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31.
Head and neck squamous cell carcinoma (HNSCC) remains difficult to treat, and despite of advances in treatment, the overall survival rate has only modestly improved over the past several years. Thus, there is an urgent need for additional therapeutic modalities. We hypothesized that treatment of HNSCC cells with a dietary product such as bitter melon extract (BME) modulates multiple signaling pathways and regresses HNSCC tumor growth in a preclinical model. We observed a reduced cell proliferation in HNSCC cell lines. The mechanistic studies reveal that treatment of BME in HNSCC cells inhibited c-Met signaling pathway. We also observed that BME treatment in HNSCC reduced phosphoStat3, c-myc and Mcl-1 expression, downstream signaling molecules of c-Met. Furthermore, BME treatment in HNSCC cells modulated the expression of key cell cycle progression molecules leading to halted cell growth. Finally, BME feeding in mice bearing HNSCC xenograft tumor resulted in an inhibition of tumor growth and c-Met expression. Together, our results suggested that BME treatment in HNSCC cells modulates multiple signaling pathways and may have therapeutic potential for treating HNSCC.  相似文献   
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The roots of the Hispanic populations of the Caribbean Islands and Central and South America go back to three continents of the Old World. In Puerto Rico major genetic contributions have come from (1) Asians in the form of the aboriginal Taino population, an Arawak tribe, present when Columbus arrived on the Island, (2) Europeans, largely Spanish explorers, settlers, government administrators, and soldiers, and (3) Africans who came as part of the slave trade. Since JC virus (JCV) genotypes characteristic of Asia, Europe, and Africa have been identified, and excretion of JCV in urine has been proposed as a marker for human migrations, we sought to characterize the JCV strains present in a Caribbean Hispanic population. We found that the strains of JCV present today in Puerto Rico are those derived from the Old World populations represented there: Types 1B and 4 from Spain, Types 3A, 3B, and 6 from Africa, and Type 2A from Asia. The Type 2A genotype represents the indigenous Taino people. This JCV genotype was represented much more frequently (61%) than would be predicted by the trihybrid model of genetic admixture. This might be attributable to characteristics of JCV Type 2A itself, as well as to the nature of the early relationships between Spanish men and native women. These findings indicate that the JCV strains carried by the Taino Indians can be found in today's Puerto Rican population despite the apparent demise of these people more than two centuries ago. Therefore, molecular characterization of JCV provides a tool to supplement genetic techniques for reconstructing population histories including admixed populations.  相似文献   
34.
Of the 29 potentially denitrifying organisms isolated from a denitrifying reactor (DNR) of a fertilizer company, two isolates; I-4 and I-5 were recognized as denitrifiers. Under aerobic conditions, with fusel oil as the carbon source, the organisms decreased nitrate from 1200 mg l–1 to 100 mg l–1 in 48 h. Optimal growth conditions for biological removal of nitrate were established in batch culture. The system was scaled up to 4-L and 50-L bioreactors under continuous culture conditions. Up to 95–100% nitrate removal was achieved in the 50-L bioreactor at a COD:NO3–N ratio of 3.45 with a retention time of 48 h. The isolates showed 1.5 fold higher denitrifying activity than reported previously.  相似文献   
35.
A lot of resources and efforts have been directed to synthesizing potentially useful new chemical entities (NCEs) by pharmaceutical scientists globally. Detailed physicochemical characterization of NCEs in an industrial setup begins almost simultaneously with preclinical testing. Most NCEs possess poor water solubility posing bioavailability issues during initial preclinical screening, sometimes resulting in dropping out of an NCE with promising therapeutic activity. Selection of right formulation approach for an NCE, based on its physicochemical properties, can aid in improving its solubility-related absorption and bioavailability issues. The review focuses on preclinical formulations stressing upon different preclinical formulation strategies and deciphers the understanding of formulation approaches that could be employed. It also provides detailed information related to a vast pool of excipients available today, which is of immense help in designing preclinical formulations. Few examples mentioned, throw light on key aspects of preclinical formulation development. The review will serve as an important guide for selecting the right strategy to improve bioavailability of NCEs for academic as well as industrial formulation scientists.  相似文献   
36.

Background  

An early dispersal of biologically and behaviorally modern humans from their African origins to Australia, by at least 45 thousand years via southern Asia has been suggested by studies based on morphology, archaeology and genetics. However, mtDNA lineages sampled so far from south Asia, eastern Asia and Australasia show non-overlapping distributions of haplogroups within pan Eurasian M and N macrohaplogroups. Likewise, support from the archaeology is still ambiguous.  相似文献   
37.
