Synthesis of highly crystalline LaFeO3 nanospheres for phenoxazinone synthase mimicking activity.

LaFeO3 nanospheres with an orthorhombic perovskite structure were synthesized by a sol-gel autocombustion method in the presence of different citric acid ratios (x = 2, 4, 8, and 16) and utilized for the photocatalytic conversion of o-aminophenol (OAP) to 2-aminophenoxazine-3-one (APX) for the first time. OAP is one of the most toxic phenolic derivatives used as a starting material in many industries; however, the dimerization product APX has diverse therapeutic properties. Photocatalytic conversion was carried out in ethanol/water and acetonitrile/water mixtures in the absence and presence of molecular oxygen at ambient temperature via the oxidative coupling reaction that mimics phenoxazinone synthase-like activity. The LaFeO3 samples showed a superior photocatalytic activity of OAP to APX with rate constants of 0.43 and 0.92 min-1 in the absence and presence of molecular oxygen, respectively. Thus, the LaFeO3 nanozymes could be used as promising candidates in industrial water treatment and phenoxazinone synthase-like activity.

Acidic Peptizing Agent Effect on Anatase-Rutile Ratio and Photocatalytic Performance of TiO2 Nanoparticles.

TiO2 nanoparticles were synthesized from titanium isopropoxide by a simple peptization method using sulfuric, nitric, and acetic acids. The effect of peptizing acid on physicochemical and photocatalytic properties of TiO2 powders was studied. The structural properties of synthesized TiO2 powders were analyzed by using XRD, TEM, N2-physisorption, Raman, DR UV-vis, FTIR, and X-ray photoelectron spectroscopy techniques. The characterization results showed that acetic acid peptization facilitated the formation of pure anatase phase after thermal treatment at 500 °C; in contrast, nitric acid peptization led to a major rutile phase formation (67%). Interestingly, the sample peptized using sulfuric acid yielded 95% anatase and 5% rutile phases. The photocatalytic activity of synthesized TiO2 nanoparticles was evaluated for degradation of selected organic dyes (crystal violet, methylene blue, and p-nitrophenol) in aqueous solution. The results confirmed that the TiO2 sample peptized using nitric acid (with rutile and anatase phases in 3:1 ratio) offered the highest activity for degradation of organic dyes, although, TiO2 samples peptized using sulfuric acid and acetic acid possessed smaller particle size, higher band gap energy, and high surface area. Interestingly, TiO2 sample peptized with nitric acid possessed relatively high theoretical photocurrent density (0.545 mAcm-2) and pore diameter (150 Å), which are responsible for high electron-hole separation efficiency and diffusion and mass transportation of organic reactants during the photochemical degradation process. The superior activity of TiO2 sample peptized with nitric acid is due to the effective transfer of photogenerated electrons between rutile and anatase phases.

Utilising an innovative digital software to grade pre-clinical crown preparation exercise.

BACKGROUND: Accurate assessment of dental students' pre-clinical work is the most critical component of the dental education process. Thus, this study came to investigate the effectiveness of using technology in students' pre-clinical work evaluation; by comparing grades generated from a digital assessment software of a prepared tooth and a traditional visual inspection carried out by four calibrated faculty members. METHODS: Ninety-six teeth were prepared for a ceramo-metal crown by fourth year dental students. The four examiners and the digital grading software evaluated independently each preparation once. A random sample of 20 preparations were graded twice to assess intra-rater reliability. Inter-class correlation (ICC) was used to measure agreement among the four examiners, and between the examiners and the digital grading software. Paired student t-test was used to assess the accuracy of grades generated from visual inspection when compared to the digital grading system. RESULTS: Intra-rater reliability for examiners 1 and 2 were 0.73 and 0.78 and for the digital grading system was 0.99. The inter-rater reliability among the four examiners was very good, ICC of 0.76. However, the agreement between scores produced by the examiners and the digital system were mostly in the low to moderate range. The paired t-test demonstrated statistically significant differences between each examiner and the digital grading by 6-25 grades. CONCLUSIONS: This study demonstrates that the digital grading system used in this study can reliably scan and compare students' tooth preparations to a known gold standard. Results of this study suggests that using digital grading will preclude the variability and the subjectivity that usually result from the traditional visual inspection grading.

Direct formation of iron oxide/MCM-41 nanocomposites via single or mixed n-alkyltrimethylammonium bromide surfactants.

