Studies toward the comprehension of fungal-macroalgae interaction in cold marine regions from a biotechnological perspective

In marine ecosystems, macroalgae are the habitat for several microorganisms, fungi being among them. In the Antarctic benthic coastal ecosystem, macroalgae play a key role in organic matter cycling. In this study, 13 different macroalgae from Potter Cove and surrounding areas were sampled and 48 fungal isolates were obtained from six species, four Rhodophyta Ballia callitricha, Gigartina skottsbergii, Neuroglossum delesseriae and Palmaria decipiens, and two Phaeophyceae: Adenocystis utricularis and Ascoseira mirabilis. Fungal isolates mostly belonged to the Ascomycota phylum (Antarctomyces, Cadophora, Cladosporium, Penicillium, Phialocephala, and Pseudogymnoascus) and only one to the phylum Mucoromycota. Two of the isolates could not be identified to genus level, implying that Antarctica is a source of probable novel fungal taxa with enormous bioprospecting and biotechnological potential. 73% of the fungal isolates were moderate eurypsychrophilic (they grew at 5–25 °C), 12.5% were eurypsychrophilic and grew in the whole range, 12.5% of the isolates were narrow eurypsychrophilic (growth at 15–25 °C), and Mucoromycota AUe4 was classified as stenopsychrophilic as it grew at 5–15 °C. Organic extracts of seven macroalgae from which no fungal growth was obtained (three red algae Georgiella confluens, Gymnogongrus turquetii, Plocamium cartlagineum, and four brown algae Desmarestia anceps, D. Antarctica, Desmarestia menziesii, Himantothallus grandifolius) were tested against representative fungi of the genera isolated in this work. All extracts presented fungal inhibition, those from Plocamium cartilagineum and G. turquetii showed the best results, and for most of these macroalgae, this represents the first report of antifungal activity and constitute a promising source of compounds for future evaluation.     

Man, monkeys and malaria

Bizarre though it may now seem, in the last century a whole series of experiments was conducted that involved injecting fresh monkey blood into human volunteers or patients. The reasons, valid at the time, were either to treat neurosyphilis with a relatively benign simian malaria infection (so-called pyrogen therapy), or to establish which monkey malaria species were potential zoonotic reservoirs of infection that then may have interfered with malaria eradication campaigns. Although direct inoculation of fresh blood is the most effective way of retroviruses as well as malaria parasites crossing the species barrier, this hypothesis was never taken up or researched. Unlikely, but not disproved, it is important to remember some of the more hazardous experiments that were done in good faith, too long ago to be recorded on electronic databases.     

Dynamic shuttling of TIA-1 accompanies the recruitment of mRNA to mammalian stress granules

Mammalian stress granules (SGs) harbor untranslated mRNAs that accumulate in cells exposed to environmental stress. Drugs that stabilize polysomes (emetine) inhibit the assembly of SGs, whereas drugs that destabilize polysomes (puromycin) promote the assembly of SGs. Moreover, emetine dissolves preformed SGs as it promotes the assembly of polysomes, suggesting that these mRNP species (i.e., SGs and polysomes) exist in equilibrium. We used green flourescent protein-tagged SG-associated RNA-binding proteins (specifically, TIA-1 and poly[A] binding protein [PABP-I]) to monitor SG assembly, disassembly, and turnover in live cells. Fluorescence recovery after photobleaching shows that both TIA-1 and PABP-I rapidly and continuously shuttle in and out of SGs, indicating that the assembly of SGs is a highly dynamic process. This unexpected result leads us to propose that mammalian SGs are sites at which untranslated mRNAs are sorted and processed for either reinitiation, degradation, or packaging into stable nonpolysomal mRNP complexes. A truncation mutant of TIA-1 (TIA-1DeltaRRM), which acts as a transdominant inhibitor of SG assembly, promotes the expression of cotransfected reporter genes in COS transfectants, suggesting that this process of mRNA triage might, directly or indirectly, influence protein expression.     

Population genetic approaches to neurological disease: Parkinson's disease as an example

Parkinson's disease (PD) is a common, progressive, incurable disabling condition. The cause is unknown but over the past few years tremendous progress in our understanding of the genetic bases of this condition has been made. To date, this has almost exclusively come from the study of relatively rare Mendelian forms of the disease and there are no currently, widely accepted common variants known to increase susceptibility.The role that the "Mendelian" genes play in common sporadic forms of PD is unknown. Moreover, most studies in PD can really be described as candidate polymorphism studies rather than true and complete assessments of the genes themselves. We provide a model of how one might tackle some of these issues using Parkinson's disease as an illustration. One of the emerging hypotheses of gene environment interaction in Parkinson's disease is based on drug metabolizing (or xenobiotic) enzymes and their interaction with putative environmental toxins. This motivated us to describe a tagging approach for an extensive but not exhaustive list of 55 drug metabolizing enzyme genes. We use these data to illustrate the power, and some of the limitations of a haplotype tagging approach. We show that haplotype tagging is extremely efficient and works well with only a modest increase in effort through different populations. The tagging approach works much less well if the minor allele frequency is below 5%. However, it will now be possible using these tags to evaluate these genes comprehensively in PD and other neurodegenerative conditions.     

