LPS induces mediators of neuroinflammation,cell proliferation,and GFAP expression in human astrocytoma cells U373MG: the anti-inflammatory and anti-proliferative effect of guggulipid

Neuroinflammation has been considered to be an integrated part of human neurodegenerative diseases. In this study, we examined the effect of guggulipid on cell proliferation, nitrite release, interleukin IL-6 and IL-1 beta release, and expression of COX-2 and glial fibrillary acidic protein (GFAP) in LPS-stimulated U373MG cells. LPS significantly stimulated human astrocytoma cells U373MG by up-regulating these neuroinflammatory mediators. Guggulipid alone had no effect on the cell proliferation of U373MG cells. The up regulation in nitrite release, cell proliferation, and release of IL-6 and IL-1 beta in LPS stimulated human astrocytoma cells were dose-dependently inhibited by co-treatment with guggulipid. The expression level of COX-2 and GFAP proteins was up regulated by LPS but the increased level of COX-2 and GFAP was significantly down regulated by treatment with guggulipid. These data indicate that guggulipid has a modulatory effect on all these parameters, which might explain its beneficial effect in the treatment of neuroinflammation-associated disorders directly relating to human aspects.     

Disordered personality traits and psychiatric morbidity in pregnancy: a population-based study

Archives of Women's Mental Health - This study aims to investigate the characteristics and mental health status of pregnant women with disordered personality traits. A cross-sectional study of...     

Detection of human G10 rotavirus strains with similarity to bovine and bovine-like equine strains from untypable samples

G10 rotaviruses, which are usually found in cattle, have also been reported in neonatal infections in recent years. During the rotavirus surveillances of children less than 4years of age between 2003 and 2006 in Kolkata, eastern India, 60 out of 1153 samples could not be typed. All 60 samples gave usual electropherotype pattern in polyacrylamide gel. Thirty-one out of these 60 G and P untypable rotavirus strains were successfully characterized during the study. Among 31 samples, G9P[4] (n=8), G12P[8] (n=8), G1P[8] (n=6), G10P[4] (n=6), and G2P[4] (n=3) genotypes were identified. In this study we report genetic analysis of the six G10 strains, which revealed close relations with Turkish (E29TR) bovine strains, as well as with bovine-like-equine strain (Erv2) from India. SimPlot of the VP7 gene segment suggested possible recombination event between the bovine and the bovine-like-equine rotaviruses in these human rotavirus infections.     

Burden of Hospitalized Pediatric Morbidity and Utilization of Beds in a Tertiary Care Hospital of Kolkata,India

Background:

Childhood morbidity consumes a substantial portion of health care resources in terms of hospital bed utilization, and overload in hospital ward remains a major concern in many countries, including India. A possible way to minimize the problem of scarcities of bed is to analyze the pattern of bed utilization by causes and plan services accordingly.

Objectives:

To determine the burden of pediatric morbidity and utilization pattern of pediatric beds in a tertiary care hospital.

Materials and Methods:

A retrospective analysis of pediatric inpatient''s records was conducted over a period of 1 year from 1 January 2007 to 31 December 2007.

Results:

Of 3983 total admitted cases, about one-third were infants, of which neonatal and post-neonatal age group constituted 45% and 55% of the cases, respectively. In terms of bed-day utilization, infants, 1-4 years and 5-11 years age group accounted for 35.10%, 32.58% and 32.32% of total days of admission, respectively. Utilization of pediatric beds by major causes of morbidity was respiratory tract infection (22.23%), convulsive disorder (12.68%), accident and poisoning (6.07%), diarrheal disease (4.97%) and chronic hemolytic anemia (4.42%).

Conclusion:

A minor change in admission policy through provision of day care unit for management of certain cases would allow efficient use of hospital beds.     

In utero and lactational exposure to triclocarban: reproductive effects on female rat offspring

Triclocarban (TCC) is an antimicrobial compound widely used in personal care products such as soaps, toothpaste, and shampoo. This agent is incompletely removed by wastewater treatment and represents an environmental contaminant. Recent studies have shown that TCC is associated with some endocrine disruptions. The aim of the present study was to evaluate if TCC exposure during critical periods of development (gestation and lactation) could lead to adverse effects on reproductive and behavior parameters of female offspring. Pregnant female Wistar rats were divided into four groups (n = 8–11/group): Control; TCC 0.3 mg/kg (TCC 0.3); TCC 1.5 mg/kg; TCC 3.0 mg/kg (TCC 3.0); and treated daily by oral gavage from gestational day 0 to lactational day 21. The female pups (F1 generation) were weaned on post-natal day 21 and included in the study. No litter-mates were used for the same group. There was a decrease in estradiol levels in the TCC 0.3 and TCC 3.0 groups. Moreover, there was a decrease in progesterone levels and an increase in pre-implantation loss in the TCC 3.0 group in adulthood. It is suggested, in this study, that the decrease in progesterone biosynthesis could interfere with implantation process. The exposure window to TCC is an important factor, as we found alterations only in the offspring.     

