The revenant: rediscovery of Margaritifera homsensis from Orontes drainage with remarks on its taxonomic status and conservation (Bivalvia: Margaritiferidae)

Since Margaritifera marocana (Pallary, 1918) and M. laosensis (Lea, 1863) were rediscovered, M. homsensis (Lea, 1865) remains the only pearl mussel species known solely based on old shell samples from natural history museums. This is also the last pearl mussel species, which is absent in a phylogeny of the family. Here, we aimed to provide an integrative revision of the taxonomic status of M. homsensis from the Orontes Basin. Using a newly collected specimen from the River Karasu, Hatay Province, southern Turkey, five gene partitions were sequenced, the cytochrome c oxidase subunit I (COI), large ribosomal subunit rRNA (16S), large ribosomal subunit rDNA (28S) and its D3 expansion segment (D3), and small ribosomal subunit rDNA (18S). The multi-gene phylogeny indicates that M. homsensis is a sister taxon of M. auricularia, but both these species are closely related to M. marocana by nuclear genes. The main conchological features, i.e., the shell shape, teeth morphology, and mantle attachment scars, as well as Fourier shell shape analysis have not shown principal differences between M. homsensis and M. auricularia. Based on these data, we concluded that M. homsensis is a valid species that is most closely related to M. auricularia. Special conservation efforts for a population of M. homsensis discovered in Turkey, including the formation of a nature reserve, might contribute to the conservation of the species. Finally, an extensive search for surviving populations in Orontes drainage (southern Turkey, Lebanon, and Syria) and the Nahr-el-Kabir River (Lebanon and Syria) remains necessary to develop a transboundary conservation strategy for this unique taxon.     

Antiproliferative activity of Humulus lupulus extracts on human hepatoma (Hep3B), colon (HT-29) cancer cells and proteases,tyrosinase, β-lactamase enzyme inhibition studies

The aims of this study were to examine the antiproliferation of Humulus lupulus extracts on human hepatoma carcinoma (Hep3B) and human colon carcinoma (HT-29) cell lines along with enzyme inhibitory effects of the crude extracts. Potential cell cytotoxicity of six different H. lupulus extracts were assayed on various cancer cells using MTT assay at 24, 48 and 72?h intervals. Methanol-1 extract has inhibited the cell proliferation with doses of 0.6–1?mg/mL in a time dependent (48 and 72 hours) manner in Hep3B cells with 70% inhibition, while inhibitory effect was not seen in colon cancer cells. Acetone extract has increased the cell proliferation at low doses of 0.1?mg/mL for 72?h in Hep3B cells and 0.1–0.2?mg/mL for 48 and 72?h in HT29 cells. The inhibitory effects of the extracts were compared by relative maximum activity values (V_max) using proteases such as α-chymotrypsin, trypsin and papain, tyrosinase and β-lactamase (penicillinase).     

6-Hydroxyflavones from Thymbra spicata

Four flavonoids, including two new compounds, were isolated from the leaf extract of Thymbra spicata. The new compounds were the 7,3′-dimethyl and 7,3′,4′-trimethyl ethers of 6-hydroxyluteolin. All the compounds were identified by spectral methods.     

Cryopreservation of immature bovine oocytes by vitrification in straws

The aim of this study was to cryopreserve by vitrification by ethylene glycol (EG) and dimethyl sulfoxide (DMSO) immature bovine oocytes in straws and to investigate the effects of vitrification on post-thaw oocyte maturation. A total of 575 cumulus oocyte complexes were obtained by follicle aspiration from 238 ovaries of cows slaughtered at a local abattoir. Following selection, oocytes with compacted cumulus cells and evenly granulated ooplasm were vitrified using one of the three different solutions with a non-vitrified group served as control. The first step vitrification solution contained 20% EG while the second step solution contained 40% EG+1M sucrose in a basic media used in group EG. Oocytes were matured in N-2-hidroxyethyl piperazine-N-2-ethanosulfonic acid (HEPES) buffered tissue culture medium (TCM) 199 for 24h at 39 degrees C in a humidified atmosphere of 5% CO2 in air. Oocytes were fixed following evaluation for polar body formation, stained with Giemsa solution and nuclear maturation was examined. The numbers of oocytes which were observed at Metaphase II (MII) stage were 41 (34.1%), 17 (14.9%), 29 (20.7%) and 78 (79.6%) in groups EG, DMSO, Mix and Control, respectively. Maturation rate distribution in group Mix was not statistically different when compared to maturation rate distributions in groups EG and DMSO (p>0.05). Differences between other groups were significant (p<0.001). However, better results were obtained in EG group compared to DMSO and mix groups. Maturation rates were lower in all treatment groups than the control group. The lowest maturation result was obtained in DMSO group. Maturation rate in group Mix was between maturation rates of EG and DMSO groups. Immature bovine oocytes can be vitrified in straws, but maturation success differs with the cryoprotectant and it seems that to obtain better maturation rates, new cryopreservation techniques specific for immature bovine oocytes are needed.     

