scholarly journals The release of an endogenous pyrogen from guinea pig leukocytes in vitro: a new model for investigating the role of lymphocytes in fevers induced by antigen in hosts with delayed hypersensitivity.

1977 ◽  
Vol 145 (5) ◽  
pp. 1288-1298 ◽  
Author(s):  
P Chao ◽  
L Francis ◽  
E Atkins
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Polymorphonuclear Leukocytes ◽  
Delayed Hypersensitivity ◽  
Endogenous Pyrogen ◽  
Phagocytic Cells ◽  
Relationship Of ◽  
The Relationship

Guinea pig periotoneal exudate (PE) cells incubated overnight in vitro with heat-killed Staphylococci released an endogenous pyrogen (EP) that could be assayed by intravenous injection in rabbits. The febrile responses were linearly related to the dosage of EP over an eightfold range. PE cells derived from guinea pigs with delayed hypersensitivity (DH) to bovine gamma globulin (BGG), also released EP when incubated with antigen in vitro. This reaction was specific and did not occur withe PE cells from normal or complete Freund's adjuvant-sensitized guinea pigs. Studies indicated that monos and/or polymorphonuclear leukocytes rather than lymphocytes were the source of EP. However, when incubated with BGG and sufficient dosages of BGG-sensitized lymphocytes, normal PE cells released EP over a 42 h period. These results suggest that antigen stimulates specifically sensitized lymphocytes to release an agent (perhaps a lymphokine) that activates phagocytic cells to release EP. This model offers unique advantages for investigating in vitro the role of the lymphocyte in antigen-induced fever in DH as well as the relationship of this lymphocyte-induced activity to other known biologic activities mediated by antigen stimulated lymphocytes.

The relationship between motor activity and transmural potential difference in the guinea pig intestine in vitro: is there a neural link?

1986 ◽  
Vol 64 (7) ◽  
pp. 993-998 ◽  
Author(s):  
Beverley Greenwood ◽  
Stephanie Diamant ◽  
J. S. Davison
Keyword(s):  
Guinea Pig ◽  
Motor Activity ◽  
Colonic Motility ◽  
Potential Difference ◽  
Histological Data ◽  
The Relationship ◽  
Spontaneous Fluctuations ◽  
Pig Jejunum

The aim of the experiments was to examine, in vitro, the role of the enteric nervous system in the relationship between motor activity and transmural potential difference (PD) in the guinea pig jejunum and colon using the nerve blocking agents tetrodotoxin (TTX) and aconitine. Histological data showed that perfusion of the intestinal segments with gassed Hepes solution was essential for the maintenance of transmural PD. Disruption of the mucosa was associated with a loss of spontaneous fluctuations in transmural PD without any loss of spontaneous motor activity. Under spontaneous conditions, a neural pathway exists linking jejunal and colonic motility with transmural PD. However, in some cases a mechanical link was also apparent, as an attenuated TTX and aconitine–resistant component.

scholarly journals A STUDY OF THE RELATIONSHIP OF THE SCROTAL SWELLING AND RICKETTSIA BODIES TO MEXICAN TYPHUS FEVER

1930 ◽  
Vol 52 (2) ◽  
pp. 195-199 ◽  
Author(s):  
M. Ruiz Castaneda
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Human Case ◽  
Tunica Vaginalis ◽  
Two Generations ◽  
Scrotal Swelling ◽  
Typhus Fever ◽  
Relationship Of ◽  
The Relationship

The experiments recorded above have demonstrated the following points: 1. Scrotal swelling can appear in guinea pigs directly inoculated from a human case of Mexican typhus fever. 2. In certain strains of this disease, a number of generations of guinea pigs may show absolutely no scrotal swelling, which, however, may reappear in subsequent animals, suggesting—though not absolutely proving—that the scrotal swelling is an integral part of the disease and is not due to an incidental accompanying organism. If the latter were true, one would expect the organisms that caused the scrotal swelling to disappear during the negative generations. 3. A typhus fever sustained by a guinea pig without scrotal swelling protects against the swelling upon subsequent inoculation with a strain which produces this with considerable regularity. 4. Louse passage increases the capacity of a strain to produce the scrotal lesion, probably because of the considerable accumulation of rickettsia in the louse, but in the experiment noted, even after louse passage, two generations without swelling occurred, followed by reoccurrence of the swelling. We believe that these observations, taken together, can be interpreted in favour of the likelihood that the swelling is a part of the disease and that the rickettsia-like organisms described by Mooser in the tunica vaginalis have etiological significance.

