Transitional dynamics of cancer stem cells in invasion and metastasis.

At the onset, few cancer cells amidst the tumor bulk, identified as cancer stem cells (CSCs) or early disseminated cancer cells (eDCCs) are capable of survival post conventional therapy and persist as minimal residual disease (MRD). Metastatic subclones emerge both early and late in the life of primary tumor ensuing an ongoing regional clonal evolution of progenitor cells in metastatic and primary tumors. In the last decade, multiple studies proposed various identities of stem-like cells that undergo transitions to adapt to the changing microenvironment as the disease progresses. This review advocates with substantial evidence the dynamic model of tumor propagation by exploring the specific cell types, reversible phenotypic plasticity between the tumorigenic leader seeds and the supporting follower cancer cells both in circulation and in solid tissue to accurately decipher tumor promoting clones and its role in metastatic dissemination and tumor re-growth. (142 words).

Effect of silver diamine fluoride-potassium iodide and 2% chlorhexidine gluconate cavity cleansers on the bond strength and microleakage of resin-modified glass ionomer cement.

BACKGROUND: Disinfection of the prepared cavity can be a crucial step in the longevity of restorations. The objective of this study was to compare the antimicrobial action (AMA) of silver diamine fluoride-potassium iodide combination (SDF-KI) with 2% chlorhexidine gluconate (CHX) and to compare the alteration in bond strength and microleakage while using SDF-KI and CHX as cavity cleansers in resin-modified glass ionomer cement (RMGIC) restorations. MATERIALS AND METHODS: Samples were grouped as follows: Group 1: Polyacrylic acid (PAA), Group 2: CHX, Group 3: SDF-KI, and Group 4: Distilled water (CTRL). AMA was assessed by measuring the zone of inhibition of the above-mentioned materials by dispensing them into the punch hole prepared on agar plates with an inoculum of Streptococcus mutans. For assessing the effect of the cavity cleansers on the bond strength of RMGIC, they were applied to the dentinal samples prepared from freshly extracted noncarious molars. After the surface was treated, cylindrical restoration of RMGIC was placed and allowed to set. The shear bond strength was then evaluated using a universal testing machine. Rhodamine-B dye penetration was viewed under a fluorescent microscope to evaluate the microleakage of RMGIC following surface treatment of the standardized cavities prepared on the cervical third of freshly extracted noncarious premolars. RESULTS: SDF-KI (34 ± 0.8 mm) showed potent AMA followed by CHX (23.9 ± 0.7 mm) and PAA (12.7 ± 0.8 mm). SDF-KI showed a drastic increase in the bond strength when compared to the PAA, CHX, and CTRL groups. Although the application of SDF-KI showed the least microleakage among all the groups, it was not statistically significant. CONCLUSION: The application of SDF-KI and CHX is useful against S. mutans in an in vitro study. Although SDF-KI group showed the least microleakage among the groups, it was not statistically significant. SDF-KI application has shown a drastic increase in the bond strength of RMGIC although further research is required for the suitable reasoning of the phenomenon.

Implications of miR cluster 143/145 as universal anti-oncomiRs and their dysregulation during tumorigenesis.

Tumorigenesis is a multistep process, de-regulated due to the imbalance of oncogenes as well as anti-oncogenes, resulting in disruption of tissue homeostasis. In many cases the effect of oncogenes and anti-oncogenes are mediated by various other molecules such as microRNAs. microRNAs are small non-coding RNAs established to post-transcriptionally regulate more than half of the protein coding genes. miR cluster 143/145 is one such cancer-related microRNA cluster which is down-regulated in most of the cancers and is able to hinder tumorigenesis by targeting tumor-associated genes. The fact that they could sensitize drug-resistant cancer cells by targeting multidrug resistant genes makes them potent tools to target cancer cells. Their low levels precede events which lead to cancer progression and therefore could be considered also as biomarkers to stage the disease. Interestingly, evidence suggests the existence of several in vivo mechanisms by which this cluster is differentially regulated at the molecular level to keep their levels low in cancer. In this review, we summarize the roles of miR cluster 143/145 in cancer, their potential prognostic applications and also their regulation during tumorigenesis.

