Critical Study on Rotational Flow of a Fractional Oldroyd-B Fluid Induced by a Circular Cylinder

We considered the unsteady flow of a fractional Oldroyd-B fluid through an infinite circular cylinder with the help of infinite Hankel and Laplace transforms. The motion of the fluid is produced by the cylinder that, at time t=0+ is subject to a time-dependent angular velocity. The established solutions have been presented under series form in terms of the generalized G functions satisfy all imposed initial and boundary conditions. The corresponding solutions for ordinary Oldroyd-B, ordinary and fractional Maxwell, ordinary and fractional second-grade, and Newtonian fluids, performing the same motion, are acquired as limiting cases of general solutions. The keynote points regarding this work to mention are that (1) we extracted the expressions for velocity field and shear stress corresponding to the motion of fractional second-grade fluid as a limiting case of general solutions; (2) the expressions for velocity field and shear stress are in the most simplified form in contrast with the studies of Siddique and Sajid (2011), in which the expression for the velocity field involves the convolution product as well as the integral of the product of generalized G functions. Finally, numerical results are presented graphically and discussed in order to reveal some physical aspects of obtained results.

Exact Solutions for the Axial Couette Flow of a Fractional Maxwell Fluid in an Annulus

The velocity field and the adequate shear stress corresponding to the rotational flow of a fractional Maxwell fluid, between two infinite coaxial circular cylinders, are determined by applying the Laplace and finite Hankel transforms. The solutions that have been obtained are presented in terms of generalized Ga,b,c(·,t) and Ra,b(·,t) functions. Moreover, these solutions satisfy both the governing differential equations and all imposed initial and boundary conditions. The corresponding solutions for ordinary Maxwell and Newtonian fluids are obtained as limiting cases of our general solutions. Finally, the influence of the material parameters on the velocity and shear stress of the fluid is analyzed by graphical illustrations.

D-Limonene modulates inflammation, oxidative stress and Ras-ERK pathway to inhibit murine skin tumorigenesis

D-Limonene, a common monoterepene has been shown to have antiproliferative, apoptosis-inducing and chemopreventive effects. In the present study, we have investigated the effects of D-limonene on the growth of 7,12-dimethylbenz[a]anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor development. We found that D-limonene (50 and 100 mg/kg body weight) treatments to the mouse skin significantly reduced the TPA-induced (a) edema and hyperplasia (p < 0.001); (b) expression of cyclooxygenase-2; (c) ornithine decarboxylase activity (p < 0.001); and (d) [(3)H] thymidine incorporation into DNA (p < 0.001). In addition, treatment of D-limonene effectively restored the level of reduced glutathione, glutathione peroxidase, glutathione reductase, glutathione S-transferase, catalase and malondialdehyde production in TPA-treated mouse skin. In a two-stage skin tumorigenesis study, D-limonene significantly reduced the tumor burden (p < 0.005) and tumor incidence as compared to DMBA/TPA-treated mice. D-Limonene treatment also extended the latency period of tumor development from 4 to 9 weeks. D-Limonene treatment decreased the expression level of Ras, Raf and phosphorylation of extracellular signal-regulated protein kinase 1/2 in DMBA/TPA-induced tumors. A decrease in the expression of Bcl-2 and an increase in Bax expression were also observed in tumor tissues of mice treated with D-limonene. Taken together, our findings suggest that D-limonene may exert its chemopreventive activity through the inhibition of inflammation, oxidative stress and Ras-signaling as well as the induction of pro-apoptotic state during TPA-mediated promotion of DMBA-induced skin cancer in mouse model.

Exact solutions for unsteady axial Couette flow of a fractional Maxwell fluid due to an accelerated shear

The velocity field and the adequate shear stress corresponding to the flow of a fractional Maxwell fluid (FMF) between two infinite coaxial cylinders, are determined by means of the Laplace and finite Hankel transforms. The motion is produced by the inner cylinder that at time t = 0+ applies a shear stress fta (a ≥ 0) to the fluid. The solutions that have been obtained, presented under series form in terms of the generalized G and R functions, satisfy all imposed initial and boundary conditions. Similar solutions for ordinary Maxwell and Newtonian fluids are obtained as special cases of general solutions. The unsteady solutions corresponding to a = 1, 2, 3, ... can be written as simple or multiple integrals of similar solutions for a = 0 and we extend this for any positive real number a expressing in fractional integration. Furthermore, for a = 0, 1 and 2, the solutions corresponding to Maxwell fluid compared graphically with the solutions obtained in [1–3], earlier by a different technique. For a = 0 and 1 the unsteady motion of a Maxwell fluid, as well as that of a Newtonian fluid ultimately becomes steady and the required time to reach the steady-state is graphically established. Finally a comparison between the motions of FMF and Maxwell fluid is underlined by graphical illustrations.

