Chlorophyll and pheophytin protonated and deprotonated ions: Observation and theory.

Pheophytin a and chlorophyll a have been investigated by electrospray mass spectrometry in the positive and negative modes, in view of the importance of the knowledge of their properties in photosynthesis. Pheophytin and chlorophyll are both observed intensely in the protonated mode, and their main fragmentation route is the loss of their phytyl chain. Pheophytin is observed intact in the negative mode, while under collisions, it is primarily cleaved beyond the phytyl chain and loses the attaching propionate group. Chlorophyll is not detected in normal conditions in the negative mode, but addition of methanol solvent molecule is detected. Fragmentation of this adduct primarily forms a product (-30 amu) that dissociates into dephytyllated deprotonated chlorophyll. Semi-empirical molecular dynamics calculations show that the phytyl chain is unfolded from the chlorin cycle in pheophytin a and folded in chlorophyll a. Density functional theory calculations have been conducted to locate the charges on protonated and deprotonated pheophytin a and chlorophyll a and have found the major location sites that are notably more stable in energy by more than 0.5 eV than the others. The deprotonation site is found identical for pheophytin a and the chlorophyll a-methanol adduct. This is in line with experiment and calculation locating the addition of methanol on a double bond of deprotonated chlorophyll a.

Attitudes of a sample of Jordanian young adults toward different available COVID-19 vaccines.

Objective: Vaccination is one of the most important measures that the world is relying on to end the COVID-19 pandemic. A number of vaccines have been authorized; however, there are several differences in the available vaccines which may lead to differences in public hesitancy levels toward each vaccine. Therefore, the aim of this study was to assess the young Jordanian population's acceptance of the COVID-19 vaccine, their knowledge, and attitudes toward different vaccine types, and to explore the variables that could influence their preferences. Material and methods: An online questionnaire was distributed via Jordanian multipurpose Facebook groups. COVID-19 knowledge, and practice scores were calculated, in addition to general and specific COVID-19 vaccine knowledge scores. Repeated measures analysis was conducted to investigate the association between the participants' knowledge about each vaccine and their willingness to take it. Quantile regressions were conducted to determine the predictors of the participants' willingness to take each vaccine. Results: A total of 1897 participants completed the survey. One fifth of the participants (19.9%) were willing to take the COVID-19 vaccine. The acceptance of Pfizer/BioNTech vaccine and the knowledge about it were significantly different from all the other vaccines. Predictors of acceptance of the different vaccines were sex, estimation of the severity of the disease, COVID-19 knowledge score, practice score, and specific vaccine knowledge score. Conclusion: The young Jordanian adults had limited acceptance of the COVID-19 vaccine. Differences in the participants' acceptance of different vaccines were observed and specific vaccine knowledge was a significant predictor of acceptance of the vaccine.

Objetivo: La vacunación es una de las medidas más importantes en la que el mundo se basa para acabar con la pandemia de la COVID-19. Varias vacunas han sido autorizadas para ser usadas; sin embargo, existen diferencias en las vacunas disponibles que pueden dar lugar a diferencias en los niveles de vacilación del público para ponerse cada una. Por lo tanto, este estudio tiene como objetivo evaluar la aceptación de la población joven jordana de la vacuna COVID-19, su conocimiento y actitudes hacia los diferentes tipos de vacunas, y variables que pueden influir sus preferencias. Material y métodos: En enero de 2021 se distribuyó un cuestionario en línea por vía de grupos jordanos usuarios de Facebook. Se calculó la puntuación de conocimiento de COVID-19, la puntuación de práctica y las puntuaciones de conocimiento de vacunas específicas. Se realizaron repetidos análisis de medidas para investigar las diferencias entre el conocimiento de los participantes acerca de cada vacuna y la voluntad para ponerse cada vacuna. Se realizaron regresiones cuantílicas para determinar los predictores de la disposición de los participantes a recibir la vacuna. Resultados: Completaron la encuesta 1.897 participantes. El 19,9% estuvo dispuesto a recibir la vacuna frente a COVID-19. La aceptación de la vacuna Pfizer/BioNTech y el conocimiento acerca de ella estaban significativamente diferenciados de todas las otras vacunas. Los factores predictivos de la aceptación de las diferentes vacunas fueron el sexo, la estimación de la gravedad de la enfermedad, la puntuación sobre el conocimiento de COVID-19, la puntuación sobre la práctica y la puntuación sobre el conocimiento de las vacunas específicas. Conclusión: Los jóvenes adultos jordanos tuvieron aceptación limitada de la vacuna de COVID-19. Se observaron diferencias en los participantes en cuanto a la aceptación de diferentes vacunas, y el conocimiento de las vacunas específicas fue un factor predictivo significativo en cuanto a su aceptación.