Umbilical cord blood-derived mesenchymal stem cells consist of a unique population of progenitors co-expressing mesenchymal stem cell and neuronal markers capable of instantaneous neuronal differentiation.

INTRODUCTION: Umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) are self-renewing multipotent progenitors with the potential to differentiate into multiple lineages of mesoderm, in addition to generating ectodermal and endodermal lineages by crossing the germline barrier. In the present study we have investigated the ability of UCB-MSCs to generate neurons, since we were able to observe varying degrees of neuronal differentiation from a few batches of UCB-MSCs with very simple neuronal induction protocols whereas other batches required extensive exposure to combination of growth factors in a stepwise protocol. Our hypothesis was therefore that the human UCB-MSCs would contain multiple types of progenitors with varying neurogenic potential and that the ratio of the progenitors with high and low neurogenic potentials varies in different batches of UCB. METHODS: In total we collected 45 UCB samples, nine of which generated MSCs that were further expanded and characterized using immunofluorescence, fluorescence-activated cell sorting and RT-PCR analysis. The neuronal differentiation potential of the UCB-MSCs was analyzed with exposure to combination of growth factors. RESULTS: We could identify two different populations of progenitors within the UCB-MSCs. One population represented progenitors with innate neurogenic potential that initially express pluripotent stem cell markers such as Oct4, Nanog, Sox2, ABCG2 and neuro-ectodermal marker nestin and are capable of expanding and differentiating into neurons with exposure to simple neuronal induction conditions. The remaining population of cells, typically expressing MSC markers, requires extensive exposure to a combination of growth factors to transdifferentiate into neurons. Interesting to note was that both of these cell populations were positive for CD29 and CD105, indicating their MSC lineage, but showed prominent difference in their neurogenic potential. CONCLUSION: Our results suggest that the expanded UCB-derived MSCs harbor a small unique population of cells that express pluripotent stem cell markers along with MSC markers and possess an inherent neurogenic potential. These pluripotent progenitors later generate cells expressing neural progenitor markers and are responsible for the instantaneous neuronal differentiation; the ratio of these pluripotent marker expressing cells in a batch determines the innate neurogenic potential.

Thioacetamide-induced fulminant hepatic failure induces cerebral mitochondrial dysfunction by altering the electron transport chain complexes.

Fulminant hepatic failure (FHF) is an acute form of hepatic encephalopathy resulting from severe inflammatory or necrotic liver damage without any previously established liver damage. This develops as a complication due to viral infections, and drug abuse. FHF also occurs in acute disorders like Reye's syndrome. Although the exact mechanisms in the etiology of FHF are not understood, elevated levels of brain ammonia have been consistently reported. Such increased ammonia levels are suggested to alter neurotransmission signals and impair cerebral energy metabolism due to mitochondrial dysfunctions. In the present study we have examined the role of cerebral electron transport chain complexes, including complex I, II, III IV, and pyruvate dehydrogenase in the non-synaptic mitochondria isolated from the cortex of the thioacetamide-induced FHF rats. Further, we have examined if the structure of mitochondria is altered. The results of the current study demonstrated a decrease in the activity of the complex I by 31 and 48% at 18 and 24 h respectively after the thioacetamide injection. Similarly, the activity of electron transport chain complex III was inhibited by 35 and 52% respectively, at 18 and 24 h, respectively. The complex II and complex IV, on the other hand, revealed unaltered activity. Further the activity of pyruvate dehydrogenase at 18 and 24 h after the induction of FHF was inhibited by 29 and 43%, respectively. Our results also suggest mitochondrial swelling in FHF induced rats. The inhibition of the respiratory complexes III and I and pyruvate dehydrogenase might lead to the increased production of free radical resulting in oxidative stress and cerebral energy disturbances thereby leading to mitochondrial swelling and further contributing to the pathogenesis of FHF.

A simple molecular theory for photo-induced smectic phase.