Conclusions and recommendations from the Helene Harris Memorial Trust Fourth Biennial International Forum on Ovarian Cancer 11–14 May 1993, Toronto, Canada

1994 ◽  
Vol 4 (2) ◽  
pp. 135-143 ◽  
Author(s):  
T. Blackett ◽  
F. Sharp
Keyword(s):  
Ovarian Cancer ◽  
Tumor Suppressor Genes ◽  
Malignant Tumors ◽  
Full Range ◽  
Brca1 Gene ◽  
Future Research ◽  
Relationship Of ◽  
The Relationship

The Helene Harris Memorial Trust organizes biennial international meetings of leading clinicians and scientists to discuss progress in the understanding and treatment of ovarian cancer. The conclusions of this meeting, together with recommendations for future research are published as a guide to others working in this field.The 107 conclusions and recommendations presented cover the full range of current topics in ovarian cancer research including the biology of early and borderline tumors, the relationship of benign to malignant tumors,in vitromodels, the role of cytokines, genetic epidemiology, oncogenes and tumor suppressor genes, allele loss, localization of the BRCA1 gene, DNA ploidy in prognosis, the therapeutic use of interferon, platinum and taxoid drugs, screening with panels of tumor antigensm immunotherapy and potenial for gene therapy.

scholarly journals Potential Role of Laccases in the Relationship of the Maize Late Wilt Causal Agent, Magnaporthiopsis maydis, and Its Host

2020 ◽  
Vol 6 (2) ◽  
pp. 63
Author(s):  
Ofir Degani ◽  
Yuval Goldblat
Keyword(s):  
Potential Role ◽  
Dry Weight ◽  
Maize Cultivars ◽  
Maize Plants ◽  
Relationship Of ◽  
The Relationship ◽  
Host Tissues ◽  
Adult Plants

Late wilt is a vascular disease of maize (Zea mays L.) caused by the soil-borne and seed-borne fungus Magnaporthiopsis maydis. The pathogen penetrates the roots of maize plants at the seedling stage, grows into the xylem vessels, and gradually spreads upwards. From the flowering stage to the kernel ripening, the fungal hyphae and secreted materials block the water supply in susceptible maize cultivars, leading to rapid dehydration and death. Laccase is an enzyme secreted by fungus for diverse purposes. The M. maydis laccase gene was identified in our laboratory, but under what conditions it is expressed and to what functions remain unknown. In the current study, we tested the influence of plant age and tissue source (roots or leaves) on M. maydis laccase secretion. The results show increasing laccase secretion as corn parts (as ground tissue) were added to the minimal medium (MM). Furthermore, roots stimulated laccase secretion more than leaves, and adult plants enhanced laccase secretion more than young plants. This implies the possibility that the richer lignin tissue of adult plants may cause increased secretion of the enzyme. In vitro pathogenicity assay proved the ability of M. maydis to develop inside detached roots of maize, barley, watermelon, and cotton but not peanut. Testing root powder from those plants in MM revealed a negative correlation between M. maydis growth (expressed as biomass) and laccase secretion. For example, while the addition of maize, barley, or cotton root powder led to increasing fungal dry weight, it also resulted in relatively lower laccase activity. Watermelon and peanut root powder led to opposite responses. These findings suggest a pivotal role of laccase in the ability of M. maydis to exploit and grow on different host tissues. The results encourage further examination and a deeper understanding of the laccase role in these interesting host–pathogen interactions.

Prestin as an Otologic Biomarker of Cisplatin Ototoxicity in a Guinea Pig Model

2017 ◽  
Vol 158 (3) ◽  
pp. 541-546 ◽  
Author(s):  
James Naples ◽  
Robert Cox ◽  
Gregory Bonaiuto ◽  
Kourosh Parham
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Auditory Brainstem ◽  
Therapeutic Interventions ◽  
Saline Injection ◽  
Brainstem Response ◽  
Experimental Animal Study ◽  
Guinea Pig Model ◽  
The Relationship

Objective To evaluate (1) whether changes in serum prestin aid in early detection of cisplatin ototoxicity, (2) the role of diltiazem as an otoprotectant, and (3) whether prestin levels are sensitive to effects of diltiazem. Study Design Experimental animal study. Setting Translational research laboratory. Subjects Twenty female guinea pigs. Methods Two groups of 10 guinea pigs were used. The relationship between serum prestin levels and auditory brainstem response (ABR) thresholds was compared between the groups. All animals had baseline blood draws and ABR thresholds recorded prior to cisplatin administration. Intraperitoneal cisplatin bolus (8 mg/kg) was administered followed by 5 consecutive days of intratympanic (IT) diltiazem (2 mg/kg) or sham IT-saline injection. Serum prestin levels and ABR thresholds were measured at days 1, 2, 3, 7, and 14 postcisplatin. Results In sham, IT-saline–treated animals, mean prestin levels were elevated above baseline on days 1 to 7. The prestin levels were significantly elevated from baseline on day 1 ( P < .001), while significant ABR threshold elevations did not occur until day 2 ( P = .028) for click-evoked ABRs and day 3 ( P = .041) for tones. In diltiazem-treated animals, prestin levels were not elevated above baseline but ABR thresholds were elevated on days 1 to 3. However, the thresholds returned toward baseline on days 7 and 14. Conclusion Changes in serum prestin levels were detectable prior to shifts in ABR thresholds in a guinea pig cisplatin ototoxicity model. These changes did not occur in diltiazem-treated animals. Prestin may serve as a biomarker of cochlear injury that is sensitive to therapeutic interventions in cisplatin ototoxicity.