Hepatic Sinusoidal Obstruction Syndrome in a child after chemotherapy for medulloblastoma.

Hepatic Sinusoidal Obstruction Syndrome (HSOS), the new name given to veno-occlusive disease (VOD) of the liver, is a well-known complication of high-dose chemotherapy employed with hematopoietic stem cell transplantation, but it has rarely been observed in children who receive conventional chemotherapy. HSOS following standard chemotherapy has been reported in patients receiving vincristine, actinomycin D, and cyclophosphamide for the treatment of Wilms tumor and more rarely rhabdomyosarcoma. We report a 14-year-old boy with high risk medulloblastoma treated with craniospinal radiation followed by chemotherapy, who experienced severe HSOS after only one course of chemotherapy including carboplatin, vincristine, and cyclophosphamide. To our knowledge, this is the second report of HSOS after standard dose chemotherapy for brain tumor in childhood.

Allogeneic stem cell transplantation for Glanzmann thrombasthenia.

Glanzmann thrombasthenia (GT) is a rare autosomal recessive bleeding disorder characterized by normal platelet count, but lack of platelet aggregation. The molecular basis is linked to quantitative and/or qualitative abnormalities of the membrane glycoprotein IIb/IIIa complexes. Usually it is associated with mild bleeding but may lead to severe and potentially fatal hemorrhages. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment. However, because of the risks associated with HSCT, it is generally not recommended unless there are life threatening hemorrhages, or the patient has developed refractoriness to platelet transfusion due to antibody formation. Herein, we report an 11-year-old female from United Arab Emirates (UAE) with severe GT and anti platelet alloimmunization successfully treated with HSCT from her HLA-identical sibling.

Curving Tuberculosis: Current Trends and Future Needs.

Tuberculosis (TB) presents new challenges as a global public health problem, especially at a time of increasing threats to some particular patients due to Human Immunodeficiency Virus (HIV) infection and multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. The World Health Assembly strives to reduce TB deaths by 95% and to decrease TB incidence by 95% by 2035. However, new approaches are necessary in order to attain these objectives. Such approaches include active ascertainment of cases in high risk populations, increasing the availability of accurate point-of-care testing, rapid detection of drug resistance, novel vaccines, and new prophylaxis and treatment regimens (particularly for MDR and XDR TB). The ultimate objective of those programs is to develop highly effective drug regimens that can achieve high cure rates regardless of strains' resistance patterns.

Surgical treatment of gastric outlet obstruction from a large trichobezoar: A case report.

INTRODUCTION: Bezoars are concretions of foreign indigestible material accumulating in the gastrointestinal tract leading to intraluminal mass formation that impairs the gastrointestinal motility and can lead to gastric obstruction of the small or the large bowel. There are different types of bezoars, named according to the material they are made of. These include phytobezoar, lactobezoar, pharmacobezoar, trichobezoar, and polybezoar. Trichobezoars (hair ball) are usually located in the stomach but may extend through the pylorus into the duodenum and small bowel (Rapunzel syndrome). CASE PRESENTATION: Herein, we report a case of a young adult female known to have a long-standing trichophagia who presented with gastric outlet obstruction due to a large trichobezoar. Endoscopy revealed a large and hard gastric trichobezoar not amenable to endoscopic retrieval leading to surgical extraction as a last resort. DISCUSSION: They are almost always associated with trichotillomania and trichophagia or other psychiatric disorders. Trichobezoar can be treated either surgically by laparotomy/laparoscopy or by endoscopic intervention. CONCLUSION: Treatment should be coupled to psychiatric evaluation and therapy to prevent recurrence.

Iron sequestration by macrophages decreases the potential for extracellular hydroxyl radical formation.

