Ecotoxicological QSAR modelling of organic chemicals against Pseudokirchneriella subcapitata using consensus predictions approach

The present study provides robust consensus quantitative structure-activity relationship (QSAR) models developed from 334 organic chemicals covering a wide chemical domain for the prediction of effective concentrations of chemicals for 50% and 10% inhibition of algal growth. Only 2D descriptors with definite physicochemical meaning were employed for QSAR model building, whereas development, validation and interpretation were achieved following the strict Organization for Economic Co-operation and Development (OECD) recommended guidelines. Genetic algorithm along with stepwise approach was used in feature selection while the final QSAR models were derived using partial least squares regression technique. The applicability domain of the developed models was also checked. The obtained consensus models were then used to predict 64 organic chemicals having no definite observed responses while the confidence of predictions was checked by the 'prediction reliability indicator' tool. The developed models should be applicable for data gap filling in case of new or untested organic chemicals provided they fall within the domain of the model and can also be implemented to design safer alternatives to the environment.

Effects of oral probiotic supplements on vaginal microbiota during pregnancy: a randomised, double-blind, placebo-controlled trial with microbiome analysis

Objective

To determine the effects on the vaginal microbiota of an oral probiotic preparation administered from early pregnancy.

Design

Randomised, double blind, placebo‐controlled trial.

Setting

Four maternity units in the UK.

Population

Women aged 16 years or older recruited at 9–14 weeks' gestation.

Methods

Participants were randomly allocated to receive oral capsules of probiotic containing Lactobacillus rhamnosus GR‐1 and Lactobacillus reuteri RC‐14 each at 2.5 × 10⁹ colony‐forming units (CFUs) or placebo once daily from recruitment until the end of pregnancy.

Main outcome measure

Rates of bacterial vaginosis (BV, defined as Nugent score ≥7) at 18–20 weeks' gestation compared by logistic regression adjusted for possible confounders.

Results

The primary analysis included 78% (238/304) of participants who initially consented (probiotic group 123, placebo group 115). Of these participants, 95% (227/238) reported an intake of 93% or more of the required number of capsules. The rates of BV did not differ between groups at 18–20 weeks' gestation (15% (19/123) in the probiotic group vs. 9% (10/115) in the placebo group, adjusted odds ratio 1.82, 95% confidence interval 0.64–5.19). There were also no differences between the groups in the proportion of women colonised with the probiotic strains, Escherichia coli, group B streptococci or other vaginal microbiota. There were no differences in the alpha diversity or composition of the bacterial communities between or within the probiotic and placebo groups at 9–14 and 18–20 weeks’ gestation.

Conclusions

Oral probiotics taken from early pregnancy did not modify the vaginal microbiota.

Tweetable abstract

The oral probiotic preparation used in this study does not prevent BV in pregnant women.

The oral probiotic preparation used in this study does not prevent BV in pregnant women.

Discriminating Clinical and Biological Features in Malaria and Dengue Patients

Background: Malaria and dengue are the most widespread infectious diseases of tropical countries with an estimated 219 and 50 million cases globally. The aim of the proposed study was to find out discriminating clinical features of falciparum malaria and dengue. Method: Falciparum malaria was diagnosed by looking at the ring and gametocyte stages by microscopic examina­tion in Giemsa stained slides. Dengue was diagnosed by ELISA for dengue-specific IgM and IgG. Liver enzymes (AST and ALT) and kidney markers (creatinine and urea) were estimated by standard biochemical techniques. Result: AST and ALT showed similar rise in both, severe malaria and dengue patients but it was much pronounced in dengue haemorrhagic fever where it attained 3–4 folds increase. Creatinine and urea showed higher levels in den­gue compared to malaria. Thrombocytopenia (76.27%), convulsions (18.64%) and hepatic dysfunction (5.08%) were more prominent in dengue than that in malaria where these parameters were 50.89, 7.14 and 2.67%, respectively. Conversely, cases with anaemia, splenomegaly and jaundice were three times more in falciparum malaria. Acute renal failures and neurological sequelae were noticed in slightly higher number of dengue patients.    Conclusion: Thrombocytopenia and hepatic dysfunction were more common in dengue, while anaemia, splenomeg­aly, jaundice and convulsions were more frequent in falciparum malaria. Neurological sequelae and cases of acute renal failure were almost equal in both the infections.

Congenital toxoplasmosis: An overview of the neurological and ocular manifestations

Toxoplasma gondii is an obligate intracellular parasite which is known to infect one-third of the total world population chronically though it is asymptomatic in immunocompetent patients. However, in an immunocompromised patient or an infected fetus, it may cause devastating effects. The parasite may cross the placenta of an infected pregnant woman and probably infect the fetus congenitally. The severity of the infection depends on the gestational age at which the infection has occurred i.e., if it has occurred in the early phase, the rate of transmission is low but the severity is high if the fetus is infected and if it has occurred in the later phase then transmission rate is higher while the severity would be low. Congenital toxoplasmosis may result in non-specific consequences like abortion, intra-uterine growth restriction, jaundice, hepatosplenomegaly or even intra-uterine death. It may also result in neurological or ocular manifestations like intracranial calcifications, hydrocephalus or retinochoroiditis. The diagnosis may be done by serological screening of anti-Toxoplasma antibodies (IgM and IgG) while PCR of the amniotic fluid or the placenta is the confirmatory test. Acute or chronic infections may be differentiated by IgG avidity tests. The treatment regimens include spiramycin to prevent congenital transmission from an infected mother, pyrimethamine, sulfadoxine and folinic acid to treat the infected fetus, CSF shunting for the treatment of hydrocephalus and a combination of pyrimethamine, azithromycin, and corticosteroids for treating ocular toxoplasmosis.

