Immunohistochemical study of α-smooth muscle actin expression in oral leukoplakia and oral squamous cell carcinoma.

CONTEXT: It is important to evaluate the role of stromal myofibroblasts (MFs) in carcinogenesis and also as a predictive marker for lymph node (LN) metastasis at the invasive front of oral squamous cell carcinoma (OSCC). AIMS: To demonstrate the expression of α-smooth muscle actin (α-SMA) by MFs in the tissues of oral leukoplakia (OL) with dysplasia and OSCC. To record and compare the distribution of MFs in OSCC with LN metastasis and without LN metastasis. SETTINGS AND DESIGN: Fifty paraffin-embedded tissue blocks with 10 cases of normal oral mucosa, 10 cases of OL with dysplasia and 30 diagnosed cases of OSCCs were studied. SUBJECTS AND METHODS: The samples were subjected to heat-induced antigen retrieval method followed by staining using primary mouse monoclonal antibodies against α-SMA and visualized using super sensitive polymer-HRP detection system. STATISTICAL ANALYSIS: Descriptive statistical analysis and ANOVA test were used for statistical analysis. RESULTS: There was no α-SMA expression in normal oral mucosa or in OL with dysplasia. All tissues of OSCC were positive for α-SMA expression. The difference in the expression between OL with dysplasia and OSCC was statistically significant (P < 0.05). The mean α-SMA count of OSCC with LN metastasis is significantly greater than in the OSCC without LN metastasis (P = 0.001). In OSCC without LN metastasis, focal and spindle patterns were predominant and in OSCC with LN metastasis network pattern was more. CONCLUSION: α-SMA expression by MFs in OSCCs indicates its role in tumor growth and invasion. The mean α-SMA count was found to correlate with tumor invasiveness and locoregional LN metastasis.

Efficacy of Rituharitaki (seasonal adjuvant of Haritaki) on disorders of Varsha Ritu (monsoon) w.s.r. to quality of life: An open labelled randomized controlled clinical trial.

BACKGROUND: Monsoon epidemics are always a serious concern in the public health sector. Administration of Haritaki with suitable vehicle as per season (Rituharitaki) is a simple, cost-effective preventive measure which can be used for such conditions. AIMS AND OBJECTIVES: Study objectives were to assess the effect of Rituharitaki in preventing the diseases in Varsha Ritu (monsoon) and its effect on the WHO quality of life BREF (QOL BREF), total leukocyte count (TLC), differential count (DC) and erythrocyte sedimentation rate (ESR) in healthy volunteers. MATERIALS AND METHODS: From 82 participants, based on inclusion criteria, 60 participants were selected and randomly allocated into trial and control group of 30 each using a computer generated random number table. Intervention given was Rituharitaki (Terminalia chebula Retz) in tablet form-3 tablets of 1g each and Saindhava (rock salt) 1g with lukewarm water at 6.30 am on empty stomach to the participants of trial group for 60 days in Varsha Ritu in Kerala and were observed during this period. RESULTS: The results were analyzed using Chi-square test and paired t-test. Significant results were obtained in the trial group in reducing the severity and frequency of common cold (p < 0.001), cough (p < 0.05), and fever (p < 0.001). In the WHO QOL BREF domain 1 & 4 showed significant result in the trial group (p < 0.05). Among the haematological parameters - total leukocyte count (TLC), eosinophil count and erythrocyte sedimentation rate (ESR) were statistically significant reduced (p < 0.05) in the trial group. CONCLUSION: Rituharitaki is found to be effective in reducing severity and frequency of diseases in Varsha Ritu and had effect on quality of life of patients.

Immunohistochemical study of alpha-smooth muscle actin in odontogenic cysts and tumors.