Taylor–Couette flow of a fractional second grade fluid in an annulus due to a time-dependent couple

Exact solutions for the velocity field and the associated shear stress, corresponding to the flow of a fractional second grade fluid between two infinite coaxial cylinders, are determined by means of Laplace and finite Hankel transforms. The motion is produced by the inner cylinder which is rotating about its axis due to a time-dependent torque per unit length 2πR1ft2. The solutions that have been obtained satisfy all imposed initial and boundary conditions. For β → 1, respectively β → 1 and α1 → 0, the corresponding solutions for ordinary second grade fluids and Newtonian fluids, performing the same motion, are obtained as limiting cases.

Exact solutions for the unsteady rotational flow of a generalized second grade fluid through a circular cylinder

Here the velocity field and the associated tangential stress corresponding to the rotational flow of a generalized second grade fluid within an infinite circular cylinder are determined by means of the Laplace and finite Hankel transforms. At time t = 0 the fluid is at rest and the motion is produced by the rotation of the cylinder around its axis with a time dependent angular velocity Ωt. The solutions that have been obtained are presented under series form in terms of the generalized G-functions. The similar solutions for the ordinary second grade and Newtonian fluids, performing the same motion, are obtained as special cases of our general solution.

Taylor–Couette flow of a generalized second grade fluid due to a constant couple

The velocity field and the adequate shear stress, corresponding to the flow of a generalized second grade fluid in an annular region between two infinite coaxial cylinders, are determined by means of Laplace and finite Hankel transforms. The motion is produced by the inner cylinder which is rotating about its axis due to a constant torque f per unit length. The solutions that have been obtained satisfy all imposed initial and boundary conditions. For β → 1 or β → 1 and α1 → 0, the corresponding solutions for an ordinary second grade fluid, respectively, for the Newtonian fluid, performing the same motion, are obtained as limiting cases.

The incidence and impact of comorbidity on survival and selection of initial treatment in elderly patients (pts) with head and neck cancer (HNC)

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Background: Comorbidity has been shown to be a determinant of survival and treatment selection in various cancers including HNC. Higher comorbidity index is associated with higher utilization of non-curative intent treatment. Methods: In this retrospective study we analyzed 182 consecutively treated HNC pts >65 years (y) old at the Dallas VAMC from January 2000 through June 2007. Comorbidity was assessed with the Charlson Comorbidity Index (CCI). Treatment was classified as curative intent versus non-curative intent. The goals were 1) to demonstrate burden of comorbidity and 2) to demonstrate the impact of comorbidity on overall survival and selection of initial treatment in elderly HNC pts. Results: Pts characteristics: 100% male; 80% white, 19.5% Black, 0.5% Hispanic; median age 72y (range 65–87); 3% stage 0, 26% stage I, 20% stage II, 18% stage III, 30% stage IV, 2% unknown; primary site - 30% oral cavity, 4% hypopharnyx, 22% oropharynx, 38% larynx, 4% other, 1% unknown; treatment - 26% radiation only, 44% surgery (S), 21% chemoradiation (CR), 9% no treatment; Median CCI -2 (range 0–11); 61% had CCI score 0–2 and 39% had CI score > 3. Median overall survival was 883 days (SE 19.31 days). Rate of curative vs. non-curative intent treatment was 80% vs. 20% respectively. Pts with CCI score 0–2 had a non-significant higher rate of curative intent treatment than pts with CCI score > 3 (83.8% vs. 74.6% p = 0.13). In multivariate analysis including CCI, age, race, alcohol use, primary site, treatment, and stage, only advanced clinical stage had significant prognostic importance (HR 1.66; 95% CI, 1.29 to 2.14; p < 0.0005). The HR for CCI was 1.11 (95% CI, .99–1.24; p = 0.08). In separate multivariate analyses of pts treated with S and pts treated with CR, CCI was not a significant predictor of survival with HR of .88 (95% CI, .69–1.11; p = 0.29) and 1.13 (95% CI, .83–1.53; p = 0.44), respectively. Conclusions: In our population of elderly HNC pts, CCI and age had no significant impact on survival or selection of curative intent treatment. Additional study is required to better define appropriate candidates for curative intent treatment in this population.

No significant financial relationships to disclose.