The response of liquid crystals to light is very important for applications of liquid crystals in display and memory devices. Recently experiments have been carried out on liquid crystals doped with photoactive azo compounds. It is seen that UV rays incident on such systems can lower the nematic isotropic transition temperature T (NI). Also, in some mixtures, a photo-induced smectic phase is observed. This is attributed to the change in the trans (longer) isomer to cis (shorter) isomer of the photoactive dopant. We have earlier developed a molecular mean-field model assuming the medium to consist of inter-converting anti-parallel and parallel pairs to explain the molecular origin of "two lengths". The model was used to explain double re-entrance, the effect of electric field on T (NI), etc. This model is modified to include the change of trans to cis isomer which is equivalent to an increase of fraction of parallel (shorter) pairs. The calculated phase diagram with respect to incident UV radiation energy shows an induced smectic phase. This is in qualitative agreement with experimental trends.

Prognostic significance of STAT3 and phosphorylated STAT3 in human soft tissue tumors - a clinicopathological analysis.

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is a key signaling molecule and a central cytoplasmic transcription factor, implicated in the regulation of growth. Its aberrant activation has been demonstrated to correlate with many types of human malignancy. However, whether constitutive STAT3 signaling plays a key role in the survival and growth of soft-tissue tumors is still unclear and hence needs to be elucidated further. In our study we examined the expression levels of STAT3 and pSTAT3 in different grades of soft tissue tumors and correlated with its clinicopathological characteristics. METHODS: Expression levels of STAT3 and pSTAT3 in soft tissue tumors were studied using Immunohistochemistry, Western blotting and Reverse transcriptase- PCR and correlated with its clinicopathological characteristics using Chi squared or Fisher's exact test and by logistic regression analysis. Statistical analysis was done using Intercooled Stata software (Intercooled Stata 8.2 version). RESULTS: Of the 82 soft tissue tumor samples, fifty four (65.8%) showed immunoreactivity for STAT3 and twenty eight (34.1%) for pSTAT3. Expression of STAT3 and pSTAT3 was significantly associated with tumor grade (P < 0.001; P < 0.001), tumor location (P = 0.025; P = 0.027), plane of tumor (P = 0.011; P = 0.006), and tumor necrosis (P = 0.001; P = 0.002). Western blotting and RT-PCR analysis showed increased expression of STAT3 and p-STAT3 as grade of malignancy increased. CONCLUSION: These findings suggest that constitutive activation of STAT3 is an important factor related to carcinogenesis of human soft tissue tumors and is significantly associated with its clinicopathological parameters which may possibly have potential diagnostic implications.

Region-wise distribution of high-risk human papillomavirus types in squamous cell carcinomas of the cervix in India.

HYPOTHESIS: Assessment of the prevalence and type distribution of human papillomavirus (HPV) in squamous cell carcinomas (SCC) of the cervix across India was undertaken to estimate the impact of available prophylactic HPV-L1 vaccines in the country and to find out additional types that might be needed to be incorporated in second-generation vaccines. METHODS: High-risk (HR) HPVs were genotyped from 667 histopathologically confirmed cases of SCC from 6 different centers representing 4 regions across India: Advanced Centre for Treatment, Research and Education in Cancer, Mumbai; All India Institute of Medical Sciences, New Delhi; Cancer Foundation of India, Kolkata; Christian Medical College, Vellore; Kidwai Memorial Institute of Oncology, Bangalore; and Regional Cancer Center, Thiruvananthapuram. Human papillomaviruses in tumor biopsies were analyzed by Xcytonscreen HPV based on PGMY09/11 multiplex polymerase chain reaction and reverse dot blot assay. RESULTS: Overall viral prevalence across India was not different; 92.1% of 667 cases harbored HPV; 8% were negative. Infection with single HR type was seen in 86.8%: predominant types being HPV-16 followed by HPV-18, -45, -73, -31, -56, -52, -58, -59, -33, -68, -51, -35, -26, and -39. Human papillomavirus types 16/18-positive fraction formed 79.6%; other types comprised 12.4%. CONCLUSIONS: Prophylactic HPV-16/18-L1 vaccines would provide greater than 75% protection against SCC in India. Ranking and frequencies of non-16/18 types were different from earlier reports. Hence, considering the possibility of promotion of persistence of nonvaccine types in the vaccinees due to original antigenic sin and the lack of organized screening programs in India, a broad-based vaccine approach would be appropriate.