Criblage de nouveaux gènes cibles des récepteurs nucléairesdes oxystérols LXRs impliqués dans le maintien de l’épithélium épididymaire et la maturation des spermatozoïdes dans l’épididyme

Liver X receptors (LXRs) are involved in cholesterol homeostasis and lipid metabolism.Ixr knock-out mice for the two isoformsIxra andIxrb exhibit severe disruption of the structure of caput epididymidis segment 1 and 2 epithelium and increased sperm fragility. These defects generate infertility in 10-month-old male mice. The role of LXRs in the epididymis have not yet been investigated. A cell line obtained from mouse caput epididymidis (B2 cells) was used to screen for LXR epididymal target genesin vitro. The presence of one isoform of LXR (LXRα) was detected by immunocytochemistry and the capacity of B2 cells to respond to a synthetic agonist of LXRs (T0901317) was verified. These results validated the use of B2 cells as a model. Bidimensional electrophoresis was performed on B2 cells treated with T0901317. Eight proteins up-regulated by LXRs were isolated. Only one protein has been identified: polyubiquitin, which has already been reported to be involved in cellular cholesterol homeostasis.     

Octreotide improves burn-induced intestinal injury in the rat

The local thermal trauma activates a number of systemic mediator cascades, e.g. a complement activation, cytokine production, resulting in a generalized sequestration and a priming of local and systemic neutrophils and macrophages. We aimed to determine the possible protective effect of octreotide (OCT), a synthetic somatostatin analogue, against burn-induced intestinal tissue damage possibly by inhibiting neutrophil infiltration. Under brief ether anaesthesia, shaved dorsum of the rats was exposed to 90 degrees C bath for 10s to induce burn injury. Rats were decapitated either 3, 24 or 72 h after burn injury. Octreotide (10 microg/kg) or saline was administered subcutaneously (s.c.) immediately after the burn injury. In the 24- and 72-h burn groups, OCT injections were repeated three times daily. In the sham group the same protocol was applied except that the dorsum was dipped in a 25 degrees C water bath for 10 s Malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) activity were determined in the intestinal tissue. The results demonstrate that burn injury results in significant neutrophil accumulation, as evidenced by increases in MPO activity. The increase in MDA and the concomitant decrease in GSH levels demonstrate the role of oxidative mechanisms in burn injury. OCT may have some beneficial therapeutic effects by reducing neutrophil-dependent injury and related lipid peroxidation following burn trauma.     

Plasma zinc levels during pregnancy and its relationship to maternal and neonatal characteristics: a longitudinal study

Forty consecutive healthy pregnant women aged 17–38 yr who attended the antenatal clinic of the Department of Obstetrics and Gynecology, Ankara University in their first trimester participated in the study. The pregnant women were followed up longitudinally until the end of their pregnancy. Forty healthy age-matched nonpregnant women were used as a control group. Each pregnant woman was interviewed and a special questionnaire recording dietary history (3-d recall) and socioeconomic status (SES) was used. Birth weight, height, and head circumference of the newborn were measured and a complete physical examination was done for each neonate by the same observer. Blood samples were obtained at each trimester and zinc determinations were made using flame atomic absorption spectrophotometer. The results of plasma Zn measurements were available in 39 pregnant women. There were 23 women of low SES (mean plasma Zn level: 59.0 ± 6.9 μg/dL) and 16 of high SES (mean plasma Zn: 70.3 ± 5.2 μg/dL). The difference between the mean plasma Zn levels of these two groups was significant (p<0.001). The nutritional status in our study appeared to be an important factor responsible for low plasma Zn levels during pregnancy. However, we did not find any correlation between plasma Zn levels and anthropometric parameters of the newborn and pregnancy outcome. Further studies using larger sample sizes are needed to clarify the role of plasma Zn levels on maternal features and fetal outcomes in Turkey.