Pregnancy and Infant Outcomes among HIV-Infected Women Taking Long-Term ART with and without Tenofovir in the DART Trial

Background

Few data have described long-term outcomes for infants born to HIV-infected African women taking antiretroviral therapy (ART) in pregnancy. This is particularly true for World Health Organization (WHO)–recommended tenofovir-containing first-line regimens, which are increasingly used and known to cause renal and bone toxicities; concerns have been raised about potential toxicity in babies due to in utero tenofovir exposure.

Methods and Findings

Pregnancy outcome and maternal/infant ART were collected in Ugandan/Zimbabwean HIV-infected women initiating ART during The Development of AntiRetroviral Therapy in Africa (DART) trial, which compared routine laboratory monitoring (CD4; toxicity) versus clinically driven monitoring. Women were followed 15 January 2003 to 28 September 2009. Infant feeding, clinical status, and biochemistry/haematology results were collected in a separate infant study. Effect of in utero ART exposure on infant growth was analysed using random effects models.382 pregnancies occurred in 302/1,867 (16%) women (4.4/100 woman-years [95% CI 4.0–4.9]). 226/390 (58%) outcomes were live-births, 27 (7%) stillbirths (≥22 wk), and 137 (35%) terminations/miscarriages (<22 wk). Of 226 live-births, seven (3%) infants died <2 wk from perinatal causes and there were seven (3%) congenital abnormalities, with no effect of in utero tenofovir exposure (p>0.4). Of 219 surviving infants, 182 (83%) enrolled in the follow-up study; median (interquartile range [IQR]) age at last visit was 25 (12–38) months. From mothers'' ART, 62/9/111 infants had no/20%–89%/≥90% in utero tenofovir exposure; most were also zidovudine/lamivudine exposed. All 172 infants tested were HIV-negative (ten untested). Only 73/182(40%) infants were breast-fed for median 94 (IQR 75–212) days. Overall, 14 infants died at median (IQR) age 9 (3–23) months, giving 5% 12-month mortality; six of 14 were HIV-uninfected; eight untested infants died of respiratory infection (three), sepsis (two), burns (one), measles (one), unknown (one). During follow-up, no bone fractures were reported to have occurred; 12/368 creatinines and seven out of 305 phosphates were grade one (16) or two (three) in 14 children with no effect of in utero tenofovir (p>0.1). There was no evidence that in utero tenofovir affected growth after 2 years (p = 0.38). Attained height- and weight for age were similar to general (HIV-uninfected) Ugandan populations. Study limitations included relatively small size and lack of randomisation to maternal ART regimens.

Conclusions

Overall 1-year 5% infant mortality was similar to the 2%–4% post-neonatal mortality observed in this region. No increase in congenital, renal, or growth abnormalities was observed with in utero tenofovir exposure. Although some infants died untested, absence of recorded HIV infection with combination ART in pregnancy is encouraging. Detailed safety of tenofovir for pre-exposure prophylaxis will need confirmation from longer term follow-up of larger numbers of exposed children.

Trial registration

www.controlled-trials.com ISRCTN13968779 Please see later in the article for the Editors'' Summary     

Comparison of cost effectiveness of directly observed treatment (DOT) and conventionally delivered treatment for tuberculosis: experience from rural South Africa.