Iron oxide/MCM-41 nanocomposites, Fe(2)O(3)/MCM-41, containing 5%, 10%, and 20% (w/w) iron oxide, were prepared via a direct nonhydrothermal method at room temperature. The preparations were preformed by using iron(III) nitrate, tetra-ethoxysilane (TEOS), and cetyltrimethylammonium bromide (CTAB) mixed or unmixed with dodecyltrimethylammonium bromide (DTAB). The produced materials were dried and calcined at 550 °C for 3 h. Test materials were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), N(2) gas adsorption/desorption isotherms, small angle and wide angle X-ray diffraction (XRD). Results indicate that mixing of CTAB with DTAB does not harm the formation of blank MCM-41 structure. For the composite Fe(2)O(3)/MCM-41 materials, results showed formation of more stable MCM-41 structure with higher surface area and improved porosity in the presence of mixed (CTAB+DTAB) than in the presence of single (CTAB) surfactants for up to 10% Fe(2)O(3)/MCM-41 (w/w). This was explained in terms of the effect DTAB on contraction of the template micellar size to compensate for the expected size expansion upon the addition of ionic iron(III) nitrate precursor. Highly dispersed Fe(2)O(3) nanoparticles were formed in all cases even with the highest iron oxide percentage. Formation of the nanocomposites was postulated to be determined by fast nucleation and slow growth of iron oxide species, which facilitated formation of well dispersed iron oxide nanoparticles inside and on the wall of the MCM-41 material.

Prenatal nutrition among rural Bangladeshi pregnant women.

The expected outcome of pregnancy is a healthy mother with a healthy child. The single most important care which could prevent the negative outcomes of pregnancy is Antenatal Care (ANC). Proper and timely antenatal care can significantly reduce the risks of maternal mortality. In pregnancy, total cost is about 80,000 Kcal, and above normal energy requirements. To find out prenatal nutrition an exploratory study was carried out in seven villages of the Ward-2 of Jamtoil Union of Kamarkhand Upazila under Sirajganj District. Thirty pregnant women of different trimesters, gravida and parity had been studied employing the methods and techniques of "Ethnographic Field Work." Mean daily calorie consumption of the Key Informants (KIs) was 1480.49 Kcal without reference to their religious affiliation, family resource base, education, occupation, gravidity, parity and duration of pregnancy. This is indicated that the mean calorie intake of the Key Informants did not meet not only their prenatal nutritional need but also their requirement during pre-pregnancy period. It was observed that food intake was in no way different from that of the non-pregnant status. Antenatal care of rural inhabitants analyzed almost exclusively from biomedical perspectives, its cultural, socio-economic, gender, ecological and other relevant perspectives are mostly ignored. In order to have safe motherhood up through compliance of prenatal advice, nutritional one in particular, these factors should be taken into consideration.

Direct formation of thermally stabilized amorphous mesoporous Fe2O3/SiO2 nanocomposites by hydrolysis of aqueous iron III nitrate in sols of spherical silica particles.

Nanocomposite materials containing 10% and 20% iron oxide/silica, Fe2O3/SiO2 (w/w), were prepared by direct hydrolysis of aqueous iron III nitrate solution in sols of freshly prepared spherical silica particles (Stöber particles) present in their mother liquors. This was followed by aging, drying, calcination up to 600 degrees C through two different ramp rates, and then isothermal calcinations at 600 degrees C for 3 h. The calcined and the uncalcined (dried at 120 degrees C) composites were characterized by thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), N2 adsorption/desorption techniques, and scanning electron microscopy as required. XRD patterns of the calcined composites showed no line broadening at any d-spacing positions of iron oxide phases, thereby reflecting the amorphous nature of Fe2O3 in the composite. The calcined composites showed nitrogen adsorption isotherms characterizing type IV isotherms with high surface area. Moreover, surface area increased with the increasing of the iron oxide ratio and lowering of the calcination ramp rate. Results indicated that iron oxide particles were dispersed on the exterior of silica particles as isolated and/or aggregated nanoparticles. The formation of the title composite was discussed in terms of the hydrolysis and condensation mechanisms of the inorganic FeIII precursor in the silica sols. Thereby, fast nucleation and limited growth of hydrous iron oxide led to the formation of nanoparticles that spread interactively on the hydroxylated surface of spherical silica particles. Therefore, a nanostructured composite of amorphous nanoparticles of iron oxide (as a shell) spreading on the surface of silica particles (as a core) was formed. This morphology limited the aggregation of Fe2O3 nanoparticles, prevented silica particle coalescence at high temperatures, and enhanced thermal stability.