The food mutagen/carcinogen amino-3-methylimidazo[4,5-f]quinoline (IQ) is activated by cytochrome p4501a-2 via N-hydrox-ylation; various P450s may contribute to detoxification via ring hydroxylation. Alterations in P450 levels by IQ treatment might therefore influence its toxicity. To examine the role of Ah locus genotype on the biochemical effects of IQ, C57BL/6 (AhbAhb; p450Ia-½ inducible) and DBA/2 (AhdAhd, noninducible) mice of both sexes were given IQ at varying doses, with different vehicles and routes of administration. Livers taken after 24 hours were assessed for total cytochrome p450 and activities of ethoxyresorufin-O-deethylase (EROD, a p4501a-l activity, inducible in Ahb mice), meth-oxyresorufin-O-demethylase (MROD, a p4501a-2 activity), and benzyloxyresorufin-O-dealkylase (BzROD, an activity of p4502b). There was little effect on total cytochrome p450, but all three enzyme activities were often induced, a maximum of 2.5-fold, in both sexes and in DBA/2 as well as C57BL/6 mice. However, Western immunoblot analysis with monoclonal antibodies demonstrated an increase only in p4501a-2 protein. p4501a-l remained undetectable. A monoclonal antibody to p4502-b recognized one protein band in liver mi-crosomes from males and two bands in female mice of both strains. Amounts of these proteins were not altered by IQ treatment. Thus, IQ specifically, if moderately, induces its activating enzyme, p4501a-2, in a process that was not clearly related to Ah responsiveness.  相似文献   
38.
Final maturation of eukaryotic ribosomes occurs in the cytoplasm and requires the sequential removal of associated assembly factors and processing of the immature 20S pre‐RNA. Using cryo‐electron microscopy (cryo‐EM), we have determined the structure of a yeast cytoplasmic pre‐40S particle in complex with Enp1, Ltv1, Rio2, Tsr1, and Pno1 assembly factors poised to initiate final maturation. The structure reveals that the pre‐rRNA adopts a highly distorted conformation of its 3′ major and 3′ minor domains stabilized by the binding of the assembly factors. This observation is consistent with a mechanism that involves concerted release of the assembly factors orchestrated by the folding of the rRNA in the head of the pre‐40S subunit during the final stages of maturation. Our results provide a structural framework for the coordination of the final maturation events that drive a pre‐40S particle toward the mature form capable of engaging in translation.  相似文献   
39.
Distinct genotypes of human polyomavirus JC (JCV) have remained population associated possibly from the time of dispersal of modern humans from Africa. Seven major genotypes with additional subtypes serve as plausible markers for following early and more recent human migrations in all parts of the world. Phylogenetic trees of JCV sequences from the major continental population groups show a trifurcation at the base indicating early division into European, African, and Asian branches. Here, we have explored JCV relationships in the island populations of the western Pacific. Since these islands were settled from the Asian mainland and islands of Southeast Asia, we expected that their virus genotypes might show an Asian connection. We found that Type 2E (Austronesian) and Type 8 (non-Austronesian) are widely distributed in western Pacific populations. A few south China strains were found (Type 7A). A subtype of Type 8, Type 8A, was confined to Papua New Guinea. In keeping with these assignments we find that phylogenetic analysis by neighbor-joining and maximum parsimony methods places Type 2E in a closer relationship to east Asian mainland strains such as Type 2A and Type 7. Our findings support the Asian origins of the western Pacific JCV strains, and suggest three broad movements: an ancient one characterized by Type 8A, and then Type 8B, followed much later by migrations carrying Type 2E, which may correlate with the arrival of Austronesian-language speakers, the bearers of the "Lapita" cultural complex (approximately 3,500 to 5,000 years ago), and relatively recent movements carrying largely Type 7A (south China) strains directly from the West.  相似文献   
40.
BACKGROUND: Imprint cytology of the thymus has not received much attention. Cytology of the thymus is important because the uninvolved thymus may be needled during aspiration procedures. CASES: In two cases, during surgery for carcinoma of the thyroid, we received thymic tissue mistakenly sampled as a pretracheal lymph node for frozen section to rule out metastasis. Imprint smears were studied. The presence of thymocytes in the cytoplasm of thymic epithelial cells (emperipolesis) was the most significant feature in the imprints. However, it was not detected on histology. CONCLUSION: Thymic epithelial cells provide mechanical support and play a major role in the maturation of lymphocytes (thymocytes). They are observed as emperipolesis on imprint cytology. Its utility in identifying thymic cells in aspiration cytology needs to be investigated.  相似文献   
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