CONTEXT: Myofibroblasts (MFs) are fibroblasts with smooth muscle-like features characterized by the presence of a contractile apparatus. Alpha-smooth muscle actin (α-SMA) is the actin isoform that predominates within vascular smooth muscle cells and plays an important role in fibrogenesis. MFs are metabolically and morphologically distinctive fibroblasts expressing α-SMA, and their activation plays a key role in development of the fibrotic response. AIMS AND OBJECTIVES: The aim of this study is to demonstrate the frequency, distribution and expression of α-SMA-positive MFs in odontogenic keratocyst (OKC), dentigerous cyst (DC) and ameloblastoma and correlate it to their aggressive biological behavior. SETTINGS AND DESIGN: A retrospective study of 45 diagnosed cases, which includes 15 cases of OKC, 15 cases of DC and 15 cases of ameloblastoma, was undertaken to demonstrate expression of α-SMA retrieved from archives of our department. MATERIALS AND METHODS: α-SMA mouse anti-human antibody and horseradish peroxidase detection system were used in this study. STATISTICAL ANALYSIS: Descriptive statistical analysis and ANOVA test were used for statistical analysis. RESULTS: The difference in mean α-SMA count was found to be statistically significant between ameloblastoma and DC group (P < 0.001) as well as OKC and DC group (P < 0.001). No significant difference is observed between ameloblastoma and OKC group (P > 0.05). Results showed that mean number of stromal MFs in OKC and ameloblastoma were significantly higher than DC. CONCLUSION: The present study has shown that the mean number of MFs was higher in OKC and ameloblastoma, while the mean number of MFs in DC was quite low and significantly different from that of ameloblastoma and OKC.

Self-Powered Analogue Smart Skin.

The progress of smart skin technology presents unprecedented opportunities for artificial intelligence. Resolution enhancement and energy conservation are critical to improve the perception and standby time of robots. Here, we present a self-powered analogue smart skin for detecting contact location and velocity of the object, based on a single-electrode contact electrification effect and planar electrostatic induction. Using an analogue localizing method, the resolution of this two-dimensional smart skin can be achieved at 1.9 mm with only four terminals, which notably decreases the terminal number of smart skins. The sensitivity of this smart skin is remarkable, which can even perceive the perturbation of a honey bee. Meanwhile, benefiting from the triboelectric mechanism, extra power supply is unnecessary for this smart skin. Therefore, it solves the problems of batteries and connecting wires for smart skins. With microstructured poly(dimethylsiloxane) films and silver nanowire electrodes, it can be covered on the skin with transparency, flexibility, and high sensitivity.

Ubiquitin binds to and regulates a subset of SH3 domains.

SH3 domains are modules of 50-70 amino acids that promote interactions among proteins, often participating in the assembly of large dynamic complexes. These domains bind to peptide ligands, which usually contain a core Pro-X-X-Pro (PXXP) sequence. Here we identify a class of SH3 domains that bind to ubiquitin. The yeast endocytic protein Sla1, as well as the mammalian proteins CIN85 and amphiphysin, carry ubiquitin-binding SH3 domains. Ubiquitin and peptide ligands bind to the same hydrophobic groove on the SH3 domain surface, and ubiquitin and a PXXP-containing protein fragment compete for binding to SH3 domains. We conclude that a subset of SH3 domains constitutes a distinct type of ubiquitin-binding domain and that ubiquitin binding can negatively regulate interaction of SH3 domains with canonical proline-rich ligands.

Maxillary second premolar with three roots and three separate root canals--case reports.

Aberrations in root canal systems are a commonly occurring phenomenon. Knowledge of the basic root canal anatomy and its variation is necessary for successful completion of endodontics. Maxillary second premolars usually have one root and one canal. The occurrence of these teeth having three roots and three canals is very rare. Three such cases of maxillary second premolar with three roots and three canals are presented here.

Solution structure of a CUE-ubiquitin complex reveals a conserved mode of ubiquitin binding.

