Acute systemic immune activation following vaginal exposure to staphylococcal enterotoxin B--implications for menstrual shock

Menstrual toxic shock syndrome (mTSS) is an acute systemic inflammatory disease associated with the superantigenic exotoxin, toxic shock syndrome toxin (TSST)-1, produced by Staphylococcus aureus and the use of high absorbency tampons. Even though S. aureus is capable of elaborating several other superantigenic exotoxins, only TSST-1 has been implicated in the pathogenesis of mTSS possibly because most other superantigenic exotoxins are known enterotoxins. Nonetheless, we have shown recently that one of the enterotoxigenic staphylococcal superantigens, staphylococcal enterotoxin B (SEB), can cause robust systemic immune activation following exposure through non-enteric mucosa, including nasal or conjunctival routes. In a similar manner, we show here that vaginal administration of SEB in HLA class II transgenic mice can cause robust systemic immune activation characterized by profound elevation of proinflammatory cytokines in the serum, activation and expansion of SEB-reactive CD4(+) and CD8(+) T cells in peripheral lymphoid organs and SEB-induced deletion of immature thymocytes. Vaginal administration of SEB also caused leukocytic infiltration in major organs, such as liver and lung, reminiscent of human toxic shock syndrome. Systemic immune activation following vaginal superantigen delivery was independent of the stage of the estrus cycle in the mouse. Using HLA class II transgenic mice, we have shown that exposure to SEB through the vaginal canal can cause robust systemic immune activation. SEB could thus play a role in the pathogenesis of mTSS.     

Experimental Investigations on Dry Sliding Wear Behavior of Kevlar and Natural Fiber-Reinforced Hybrid Composites through an RSM–GRA Hybrid Approach

The present work aimed to investigate the dry sliding wear behaviors of hybrid polymer matrix composites made up of Kevlar, bamboo, palm, and Aloe vera as reinforcement materials of varying stacking sequences, along with epoxy as the matrix material. Three combinations of composite laminates with different stacking sequences such as AB, BC, and CA were fabricated by a vacuum-assisted compression molding process. The influence of composite laminates fabricated through various stacking sequences and dry sliding wear test variables such as load, sliding distance, and sliding velocity on the specific wear rate and co-efficient of friction were investigated. Experiments were designed and statistical validation was performed through response surface methodology-based D-optimal design and analysis of variance. The optimization was performed using grey relational analysis (GRA) to identify the optimal parameters to enhance the wear resistance of hybrid polymer composites under dry sliding conditions. The optimal parameters, such as composite combinations of CA, a load of 5 N, a sliding velocity of 3 m/s, and a sliding distance of 1500 m, were obtained. Furthermore, the morphologies of worn-out surfaces were investigated using SEM analysis.     

Improved biorefinery pathways of marine diatoms using a water miscible ionic liquid and its colloidal solution: efficient lipid extraction and in situ synthesis of fluorescent carbon dots for bio-imaging applications

In this study, a water-miscible ‘classic’ ionic liquid (IL), 1-ethyl-3-methylimidazoliumacetate ([EMIM][Ac]), has been used for lipid extraction from marine diatoms Thalassiosira lundiana CSIR-CSMCRI 001 by following a non-polar solvent partition method. The composition of lipid was determined using gas chromatography-mass spectrometry (GC-MS). In total, 91.4 mg g⁻¹ (dry wt) of lipid was produced, out of which the percentage of docosahexaenoic acids (DHA), myristic acid, palmitic acid, and arachidonic acid was 19.6%, 15.1%, 11.2%, and 10.4%, respectively. The IL-inseparable residual waste solution was directly used to generate green fluorescent carbon dots (FCDs) by constructing a colloidal solution with the help of a surface-active IL, choline dioctyl sulfosuccinate ([Cho][AOT]). The stability of colloidal FCDs was examined using FTIR, FT-NMR, and Raman spectroscopy. FCDs were extracted from the colloidal solutions via the demicellization process and characterized using HR-TEM (2 to 5 nm) and PXRD techniques. The optical properties of colloidal FCDs were measured using UV-Vis and fluorescence spectroscopy and showed a wide range of emission (λ_{460 nm} to λ_{590 nm}). Such FCD stabilized colloidal solutions could be effectively used in fluorescence imaging of yeast cells, thus making the biorefinery approach more sustainable.

