A transmission electron microscopy study of the diversity of Candida albicans cells induced by Euphorbia hirta L. leaf extract in vitro

Objective

To determine the major changes in the microstructure of Candida albicans (C. albicans) after treatment with Euphorbia hirta (E. hirta) L. leaf extract.

Methods

Transmission electron microscopy was used to study the ultrastructural changes caused by E. hirta extract on C. albicans cells at various exposure time.

Results

It was found that the main abnormalities were the alterations in morphology, lysis and complete collapse of the yeast cells after 36 h of exposure to the extract. Whereas the control cultures showed a typical morphology of Candida with a uniform central density, typically structured nucleus, and a cytoplasm with several elements of endomembrane system and enveloped by a regular, intact cell wall.

Conclusions

The significant antifungal activity shown by this methanol extract of E. hirta L. suggests its potential against infections caused by C. albicans. The extract may be developed as an anticandidal agent.     

Clinical response to antibiotics among children with bloody diarrhea

WHO recommends ciprofloxacin as the drug of choice for bloody diarrhea. We retrospectively analyzed antibiotic response in 100 children with bloody diarrhea admitted between 2006–2010. Cotrimoxazole (n=55) had higher chance of attaining improved appetite and normal activity in 48h, hospitalization of <3d, blood disappearance in ≤5d and not requiring a second antibiotic compared to others (n=45). Older antimicrobials should be tried in all possible situations.     

Self-similar Rayleigh–Taylor mixing with accelerations varying in time and space

As a ubiquitous paradigm of instabilities and mixing that occur in instances as diverse as supernovae, plasma fusion, oil recovery, and nanofabrication, the Rayleigh–Taylor (RT) problem is rightly regarded as important. The acceleration of the fluid medium in these instances often depends on time and space, whereas most past studies assume it to be constant or impulsive. Here, we analyze the symmetries of RT mixing for variable accelerations and obtain the scaling of correlations and spectra for classes of self-similar dynamics. RT mixing is shown to retain the memory of deterministic conditions for all accelerations, with the dynamics ranging from superballistic to subdiffusive. These results contribute to our understanding and control of the RT phenomena and reveal specific conditions under which Kolmogorov turbulence might be realized in RT mixing.

Turbulence is an unfinished problem of classical physics. Its theoretical richness attracts physicists and mathematicians alike, while its practical importance demands the attention of engineers and practitioners. Isotropy, homogeneity, and localness of scale-to-scale interactions are some of the fundamental paradigms that have advanced our understanding of turbulent dynamics. However, realistic processes often depart from these ideal paradigms. An important class of such processes is linked to the Rayleigh–Taylor (RT) mixing encountered in a large variety of configurations (1, 2).RT instability occurs when the fluid interface is perturbed near the equilibrium state and develops under an accelerating velocity field. When the acceleration is constant, the instability is referred to as the classical RT instability, and the impulsive (e.g., shock-driven) case is known as the Richtmyer–Meshkov (RM) instability (3, 4). In general, the flow transitions from an initial stage of quick perturbation growth to a nonlinear stage, in which the growth rate slows and the interface is transformed to a combination of the large-scale coherent structure and shear-driven small scales. The final stage of this instability is an intense interfacial mixing, whose dynamics is believed to be self-similar. For an appreciation of the problem in a rich variety of contexts, see refs. 5–22.This work adopts continuum fluid equations and advances the significant success achieved via the group-theory approach analyzing symmetries and invariant properties of RT dynamics (19, 22, 23). We explore the special classes of self-similar dynamics of RT mixing driven by accelerations that obey power laws in time and in space, which have not been discussed in earlier work (22–25). Our results explain existing experiments, broaden the horizons of studies of RT-relevant processes, and outline conditions under which Kolmogorov turbulence may manifest in RT/RM mixing.     

Evaluation of hepatoprotective effect of methanolic extract of Clitoria ternatea (Linn.) flower against acetaminophen-induced liver damage

Objective

To evaluate the hepatoprotective and antioxidant activity of Clitoria ternatea (C. ternatea) flower extract against acetaminophen-induced liver toxicity.

Methods

The antioxidant property of C. ternatea flower extract was investigated by employing established in vitro antioxidant assay. The C. ternatea flower extract was studied in this work for its hepatoprotective effect against acetaminophen-induced liver toxicity in mice. Activity was measured by monitoring the levels of aspartate aminotransferase, alanine aminotransferase, billirubin and glutathione with histopathological analysis.

Results

The amount of total phenolics and flavonoids were estimated to be 105.40±2.47 mg/g gallic acid equivalent and 72.21±0.05 mg/g catechin equivalent respectively. The antioxidant activity of C. ternatea flower extract was 68.9% at a concentration of 1 mg/mL and was also concentration dependant, with an IC₅₀ value of 327.00 µg/mL. The results of acetaminophen-induced liver toxicity experiment showed that mice treated with the extract (200 mg/kg) showed a significant decrease in alanine aminotransferase, aspartate aminotransferase, and bilirubin levels, which were all elevated in the paracetamol group (P<0.05). Meanwhile, the level of glutathione was found to be restored in extract treated animals compared to the groups treated with acetaminophen alone (P<0.05). Therapy of extract also showed its protective effect on histopathological alterations and supported the biochemical finding.

Conclusion

The present work confirmed the hepatoprotective effect of C. ternatea flower against model hepatotoxicant acetaminophen.     

A rapid procedure to ascertain the antimicrobial efficacy of oral care formulations

A rapid method examining the antimicrobial efficacy of oral care formulations with alamar blue, an oxidation-reduction dye with fluorescent end-points, is described. Significant correlations between increasing viable plate counts of the oral bacteria Actinomyces viscosus, Streptococcus sanguis, Streptococcus mutans and Actinobacillus actinomycetemcomitans and increased alamar fluorescence were noted. Metabolically active bacteria reduced alamar with the reduced dye found in the cell-free filtrate. Insignificant alamar reductions were noted in the absence of bacteria or by spent culture supernatants. The efficacy of mouthrinses with clinically proven antiplaque agents such as chlorhexidine or cetylpyridinium chloride were determined by alamar blue. In a model system with A. viscosus, triclosan dentifrices demonstrate a dose-dependent effect on bacteria. Human salivary bacteria demonstrate increasing alamar fluorescence with increasing plate counts. A clinical study examined the effects of rinsing with chlorhexidine or cetylpyridinium chloride mouthrinses in comparison with a placebo mouthrinse and water on salivary bacteria. Rinsing with chlorhexidine resulted in the least number of bacteria by alamar and plate count methods. In summary, the current study demonstrates the utility of alamar blue to examine the antimicrobial effects of oral care formulations in laboratory and clinical studies.     

Expert testimony in sexually violent predator commitments: conceptualizing legal standards of "mental disorder" and "likely to reoffend"

The most recent type of civil commitment for dangerous sex offenders is found under the sexually violent predator laws. Forensic psychiatrists or psychologists must render an opinion as to whether the sex offender has a diagnosed mental disorder and, as such, represents a risk to public safety if released from custody into the community. Thus, expert testimony provided by these professionals has taken a central role in the commitment determinations. There is considerable debate as to what disorders predispose individuals to sexual recidivism and what the term "likely" signifies. In this article, the authors explore the debate in terms of whether Antisocial Personality Disorder is a qualifying diagnosed mental disorder for classification as a sexually violent predator and how a likely threshold of risk of sexual recidivism can be conceptualized.