scholarly journals FATAL INFECTION OF IRRADIATED WHITE MICE WITH EUROPEAN TYPHUS BY THE INTRA-ABDOMINAL ROUTE

1941 ◽  
Vol 73 (5) ◽  
pp. 669-680
Author(s):  
P. Y. Liu ◽  
John C. Snyder ◽  
John F. Enders
Keyword(s):  
Guinea Pigs ◽  
Brain Lesions ◽  
Rickettsial Infection ◽  
X Ray ◽  
Fatal Infection ◽  
Adult Mice ◽  
Abdominal Route ◽  
Peritoneal Washings ◽  
Cross Immunity ◽  
Observation Period

A fatal infection of irradiated white mice with the Breinl strain of European typhus has been established and passed serially for 22 passages by the intra-abdominal route. Rickettsiae were abundant and easily demonstrable in the moribund or dead mice. The mortality of irradiated mice infected with passage material (peritoneal washings or blood) was nearly 100 per cent as contrasted to no mortality in the control mice given the same dose of x-ray (450 R) and the same volume of fluid intra-abdominally. (The observation period of control mice was arbitrarily limited to 14 days.) After eighteen passages in irradiated mice no increase in virulence for non-irradiated adult mice was detected. After passage in guinea pigs, the rickettsial infection deriving from the mouse passage material was identical with the Breinl strain as judged by fever, cross immunity tests, and brain lesions in sections.

scholarly journals GP management of community-acquired pneumonia in Italy: the ISOCAP study

2005 ◽  
Vol 63 (1) ◽  
Author(s):  
C.M. Sanguinetti ◽  
F. De Benedetto ◽  
C.F. Donner
Keyword(s):  
Outpatient Treatment ◽  
The Elderly ◽  
Community Acquired Pneumonia ◽  
Microbiological Analysis ◽  
X Ray ◽  
Systemic Arterial Hypertension ◽  
Chest X Ray ◽  
Socioeconomic Burden ◽  
Copd Diagnosis ◽  
Observation Period

Background. Community-Acquired Pneumonia (CAP) is still a significant problem in terms of incidence, mortality rate, particularly in infants and the elderly, and socioeconomic burden. General Practitioners (GPs) are the first reference for patients with this disease, but there are few published studies regarding the outpatient treatment of CAP. Methods. The ISOCAP study aimed to identify the type and outcome of the diagnostic-therapeutic management of CAP by GPs in Italy, within the framework of developing a closer interrelationship between GPs and pulmonary specialists. Thirty-six Pulmonary Divisions throughout Italy each contacted 5 local GPs who agreed to recruit the first 5 consecutive patients who consulted them for suspected CAP within the study’s 1-year observation period. Results. A total of 183 GPs took part in the study and enrolled, by the end of the observation period, 763 CAP patients; of these, complete data was available for 737 patients [males=373, females=364, mean age (±SD) 58.8±19.6 years]. 64.4% of patients had concomitant diseases, mainly systemic arterial hypertension and COPD. Diagnosis of CAP was based by GPs on physical examination only in 41.6% of cases; in the remaining chest X-ray was also performed. In only 4.6% of patients were samples sent for microbiological analysis. All patients were treated with antibiotics: 76.7% in mono-therapy, 23.3% with a combination of antibiotics. The antibiotic class most prevalently used in mono-therapy was cephalosporin, primarily ceftriaxone; the most frequently used combinations were cephalosporin+macrolide and cephalosporin+quinolone. Mono-therapy was effective in 70% of cases, the combination of two or more antibiotics in 91.2% of patients. Overall treatment efficacy was 94.7%; hospitalisation was required in 8.5% of cases. Conclusions. Outpatient management of CAP by GPs in Italy is effective, hospitalisation being necessary only in the most severe cases due to age, co-morbidities or extent of pneumonia. This signifies a very significant savings in national health costs.

scholarly journals EFFECT OF LOCAL UV RADIATION ON THE MORPHOFUNCTIONAL STATE OF THE SKIN OF GUINEA PIGS IN EARLY AND REMOTE PERIODS AFTER IRRADIATION

2020 ◽  
Vol 73 (4) ◽  
pp. 705-707
Author(s):  
Tetyana V. Zvyagintseva ◽  
Svitlana I. Myronchenko ◽  
Nataliia I. Kytsiuk ◽  
Olga V. Naumova
Keyword(s):  
Ultraviolet Irradiation ◽  
Guinea Pigs ◽  
Acute Inflammation ◽  
Elastic Fibers ◽  
Control Group ◽  
Entire Observation Period ◽  
Morphological Picture ◽  
Morphometric Methods ◽  
Observation Period