Synthesis and characterization of mesoporous ceria/alumina nanocomposite materials via mixing of the corresponding ceria and alumina gel precursors.

Mesoporous ceria/alumina, CeO(2)/Al(2)O(3), composites containing 10, 20 and 30% (w/w) ceria were prepared by a novel gel mixing method. In the method, ceria gel (formed via hydrolysis of ammonium cerium(IV) nitrate by aqueous ammonium carbonate solution) and alumina gel (formed via controlled hydrolysis of aluminum tri-isopropoxide) were mixed together. The mixed gel was subjected to subsequent drying and calcination for 3 h at 400, 600, 800 and 1000 degrees C. The uncalcined (dried at 110 degrees C) and the calcined composites were investigated by different techniques including TGA, DSC, FTIR, XRD, SEM and nitrogen adsorption/desorption isotherms. Results indicated that composites calcined for 3 h at 800 degrees C mainly kept amorphous alumina structure and gamma-alumina formed only upon calcinations at 1000 degrees C. On the other hand, CeO(2) was found to crystallize in the common ceria, cerinite, phase and it kept this structure over the entire calcination range (400-1000 degrees C). Therefore, high surface areas, stable surface textures, and non-aggregated nano-sized ceria dispersions were obtained. A systematic texture change based on ceria ratio was observed, however in all cases mesoporous composite materials exposing thermally stable texture and structure were obtained. The presented method produces composite ceria/alumina materials that suit different applications in the field of catalysis and membranes technology, and throw some light on physicochemical factors that determine textural morphology and thermal stability of such important composite.

Augmentation of partially regenerated nerves by end-to-side side-to-side grafting neurotization: experience based on eight late obstetric brachial plexus cases.

OBJECTIVE: The effect of end-to-side neurotization of partially regenerated recipient nerves on improving motor power in late obstetric brachial plexus lesions, so-called nerve augmentation, was investigated. METHODS: Eight cases aged 3-7 years were operated upon and followed up for 4 years (C5,6 rupture C7,8 T1 avulsion: 5; C5,6,7,8 rupture T1 avulsion: 1; C5,6,8 T1 rupture C7 avulsion: 1; C5,6,7 rupture C8 T1 compression: one 3 year presentation after former neurotization at 3 months). Grade 1-3 muscles were neurotized. Grade 0 muscles were neurotized, if the electromyogram showed scattered motor unit action potentials on voluntary contraction without interference pattern. Donor nerves included: the phrenic, accessory, descending and ascending loops of the ansa cervicalis, 3rd and 4th intercostals and contralateral C7. RESULTS: Superior proximal to distal regeneration was observed firstly. Differential regeneration of muscles supplied by the same nerve was observed secondly (superior supraspinatus to infraspinatus regeneration). Differential regeneration of antagonistic muscles was observed thirdly (superior biceps to triceps and pronator teres to supinator recovery). Differential regeneration of fibres within the same muscle was observed fourthly (superior anterior and middle to posterior deltoid regeneration). Differential regeneration of muscles having different preoperative motor powers was noted fifthly; improvement to Grade 3 or more occurred more in Grade 2 than in Grade 0 or Grade 1 muscles. Improvements of cocontractions and of shoulder, forearm and wrist deformities were noted sixthly. The shoulder, elbow and hand scores improved in 4 cases. LIMITATIONS: The sample size is small. Controls are necessary to rule out any natural improvement of the lesion. There is intra- and interobserver variability in testing muscle power and cocontractions. CONCLUSION: Nerve augmentation improves cocontractions and muscle power in the biceps, pectoral muscles, supraspinatus, anterior and lateral deltoids, triceps and in Grade 2 or more forearm muscles. As it is less expected to improve infraspinatus power, it should be associated with a humeral derotation osteotomy and tendon transfer. Function to non improving Grade 0 or 1 forearm muscles should be restored by muscle transplantation. LEVEL OF EVIDENCE: Level IV, prospective case series.

Formation and characterization of different ceria/silica composite materials via dispersion of ceria gel or soluble ceria precursors in silica sols.