Alveolar macrophages (AM) from smokers contain a much higher quantity of intracellular iron than AM from nonsmokers. Since some forms of iron will catalyze the formation of hydroxyl radical (.OH) from superoxide and hydrogen peroxide, the ability of AM derived from smokers and nonsmokers to generate .OH was assessed. No detectable .OH was produced by AM from either source, suggesting that iron sequestration by AM may limit the potential for .OH-mediated lung injury. Consistent with this hypothesis, the ability of bronchoalveolar lavage fluid (BAL) from smokers and nonsmokers to act as an .OH catalyst decreased after exposure to AM. We found that, like AM, human monocyte-derived macrophages (MDM) have the ability to acquire large quantities of iron from small low molecular weight iron chelates as well as decrease the ability of BAL to act as a .OH catalyst. When MDM or AM were exposed to the iron chelates or BAL they were then able to generate .OH after phorbol myristate acetate stimulation. However, when acutely iron-loaded or BAL-exposed MDM were placed in culture, their ability to produce .OH decreased with time to the level of non-iron-exposed controls. This process correlated with iron translocation from the plasma membrane to the cytosol as well as a 3-9-fold increase in cellular ferritin. No increase in antioxidant enzyme levels or induction of the heat shock response was observed. Iron sequestration by macrophages may protect nearby cells from exposure to potentially cytotoxic iron-catalyzed oxidants such as .OH.

Antioxidants and immune response in aged persons: overview of present evidence.

The oxidant-antioxidant balance is an important determinant of immune cell function, including maintaining the integrity and functionality of membrane lipids, cellular proteins, and nucleic acids and controlling signal transduction and gene expression in immune cells. Optimal amounts of antioxidants are needed for maintenance of the immune response across all age groups. This need might be more critical, however, in aged persons. Age-associated dysregulation of immune response, particularly of T cell-mediated function, is well documented. The well-known age-related increase in free radical formation and lipid peroxidation contributes, at least in part, to this phenomenon. We summarize animal and human studies undertaken by ourselves as well as other investigators on the effects of antioxidants, vitamin E, beta-carotene, and glutathione on the immune response of aged persons. The underlying mechanisms for the antioxidant nutrients' effects as well as their health implications for aged persons are discussed.

Immunologic effects of marine- and plant-derived n-3 polyunsaturated fatty acids in nonhuman primates.

The effect of marine- and plant-derived n-3 polyunsaturated fatty acids (PUFAs) on T cell-mediated immune response was studied in cynomolgus monkeys. Animals were first fed a 14-wk baseline diet; 10 animals were then fed diets containing 1.3% or 3.3% of energy as eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) which the other 10 were fed diets containing 3.5% or 5.3% of energy as alpha-linolenic acid (ALA) for two consecutive 14-wk periods. Both diets significantly decreased the percentage of T cells (except 1.3% EPA + DHA), T helper cells (except 1.3% EPA + DHA and 3.5% ALA), and T suppressor cells. Proliferative response of lymphocytes to T cell mitogens significantly increased after the diet containing 3.3% EPA + DHA. Interleukin 2 production significantly increased after the diets containing 1.3% and 3.3% EPA + DHA. No significant changes in mitogenic response or interleukin 2 production were found after ALA diets. Feeding 1.3% or 3.3% EPA + DHA or 5.3% ALA significantly suppressed prostaglandin E2 production in response to T cell mitogens. Plasma tocopherol concentrations were decreased significantly only in monkeys fed ALA diets. We conclude that after adjustment for the tocopherol concentration, marine-derived n-3 PUFAs but not plant-derived n-3 PUFAs increased T cell-mediated mitogenic response and interleukin 2 production. This is most likely due to diet-induced quantitative differences in cellular fatty acid composition and, thus, in prostaglandin E2 production and tocopherol status.

Epidemiology of gastric cancer.

The incidence of gastric cancer varies widely by country and population, with higher rates among the lower socioeconomic groups. Although the most common cause of cancer death in the United States in 1930, its incidence has decreased dramatically during the past 60 years. Most populations show a 2-1 ratio for male to female gastric cancer cases, and a higher incidence rate among United States blacks than whites. Although rates have generally decreased, there has been a dramatic increase in the incidence of gastric cancer in the cardia. Diet has been the most studied risk factor for gastric cancer. Of particular interest have been N-nitroso compounds derived from the consumption of preserved, smoked, and cured foods. An inverse association with the consumption of fruits and vegetables has also been consistently demonstrated, though the specific nutrient(s) that this represents has been unclear, although ascorbate and beta-carotene have been intensively studied. Among nondietary factors, substantial evidence has accumulated for an increased risk with Helicobacter pylori infection. Other exposures which have been fairly consistently associated with gastric cancer include cigarette smoking, partial gastrectomy, radiation exposure, family history, pernicious anemia, blood group A, certain occupational exposures, and Epstein-Barr virus.