In this study, a water-miscible ionic liquid (IL), 1-ethyl-3-methylimidazoliumacetate ([EMIM][Ac]), has been used for lipid extraction from marine diatoms Thalassiosira lundiana CSIR-CSMCRI 001 by following a non-polar solvent partition method.     

Effect of sensorineural hearing loss on neurocognitive and adaptive functioning in survivors of pediatric embryonal brain tumor

Journal of Neuro-Oncology - Survivors of pediatric embryonal brain tumors (BT) are at high risk for sensorineural hearing loss (SNHL) associated with neurocognitive decline. However, previous...     

Activation of GPCRs modulates quantal size in chromaffin cells through G(betagamma) and PKC

Exocytosis proceeds by either full fusion or 'kiss-and-run' between vesicle and plasma membrane. Switching between these two modes permits the cell to regulate the kinetics and amount of secretion. Here we show that ATP receptor activation reduces secretion downstream from cytosolic Ca2+ elevation in rat adrenal chromaffin cells. This reduction is mediated by activation of a pertussis toxin-sensitive G(i/o) protein, leading to activation of G(betagamma) subunits, which promote the 'kiss-and-run' mode by reducing the total open time of the fusion pore during a vesicle fusion event. Furthermore, parallel activation of the muscarinic acetylcholine receptor removes the inhibitory effects of ATP on secretion. This is mediated by a G(q) pathway through protein kinase C activation. The inhibitory effects of ATP and its reversal by protein kinase C activation are also shared by opioids and somatostatin. Thus, a variety of G protein pathways exist to modulate Ca2+-evoked secretion at specific steps in fusion pore formation.     

An unusual manifestation of tuberculous hypersensitivity

This report describes a 6-year-old boy with symmetrical, painful soft tissue swelling of all the fingers and toes, without apparent joint involvement. The Mantoux test was strongly positive. A dramatic response was observed with anti-tuberculosis chemotherapy.     

Imaging features of low-grade central osteosarcoma of the long bones and pelvis

Purpose To determine the age and gender distribution and imaging features of low-grade central osteosarcoma (LGCOS) of the long bones and pelvis and to discuss our findings in the context of lesions for which LGCOS has been mistaken.Materials and methods We reviewed 99 cases of LGCOS collected between 1919 and 2002 from our institution and pathology consultation files. Adequate imaging was available in 70 cases (36 radiographs only, 17 radiographs/CT, 12 radiographs/MRI, 2 radiographs/CT/MRI, 2 CT only, 1 MRI only, 5 bone scans).Results Patient average age was 30.1±14.2 years, with a slight female predominance. The femur and tibia were the most common long bones involved (29 and 20 each) with the majority of these tumors arising around the knee, followed by the fibula, radius, humerus and ulna (four, three, two and one case each). Flat bones were involved in six cases (three pelvis, one rib, two scapulae). Short tubular bones were involved in five cases (two metatarsal, two phalanges, one clavicle). The lesion extended to the end of the affected long bone in 22 of 59 cases. Lesions were large at presentation (mean 7.9±4.6 cm, range 2–24). Four radiographic patterns were identified: lytic with varying amounts of thick and coarse trabeculation (n=22), predominantly lytic with few thin, incomplete trabecula (n=21), densely sclerotic (n=17) and mixed lytic and sclerotic (n=10). Lesions were benign-appearing overall with focally aggressive features. CT or MRI demonstrated cortical breech or extension into the soft tissues in all cases.Conclusions LGCOS has a variable appearance on radiographs. A frequent pattern is a slow-growing large intracompartmental fibro-osseous lesion with varying amounts of septal ossification associated with focal areas of aggression. A homogeneously sclerotic pattern was also noted. Imaging with CT or MRI was helpful in every instance in our series in identifying areas of soft tissue extension or cortical disruption suggestive of a low-grade malignancy.