Composite ceria/silica materials of 10 and 20% (w/w) were prepared by calcination, at 650 degrees C for 3 h, of the xerogels obtained by mixing the corresponding amount of a ceria precursor with freshly prepared sols of spherical silica particles (Stober particles) in their mother liquors. Two different ceria precursors were examined in this investigation. The first was a gel produced by the prehydrolysis of cerium(IV) isopropoxide in isopropanol medium, and the second was an aqueous solution of cerium(IV) ammonium nitrate. Different textural and morphological characteristics that developed by calcination were investigated by TGA, FTIR, XRD, SEM, and analyses of N2 adsorption isotherms. The results indicated that ceria dispersion and formation of mesoporous textural composite materials produced by the second precursor, cerium(IV) ammonium nitrate, are better than those produced by the first precursor, prehydrolyzed cerium(IV) isopropoxide. The results are discussed in terms of the effect of precursors and mixing media on nucleation and growth of ceria particles and their protection from sintering on calcination at the test temperature.

The role of Rho GTPases in the regulation of the rearrangement of actin cytoskeleton and cell movement.

The rearrangement of the actin cytoskeleton has been shown to play a critical role in the development of transformation and malignant phenotype of cancer cells. Rho family GTPases regulate the arrangement of the actin cytoskeleton. By wound-healing assay, we have found that NIH 3T3 fibroblast cells move towards the wound- gaps by extending filopodial and lamellipdial structures at the leading edge of the moving cells. We have inactivated the function of Rho GTPases of v-Ras transformed NIH 3T3 cells by overexpressing Rho GTPase-activating (RhoGAP) domain of RhoGAP of p190. We have observed that inactivation of Rho, Rac and Cdc42 GTPases by overexpressing RHG causes inhibition of: (i) polymerization of actin to form filaments, (ii) formation of lamellipodia, filopodia and stress fibres, (iii) cell motility, (iv) cell spreading and (v) cell-to-cell adhesions. These results further strengthen the current knowledge on the role of Rho, Rac and Cdc42 GTPases in the regulation of the rearrangement of actin cytoskeleton. Our results, for the first time, demonstrate that RhoGAP domain of RhoGAP could be used to study the molecular mechanism of Ras-mediated signalling in growth, differentiation and carcinogenesis.

Formation and characterization of high surface area thermally stabilized titania/silica composite materials via hydrolysis of titanium(IV) tetra-isopropoxide in sols of spherical silica particles.

A direct synthetic route leading to titania particles dispersed on nonporous spherical silica particles has been investigated; 5, 10, and 20% (w/w) titania/silica sols mixtures were achieved via hydrolyzation of titanium tetra-isopropxide solution in the mother liquor of a freshly prepared sol of spherical silica particles (Stöber particles). Titania/silica materials were produced by subsequent drying and calcination of the xerogels so obtained for 3 h at 400 and 600 degrees C. The materials were investigated by means of thermal analyses (TGA and DSC), FT-IR, N(2) gas adsorption-desorption, powder X-ray diffraction (XRD), and transmission electron microscopy (TEM). In spite of the low surface area (13.1 m(2)/g) of the pure spherical silica particles calcined at 400 degrees C, high surface area and mesoporous texture titania/silica materials were obtained (e.g., S(BET) ca. 293 m(2)/g for the 10% titania/silica calcined at 400 degrees C). Moreover, the materials were shown to be amorphous toward XRD up to 600 degrees C, while reasonable surface areas were preserved. It has been concluded that dispersion of titania particles onto the surface of the nonporous spherical silica particles increase their roughness, therefore leading to composite materials of less firm packing and mesoporosity.

Identification of a neurite outgrowth-promoting motif within the alternatively spliced region of human tenascin-C.

Our work centers on understanding how the extracellular matrix molecule tenascin-C regulates neuronal growth. We have found that the region of tenascin-C containing only alternately spliced fibronectin type-III repeat D, called fnD, when used by itself, dramatically increases neurite outgrowth in culture. We used overlapping synthetic peptides to localize the neurite outgrowth-promoting site within fnD to a 15 amino acid sequence, called D5. An antibody against D5 blocked promotion of neurite outgrowth by fnD as well as tenascin-C, indicating that this peptide sequence is functional in the context of the native molecule. Further testing of shorter synthetic peptides restricted the neurite outgrowth-promoting site to eight amino acids, VFDNFVLK. Of these, "FD" and "FV" are conserved in tenascin-C sequences derived from all the species available in the GenBank. To investigate the hypothesis that FD and FV are critical for the interaction with neurons, we tested a recombinant fnD protein and synthetic peptides with alterations in FD and/or FV. These molecules did not facilitate process extension, suggesting that the conserved amino acids are required for formation of the active site in fnD. We next investigated whether VFDNFVLK could be used as a reagent to overcome the neurite outgrowth inhibitory properties of chondroitin sulfate proteoglycans, the major inhibitory molecules in the glial scar. The peptide significantly enhanced outgrowth on proteoglycans and was more effective than laminin-1, L1-Fc, or intact tenascin-C, thus demonstrating the potential applicability of tenascin-C regions as therapeutic reagents.