Clinical presentation and outcome of tuberculosis in kidney, liver, and heart transplant recipients in Spain. Spanish Transplantation Infection Study Group, GESITRA.

BACKGROUND: Tuberculosis is unusual in transplant recipients. The incidence, clinical manifestations, and optimal treatment of this disease in this population has not been adequately defined. The present study was undertaken to assess the incidence, clinical features, and response to therapy of Mycobacterium tuberculosis infection in solid-organ transplant recipients. METHODS: We evaluated retrospectively the incidence, clinical characteristics, diagnostic procedures, antituberculous treatment, clinical course, and factors influencing mortality in 51 solid-organ transplant recipients who developed tuberculosis after transplantation. We also reviewed the world literature on tuberculosis in solid-organ transplantation. RESULTS: The overall incidence of tuberculosis was 0.8%. The localization was pulmonary in 63% of the cases, disseminated in 25%, and extrapulmonary in 12%. Tuberculosis developed from 15 days to 13 years after surgery (mean, 23 months). In one third of the cases, diagnosis was not suspected initially, and in three cases, diagnosis was made at necropsy. Fever was the most frequent symptom, followed by constitutional symptoms, cough, respiratory insufficiency, and pleuritic pain. Fifteen patients (33%) developed hepatotoxicity during treatment; hepatotoxicity was severe in seven cases. Hepatotoxicity was higher in patients receiving four or more antituberculous drugs (50%) than in patients receiving three drugs (21%; P=0.03). Serum levels of cyclosporine decreased in the 26 patients under the simultaneous use of rifampin. Nine of them (35%) developed acute rejection, and five (56%) died, in comparison with 3 of 17 patients (18%) who did not develop rejection after the use of cyclosporine and rifampin (P=0.03). Although microbiological response was favorable in 94% of the 35 patients who completed 6 or more months of treatment, 16 other patients (31%) died before diagnosis or in the course of treatment. None of the patients treated for more than 9 months died as a consequence of tuberculosis, whereas the mortality rate was 33% among those treated for 6 to 9 months (P=0.03). Use of antilymphocyte antibodies or high doses of steroids for acute rejection before tuberculosis was associated with a higher mortality rate. CONCLUSIONS: M tuberculosis causes serious and potentially life-threatening disease in solid-organ transplant recipients. Treatment with at least three drugs during 9 months or more, avoiding the use of rifampin, appears to be appropriate.

Severe hypophosphatemia following the institution of enteral feedings.

Although severe hypophosphatemia has been recognized in refeeding syndromes, it is not a commonly reported complication of enteral nutrition. The present study was designed to identify cases of severe hypophosphatemia (less than 0.32 mmol/L [less than 1.0 mg/dL]) related to the administration of carbohydrates via the enteral route. Serum phosphorus levels were evaluated at the time of admission of 25 patients to two midwestern teaching hospitals and during their postoperative enteral support in the surgical intensive care unit. The initial serum phosphorus levels ranged from 0.77 to 1.55 mmol/L (2.4 to 4.8 mg/dL), serum calcium levels ranged from 1.80 to 2.44 mmol/L (7.2 to 9.8 mg/dL). From two to five days following the initiation of isotonic enteral feedings, the serum phosphorus level decreased to 0.16 to 0.39 mmol/L (0.5 to 1.2 mg/dL). Serum phosphorus levels were corrected within two to ten days with oral supplementation only. Patients with high metabolic demand may have a higher daily requirement for phosphorus than that available in routine isotonic enteral formulas.

Prostaglandin E2 concentrations in naturally occurring canine cancer.

