Synthesis of 3-(1-alkyl/aminoalkyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-ones and their 2-methylene derivatives as potential spermicidal and microbicidal agents

A series of twenty two derivatives of 3-(1-alkyl/aminoalkyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one and their 2-methylene derivatives were synthesized from naturally abundant cinchonine (I). Tartarate salts of these compounds were prepared and evaluated for spermicidal activity. The most active compounds (24, 27, 34, 36, and 38) showing potent spermicidal activity were further evaluated against different strains of Trichomonas vaginalis, for antimicrobial activity, in HeLa cell lines for cytotoxicity and against Lactobacillus jensenii for eco-safety. The tartarate of 3-(1-pentyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one (27) was found to be more active than N-9 in spermicidal activity.     

Localization of PBP3 in Caulobacter crescentus is highly dynamic and largely relies on its functional transpeptidase domain

In rod-shaped bacteria, septal peptidoglycan synthesis involves the late recruitment of the ftsI gene product (PBP3 in Escherichia coli) to the FtsZ ring. We show that in Caulobacter crescentus, PBP3 accumulates at the new pole at the beginning of the cell cycle. Fluorescence recovery after photobleaching experiments reveal that polar PBP3 molecules are, constantly and independently of FtsZ, replaced by those present in the cellular pool, implying that polar PBP3 is not a remnant of the previous division. By the time cell constriction is initiated, all PBP3 polar accumulation has disappeared in favour of an FtsZ-dependent localization near midcell, consistent with PBP3 function in cell division. Kymograph analysis of time-lapse experiments shows that the recruitment of PBP3 to the FtsZ ring is progressive and initiated very early on, shortly after FtsZ ring formation and well before cell constriction starts. Accumulation of PBP3 near midcell is also highly dynamic with a rapid exchange of PBP3 molecules between midcell and cellular pools. Localization of PBP3 at both midcell and pole appears multifactorial, primarily requiring the catalytic site of PBP3. Collectively, our results suggest a role for PBP3 in pole morphogenesis and provide new insights into the process of peptidoglycan assembly during division.     

Modulation of haloperidol induced electrophysiological alterations on cardiac action potential by various risk factors and gender difference

Haloperidol (HPL), well known antipsychotic drug can induce a marked QT prolongation and polymorphic arrhythmias. In this study we evaluated the influence of various induced risk factors such as electrolyte imbalance (hypokalemia and hypomagnesemia), gender difference, low pacing frequency, ischemia reperfusion insult on electrophysiological effect by haloperidol on electrically driven action potentials recorded from guinea pig papillary muscle. The doses of HPL ranging from 1 to 16 μM were used in this investigation. Action potentials (APs) were elicited electrically and recorded by classical microelectrode technique. HPL caused dose dependent prolongation of APD₉₀ the final stage of repolarization, increased triangulation, and led into dispersion of action potential, conduction delay and conduction block. Magnitude of the effect of haloperidol was amplified significantly by most of the risk factors. Among the various risk factors, electrolyte imbalance (hypokalemia, hypomagnesemia) caused more amplification of HPL effect. Most of the risk factors amplified prolongation of APD₉₀ by HPL. This effect is mainly due to the influence of these electrolytes and sex hormone on various ion channels involved in the repolarization phase of cardiac AP. This is the first report which provides an experimental evidence of amplification of electrophysiological effects of HPL in the presence of various risk factors.     

Recognizing Age-Separated Face Images: Humans and Machines

Humans utilize facial appearance, gender, expression, aging pattern, and other ancillary information to recognize individuals. It is interesting to observe how humans perceive facial age. Analyzing these properties can help in understanding the phenomenon of facial aging and incorporating the findings can help in designing effective algorithms. Such a study has two components - facial age estimation and age-separated face recognition. Age estimation involves predicting the age of an individual given his/her facial image. On the other hand, age-separated face recognition consists of recognizing an individual given his/her age-separated images. In this research, we investigate which facial cues are utilized by humans for estimating the age of people belonging to various age groups along with analyzing the effect of one''s gender, age, and ethnicity on age estimation skills. We also analyze how various facial regions such as binocular and mouth regions influence age estimation and recognition capabilities. Finally, we propose an age-invariant face recognition algorithm that incorporates the knowledge learned from these observations. Key observations of our research are: (1) the age group of newborns and toddlers is easiest to estimate, (2) gender and ethnicity do not affect the judgment of age group estimation, (3) face as a global feature, is essential to achieve good performance in age-separated face recognition, and (4) the proposed algorithm yields improved recognition performance compared to existing algorithms and also outperforms a commercial system in the young image as probe scenario.     

Effect of Homocysteine on Biofilm Formation by Mycobacteria

Mycobacteria show peculiar aggregated outgrowth like biofilm on the surface of solid or liquid media. Biofilms harbor antibiotic resistant bacteria in a self-produced extracellular matrix that signifies the bacterial fate to sedentary existence. Despite years of research, very little is known about the mechanisms that contribute to biofilm formation. LuxS has been previously known to play a role in biofilm formation in Autoinducer-2 dependent manner. We here show the effect of LuxS product-homocysteine, on the biofilm forming ability of non-tuberculous mycobacteria, Mycobacterium smegmatis and Mycobacterium bovis BCG showing AI-2 independent phenotypic effect of LuxS. Exogenous supplementation of homocysteine in the culture media leads to aberrant cording, pellicle outgrowth, and biofilm formation. Thus, our study contributes to the better understanding of the mechanism of mycobacterial biofilm formation and sheds light on the role of LuxS product homocysteine. In addition, we highlight the contribution of activated methyl cycle in bacterial quorum sensing.     