Differential requirement for Rho family GTPases in an oncogenic insulin-like growth factor-I receptor-induced cell transformation.

Insulin-like growth factor I receptor (IGFR) plays an important role in cell growth and transformation. We dissected the downstream signaling pathways of an oncogenic variant of IGFR, Gag-IGFR, called NM1. Loss of function mutants of NM1, Phe-1136 and dS2, that retain kinase activity but are attenuated in their transforming ability were used to identify signaling pathways that are important for transformation of NIH 3T3 cells. MAPK, phospholipase C gamma, and Stat3 were activated to the same extent by NM1 and its two mutants, suggesting that activation of these pathways, individually or in combination, was not sufficient for NM1-induced cell transformation. The mutant dS2 has decreased IRS-1 phosphorylation levels and IRS-1-associated phosphatidylinositol 3'-kinase activity, suggesting that this impairment may be in part responsible for the defectiveness of dS2. We show that Rho family members, RhoA, Rac1, and Cdc42 are activated by NM1, and this activation, particularly RhoA and Cdc42, is attenuated in both mutants of NM1. Dominant negative mutants of Rho, Rac, and Cdc42 inhibited NM1-induced cell transformation, as measured by focus and colony forming ability. Dominant negative Rho most potently inhibited the focus forming activity, whereas Cdc42 was most effective in inhibiting the colony forming ability of NM1-expressing cells. Conversely, constitutively activated (ca) Rho is more effective than ca Rac or ca Cdc42 in rescuing the focus forming ability of the mutants. By contrast, ca Cdc42 is most effective in rescuing the colony forming ability of both mutants.

Serum-dependent perinuclear accumulation of Cdc42 in mammalian cells.

Cdc42 is a member of the Rho family of GTPase. Cdc42 has been implicated to be involved in the movement, multiplication and transformation of mammalian cells by controlling the rearrangement of actin cytoskeleton and gene expression. But the mechanism of Cdc42 function has not yet been discovered. In this report we present data showing a perinuclear accumulation of Cdc42 in response to fetal bovine serum (FBS). There was no change in the amount of Cdc42 in response to FBS in the cell. It was found that protein component(s) of serum plays a major role in the perinuclear accumulation of Cdc42. Epidermal growth factor has also been found to stimulate the perinuclear accumulation of Cdc42 while NGF has no effect. Kinase inhibitors, quercetin and NDGA were found to block signals for the perinuclear accumulation of Cdc42. This suggests that phosphorylation of cellular proteins is essential for transducing signals generated from the serum component(s) to induce the perinuclear accumulation of Cdc42. These results indicate that redistribution of Cdc42 might be an important step in alteration of gene expression for controlling various functions of the cell including cell division.

Proto-oncogene ras GTPase-linked induction of glutathione-S-transferase by growth factors in PC12 cells.

This report provides evidence linking activation of Ras GTPase by growth factors and induction of glutathione-S-transferase isozymes in PC12 cells. Ras GTPase was activated by EGF, NGF, insulin and phorbolester in PC12 cells. Activation of Ras GTPase was found to be associated with induction of the expression of GST mu and pi isoenzymes while there was no detectable induction of GST alpha expression. GST pi was found to be induced by all the Ras GTPase activating agents tested while activation of Ras by phorbolester and insulin induced expression of GST mu only. These results suggest a role of Ras, at least in part, in controlling the expression of GST and that there might be independent signalling pathways for the expression of different GST isoenzymes. GST activity was found to be very high (4-fold) in the lysate obtained from retinoic acid treated PC12 cells when compared with untreated cells. Induction of GST expression was found to be initiated within 30 min of retinoic acid treatment in PC12 cells reaching a maximum level at 4 h. However, immunoblot analysis showed that retinoic acid (RA), unlike mitogens/growth factors, weakly induced the expression of GST pi but not the expression of alpha, mu and microsomal GSTs. Overxpression of inhibitory polypeptides that block signals generated from Ras and Cdc42 was found to reverse the retinoic acid activation-dependent induction of GST expression in PC12 cells. These results provide evidence for the first time suggesting a novel role of Ras GTPase in the regulation of GST expression which might have a significant implication in developing drug resistance and/or growth of cancer cells.

