Johne's disease is a chronic enteric disease characterized by intermittent diarrhea, weight loss ... more Johne's disease is a chronic enteric disease characterized by intermittent diarrhea, weight loss and death. The causative agent of Johne's disease is Mycobacterium avium subsp. paratuberculosis (MAP), an intracellular pathogen that resides and replicates within the phagosome of nonactive macrophages (Hostetter et al., 2002). Activation of macrophages by treatment with recombinant IFN-g and LPS has resulted in increased acidification and maturation of phagosomes and a decrease in the number of viable MAP within macrophages (Hostetter et al., 2002). Further,
Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available e... more Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available essential oil (EO) blends and characterize the effect on the expression of some virulence genes against methicillin-resistant Staphylococcus aureus (MRSA). Materials and Methods: In vitro evaluation of the antimicrobial effects of oils against MRSA was performed using the disk diffusion method and by measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The EOs (A-F) were contained (β-pinene, carvacrol, carvone, dimethyl trisulfide, linalool, limonene, menthol, monoterpene hydrocarbons, and thymol) in different amounts. In addition, a real-time polymerase chain reaction was also used to determine the gene expression of the virulence genes (intercellular adhesion cluster [ica]-9, ica-15, and RNA III) against MRSA (ATCC 43300) after treatment with selected oils. Results: Among the eight EOs evaluated, EO (D), (E), and (A) showed, in general, ...
Background and Aim: Middle East respiratory syndrome coronavirus (MERS-CoV) has rapidly spread th... more Background and Aim: Middle East respiratory syndrome coronavirus (MERS-CoV) has rapidly spread throughout the Middle East since its discovery in 2012. The virus poses a significant global public health threat with potentially devastating effects. In this study, a recombinant adenoviral-based vaccine encoding the spike 1 (S1) subunit of the MERS-CoV genome was constructed, and its humoral, and cellular immune responses were evaluated in mice. Materials and Methods: Mice were immunized initially by intramuscular injection and boosted 3 weeks later by intranasal application. Expression of the S1 protein in the lungs and kidneys was detected using conventional polymerase chain reaction (PCR) and immunohistochemistry (IHC) targeting specific regions within the S1 subunit at weeks 3, 4, 5, and 6 after the first vaccination. Antigen-specific humoral and cellular immune responses were evaluated in serum and in cell culture following in vitro stimulation with a specific 9-mer epitope within ...
Liposomes were evaluated as an alternative carrier to deliver inactivated Newcastle disease virus... more Liposomes were evaluated as an alternative carrier to deliver inactivated Newcastle disease virus (NDV). The ability of a liposomal-based NDV vaccine to activate both cell-mediated immunity (CMI) and humoral immunity against NDV was assessed and compared with conventional NDV vaccines. Birds were assigned to 4 groups and received either no vaccine (control), NDV entrapped into liposomes (LN-NDV), NDV with oil adjuvant (oil-NDV), or live attenuated NDV (live-NDV). All birds were stimulated after 40 days of vaccination in vivo by an intravenous injection of inactivated NDV crude antigen, which is considered an in vivo NDV-specific stimulation of the chicken immune system. After vaccination and in vivo stimulation, serum samples were collected for NDV-specific antibody response evaluation by a hemagglutination inhibition test (HI) and an enzyme-linked immune sorbent assay (ELISA). The CMI and humoral immunity were evaluated by a measurement of the chicken interferon gamma and specific ...
Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available e... more Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available essential oil (EO) blends and characterize the effect on the expression of some virulence genes against methicillin-resistant Staphylococcus aureus (MRSA). Materials and Methods: In vitro evaluation of the antimicrobial effects of oils against MRSA was performed using the disk diffusion method and by measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The EOs (A-F) were contained (β-pinene, carvacrol, carvone, dimethyl trisulfide, linalool, limonene, menthol, monoterpene hydrocarbons, and thymol) in different amounts. In addition, a real-time polymerase chain reaction was also used to determine the gene expression of the virulence genes (intercellular adhesion cluster [ica]-9, ica-15, and RNA III) against MRSA (ATCC 43300) after treatment with selected oils. Results: Among the eight EOs evaluated, EO (D), (E), and (A) showed, in general, ...