Discriminating Clinical and Biological Features in Malaria and Dengue Patients

BACKGROUND

Malaria and dengue are the most widespread infectious diseases of tropical countries with an estimated 219 and 50 million cases globally. The aim of the proposed study was to find out discriminating clinical features of falciparum malaria and dengue.

METHOD

Falciparum malaria was diagnosed by looking at the ring and gametocyte stages by microscopic examination in Giemsa stained slides. Dengue was diagnosed by ELISA for dengue-specific IgM and IgG. Liver enzymes (AST and ALT) and kidney markers (creatinine and urea) were estimated by standard biochemical techniques.

RESULT

AST and ALT showed similar rise in both, severe malaria and dengue patients but it was much pronounced in dengue haemorrhagic fever where it attained 3-4 folds increase. Creatinine and urea showed higher levels in dengue compared to malaria. Thrombocytopenia (76.27%), convulsions (18.64%) and hepatic dysfunction (5.08%) were more prominent in dengue than that in malaria where these parameters were 50.89, 7.14 and 2.67%, respectively. Conversely, cases with anaemia, splenomegaly and jaundice were three times more in falciparum malaria. Acute renal failures and neurological sequelae were noticed in slightly higher number of dengue patients.

CONCLUSION

Thrombocytopenia and hepatic dysfunction were more common in dengue, while anaemia, splenomegaly, jaundice and convulsions were more frequent in falciparum malaria. Neurological sequelae and cases of acute renal failure were almost equal in both the infections.

Incomplete inhibition of HIV infection results in more HIV infected lymph node cells by reducing cell death

HIV has been reported to be cytotoxic in vitro and in lymph node infection models. Using a computational approach, we found that partial inhibition of transmissions of multiple virions per cell could lead to increased numbers of live infected cells. If the number of viral DNA copies remains above one after inhibition, then eliminating the surplus viral copies reduces cell death. Using a cell line, we observed increased numbers of live infected cells when infection was partially inhibited with the antiretroviral efavirenz or neutralizing antibody. We then used efavirenz at concentrations reported in lymph nodes to inhibit lymph node infection by partially resistant HIV mutants. We observed more live infected lymph node cells, but with fewer HIV DNA copies per cell, relative to no drug. Hence, counterintuitively, limited attenuation of HIV transmission per cell may increase live infected cell numbers in environments where the force of infection is high.

The HIVvirus infects cells of the immune system. Once inside, it hijacks the cellular molecular machineries to make more copies of itself, which are then transmitted to new host cells. HIV eventually kills most cells it infects, either in the steps leading to the infection of the cell, or after the cell is already producing virus. HIV can spread between cells in two ways, known as cell-free or cell-to-cell. In the first, individual viruses are released from infected cells and move randomly through the body in the hope of finding new cells to infect. In the second, infected cells interact directly with uninfected cells. The second method is often much more successful at infecting new cells since they are exposed to multiple virus particles.

HIV infections can be controlled by using combinations of antiretroviral drugs, such as efavirenz, to prevent the virus from making more of itself. With a high enough dose, the drugs can in theory completely stop HIV infections, unless the virus becomes resistant to treatment. However, some patients continue to use these drugs even after the virus they are infected with develops resistance. It is not clear what effect taking ineffective, or partially effective, drugs has on how HIV progresses.

Using efavirenz, Jackson, Hunter et al. partially limited the spread of HIV between human cells grown in the laboratory. The experiments mirrored the situation where a partially resistant HIV strain spreads through the body. The results show that the success of cell-free infection is reduced as drug dose increases. Yet paradoxically, in cell-to-cell infection, the presence of drug caused more cells to become infected. This can be explained by the fact that, in cell-to-cell spread, each cell is exposed to multiple copies of the virus. The drug dose reduced the number of viral copies per cell without stopping the virus from infecting completely. The reduced number of viral copies per cell made it more likely that infected cells would survive the infection long enough to produce virus particles themselves.

Viruses that can kill cells, such as HIV, must balance the need to make more of themselves against the speed that they kill their host cell to maximize the number of infected cells. If transmission between cells is too effective and too many virus particles are delivered to the new cell, the virus may not manage to infect new hosts before killing the old ones. These findings highlight this delicate balance. They also indicate a potential issue in using drugs to treat partially resistant virus strains. Without care, these treatments could increase the number of infected cells in the body, potentially worsening the effects of living with HIV.

Patient experiences of receiving a diagnosis of Parkinson's disease

OBJECTIVE

To report patients' own experiences of receiving a diagnosis of Parkinson's disease (PD) and to identify factors influencing this experience.

METHODS

A survey by the European Parkinson's Disease Association in 11 European countries.

RESULTS

1775 patients with an average age of 69.7 years participated of whom 54% were male. Those living in rural areas reported having waited longer to seek medical help (p < 0.05). A possible diagnosis of PD was made at the first appointment in a third of respondents. When the diagnosis was made, only 50% reported that the diagnosis was communicated sensitively. 38% of patients reported having been given enough time to ask questions and discuss concerns, but 29% did not. 98% of participants reported having been given information about PD at the time of diagnosis but 36% did not find the information given helpful. Patient satisfaction with the diagnostic consultation was positively associated with more sensitive delivery of diagnosis, the helpfulness and quantity of the information provided and time to ask questions (all p < 0.001). Where diagnosis was given by a specialist, participants reported greater perceived satisfaction with the diagnostic consultation, greater sensitivity of communicating the diagnosis, time to ask questions, provision and helpfulness of information, and earlier medication prescription (all p < 0.0001).

CONCLUSIONS

There is a need to improve how the diagnosis of PD is communicated to patients, the opportunity to ask questions soon after diagnosis, and the amount, timing and quality of life information provided, as this is associated with greater satisfaction with the diagnostic process.