Monoubiquitination serves as a regulatory signal in a variety of cellular processes. Monoubiquitin signals are transmitted by binding to a small but rapidly expanding class of ubiquitin binding motifs. Several of these motifs, including the CUE domain, also promote intramolecular monoubiquitination. The solution structure of a CUE domain of the yeast Cue2 protein in complex with ubiquitin reveals intermolecular interactions involving conserved hydrophobic surfaces, including the Leu8-Ile44-Val70 patch on ubiquitin. The contact surface extends beyond this patch and encompasses Lys48, a site of polyubiquitin chain formation. This suggests an occlusion mechanism for inhibiting polyubiquitin chain formation during monoubiquitin signaling. The CUE domain shares a similar overall architecture with the UBA domain, which also contains a conserved hydrophobic patch. Comparative modeling suggests that the UBA domain interacts analogously with ubiquitin. The structure of the CUE-ubiquitin complex may thus serve as a paradigm for ubiquitin recognition and signaling by ubiquitin binding proteins.

A ubiquitin-binding motif required for intramolecular monoubiquitylation, the CUE domain.

Monoubiquitylation is a regulatory signal, like phosphorylation, that can alter the activity, location or structure of a protein. Monoubiquitin signals are likely to be recognized by ubiquitin-binding proteins that transmit the regulatory information conferred by monoubiquitylation. To identify monoubiquitin-binding proteins, we used a mutant ubiquitin that lacks the primary site of polyubiquitin chain formation as bait in a two-hybrid screen. The C-terminus of Vps9, a protein required in the yeast endocytic pathway, interacted specifically with monoubiquitin. The region required for monoubiquitin binding mapped to the Vps9 CUE domain, a sequence previously identified by database searches as similar to parts of the yeast Cue1 and mammalian Tollip proteins. We demonstrate that CUE domains bind directly to monoubiquitin and we have defined crucial interaction surfaces on both binding partners. The Vps9 CUE domain is required to promote monoubiquitylation of Vps9 by the Rsp5 hect domain ubiquitin ligase. Thus, we conclude that the CUE motif is an evolutionarily conserved monoubiquitin-binding domain that mediates intramolecular monoubiquitylation.

ErbB family targeting.

Drugs for specific molecular targets have generated a great deal of excitement for their potential in cancer treatment, particularly with respect to our molecular understanding of cancer in recent years. The clinical utility of antibodies and small molecule kinase inhibitors has been demonstrated. The ErbB family of receptors is at the forefront of targets that are the subject of clinical trials. However, the activities of epidermal growth factor receptor antagonists have not been impressive as single agents. One of the lessons learned with this class of targets is that we currently do not know how to optimally apply them to the treatment of cancer. This review will discuss the issues contributing to this situation and the approaches that are currently being launched to resolve these issues.

Mutational analysis of the subunit C (Vma5p) of the yeast vacuolar H+-ATPase.

Subunit C is a V(1) sector subunit found in all vacuolar H(+)-ATPases (V-ATPases) that may be part of the peripheral stalk connecting the peripheral V(1) sector with the membrane-bound V(0) sector of the enzyme (Wilkens, S., Vasilyeva, E., and Forgac, M. (1999) J. Biol. Chem. 274, 31804--31810). To elucidate subunit C function, we performed random and site-directed mutagenesis of the yeast VMA5 gene. Site-directed mutations in the most highly conserved region of Vma5p, residues 305--325, decreased catalytic activity of the V-ATPase by up to 48% without affecting assembly. A truncation mutant (K360stop) identified by random mutagenesis suggested a small region near the C terminus of the protein (amino acids 382--388) might be important for subunit stability. Site-directed mutagenesis revealed that three aromatic amino acids in this region (Tyr-382, Phe-385, and Tyr-388) in addition to four other conserved aromatic amino acids (Phe-260, Tyr-262, Phe-296, Phe-300) are essential for stable assembly of V(1) with V(0), although alanine substitutions at these positions support some activity in vivo. Surprisingly, three mutations (F260A, Y262A, and F385A) greatly decrease the stability of the V-ATPase in vitro but increase its k(cat) for ATP hydrolysis and proton transport by at least 3-fold. The peripheral stalk of V-ATPases must balance the stability essential for productive catalysis with the dynamic instability involved in regulation; these three mutations may perturb that balance.