The purpose of this study was to determine the PGE2 concentration in naturally-occurring cancer in pet dogs and in canine cancer cell lines in order to identify specific types of canine cancer with high PGE2 production which could serve as preclinical models to evaluate anticancer strategies targeting PGE2. PGE2 concentrations were measured by enzyme immunoassay in canine melanoma, soft tissue sarcoma, transitional cell carcinoma, osteosarcoma, and prostatic carcinoma cell lines; in 80 canine tumor tissue samples including oral melanoma (MEL), oral squamous cell carcinoma (SCC), transitional cell carcinoma of the urinary bladder (TCC), lymphoma (LSA), mammary carcinoma (MCA), osteosarcoma (OSA), prostatic carcinoma (PCA); and in corresponding normal organ tissues. High concentrations of PGE(2)(range 400-3300 pg/10(4)cells) were present in cell culture medium from the transitional cell carcinoma, prostatic carcinoma, and osteosarcoma cell lines. PGE2 concentrations in tumor tissues were elevated (tumor PGE2 concentration>mean+2X sd PGE(2)concentration of normal organ tissue) in 21/22 TCC, 5/6 PCA, 7/10 SCC, 5/10 MEL, 3/8 MCA, 4/15 OSA, and 0/9 LSA. Results of this study will help guide future investigations of anticancer therapies that target cyclooxygenase and PGE2.

Expression of cyclooxygenase-1 and 2 in naturally-occurring canine cancer.

The purpose of this work was to determine cox-1 and cox-2 expression by immunohistochemistry in forms of naturally occurring canine cancer in order to identify animal systems for pre-clinical evaluation of cox inhibitors and cox-2 inhibitors in cancer. Canine lymphoma (LSA), prostatic carcinoma (PCA), osteosarcoma (OSA), oral melanoma (MEL), oral squamous cell carcinoma (SCC), oral fibrosarcoma (FSA), mammary carcinoma (MCA), and normal tissues were included. Cox-2 was expressed in epithelial tumors (17 of 26 SCC, 8 of 13 MCA, 5 of 9 PCA cases) and MEL (9 of 15 cases), but was generally absent in normal tissues. Cox-2 expression was minimal or absent in mesenchymal tumors and LSA. Cox-1 was expressed in normal epithelial tissues and in some osteoclast and osteoblast in bone, but was absent in normal lymph node. In conclusion, forms of canine cancer were identified for in vivo studies of the effects of cox inhibitors and selective cox-2 inhibitors on cancer.

A standardized gating technique for the generation of flow cytometry data for normal canine and normal feline blood lymphocytes.

Flow cytometry is becoming a commonly used technique to characterize a variety of cells. It provides a powerful application to rapidly determine the relative percentages of T-lymphocyte subsets and B-lymphocytes. The effectiveness of its application, however, is dependent on standardization, especially in a clinical setting. Application of flow cytometry to veterinary diagnostics has been limited by the unavailability of reagents and by the unstandardized characterization of normal values using antibodies not commercially available, but typically provided through the generosity of other researchers. This paper presents a standardized gating protocol, and average values and ranges observed for normal canine and feline blood lymphocytes using commercially available antibodies to cell surface markers for CD5, CD3, CD4, CD8, MHC II, and B lymphocytes. The averages for these markers on gated lymphocytes were as follows: Canine CD5 83.3%, Canine CD4 45.0%, Canine CD8 28.8%, Canine MHC II 98.0%, Canine B Cell 12.9%, Canine CD4/CD8 ratio 1.87, Feline T lymphocytes 77.3%, Feline CD4 44.5%, Feline CD8 25.7%, Feline B Cell 24.1%, Feline CD4/CD8 Ratio 1.75. Normal values were also established for a mixed breed group of dogs, and old versus young dogs. This information will provide researchers and clinicians with a standardized protocol for gating, which establishes a basis for comparison between techniques, and a measure of phenotypic percentages for flow cytometry in normal dogs and cats based on this standardization and commercially available antibodies.

The fermentable fiber content of the diet alters the function and composition of canine gut associated lymphoid tissue.

