324 resultados para lymphatic
Resumo:
Experimental lemurs either were infected orally with the agent of bovine spongiform encephalopathy (BSE) or were maintained as uninfected control animals. Immunohistochemical examination for proteinase-resistant protein (prion protein or PrP) was performed on tissues from two infected but still asymptomatic lemurs, killed 5 months after infection, and from three uninfected control lemurs. Control tissues showed no staining, whereas PrP was detected in the infected animals in tonsil, gastrointestinal tract and associated lymphatic tissues, and spleen. In addition, PrP was detected in ventral and dorsal roots of the cervical spinal cord, and within the spinal cord PrP could be traced in nerve tracts as far as the cerebral cortex. Similar patterns of PrP immunoreactivity were seen in two symptomatic and 18 apparently healthy lemurs in three different French primate centers, all of which had been fed diets supplemented with a beef protein product manufactured by a British company that has since ceased to include beef in its veterinary nutritional products. This study of BSE-infected lemurs early in their incubation period extends previous pathogenesis studies of the distribution of infectivity and PrP in natural and experimental scrapie. The similarity of neuropathology and PrP immunostaining patterns in experimentally infected animals to those observed in both symptomatic and asymptomatic animals in primate centers suggests that BSE contamination of zoo animals may have been more widespread than is generally appreciated.
Resumo:
Vascular endothelial growth factor C (VEGF-C) recently has been described to be a relatively specific growth factor for the lymphatic vascular system. Here we report that ectopic application of recombinant VEGF-C also has potent angiogenic effects in vivo. VEGF-C is sufficiently potent to stimulate neovascularization from limbal vessels in the mouse cornea. Similar to VEGF, the angiogenic response of corneas induced by VEGF-C is intensive, with a high density of new capillaries. However, the outgrowth of microvessels stimulated by VEGF-C was significantly longer than that induced by VEGF. In the developing embryo, VEGF-C was able to induce branch sprouts from the established blood vessels. VEGF-C also induced an elongated, spindle-like cell shape change and actin reorganization in both VEGF receptor (VEGFR)-2 and VEGFR-3-overexpressing endothelial cells, but not in VEGFR-1-expressing cells. Further, both VEGFR-2 and VEGFR-3 could mediate proliferative and chemotactic responses in endothelial cells on VEGF-C stimulation. Thus, VEGF-C may regulate physiological angiogenesis and participate in the development and progression of angiogenic diseases in addition to lymphangiogenesis.
Resumo:
Interleukin 16 (IL-16) has been shown to function as chemoattractant factor, as a modulator of T-cell activation, and as an inhibitor of immunodeficiency virus replication. The recent identification of inconsistencies in published IL-16 cDNA nucleotide sequences led to the proposal that IL-16 is synthesized in the form of a large precursor protein (pro-IL-16). To identify the true transcriptional start of the IL-16 mRNA rapid amplification of cDNA ends methods were applied. The complete pro-IL-16 cDNA was subsequently molecularly cloned, sequenced, and expressed in COS-7 cells. We report here that pro-IL-16 is most likely synthesized as a 67-kDa protein and is encoded from a major 2.6-kb transcript. Recombinant pro-IL-16 polypeptides are specifically cleaved in lysates of CD8(+) cells, suggesting that the naturally secreted bioactive form of IL-16 is smaller than the originally published 130 amino acids fragment. Moreover, in contrast to other interleukins such as IL-15, IL-16 mRNA expression is almost exclusively limited to lymphatic tissues underlining the potential of IL-16 as an immune regulatory molecule.
Resumo:
Neuroblastoma (NB) is characterized by the second highest spontaneous regression of any human malignant disorder, a phenomenon that remains to be elucidated. In this study, a survey of 94 normal human adult sera revealed a considerable natural humoral cytotoxicity against human NB cell lines in approximately one-third of the tested sera of both genders. Specific cell killing by these sera was in the range of 40% to 95%. Serum cytotoxicity was dependent on an intact classical pathway of complement. By several lines of evidence, IgM antibodies were identified as the cytotoxic factor in the sera. Further analyses revealed that a 260-kDa protein was recognized by natural IgM of cytotoxic sera in Western blots of NB cell extracts. The antigen was expressed on the surface of seven human NB cell lines but not on human melanoma or other control tumor cell lines derived from kidney, pancreas, colon, bone, skeletal muscle, lymphatic system, and bone marrow. Furthermore, no reactivity was observed with normal human fibroblasts, melanocytes, and epidermal keratinocytes. The antigen was expressed in vivo as detected by immunohistochemistry in both the tumor of a NB patient and NB tumors established in nude rats from human NB cell lines. Most interestingly, the IgM anti-NB antibody was absent from the sera of 11 human NB patients with active disease. The anti-NB IgM also could not be detected in tumor tissue obtained from a NB patient. Collectively, our data suggest the existence of a natural humoral immunological tumor defense mechanism, which could account for the in vivo phenomenon of spontaneous NB tumor regression.
Resumo:
The tyrosine kinases Flt4, Flt1, and Flk1 (or KDR) constitute a family of endothelial cell-specific receptors with seven immunoglobulin-like domains and a split kinase domain. Flt1 and Flk1 have been shown to play key roles in vascular development; these two receptors bind and are activated by vascular endothelial growth factor (VEGF). No ligand has been identified for Flt4, whose expression becomes restricted during development to the lymphatic endothelium. We have identified cDNA clones from a human glioma cell line that encode a secreted protein with 32% amino acid identity to VEGF. This protein, designated VEGF-related protein (VRP), specifically binds to the extracellular domain of Flt4, stimulates the tyrosine phosphorylation of Flt4 expressed in mammalian cells, and promotes the mitogenesis of human lung endothelial cells. VRP fails to bind appreciably to the extracellular domain of Flt1 or Flk1. The protein contains a C-terminal, cysteine-rich region of about 180 amino acids that is not found in VEGF. A 2.4-kb VRP mRNA is found in several human tissues including adult heart, placenta, ovary, and small intestine and in fetal lung and kidney.