Tenascin-C contains domains that independently regulate neurite outgrowth and neurite guidance.

Tenascin-C has been implicated in regulation of both neurite outgrowth and neurite guidance. We have shown previously that a particular region of tenascin-C has powerful neurite outgrowth-promoting actions in vitro. This region consists of the alternatively spliced fibronectin type-III (FN-III) repeats A-D and is abbreviated fnA-D. The purpose of this study was to investigate whether fnA-D also provides neurite guidance cues and whether the same or different sequences mediate outgrowth and guidance. We developed an assay to quantify neurite behavior at sharp substrate boundaries and found that neurites demonstrated a strong preference for fnA-D when given a choice at a poly-L-lysine-fnA-D interface, even when fnA-D was intermingled with otherwise repellant molecules. Furthermore, neurites preferred cells that overexpressed the largest but not the smallest tenascin-C splice variant when given a choice between control cells and cells transfected with tenascin-C. The permissive guidance cues of large tenascin-C expressed by cells were mapped to fnA-D. Using a combination of recombinant proteins corresponding to specific alternatively spliced FN-III domains and monoclonal antibodies against neurite outgrowth-promoting sites, we demonstrated that neurite outgrowth and guidance were facilitated by distinct sequences within fnA-D. Hence, neurite outgrowth and neurite guidance mediated by the alternatively spliced region of tenascin-C are separable events that can be independently regulated.

The CDC42-specific inhibitor derived from ACK-1 blocks v-Ha-Ras-induced transformation.

Based on the previous experiments with the N17 mutant of CDC42, it has been speculated, but not proved as yet, that CDC42 is required for Ras-induced malignant transformation of fibroblasts. However, since this inhibitor could sequester many GDP-dissociation stimulators (GDSs), such as DBL, OST and Tiam-1 which activate not only CDC42, but also Rho or Rac, in fact it is not a specific inhibitor that inactivates only CDC42. Thus, we have taken the minimum CDC42-binding domain (residues 504 - 545, called ACK42) of the Tyr-kinase ACK-1 that binds only CDC42 in the GTP-bound form, and thereby blocking the interactions of CDC42-GTP with its downstream effectors such as ACKs, PAKs and N-WASP. First of all, using the ACK42-GST fusion protein as a specific ligand for the GTP-CDC42 complex, we have revealed that CDC42 is activated by oncogenic Ras mutants such as v-Ha-Ras in NIH3T3 fibroblasts, and similarly in PC12 cells by both NGF (Nerve Growth Factor) and EGF (Epidermal Growth Factor) which activate the endogenous normal Ras, providing the first direct evidence that CDC42 acts downstream of Ras and NGF/EGF. Furthermore, over-expression of ACK42 completely reversed Ras-induced malignant phenotypes such as focus formation and anchorage/serum-independent growth of the fibroblasts, and a cell-permeable derivative of ACK42 called WR-ACK42 strongly inhibited the growth of Ras transformants, with little effect on the parental normal cell growth, and also abolished Ras-induced filopodium/microspike formation of the fibroblasts which is CDC42-dependent. These observations unambiguously proved for the first time that the RAS-induced activation of CDC42 is indeed essential for Ras to transform the fibroblasts, and furthermore suggest that ACK42 or its peptidomimetics are potentially useful for genotherapy or chemotherapy of Ras-associated cancer.

Inhibition of rotavirus infection in vitro and in vivo by a synthetic peptide from VP4.

A synthetic peptide corresponding to bovine rotavirus C486 (BRV) VP4 amino acid sequence 232-255 (VP4-peptide) was studied with the objective of defining the origin of the protective immune response reported previously by Ijaz et al. (J. Virol. 1991, 65, 3106-3113). Pretreatment of MA-104 cells with the VP4-peptide before infection with rotavirus prevented both the attachment of 35S-labelled virus and plaque formation in vitro. In vivo studies using a murine rotavirus model demonstrated that intragastric administration of VP4-peptide protected subjects from challenge with virulent rotavirus. These results clearly indicate the importance of this epitope in virus-cell interactions and their potential as a rotavirus vaccine candidate.