The ingestion of plant fibers and their susceptibility to microbial fermentation in the large bowel modulate intestinal morphology but little is known about effects on the gut associated lymphoid tissue (GALT). The aim of the present study was to determine the effect of consuming diets containing different levels of fermentability fiber on immune function. Sixteen adult mongrel dogs (23 +/- 2 kg) were fed (14 days) in a randomized cross over design two isoenergetic isonitrogenous diets containing 8.3 g/kg non-fermentable or 8.7 g/kg fermentable fibers. Lymphocytes were isolated from blood prior to starting the study and at the end of each diet period. At study completion, lymphocytes were isolated from the gut associated lymphoid tissue (GALT) of the small intestine for characterization by immunofluorescence and to determine their ability to respond to mitogenic stimulation. Feeding high fermentable fibers increased (P < 0.05) the CD4/CD8 ratio and decreased (P < 0.05) the proportion of B cells in peripheral blood without changing natural killer cell activity or the response to mitogens. Mesenteric lymph node cells from dogs fed the low then high fermentable fiber diet contained a higher (P < 0.05) proportion of CD4+ cells and a higher (P < 0.05) response to mitogens. Intraepithelial, Peyer's patches and lamina propria cells contained a greater (P < 0.05) proportion of CD8+ cells when dogs were fed a low fermentable fiber diet followed by a high fermentable fiber diet. T cell mitogen responses in vitro were higher for intraepithelial but lower for Peyer's patches and lamina propria cells from dogs who were fed the low fermentable fiber diet followed by the high fermentable fiber diet (P < 0.05). In conclusion, the fermentable fiber content of the diet had very little effect on the type and function of immune cells in peripheral blood. However, feeding dogs a high fermentable fiber diet for 2 weeks (after 2 weeks of consuming a low fermentable fiber diet) altered the T-cell composition of GALT and produced a higher mitogen response in the predominantly T cell tissues and a lower response in areas involved in B cell functions. In conclusion, the level of fermentable fiber in the diet appears to alter GALT properties. Further studies are required to determine the direct contribution of a high or low fiber diet to these changes and the physiological implications to the health of the animal.

Dietary lutein stimulates immune response in the canine.

The possible immuno-modulatory action of dietary lutein in dogs is not known. Female Beagle dogs (17-18-month old; 11.4+/-0.4kg body weight) were supplemented daily with 0, 5, 10 or 20mg lutein for 12 weeks. Delayed-type hypersensitivity (DTH) response to saline, phytohemagglutinin (PHA) and a polyvalent vaccine was assessed on Weeks 0, 6 and 12. Blood was sampled on Weeks 0, 2, 4, 8 and 12 to assess (1) lymphocyte proliferative response to PHA, concanavalin A (Con A), and pokeweed mitogen (PWM), (2) changes in peripheral blood mononuclear cell (PBMC) populations, (3) interleukin-2 (IL-2) production and (4) IgG and IgM production. After the completion of 12-week study, we continued to collect the blood weekly up to 17 weeks to evaluate the changes in immunoglobulin production upon first and second antigenic challenges on Weeks 13 and 15. Plasma lutein+zeaxanthin was undetectable in unsupplemented dogs but concentrations increased (P<0.05) rapidly on Week 2 in lutein-supplemented dogs. Thereafter, concentrations generally continued to increase in dose-dependent manner, albeit at a much slower rate. Dogs fed lutein had heightened DTH response to PHA and vaccine by Week 6. Dietary lutein increased (P<0.05) lymphocyte proliferative response to all three mitogens and increased the percentages of cells expressing CD5, CD4, CD8 and major histocompatibility complex class II (MHC II) molecules. The production of IgG increased (P<0.05) in lutein-fed dogs after the second antigenic challenge. Lutein did not influence the expression of CD21 lymphocyte marker, plasma IgM or IL-2 production. Therefore, dietary lutein stimulated both cell-mediated and humoral immune responses in the domestic canine.

Modulation of humoral and cell-mediated immune responses by dietary lutein in cats.

The immuno-modulatory role of dietary lutein in domestic cats is unknown. Female Tabby cats (10-month old; n=56) were supplemented daily for 12 weeks with 0, 1, 5 or 10mg lutein. Blood was collected on Weeks 0, 2, 4, 8 and 12 to assess the following: (1) mitogen-induced peripheral blood mononuclear cells (PBMCs) proliferation, (2) changes in PBMC subpopulations, (3) interleukin-2 (IL-2) production and (4) plasma immunoglobulin (Ig)G production. In addition, delayed-type hypersensitivity (DTH) response to concanavalin A (Con A) or a polyvalent vaccine was performed on Weeks 0, 6 and 12. Dietary lutein increased plasma lutein concentrations in a dose-dependent manner (p<0.001) and concentrations had not reached steady state after 12 weeks of feeding in cats given 5 or 10mg lutein. Concentrations of plasma retinol and alpha-tocopherol were not influenced by diet. The DTH response to vaccine but not to Con A increased (p<0.05) in a dose-dependent manner on Week 6. Compared to control, cats fed lutein also showed enhanced Con A- and pokeweed mitogen-stimulated PBMCs proliferation. Dietary lutein also increased the percentages of CD4+ and CD21+ lymphocytes on Week 12 but had no significant effect on pan T, CD8 and MHC class II markers. Plasma IgG was higher (p<0.05) in cats fed 10mg lutein on Weeks 8 and 12. These results support the immuno-modulatory action of lutein in domestic cats.