Use of immunization as strategy for outbreak control of varicella zoster in an institutional setting

Background

Outbreaks of varicella gets reported often in India. However, outbreak in health care providers living in closed institutional setting and role of vaccination as post exposure prophylaxis for control of outbreak has not been studied extensively. This paper presents epidemiological investigation and control strategy undertaken in such scenario.

Methods

This is an epidemiological investigation of chickenpox in nursing students which highlights role of early identification and appropriate control strategy to prevent explosive outbreak in high risk vulnerable population. Vaccination of all susceptible in addition to isolation of cases, quarantine of suspects and proper screening for new cases was the major control strategy adopted.

Results

The index case was imported and all eight cases occurred within the incubation period of the case. Two cases occurred in students previously vaccinated for chickenpox. No second or third wave of infection occurred showing vaccination as effective tool in outbreak control strategy.

Conclusion

Early identification of cases and vaccination of all susceptible contributed to effective control of the outbreak.     

HIV3B和HIV Ada-M可感染培养的人背根神经节神经元

为探讨HIV3B和HIV Ada-M是否能感染培养的人背根神经节(DRG)神经元,我们建立了人DRG器官型培养和分散培养模型。DRG组织块培养14 d后,用游离的HIV3B或HIV Ada-M病毒颗粒处理并继续培养14 d,用倒置相差显微镜定期观察神经元突起的生长和形态变化。分散的DRG神经元培养3 d后,用游离的HIV3B或HIV Ada-M病毒颗粒处理并继续培养3 d。终止培养后,行微管相关蛋白2(MAP2)免疫荧光染色,然后利用荧光显微镜观察神经元突起的变化情况。DRG组织块培养28d、分散的DRG神经元培养6 d后,用电子显微镜观察神经元超微结构的改变。未用HIV处理的标本作为对照。在器官型培养的DRG神经元突起内发现了未成熟的HIV样病毒颗粒。在分散培养的DRG神经元突起内发现了大量的HIV样病毒颗粒。但HIV感染并不影响两种培养神经元的形态和超微结构的改变。以上结果对于进一步研究HIV感染以及与HIV感染有关的周围神经病变的病理发生机制具有重要意义。     

Road-blocker HSP disease mutation disrupts pre-organization for ATP hydrolysis in kinesin through a second sphere control

Kinesin motor proteins perform several essential cellular functions powered by the adenosine triphosphate (ATP) hydrolysis reaction. Several single-point mutations in the kinesin motor protein KIF5A have been implicated to hereditary spastic paraplegia disease (HSP), a lethal neurodegenerative disease in humans. In earlier studies, we have shown that a series of HSP-related mutations can impair the kinesin’s long-distance displacement or processivity by modulating the order–disorder transition of the linker connecting the heads to the coiled coil. On the other hand, the reduction of kinesin’s ATP hydrolysis reaction rate by a distal asparagine-to-serine mutation is also known to cause HSP disease. However, the molecular mechanism of the ATP hydrolysis reaction in kinesin by this distal mutation is still not fully understood. Using classical molecular dynamics simulations combined with quantum mechanics/molecular mechanics calculations, the pre-organization geometry required for optimal hydrolysis in kinesin motor bound to α/β-tubulin is determined. This optimal geometry has only a single salt-bridge (of the possible two) between Arg203-Glu236, putting a reactive water molecule at a perfect position for hydrolysis. Such geometry is also needed to create the appropriate configuration for proton translocation during ATP hydrolysis. The distal asparagine-to-serine mutation is found to disrupt this optimal geometry. Therefore, the current study along with our previous one demonstrates how two different effects on kinesin dynamics (processivity and ATP hydrolysis), caused by a different set of genotypes, can give rise to the same phenotype leading to HSP disease.