An endophytic Neurospora sp. from Nothapodytes foetida producing camptothecin

The medicinal plant, Nothapodytes foetida contains a number of important alkaloids like camptothecin (an anticancer drug molecule) but its concentration is less to meet the existing demand of this important molecule, so in an effort for accessible availability of camptothecin. An endophyte (designated ZP5SE) was isolated from the seed of Nothapodytes foetida and was examined as potential source of anticancer drug lead compound i.e. camptothecin, when grown in Sabouraud liquid culture media under shake flask conditions. The presence of anticancer compound (camptothecin) in this fungus was confirmed by chromatographic and spectroscopic methods in comparison with authentic camptothecin. Isolated endophyte (Neurospora crassa) producing camptothecin may become an easily accessible source for the production of precursor anticancer drug molecule in future at large scale.

Effect of pre-treatment of almond oil on ultraviolet B?induced cutaneous photoaging in mice

BACKGROUND

Ultraviolet (UV) radiation has been implicated in photoaging and various types of skin carcinomas. Although the human skin has evolved several defense mechanisms to survive the insults of actinic damage like keratinization, melanin pigmentation, etc., it is still subjected to the harmful effects of sunlight.

AIMS

In this study, the role of almond oil in reducing the degradative changes induced in skin upon exposure to UV radiation was investigated.

METHODS

Mice were divided in four groups of 20 animals. Group I was the control group. Group II was negative control, which received almond oil treatment alone. Group III was exposed to UV radiation only and Group IV received both UV treatment and almond oil treatment. Visible skin grading assessed the changes based on a rating scale, biochemical tests (glutathione estimation and lipid peroxidation), and histopathologic studies.

RESULTS

Upon exposure of mice to UV radiation, it was found that pronounced visible skin changes were seen after 12 weeks of exposure. The results of the biochemical tests, glutathione estimation, and lipid peroxidation showed that almond oil reduced the effect of UV light-induced photoaging on the skin. Histopathologic studies also indicated a photoprotective effect of almond oil on the skin after UV exposure.

CONCLUSIONS

It was concluded that topical almond oil is capable of preventing the structural damage caused by UV irradiation and it was also found useful in decelerating the photoaging process.

A preliminary passive surveillance of clinical diseases of cart pulling camels in Faisalabad metropolis (Pakistan)

We identified clinical disorders of all 200 city-dwelling cart pulling male camels attending the Veterinary Teaching Hospital, University of Agriculture, Faisalabad, Pakistan during a 7-year period (1993-1999). Data were collected prospectively on a predesigned form and collated. Diagnoses of different diseases/disorders were based on clinical examination supplemented with relevant laboratory tests. A total of 463 entries of 34 different clinical diseases/disorders were recorded. Sarcoptic mange (35% of 200 camels) followed by anhidrosis (23%) and trypanosomosis (19%) were the three most frequently encountered disorders. The body system most often involved was the integument (31%) followed by gastrointestinal (21%), locomotory (12%), thermoregulatory (6%), blood (6%), urogenital (6%), lymphatic (3%), nervous (3%), respiratory (3%) and ocular (3%).

Augmentation and proliferation of T lymphocytes and Th-1 cytokines by Withania somnifera in stressed mice

Stress has been associated with reports of both greater severity and prolongation of diseases in patients with the infectious origin as well as other immune-mediated diseases. Withania somnifera, an Indian medicinal plant used widely in the treatment of many clinical conditions in India, was investigated for its anti-stress properties using BALB/c mice subjected to chronic stress. The study aimed to investigate chronic stress-induced alterations on Th1 lymphocyte subset distribution and corresponding cytokine secretion patterns. Oral administration of chemically standardized and identified aqueous fraction of W. somnifera root (WS) at the graded doses of 25, 50, 100 and 200 mg/kg p.o. caused significant increase in the stress-induced depleted T-cell population and increased the expression of Th1 cytokines in chronically stressed mice.

Ethnoveterinary practices of owners of pneumatic-cart pulling camels in Faisalabad City (Pakistan)

The present study was planned to investigate the ethnoveterinary methods practiced by the owners of pneumatic-cart pulling camels in Faisalabad Metropolis (Pakistan). During a 7-year-period (November 1992-November 1999), 200 owners of draught camels working in the city were interviewed. Information concerning the ethnoveterinary practices for the treatment of common disorders of digestive tract (indigestion, colic and diarrhea), respiratory tract (cold/rhinitis, pneumonia), skin problems (mange, ulceration of nostrils with or without nasal myiasis, ticks and lice, harness sores), systemic states (fever, ze/rba/d, anhidrosis) and preventive therapy of indigestion and halitosis was collected through interviews and collated with those documented for the treatment of desert-dwelling camels. Familiarity of owners with two traditional methods of surra (trypanosomiasis) diagnosis ('Sand-ball test' and 'Hair-stick test') known to pastorilists was also probed. In addition, the dose and frequency of use of common salt was investigated. Traditional inputs utilized by the camel owners included various plant products, insecticides, sulphur, sump oil, common salt, aspirin, naphthalene balls and milk fat. Different owners used different combinations of traditional drugs for the treatment of disorders/conditions investigated. None of the camel owners was found familiar with the 'Sand-ball test' or 'Hair-stick test' of trypanosomiasis diagnosis. For the prevention of indigestion and halitosis all camel owners had practiced administration of 'massaulas' (physic drench/balls) along with common salt (average 250 g) on weekly basis. Firing had not been used by any owner. In general, the ethnoveterinary treatment practices used by the owners of city-dwelling camels appear to be different from those documented for the treatment of diseases of desert-dwelling camels.