MTar: a computational microRNA target prediction architecture for human transcriptome.

BACKGROUND: MicroRNAs (miRNAs) play an essential task in gene regulatory networks by inhibiting the expression of target mRNAs. As their mRNA targets are genes involved in important cell functions, there is a growing interest in identifying the relationship between miRNAs and their target mRNAs. So, there is now a imperative need to develop a computational method by which we can identify the target mRNAs of existing miRNAs. Here, we proposed an efficient machine learning model to unravel the relationship between miRNAs and their target mRNAs. RESULTS: We present a novel computational architecture MTar for miRNA target prediction which reports 94.5% sensitivity and 90.5% specificity. We identified 16 positional, thermodynamic and structural parameters from the wet lab proven miRNA:mRNA pairs and MTar makes use of these parameters for miRNA target identification. It incorporates an Artificial Neural Network (ANN) verifier which is trained by wet lab proven microRNA targets. A number of hitherto unknown targets of many miRNA families were located using MTar. The method identifies all three potential miRNA targets (5' seed-only, 5' dominant, and 3' canonical) whereas the existing solutions focus on 5' complementarities alone. CONCLUSION: MTar, an ANN based architecture for identifying functional regulatory miRNA-mRNA interaction using predicted miRNA targets. The area of target prediction has received a new momentum with the function of a thermodynamic model incorporating target accessibility. This model incorporates sixteen structural, thermodynamic and positional features of residues in miRNA: mRNA pairs were employed to select target candidates. So our novel machine learning architecture, MTar is found to be more comprehensive than the existing methods in predicting miRNA targets, especially human transcritome.

Drug susceptibility profiles of Mycobacterium tuberculosis isolates at Mangalore.

BACKGROUND AND OBJECTIVES: Tuberculosis (TB) remains one of the major causes of death from a single infectious agent worldwide. Its resurgence in 1990s is primarily due to co-infection with HIV and the emergence of multi-drug-resistant (MDR) strains. Our objectives in this study were demonstration and grading of acid-fast bacilli in smears from sputum specimens of clinically newly diagnosed pulmonary TB patients, isolation of the organism, speciation and drug susceptibility testing of Mycobacterium tuberculosis isolates to isoniazid (H), rifampicin (R), streptomycin (S), and ethambutol (E). MATERIALS AND METHODS: Sputum specimens were collected from 150 patients. Smear examination was done after Ziehl-Neelsen staining. The specimens were cultured onto Lowenstein Jensen media after Petroff's method of concentration. The growth was identified as M. tuberculosis with standard tests. Sensitivity of 50 isolates of tubercle bacilli to anti-TB drugs H, R, S, E were determined by Resistance-Ratio method. RESULTS: Out of 150 sputum specimens examined, 62(41.3%) were smear positive. Out of these 62,56 grew on culture. 50 isolates of M. tuberculosis were picked up for drug susceptibility testing. Total of 31 (62%) were resistant to S, 14(28%) to H, 9(18%) to R, 6(12%) were resistant to E and 2 strains (4%) were resistant to H and R. CONCLUSION: From the small cohort, incidence of primary MDR-TB was found to be 4% in this region, which is within the expected range.

Bacteriological study of bottled drinking water marketed in Mangalore.

Bottled water is generally accepted as safe for consumption. However, its potability is uncertain. Ninety samples of Six national and 3 local brands marketed in Mangalore City were studied. Seven of these were ISI certified. Bacteriological analysis of these samples were carried out for viable count, presumtive coliform count by multiple tube method, confirmed Esch. coli count by Eijkman test and specific intestinal pathogens, such as Salmonella, Shigella and Vibrios. Thirty out of 90 samples though free from coliforms, had viable count much higher than specified by Bureau of Indian Standard. Three samples of one of the brands which is ISI not certified had Esch. coli with most probable number 18/100 ml and Salmonella typhimurium. It is concluded that bottled water can not be taken for granted to be safe.