GroEL Mediates Folding of <Emphasis Type="Italic">Bacillus anthracis</Emphasis> Serine/Threonine Protein Kinase,PrkC

Bacillus anthracis causes anthrax in human and animals. Both, signaling system such as two component system and endogenous chaperone system such as GroEL–GroES help bacteria to cope with the environmental challenges. Such molecular chaperones are the stress induced proteins that help bacteria to override unfavorable conditions by their moonlighting functions. Previous reports showed that PrkC and PrpC, the Ser/Thr kinase–phosphatase pair in B. anthracis, control phosphorylation of GroEL and regulate biofilm formation. In this study, we show that GroEL is involved in the folding of PrkC to active form. The proteins (GroEL, PrkC and PrpC) were expressed and purified by affinity chromatography. Purified GroEL was used for refolding of denatured PrkC and PrpC and observed that GroEL refolds PrkC but not PrpC as measured by their enzymatic activity. We also observed that purification of GroEL with six histidine tag using Cobalt-Agarose resin yielded superior quality GroEL protein with negligible contamination of non-specific proteins. Thus, cobalt resin can be a better choice for purification of many histidine tagged proteins, where Ni-NTA does not work very well.     

Hepatocytes of Wistar and Sprague Dawley rats differ significantly in their central metabolism

Wistar and Sprague‐Dawley (SD) rats are most commonly used experimental rats. They have similar genetic background and are therefore, not discriminated in practical research. In this study, we compared metabolic profiles of Wistar and SD rat hepatocytes from middle (6 months) and old (23 months) age groups. Principle component analysis (PCA) on the specific uptake and production rates of amino acids, glucose, lactate and urea indicated clear differences between Wistar and SD rat hepatocytes. SD rat hepatocytes showed higher uptake rates of various essential and non‐essential amino acids, particularly in early culture phases (0‐12 h) compared to later phases (12‐24 h). SD hepatocytes seem to be more sensitive to isolation procedure and in vitro culture requiring more amino acids for cellular maintenance and repair. Major differences between Wistar and SD rat hepatocytes were observed for glucose and branched chain amino acid metabolism. We conclude that the observed differences in the central carbon metabolism of isolated hepatocytes from these two rats should be considered when using one or the other rat type in studies on metabolic effects or diseases such as diabetes or obesity.     

T cell phenotypes in women with Chlamydia trachomatis infection and influence of treatment on phenotype distributions

T cell phenotypes involved in the immune response to Chlamydia trachomatis (CT) have not been fully elucidated in humans. We evaluated differences in T cell phenotypes between CT-infected women and CT-seronegative controls and investigated changes in T cell phenotype distributions after CT treatment and their association with reinfection. We found a higher expression of T cell activation markers (CD38⁺HLA-DR⁺), T helper type 1 (Th1)- and Th2-associated effector phenotypes (CXCR3⁺CCR5⁺ and CCR4⁺, respectively), and T cell homing marker (CCR7) for both CD4⁺ and CD8⁺ T cells in CT-infected women. At follow-up after treatment of infected women, there were a lower proportion of CD4⁺ and CD8⁺ T cells expressing these markers. These findings suggest a dynamic interplay of CD4⁺ and CD8⁺ T cells in CT infection, and once the infection is treated, these cell markers return to basal expression levels. In women without reinfection, a significantly higher proportion of CD8⁺ T cells co-expressing CXCR3 with CCR5 or CCR4 at follow-up was detected compared to women with reinfection, suggesting they might play some role in adaptive immunity. Our study elucidated changes in T cell phenotypes during CT infection and after treatment, broadening our understanding of adaptive immune mechanisms in human CT infections.     

Elevation of Defense Network in Chilli Against <Emphasis Type="Italic">Colletotrichum capsici</Emphasis> by Phyllospheric <Emphasis Type="Italic">Trichoderma</Emphasis> Strain

Biocontrol strategies have been mainly focused on proposing the use of biocontrol agents (BCAs) isolated from the rhizospheric region of the plant for protection against phytopathogens. The present study evaluates the effectiveness of phyllospheric Trichoderma isolates in elevating the defense responses in chilli against Colletotrichum capsici infection and comparing its efficiency to the conventionally recommended rhizospheric Trichoderma strains. The elicitation of the defense network in the plants was analyzed using biochemical assays for important enzymes, that is, PAL, PO, PPO, TPC, SOD along with the total protein level in challenged plants over untreated and unchallenged control plants. The results recorded 2.1, 5.18, 3, 0.67, and 0.5-fold increases in TPC, PAL, PO, PPO, and total protein content in BHUF4 (phyllopsheric Trichoderma isolate)-treated plants when compared to control plants under C. capsici challenge. This was at par with the increment recorded in T16A (rhizospheric Trichoderma isolate)-treated chilli plants. The increment in growth parameters was also recorded after treatment with the isolated Trichoderma strains. Interestingly, the phyllospheric isolate (BHUF4) treatment recorded comparable growth promotion in chilli plants recording 36, 62, and 60 % increases in one of the major parameters of plant growth, that is, root length, no. of leaves, and dry weight, respectively. This study proposes the use of combined application of both rhizospheric as well as phyllospheric Trichoderma isolates for better and all around protection of plants against foliar as well as soil phytopathogens. This would be a novel approach in biological control strategy for better management of anthracnose disease of chilli.