Effect of age, breed and dietary omega-6 (n-6): omega-3 (n-3) fatty acid ratio on immune function, eicosanoid production, and lipid peroxidation in young and aged dogs.

The focus of this study was to examine the influence of age and diet on various parameters of immune function in young and old Fox Terriers and Labrador Retrievers. Eighteen young and old dogs were utilized for this study. Young and old dogs were fed a basal diet containing an (n-6):(n-3) ratio of 25:1 for sixty days (Phase I). Half of the dogs were then switched to a diet with an (n-6):(n-3) ratio of 5:1, and all were maintained on their respective diets for an additional sixty days (Phase II). Results from these studies revealed an age-associated decline in several immune parameters measured. Both these breeds demonstrated a reduction in sheep red blood cell titers, as well as in their ability to respond to different mitogens. Interestingly, this decline was greater in Fox Terriers, suggesting a decrease in cellular proliferative capacity in lymphocytes isolated from the larger breed. Neither cytokine production or DTH response was affected by age. Diet and breed interactions resulted in a significant increase in T- and B-cell mitogen responsiveness. In contrast, supplementation with n-3 fatty acids did not affect IL-1, IL-6 or TNF-alpha production. Supplementation with n-3 fatty acids resulted in increased PGE3 production from peritoneal macrophages but had no effect on PGE2 production from peripheral blood mononuclear cells or peritoneal macrophages. The n-3 fatty acid supplementation did not influence alpha-tocopherol status although older dogs had significantly lower serum alpha-tocopherol concentrations. Oxidative status of these dogs was assessed by serum levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Feeding an n-3-enriched diet did not affect 4-HNE levels but significantly decreased MDA levels in old dogs. In summary, this study indicates that feeding a diet containing an (n-6):(n-3) fatty acid ratio of 5:1 had a positive, rather than a negative, effect on the immune response of young or geriatric dogs.

Isolation and characterization of canine satellite cells.

Satellite cells were isolated from biopsies of the biceps femoris of adult dogs. Virtually all cells expressed muscle-specific proteins. Proliferation of satellite cells increased as the concentration of fetal calf serum (FCS) was increased from 1 to 10% of the basal medium. The addition of mitogenic growth factors resulted in greater proliferation than that of cells cultured in basal medium alone. Maximum proliferation was obtained when fibroblast growth factor-basic (FGF2) was added to the medium, but differences existed between sources or types. Proliferation did not plateau when the concentration of recombinant human FGF2 was 75 ng/ml but reached maximum levels when 50 ng/ml of bovine FGF2 or 10 ng/ml of growth hormone or insulin-like growth factor-1 were added to the medium. Proliferation of satellite cells decreased when more than 5 ng/ml of transforming growth factor-alpha was included in the medium. Exposure of canine satellite cells to chemically defined media induced greater fusion of total nuclei (ODM-34%; 4F, ITT-CF, and SFG-23%) than exposure to other treatments, such as basal medium plus 2 mg/ml of 1-beta-d-arabinofuranosylcytosine, 5% chick embryo extract, 1% horse serum (average 9% fused nuclei), or 1% FCS (2% fused nuclei). Actin, myosin, desmin, neural cell adhesion molecule, MyoD1, and myogenin were expressed by canine satellite cells, but expression of major histocompatibility complex class II antigen was not detected. Reverse transcriptase-polymerase chain reaction detected expression of messenger ribonucleic acid for interleukin-6 (IL-6), IL-15, and leukemia inhibitory factor by canine satellite cells. Collectively, these data suggest that isolated canine satellite cells display properties of other types of myogenic cells and may be useful for further study of the regulation of postnatal myogenesis.