Resumo:
The volumes contain student notes on a course of medical lectures given by Dr. Benjamin Rush (1746-1813) while he was Professor of the Institutes of Medicine and Clinical Practice at the University of Pennsylvania Medical School, likely in circa 1800-1813. The notes indicate Rush often referenced the works or teachings of contemporaries such as Scottish physicians William Cullen, John Brown, John Gregory, and Robert Whytt, and Dutch physician Herman Boerhaave. He frequently included anecdotes and case histories of his own patients, as well as those of other doctors, to illustrate his lecture topics. He also advised students to take notes on the lectures after they ended to allow them to focus on what they were hearing. Volume 1 includes notes on: physician conduct during visits to patients; human and animal physiology; voice and speech; the nervous system; the five senses; and faculties of the mind. Volume 2 includes notes on: food, the sources of appetite and thirst, and digestion; the lymphatic system; secretions; excretions; theories of nutrition; differences in the minds and bodies of women and men; reproduction; pathology; a table outlining the stages of disease production; “disease and the origin of moral and natural evil”; contagions; the role of food, drink, and clothing in producing disease; worms; hereditary diseases; predisposition to diseases; proximate causes of diseases; and pulmonary conditions. Volume 3 includes notes on: the pulse; therapeutics, such as emetics, sedatives, and digitalis, and treatment of various illnesses like pulmonary consumption, kidney disease, palsy, and rheumatism; diagnosis and prognosis of fever; treatment of intermitting fever; and epidemics including plague, smallpox, and yellow fever, with an emphasis on the yellow fever outbreaks in Philadelphia in 1793 and 1797.
Resumo:
Adenoids are a mass of lymphatic tissue located within the nasopharynge. This work aims assessing the relationship between the formation of bacterial biofilms on the adenoid surface and the incidence of infections in the pediatric age.
Resumo:
Continued as the American anatomical memoirs.
Resumo:
Johnstone's work was first published under the title: Some account of the Walton water, near Tewkesbury.
Resumo:
v. 1. The anatomy of the bones, muscles, and joints -- v. 2. The anatomy of the heart and arteries -- v. 3. The nervous system / by Charles Bell -- v. 4. The anatomy of the viscera of the abdomen, the parts in the male and female pelvis, and the lymphatic system / by Charles Bell.
Resumo:
v. 1. Bones, muscles and joints. 4th ed. 1808 -- v. 2. Heart and arteries. 3rd ed. corr. 1808 -- v. 3. Nervous system, with plates / by Charles Bell. 1803 -- v. 4. Viscera of the abdomen, the parts in the male and female pelvis, and the lymphatic system / by Charles Bell. 1804.
Resumo:
Thesis (Master's)--University of Washington, 2016-06
Resumo:
A description of Anopheles (Cellia) irenicus Schmidt, sp.n. (formerly A. farauti No. 7) is provided. This species is one of six recorded from the Solomon Islands within the A. punctulatus group, which contains the major vectors of the causative agents of malaria and lymphatic filariasis in the southwest Pacific. Morphological markers are described for adult females, fourth-instar larvae and pupae that identify most specimens of A. irenicus. Keys are presented to distinguish members of the A. punctulatus group in the Solomon Islands.
Resumo:
Merkel-cell carcinoma (MCC) is a rare form of skin cancer of neuroendocrine origin that has been described as the most aggressive cutaneous malignancy. The cell of origin is thought to be the Merkel cell or skin-pressure receptor. It has the propensity for dermal-lymphatic invasion, and nodal and haematogenous spread. Factors that have been implicated in its cause include exposure to sunlight and immunosuppression. The tumour has many similarities to small-cell carcinoma of the lung, with intrinsic sensitivity to ionising radiation and chemotherapy, and an aggressive metastatic potential. The best treatment outcomes can be achieved with early diagnosis and the integration of surgery, radiation, and chemotherapy. The treatment challenges for the clinician are often enormous because many of the patients are elderly and because lesions occur in difficult sites such as the head and neck region and the lower leg.
Resumo:
This paper describes a study undertaken to: (1) determine the prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm infections and nutritional status among Pacific Island school children; (2) identify factors influencing helminthiasis; (3) identify interventions to improve school health. A total of 3,683 children aged 5-12 years attending 27 primary schools in 13 Pacific Island countries were surveyed along with school environmental data. Stool samples were collected from 1996 children (54.2%) and analysed for ova and helminths. Total prevalence of helminthiasis was 32.8%. Anaemia prevalence was 12.4%. Children with helminthiasis and anaemia were found to be 8.7 times more likely to be stunted and 4.3 times more likely to be underweight than non-anaemic and non-infected children. Four significant environmental influences on helminthiasis were identified: (1) an inadequate water supply; (2); availability of a school canteen; (3) regular water/sanitation maintenance regimes; and (4) overcrowded classrooms. Helminthiasis was found to be strongly associated with anaemia, stunting and underweight and environmental influences identified. Although mass anti-helminthic drug administrations (MDA) have been taking place, reinfection is common as drug therapy alone is not enough. Programme effectiveness depends upon upgrading school environments to include an adequate water supply, controlled food preparation/provision, well-maintained water/sanitation facilities and class sizes of 30 students or less.