OBJECTIVE: To conduct an economic evaluation of directly observed treatment (DOT) and conventionally delivered treatment for the management of new cases of tuberculosis in adults. DESIGN: Community based directly observed treatment, which has been implemented in the Hlabisa district of South Africa since 1991, was compared with a conventional approach to tuberculosis treatment widely used in Africa. Each was assessed in terms of cost, cost effectiveness, and feasibility of implementation within existing resource constraints. SETTING: Hlabisa Health District, South Africa. SUBJECTS: Adult patients with new cases of tuberculosis on smear testing; the number of cases increased from 20 per month to over 100 from 1991 to 1996. MAIN OUTCOME MEASURES: Cost of case management in 1996, cost effectiveness in terms of the cost per case cured, and bed requirements in comparison with bed availability for the 1990, 1993, and 1996 caseload. Costs are expressed in US dollars at values for 1996. RESULTS: Directly observed treatment was 2.8 times cheaper overall than conventional treatment ($740.90 compared with $2047.70) to deliver. Directly observed treatment worked out 2.4-4.2 times more cost effective, costing $890.50 per patient cured compared with either $2095.60 (best case) or $3700.40 (worst case) for conventional treatment. The 1996 caseload of tuberculosis required 47 beds to be dedicated to tuberculosis to implement directly observed treatment, whereas conventionally delivered treatment would have required 160 beds; the current number of beds for tuberculosis treatment in Hlabisa is fixed at 56. CONCLUSIONS: Because of the reduced stay in hospital, directly observed treatment is cheaper, more cost effective, and more feasible than conventional treatment in managing tuberculosis in Hlabisa, given the existing hospital bed capacity and the escalating caseload due to the HIV/AIDS epidemic. Such results may hold elsewhere, and wherever conventional tuberculosis management is practised a switch to directly observed treatment will increase hospital capacity to cope with a growing caseload.     

Distal upstream tyrosinase S/MAR‐containing sequence has regulatory properties specific to subsets of melanocytes

A distal upstream regulatory element of the mouse tyrosinase gene has locus control region (LCR)‐like activity and is required for position‐independent expression of linked genes. It consists of a DNAse I hypersensitive site, which has enhancer activity in neural crest‐derived melanocytes, embedded within a scaffold/matrix attachment region (S/MAR), both of which are necessary for LCR activity. To address the role of the S/MAR in position‐independent expression, we assessed the ability of a fragment containing most of the S/MAR to insulate a transgene from position effects. The S/MAR sequence showed a striking cell type specificity in its function in all six multicopy transgenic lines, dampening position effects considerably in cutaneous melanocytes while allowing no expression in other neural crest‐derived melanocytes, and causing elevated expression in ocular melanocytes derived from the neural tube. The specificity of transgene expression in the eye suggested the presence of both positive and negative regulatory elements in this enhancer/S/MAR region, which was confirmed by transient transfection analyses. This is the first known regulatory element to exhibit different activities in melanocytes of different developmental origins. Dev. Genet. 25:40–48, 1999. © 1999 Wiley‐Liss, Inc.     

Ovarian Carcinoma Subtypes Are Different Diseases: Implications for Biomarker Studies

Background

Although it has long been appreciated that ovarian carcinoma subtypes (serous, clear cell, endometrioid, and mucinous) are associated with different natural histories, most ovarian carcinoma biomarker studies and current treatment protocols for women with this disease are not subtype specific. With the emergence of high-throughput molecular techniques, distinct pathogenetic pathways have been identified in these subtypes. We examined variation in biomarker expression rates between subtypes, and how this influences correlations between biomarker expression and stage at diagnosis or prognosis.

Methods and Findings

In this retrospective study we assessed the protein expression of 21 candidate tissue-based biomarkers (CA125, CRABP-II, EpCam, ER, F-Spondin, HE4, IGF2, K-Cadherin, Ki-67, KISS1, Matriptase, Mesothelin, MIF, MMP7, p21, p53, PAX8, PR, SLPI, TROP2, WT1) in a population-based cohort of 500 ovarian carcinomas that was collected over the period from 1984 to 2000. The expression of 20 of the 21 biomarkers differs significantly between subtypes, but does not vary across stage within each subtype. Survival analyses show that nine of the 21 biomarkers are prognostic indicators in the entire cohort but when analyzed by subtype only three remain prognostic indicators in the high-grade serous and none in the clear cell subtype. For example, tumor proliferation, as assessed by Ki-67 staining, varies markedly between different subtypes and is an unfavourable prognostic marker in the entire cohort (risk ratio [RR] 1.7, 95% confidence interval [CI] 1.2%–2.4%) but is not of prognostic significance within any subtype. Prognostic associations can even show an inverse correlation within the entire cohort, when compared to a specific subtype. For example, WT1 is more frequently expressed in high-grade serous carcinomas, an aggressive subtype, and is an unfavourable prognostic marker within the entire cohort of ovarian carcinomas (RR 1.7, 95% CI 1.2%–2.3%), but is a favourable prognostic marker within the high-grade serous subtype (RR 0.5, 95% CI 0.3%–0.8%).

Conclusions

The association of biomarker expression with survival varies substantially between subtypes, and can easily be overlooked in whole cohort analyses. To avoid this effect, each subtype within a cohort should be analyzed discretely. Ovarian carcinoma subtypes are different diseases, and these differences should be reflected in clinical research study design and ultimately in the management of ovarian carcinoma.