The effect of tilmicosin, florfenicol, or enrofloxacin on humoral and cell-mediated immune respon... more The effect of tilmicosin, florfenicol, or enrofloxacin on humoral and cell-mediated immune response induced by Newcastle disease (ND) vaccination was evaluated in 20-wk-old specific-pathogen-free layer chickens. Humoral immunity was measured by detection of ND virus (NDV) antibody titer and anti-NDV IgG response using the hemagglutination inhibition (HI) test and ELISA, respectively, whereas cell-mediated immunity was evaluated by measurement of chicken interferon gamma (ChIFN-gamma) produced in splenocytes cell culture stimulated with concanavalin A, inactivated NDV antigen, or live attenuated La Sota strain using ELISA. Florfenicol hampered the ND antibody production measured by both HI and ELISA. Tilmicosin and enrofloxacin reduced the production of ND antibody in the first 3 wk after the last ND vaccination measured by HI test, which suggests that these antibiotics exert their effect mainly on the IgM isotype. The ND-vaccinated, but not treated group, showed an increase in ChIFN-gamma production after NDV antigen-specific stimulation above the nonstimulated cell culture, whereas this effect was masked in all the antibiotic-treated groups due to the stronger ChIFN-gamma production background value reported in the nonstimulated cell culture. In conclusion, our results showed, for the first time, that tilmicosin, florfenicol, or enrofloxacin reduced the humoral immune response and had beneficial effects on the cell-mediated immune response. In addition, we demonstrated that the combination of both inactivated and attenuated ND vaccine gave a strong immune response at both the humoral and cellular level.
European journal of pediatric surgery : official journal of Austrian Association of Pediatric Surgery ... [et al] = Zeitschrift für Kinderchirurgie, 2006
Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur pred... more Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur predominantly in young women, with very few cases reported in men. While the origin of the tumor may be unclear, it is characterized by a distinct histological appearance and a clinical course highlighting its low malignant potential. SPNP have an excellent prognosis and are potentially curable provided they are managed appropriately by complete surgical resection. In the rare instances where metastatic disease is encountered, surgical debulking has been shown to prolong survival. The role of chemotherapy and radiation therapy in the management of SPNP is still controversial. We report here on an unusual occurrence of SPNP in the area of the head of the pancreas in a 12-year-old female treated by pancreatico-duodenectomy, together with a review of the literature.
Johne's disease progresses through distinct stages including a protracted subclinical stage in wh... more Johne's disease progresses through distinct stages including a protracted subclinical stage in which the infection appears to be controlled; followed by a more acute stage in which the host animal demonstrates clinical signs such as diarrhea and weight loss.
Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur pred... more Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur predominantly in young women, with very few cases reported in men. While the origin of the tumor may be unclear, it is characterized by a distinct histological appearance and a clinical course highlighting its low malignant potential. SPNP have an excellent prognosis and are potentially curable provided they are managed appropriately by complete surgical resection. In the rare instances where metastatic disease is encountered, surgical debulking has been shown to prolong survival. The role of chemotherapy and radiation therapy in the management of SPNP is still controversial. We report here on an unusual occurrence of SPNP in the area of the head of the pancreas in a 12-year-old female treated by pancreatico-duodenectomy, together with a review of the literature.
CD40 and CD40 ligand (CD40L) have costimulatory effects as part of a complex series of events in ... more CD40 and CD40 ligand (CD40L) have costimulatory effects as part of a complex series of events in host immunity. In this study, the expression of CD40 and CD40L on peripheral blood mononuclear cells (PBMCs) isolated from cattle with Johne's disease were measured on freshly isolated PBMCs and on cells cultured for 8, 24, and 72 h in the presence or absence of live Mycobacterium avium subsp. paratuberculosis and exogenous gamma interferon, interleukin 10, and transforming growth factor . Results demonstrated greater CD40 and CD40L expression on fresh PBMCs obtained from animals in the clinical stage of disease (symptomatic) than those from healthy control animals or cows in the subclinical stage of disease (asymptomatic). A similar expression profile with greater magnitude was noted for cultured PBMCs, with increased expression after 8 and 24 h of culture and increased CD40L expression between 24 and 72 h on PBMCs obtained from clinically infected animals. The addition of live M. avium subsp. paratuberculosis to cell cultures resulted in downregulation of CD40L expression in naturally infected cows, regardless of the disease stage. In contrast, the addition of live M. avium subsp. paratuberculosis to cultures resulted in upregulation of CD40 expression on cells obtained from clinically infected animals, while a decrease in expression was noted for healthy and subclinically infected cows. No effects of exogenous cytokines on CD40 or CD40L expression were observed. These results clearly point for the first time to a disparity in the expression of these costimulatory molecules on immune cells from cattle in different stages of Johne's disease and suggest further investigation into their roles in paratuberculosis pathogenesis. FIG 2 Expression of CD40 (A) and CD40L (B) on subpopulations of cells within freshly isolated PBMCs obtained from healthy control cows and cows naturally infected with M. avium subsp. paratuberculosis in the subclinical and clinical stages of infection. Data are presented as percentage of cells (mean Ϯ SEM). Significant differences between treatment groups are designated by different numbers of asterisks (P Ͻ 0.05).