Nimbidin suppresses functions of macrophages and neutrophils: relevance to its antiinflammatory mechanisms

Nimbidin is a mixture of tetranortriterpenes and is the major active principle of the seed oil of Azadirachta indica A. Juss (Meliaceae) possessing potent antiinflammatory and antiarthritic activities. The present study revealed that nimbidin significantly inhibited some of the functions of macrophages and neutrophils relevant to the inflammatory response following both in vivo and in vitro exposure. Oral administration of 5-25 mg/kg nimbidin to rats for 3 consecutive days significantly inhibited the migration of macrophages to their peritoneal cavities in response to inflammatory stimuli and also inhibited phagocytosis and phorbol-12-myristate-13-acetate (PMA) stimulated respiratory burst in these cells. In vitro exposure of rat peritoneal macrophages to nimbidin also inhibited phagocytosis and PMA stimulated respiratory burst in these cells. Nimbidin also inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS) stimulated macrophages following in vitro exposure, whereas interleukin 1 (IL-1) was only weakly inhibited. Probing the mechanism of NO inhibition revealed that nimbidin ameliorated the induction of inducible NO synthase (iNOS) without any inhibition in its catalytic activity. In addition, nimbidin also attenuated degranulation in neutrophils assessed in terms of release of beta-glucuronidase, myeloperoxidase and lysozyme. The results suggest that nimbidin suppresses the functions of macrophages and neutrophils relevant to inflammation. Thus nimbidin can be valuable in treating inflammation/inflammatory diseases.

Host-pathogen interactions during apoptosis

Host pathogen interaction results in a variety of responses, which include phagocytosis of the pathogen, release of cytokines, secretion of toxins, as well as production of reactive oxygen species (ROS). Recent studies have shown that many pathogens exert control on the processes that regulate apoptosis in the host. The induction of apoptosis upon infection results from a complex interaction of parasite proteins with cellular host proteins. Abrogation of host cell apoptosis is often beneficial for the pathogen and results in a successful host invasion. However, in some cases, it has been shown that induction of apoptosis in the infected cells significantly imparts protection to the host from the pathogen. There is a strong correlation between apoptosis and the host protein translation machinery: the pathogen makes all possible efforts to modify this process so as to inhibit cell suicide and ensure that it can survive and, in some cases, establish latent infection. This review discusses the significance of various pathways/steps during virus-mediated modulation of host cell apoptosis.

Low iron state is associated with reduced tumor promotion in a two-stage mouse skin carcinogenesis model

The purpose of this study was to investigate the effect of low iron state in a two-stage mouse skin carcinogenesis model using 7,12-dimethylbenz[a]anthracene (DMBA)-initiated and benzoyl peroxide (BPO)-promoted cutaneous tumorigenesis. All mice were treated with DMBA. Low iron state was achieved by injection with phenylhydrazine hydrochloride and feeding low iron diet. A low iron state resulted in a decrease in tumor incidence (papillomas and carcinomas) and number of tumors/mouse. Also, the conversion of papillomas to carcinomas was lower in mice on a low iron state. BPO treatment enhanced epidermal lipid peroxidation (LPO) and was accompanied by a depletion in the level of epidermal reduced glutathione (GSH) and decrease in the activities of antioxidant enzymes. BPO treatment also increased ornithine decarboxylase (ODC) activity and [3H]thymidine incorporation into cutaneous DNA. Mice in a low iron state were less susceptible to the effects of BPO treatment, as was apparent from a partial recovery of GSH levels and the activities of antioxidant enzymes, as well as a lower induction in ODC activity, [3H]thymidine incorporation into cutaneous DNA and lesser epidermal LPO. As expected, cutaneous iron levels were lower in mice on a low iron state. Thus, our data show that the tumor-promoting potential of BPO is reduced by low iron state in a two-stage mouse skin carcinogenesis model.