Kinesin-1 is a motor protein that walks along microtubule (MT) filaments toward the plus-ends using energy acquired from the adenosine triphosphate (ATP) hydrolysis reaction while performing various cellular activities. For instance, it is responsible for the intracellular transport of vesicles, organelles, and signaling complexes (1–3). Neuronal kinesin KIF5A, for example (4, 5), is particularly important for retrograde axonal transport inside neurons. Several single-point mutations of the KIF5A kinesin are found to be extremely pathological, leading to a lethal neurodegenerative disease in humans, hereditary spastic paraplegia (HSP) disease (6, 7).Generally, kinesin motor proteins function in a homodimeric state. In earlier studies (8, 9), we have shown that all kinesins have some structurally important regions: motor domains which perform the catalytic conversion of ATP as well as binding to the MT, the coiled-coil stalk region that is essential for dimerization, and the neck linker region that connects the motor domain to the coiled-coil stalk region. It was shown that the energetic balance between kinesin binding to the MT and coiled-coil interactions in the dimerization interface is crucially important for the required order–disorder transition of the neck linker (8). This transition mediates the coordination between two motor domains of the kinesin dimer faithfully, which is required for a long-distance run on the MT. This process is referred to as processivity (10, 11). On the other hand, the rate of hydrolysis of ATP determines the gliding velocity of the kinesin on the MT. It is important to note here that the processivity, directionality of stepping, and gliding velocity are crucial for their function (7–12).Mutations related to HSP disease are genotypic. While most of these mutations are found to be in the motor domain of the kinesin, some are also found to be in the dimerization region. As shown in our earlier studies, which investigated the effect of HSP disease-related mutations on the dynamics of kinesin, these mutations are either at the MT-binding interface or at the dimerization region. Therefore, they destroy the energetic balance between the relative strength of these interactions, impairing the kinesin processivity that leads to HSP disease (8, 9). However, some other mutations in the motor domain are found not to affect the MT-binding strength but also lead to the disease. Experiments have shown that those mutations actually reduce the rate of ATP hydrolysis and thereby affect the gliding velocity of the kinesin (6, 7). It has been proposed that such kinesins, due to their sluggish movement, act as road blockers for other normally moving kinesis. In this article, we will concentrate on one of such mutations which is distal to the ATP hydrolysis reaction center.Like other motor proteins (13–25), the hydrolysis of the ATP molecule is an essential step in the mechanochemical cycle of kinesin. Here we focus on the mutation of the asparagine residue at a distal position with respect to the hydrolysis reaction center that is changed to a serine residue (Asn255Ser for PDB ID: 4HNA) (26). This mutation causes a reduction in the kinesin gliding velocity on the MT and in the ATPase rate compared to the wild-type one (8). The large distance (~11.5 Å) between the asparagine residue and the terminal γ-phosphorus atom of the ATP in the kinesin-1 structure suggests a long-distance or second sphere control of the ATP hydrolysis reaction (Fig. 1). Similar large distance effects have been previously observed. Biochemical studies have shown that the rate of ATP hydrolysis of kinesin-1 increases by ~33-fold upon binding to the MT (6). The MT-binding site and ATP hydrolysis reaction center are also far apart from each other (Fig. 1). Herein, using all-atom explicit solvent molecular dynamics (MD) simulations, hybrid quantum mechanics/molecular mechanics (QM/MM) methods, and an enhanced sampling approach for calculating free energies, we provide an explanation for the molecular origin of this second sphere control of the ATP hydrolysis reaction in kinesin-1, which is needed to understand its connection to HSP disease. In this connection, it is important to note that an earlier study (23) on this topic focusing on the ATP hydrolysis mechanism of kinesin did not consider the effect of MT binding and was limited to aqueous kinesin only. Inclusion of the MT-bound state is required to understand the complete process of ATP hydrolysis which is attempted in this study.Open in a separate windowFig. 1.ATP-bound kinesin-α/β-tubulin complex. It is composed of the kinesin motor domain region, α-tubulin, and β-tubulin. The tubulins are the units of the microtubule filaments. The γ-phosphate group of the ATP is surrounded by the Glu236, Arg203, Ser202, Thr92, Mg²⁺ ion, and six water molecules. The HSP disease-related residue, Asn255, is also shown, and the proposed second sphere interactions are highlighted.In this study, we will first present the three different reaction schemes for the ATP hydrolysis reaction in the wild-type kinesin bound to MT. We will then discuss our findings on the reaction mechanism and energetics for those three reaction schemes using hybrid QM/MM calculations and most importantly determine the pre-organization geometry for the reaction. Next, the effect of mutation and MT unbinding on the pre-organization geometry will be described using all-atom explicit solvent MD simulations and an enhanced sampling approach for calculating free energies. A multiple sequence alignment will also be presented to show how important are the residues/interactions of pre-organization geometry. Finally, we will discuss our results in the context of the HSP disease.