Johne's disease is a chronic enteric disease characterized by intermittent diarrhea, weight loss ... more Johne's disease is a chronic enteric disease characterized by intermittent diarrhea, weight loss and death. The causative agent of Johne's disease is Mycobacterium avium subsp. paratuberculosis (MAP), an intracellular pathogen that resides and replicates within the phagosome of nonactive macrophages (Hostetter et al., 2002). Activation of macrophages by treatment with recombinant IFN-g and LPS has resulted in increased acidification and maturation of phagosomes and a decrease in the number of viable MAP within macrophages (Hostetter et al., 2002). Further,
Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available e... more Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available essential oil (EO) blends and characterize the effect on the expression of some virulence genes against methicillin-resistant Staphylococcus aureus (MRSA). Materials and Methods: In vitro evaluation of the antimicrobial effects of oils against MRSA was performed using the disk diffusion method and by measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The EOs (A-F) were contained (β-pinene, carvacrol, carvone, dimethyl trisulfide, linalool, limonene, menthol, monoterpene hydrocarbons, and thymol) in different amounts. In addition, a real-time polymerase chain reaction was also used to determine the gene expression of the virulence genes (intercellular adhesion cluster [ica]-9, ica-15, and RNA III) against MRSA (ATCC 43300) after treatment with selected oils. Results: Among the eight EOs evaluated, EO (D), (E), and (A) showed, in general, ...
Background and Aim: Middle East respiratory syndrome coronavirus (MERS-CoV) has rapidly spread th... more Background and Aim: Middle East respiratory syndrome coronavirus (MERS-CoV) has rapidly spread throughout the Middle East since its discovery in 2012. The virus poses a significant global public health threat with potentially devastating effects. In this study, a recombinant adenoviral-based vaccine encoding the spike 1 (S1) subunit of the MERS-CoV genome was constructed, and its humoral, and cellular immune responses were evaluated in mice. Materials and Methods: Mice were immunized initially by intramuscular injection and boosted 3 weeks later by intranasal application. Expression of the S1 protein in the lungs and kidneys was detected using conventional polymerase chain reaction (PCR) and immunohistochemistry (IHC) targeting specific regions within the S1 subunit at weeks 3, 4, 5, and 6 after the first vaccination. Antigen-specific humoral and cellular immune responses were evaluated in serum and in cell culture following in vitro stimulation with a specific 9-mer epitope within ...
Liposomes were evaluated as an alternative carrier to deliver inactivated Newcastle disease virus... more Liposomes were evaluated as an alternative carrier to deliver inactivated Newcastle disease virus (NDV). The ability of a liposomal-based NDV vaccine to activate both cell-mediated immunity (CMI) and humoral immunity against NDV was assessed and compared with conventional NDV vaccines. Birds were assigned to 4 groups and received either no vaccine (control), NDV entrapped into liposomes (LN-NDV), NDV with oil adjuvant (oil-NDV), or live attenuated NDV (live-NDV). All birds were stimulated after 40 days of vaccination in vivo by an intravenous injection of inactivated NDV crude antigen, which is considered an in vivo NDV-specific stimulation of the chicken immune system. After vaccination and in vivo stimulation, serum samples were collected for NDV-specific antibody response evaluation by a hemagglutination inhibition test (HI) and an enzyme-linked immune sorbent assay (ELISA). The CMI and humoral immunity were evaluated by a measurement of the chicken interferon gamma and specific ...
Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available e... more Aim: This study aimed to investigate the antibacterial efficacy of eight commercially available essential oil (EO) blends and characterize the effect on the expression of some virulence genes against methicillin-resistant Staphylococcus aureus (MRSA). Materials and Methods: In vitro evaluation of the antimicrobial effects of oils against MRSA was performed using the disk diffusion method and by measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The EOs (A-F) were contained (β-pinene, carvacrol, carvone, dimethyl trisulfide, linalool, limonene, menthol, monoterpene hydrocarbons, and thymol) in different amounts. In addition, a real-time polymerase chain reaction was also used to determine the gene expression of the virulence genes (intercellular adhesion cluster [ica]-9, ica-15, and RNA III) against MRSA (ATCC 43300) after treatment with selected oils. Results: Among the eight EOs evaluated, EO (D), (E), and (A) showed, in general, ...
