of an archaeal core exosome for RNA is significantly increased in the presence of the S1-KH subunit Rrp4, indicating that multiple subunits might contribute to cooperative binding of RNA substrates by the exosome.     

Size at first sexual maturity of two species of rajoid skates, genera Atlantoraja and Dipturus (Pisces, Elasmobranchii, Rajidae), from the south-western Atlantic Ocean

Total length (TL) at first sexual maturity was estimated for Atlantoraja castelnaui and Dipturus chilensis from the south‐western Atlantic Ocean. Total length at which 50% of the females were captured (50% c) was less than the TL at first sexual maturity (ML) in both species. Immature females are being captured and thus will not become sexually mature to reproduce because of early fishing mortality. Females of A. castelnaui and D. chilensis reach sexual maturity at TLs of 110–114 cm and 102–106 cm, respectively. Males mature with TL between 91 and 95 cm for A. castelnaui and between 83 and 87 cm for D. chilensis.     

THE LIFE HISTORY OF ALEXANDRIUM TAYLORI (DINOPHYCEAE)

The gonyaulacoid dinoflagellate Alexandrium taylori Balech is reported for the first time from Italian waters. In July 1997, nonmotile stages of this species, both temporary and sexual resting cysts, were found in surface Ionian coastal waters (Mediterranean Sea) producing localized brownish-yellow patches. Clonal cultures were established, and the life history of A. taylori was studied in the laboratory. Asexual reproduction took place during a motile phase and produced two daughter cells remaining temporarily attached in pairs. This species exhibited isogamy. Small gametes were produced from vegetative cells through the release of a division cyst and multiple fission of the protoplast. Isogametes from the same clonal strain fused and underwent sexual reproduction, forming planozygotes that subsequently developed storage bodies and dark pigmentation. The maturation of the planozygote into hypnozygote also involved an increase in size and final shedding of flagella and theca. Hypnozygotes germinated within 15 days of their formation, and a naked planomeiocyte emerged from the archeopyle to undergo successive divisions and reestablish a haploid motile population.     

Cost effectiveness analysis of early zidovudine treatment of HIV infected patients.

OBJECTIVE--To compare cost effectiveness of early and later treatment with zidovudine for patients infected with HIV. DESIGN--Markov chain analysis of cost effectiveness based on results of use of health care and efficacy from a trial of zidovudine treatment. SETTING--Seven Veterans Affairs medical centres in the United States. SUBJECTS--338 patients with symptomatic HIV infection and a lymphocyte count of 200 x 10(6) to 500 x 10(6) CD4 cells/l. INTERVENTIONS--Zidovudine 1500 mg/day started either at recruitment to the trial or when CD4 cell count fell below 200 x 10(6)/l. MAIN OUTCOME MEASURES--Health care costs and rates of disease progression between six clinical states of HIV infection. RESULTS--Patients given early treatment with zidovudine remained without AIDS for an extra two months at a cost of $10,750 for each extra month without AIDS (at 1991 costs). Cost effectiveness ratio was most sensitive to the cost of zidovudine and to the quality of life of patients receiving early treatment. At treatment of 500 mg/day the cost effectiveness ratio for early treatment was $5432 for each extra month without AIDS. Patients given early treatment experienced more side effects, and if their quality of life was devalued by 8% compared with patients treated later the two treatments were equivalent in terms of quality adjusted months of life without AIDS. CONCLUSIONS--Early treatment with zidovudine is expensive and is very sensitive to the cost of zidovudine and to potential reductions in quality of life of patients who experience side effects. Doctors should reconsider early treatment with zidovudine for patients who experience side effects that substantially compromise their quality of life.