Infrared skin temperature measurement cannot be used to detect myofascial tender spots.

OBJECTIVE: To determine the relationship between skin temperature and pressure tolerance in patients with myofascial pain. DESIGN: Blinded, criterion standard. SETTING: Community physiatry clinic. PATIENTS: Sixteen consecutive female patients with myofascial pain or fibromyalgia with shoulder girdle symptoms above the T4 level for at least 3 months. No patient met the exclusion criteria of recent trauma to the area or therapy within 48 hours. INTERVENTIONS: Skin temperature was measured by using a hand-held infrared thermometer over 36 points arranged in a grid on the upper and midtrapezius. Pressure threshold was then assessed at each point by using a pressure threshold meter. A second, blinded examiner then examined each patient to find any myofascial tender spots and noted within which square on the grid they occurred. MAIN OUTCOME MEASURES: The correlation between temperature and pressure threshold and the temperature differences between tender and nontender areas. RESULTS: A nonsignificant correlation of.023 (p =.57) was found between temperature and pressure threshold. The mean temperature of the tender spots was 32.1 degrees C. No significant difference existed between tender spot temperature and temperature of nontender points (32.1 degrees C, p =.653) or contralateral points (32 degrees C, p =.893). CONCLUSIONS: Skin temperature, measured with a hand-held infrared thermometer, cannot be used to diagnose and follow treatment progress of myofascial tender spots, because skin temperature over tender spots does not correlate with pressure sensitivity.

Acylated C-21 steroidal bisdesmosidic glycosides from Caraluma umbellata.

From the whole plant of Caraluma umbellata, three new C-21 steroidal glycosides, named as carumbellosides III-V, were isolated and their structures elucidated by extensive spectroscopic experiments, devoid of any derivatisation, as caralumagenin 3-O-beta-D-glucopyranosyl(1-->4)-beta-D-digitalopyranoside-20-O-be ta- D-glucopyranoside, caralumagenin 3-O-beta-D-glucopyranosy(1-->4)- beta-D-digitalopyranoside-20-O-(2-O- benzoyl)-beta-D-glucopyranoside and caralumagenin 3-O-[6-O-benzoyl-beta-D-glucopyranosyl(1-->4)]-beta-D- digitalopyranoside-20-O-(2-O-benzoyl)-beta-D-glucopyranoside. The determination of the absolute configuration of the aglycone as (20 R), the conformations of the sugars and the unambiguous assignments of their NMR spectroscopic signals were achieved by a combination of 2D-NMR techniques. The isolates were devoid of significant cytotoxity in the UIC human cancer cell panel.

Protein kinases mediate basic fibroblast growth factor's stimulation of proliferation and c-fos induction in oligodendrocyte progenitors.

Primary culture was used to examine the effects of basic fibroblast growth factor (bFGF) on oligodendrocyte progenitor proliferation and c-fos expression. Basic FGF induced proliferation approximately six fold. This increased DNA synthesis could be blocked both with genistein, a tyrosine kinase inhibitor, and H-7, a protein kinase C (PKC) inhibitor. These results indicate that protein tyrosine kinase activity and protein kinase C are involved in mediating oligodendrocyte progenitor proliferation. The protooncogene c-fos was investigated as a likely proliferation mediator. Firstly, optimal conditions for bFGF-induced c-fos expression were determined. The oncogene responded maximally between 30 and 60 min of bFGF stimulation. Induction in response to bFGF occurred at 1 ng/ml, increased in a concentration-dependent manner and was maximal at 50 ng/ml. H-7 (50 microM) and genistein (100 microM) blocked c-fos induction as did PKC down-regulation with chronic treatment of phorbol 12-myristate 13-acetate. These results indicate that bFGF induces c-fos expression through receptor tyrosine phosphorylation and PKC activation. Thus similar early signals lead to bFGF-driven proliferation and c-fos induction suggesting a link between these two processes.