The effect of tilmicosin, florfenicol, or enrofloxacin on humoral and cell-mediated immune respon... more The effect of tilmicosin, florfenicol, or enrofloxacin on humoral and cell-mediated immune response induced by Newcastle disease (ND) vaccination was evaluated in 20-wk-old specific-pathogen-free layer chickens. Humoral immunity was measured by detection of ND virus (NDV) antibody titer and anti-NDV IgG response using the hemagglutination inhibition (HI) test and ELISA, respectively, whereas cell-mediated immunity was evaluated by measurement of chicken interferon gamma (ChIFN-gamma) produced in splenocytes cell culture stimulated with concanavalin A, inactivated NDV antigen, or live attenuated La Sota strain using ELISA. Florfenicol hampered the ND antibody production measured by both HI and ELISA. Tilmicosin and enrofloxacin reduced the production of ND antibody in the first 3 wk after the last ND vaccination measured by HI test, which suggests that these antibiotics exert their effect mainly on the IgM isotype. The ND-vaccinated, but not treated group, showed an increase in ChIFN-gamma production after NDV antigen-specific stimulation above the nonstimulated cell culture, whereas this effect was masked in all the antibiotic-treated groups due to the stronger ChIFN-gamma production background value reported in the nonstimulated cell culture. In conclusion, our results showed, for the first time, that tilmicosin, florfenicol, or enrofloxacin reduced the humoral immune response and had beneficial effects on the cell-mediated immune response. In addition, we demonstrated that the combination of both inactivated and attenuated ND vaccine gave a strong immune response at both the humoral and cellular level.
European journal of pediatric surgery : official journal of Austrian Association of Pediatric Surgery ... [et al] = Zeitschrift für Kinderchirurgie, 2006
Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur pred... more Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur predominantly in young women, with very few cases reported in men. While the origin of the tumor may be unclear, it is characterized by a distinct histological appearance and a clinical course highlighting its low malignant potential. SPNP have an excellent prognosis and are potentially curable provided they are managed appropriately by complete surgical resection. In the rare instances where metastatic disease is encountered, surgical debulking has been shown to prolong survival. The role of chemotherapy and radiation therapy in the management of SPNP is still controversial. We report here on an unusual occurrence of SPNP in the area of the head of the pancreas in a 12-year-old female treated by pancreatico-duodenectomy, together with a review of the literature.
Johne's disease progresses through distinct stages including a protracted subclinical stage in wh... more Johne's disease progresses through distinct stages including a protracted subclinical stage in which the infection appears to be controlled; followed by a more acute stage in which the host animal demonstrates clinical signs such as diarrhea and weight loss.
Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur pred... more Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare pancreatic tumors that occur predominantly in young women, with very few cases reported in men. While the origin of the tumor may be unclear, it is characterized by a distinct histological appearance and a clinical course highlighting its low malignant potential. SPNP have an excellent prognosis and are potentially curable provided they are managed appropriately by complete surgical resection. In the rare instances where metastatic disease is encountered, surgical debulking has been shown to prolong survival. The role of chemotherapy and radiation therapy in the management of SPNP is still controversial. We report here on an unusual occurrence of SPNP in the area of the head of the pancreas in a 12-year-old female treated by pancreatico-duodenectomy, together with a review of the literature.
CD40 and CD40 ligand (CD40L) have costimulatory effects as part of a complex series of events in ... more CD40 and CD40 ligand (CD40L) have costimulatory effects as part of a complex series of events in host immunity. In this study, the expression of CD40 and CD40L on peripheral blood mononuclear cells (PBMCs) isolated from cattle with Johne's disease were measured on freshly isolated PBMCs and on cells cultured for 8, 24, and 72 h in the presence or absence of live Mycobacterium avium subsp. paratuberculosis and exogenous gamma interferon, interleukin 10, and transforming growth factor . Results demonstrated greater CD40 and CD40L expression on fresh PBMCs obtained from animals in the clinical stage of disease (symptomatic) than those from healthy control animals or cows in the subclinical stage of disease (asymptomatic). A similar expression profile with greater magnitude was noted for cultured PBMCs, with increased expression after 8 and 24 h of culture and increased CD40L expression between 24 and 72 h on PBMCs obtained from clinically infected animals. The addition of live M. avium subsp. paratuberculosis to cell cultures resulted in downregulation of CD40L expression in naturally infected cows, regardless of the disease stage. In contrast, the addition of live M. avium subsp. paratuberculosis to cultures resulted in upregulation of CD40 expression on cells obtained from clinically infected animals, while a decrease in expression was noted for healthy and subclinically infected cows. No effects of exogenous cytokines on CD40 or CD40L expression were observed. These results clearly point for the first time to a disparity in the expression of these costimulatory molecules on immune cells from cattle in different stages of Johne's disease and suggest further investigation into their roles in paratuberculosis pathogenesis. FIG 2 Expression of CD40 (A) and CD40L (B) on subpopulations of cells within freshly isolated PBMCs obtained from healthy control cows and cows naturally infected with M. avium subsp. paratuberculosis in the subclinical and clinical stages of infection. Data are presented as percentage of cells (mean Ϯ SEM). Significant differences between treatment groups are designated by different numbers of asterisks (P Ͻ 0.05).
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Papers by M. Khalifeh