scholarly journals THE RELATIONSHIP OF DELAYED HYPERSENSITIVITY AND CIRCULATING ANTIBODY TO EXPERIMENTAL ALLERGIC THYROIDITIS IN INBRED GUINEA PIGS

1961 ◽  
Vol 113 (4) ◽  
pp. 611-624 ◽  
Author(s):  
Philip R. B. McMaster ◽  
Edwin M. Lerner ◽  
Eurmal D. Exum
Keyword(s):  
Antibody Titer ◽  
Guinea Pigs ◽  
Delayed Hypersensitivity ◽  
Thyroid Extract ◽  
Thyroid Antibody ◽  
Delayed Reactions ◽  
Relationship Of ◽  
The Relationship ◽  
Experimental Allergic ◽  
Circulating Antibody

Strain 13 histocompatible guinea pigs developed allergic thyroiditis after immunization with thyroid extracts derived from the same strain or from other strains of guinea pigs. This thyroiditis appeared as early as 5 days after immunization, and by 7 weeks was uniformly present and generally severe. 7 weeks after immunization, the anti-thyroid antibody titer correlated with the presence and degree of thyroiditis. However, at certain other times after immunization, the titer did not correlate with the thyroiditis. By contrast, all animals with thyroiditis, which were skin-tested with thyroid extract, exhibited delayed hypersensitivity. Moreover, all those which failed to respond with delayed reactions, when skin-tested, had not developed thyroiditis. The present work correlates the presence of experimental allergic thyroiditis with delayed hypersensitivity.

scholarly journals THE "DELAYED HYPERSENSITIVITY" INDUCED BY ANTIGEN-ANTIBODY COMPLEXES

1958 ◽  
Vol 108 (6) ◽  
pp. 823-841 ◽  
Author(s):  
Sidney Raffel ◽  
J. Michael Newel
Keyword(s):  
Delayed Hypersensitivity ◽  
Small Doses ◽  
Circulating Antibodies ◽  
Antigen Antibody ◽  
Relationship Of ◽  
The Relationship ◽  
Relative Persistence

The "delayed hypersensitive" reactivity induced by antigen-antibody complexes has been studied from the standpoints of the role of such complexes in establishing this state, and the relationship of this state to classical delayed hypersensitivity. It has been shown that the reactivity established by antigen-antibody complexes appears early after injection, disappears within a few days, and is characterized by several properties which make it appear similar to true delayed hypersensitivity, including its appearance, its relative persistence for 48 hours, and its occurrence in the absence of antibodies. By the same tokens, it may be distinguished from hypersensitive reactions of the immediate type. It is referred to here as reactivity of the Jones-Mote type. Antigen alone stimulates exactly the same kind of early reactive state, but with larger doses of antigen this is later replaced by other immunologic responses including circulating antibodies and Arthus reactivity. If sufficiently small doses of antigen are employed, however, the "monophasic" reaction which follows antigen-antibody complexes consisting of the Jones-Mote type of skin responsiveness may be seen. The dermal reactivity under discussion is unlike classical delayed hypersensitivity chiefly in its evanescent character; it is present only during a few days early after antigen administration. It is suggested that this kind of reactivity, which may perhaps require a category of its own, may be related to the "tissue immunity" to tumor transplants which has been observed in mice.

scholarly journals Studies on respiratory infection: I. The influence of particle size on respiratory infection with anthrax spores

1953 ◽  
Vol 51 (3) ◽  
pp. 359-371 ◽  
Author(s):  
H. A. Druett ◽  
D. W. Henderson ◽  
L. Packman ◽  
S. Peacock
Keyword(s):  
Particle Size ◽  
Respiratory Infection ◽  
Guinea Pigs ◽  
Particle Sizes ◽  
Single Spore ◽  
Concentration Time ◽  
Anthrax Spores ◽  
Relationship Of ◽  
The Relationship

Experiments to determine the role of particle size in the infectivity of anthrax spores are described. Clouds of homogeneous particles were produced. The mortality-dosage curves for guinea-pigs and monkeys are given for clouds of various particle sizes. Data are given on the effect of time in the concentration-time relationship. The results are compared with those recorded by other workers on the relationship of particle size to respiratory retention.Infectivity was highest with single-spore clouds, falling off as particle size increased. Reasons are given for attributing this effect to difference in site of deposition of different-sized particles.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

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