The aim is to establish the features of morphological and morphometric changes in the skin of guinea pigs in erythemal, early post-erythemal and late post-erythemic periods after local ultraviolet irradiation. Materials and methods: Studies were conducted on 54 albino guinea pigs weighing 400-500 g. Ultraviolet erythema was caused by irradiation in 1 minimum erythemal dose. The control group included intact guinea pigs. After 2, 4 hours, on the 3rd, 8th, 15th, 21st, 28th day, the fragments of the irradiated skin were investigated using histochemical and morphometric methods. Results: After 2, 4 hours after irradiation, dyscirculatory changes in the skin develop. By the 3rd day of the experiment a morphological picture of acute inflammation in the epidermis and dermis develops, apoptotic keratinocytes appear (sunburn cells), which is accompanied by thickening of the epidermis and an increase in the density of fibroblasts. By the 8th day proliferative-hyperplastic and degenerative changes begin to prevail, including dystrophic nature, the thickness of the epidermis and the density of fibroblasts reach a maximum. In the long term, on the 15-28th day, dystrophic changes of the epidermis, dyskeratosis, changes in the number and structure of elastic fibers with an increase in uneven fibrosis, collagenization processes and the development of sclerotic changes, as well as a significant thickening of the epidermis, an increase in the density of fibroblasts are observed. Conclusions: The data obtained indicate pronounced morphofunctional changes in the skin in the zone of local ultraviolet irradiation observed throughout the entire observation period.

scholarly journals Broadband study of blazar 1ES 1959+650 during flaring state in 2016

2018 ◽  
Vol 611 ◽  
pp. A44 ◽  
Author(s):  
S. R. Patel ◽  
A. Shukla ◽  
V. R. Chitnis ◽  
D. Dorner ◽  
K. Mannheim ◽  
...  
Keyword(s):  
High Energy ◽  
Spectral Energy ◽  
Quiescent State ◽  
Energy Bands ◽  
Energy Distributions ◽  
X Ray ◽  
Broadband Emission ◽  
June July ◽  
Power Law Index ◽  
Observation Period

Aims. The nearby TeV blazar 1ES 1959+650 (z = 0.047) was reported to be in flaring state during June–July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS collaborations. We studied the spectral energy distributions (SEDs) in different states of the flare during MJD 57530–57589 using simultaneous multiwaveband data with the aim of understanding the possible broadband emission scenario during the flare. Methods. The UV-optical and X-ray data from UVOT and XRT respectively on board Swift and high energy γ-ray data from Fermi-LAT were used to generate multiwaveband lightcurves as well as to obtain high flux states and quiescent state SEDs. The correlation and lag between different energy bands was quantified using discrete correlation function. The synchrotron self-Compton (SSC) model was used to reproduce the observed SEDs during flaring and quiescent states of the source. Results. A good correlation is seen between X-ray and high energy γ-ray fluxes. The spectral hardening with increase in the flux is seen in X-ray band. The power law index vs. flux plot in γ-ray band indicates the different emission regions for 0.1–3 GeV and 3–300 GeV energy photons. Two zone SSC model satisfactorily fits the observed broadband SEDs. The inner zone is mainly responsible for producing synchrotron peak and high energy γ-ray part of the SED in all states. The second zone is mainly required to produce less variable optical-UV and low energy γ-ray emission. Conclusions. Conventional single zone SSC model does not satisfactorily explain broadband emission during observation period considered. There is an indication of two emission zones in the jet which are responsible for producing broadband emission from optical to high energy γ-rays.

scholarly journals Synaptic migration and reorganization after noise exposure suggests regeneration in a mature mammalian cochlea

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tyler T. Hickman ◽  
Ken Hashimoto ◽  
Leslie D. Liberman ◽  
M. Charles Liberman
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Auditory Nerve ◽  
Guinea Pigs ◽  
Noise Exposure ◽  
Recovery Period ◽  
Nerve Fibers ◽  
Neural Regeneration ◽  
Adult Mice ◽  
Synaptic Markers

AbstractOverexposure to intense noise can destroy the synapses between auditory nerve fibers and their hair cell targets without destroying the hair cells themselves. In adult mice, this synaptopathy is immediate and largely irreversible, whereas, in guinea pigs, counts of immunostained synaptic puncta can recover with increasing post-exposure survival. Here, we asked whether this recovery simply reflects changes in synaptic immunostaining, or whether there is actual retraction and extension of neurites and/or synaptogenesis. Analysis of the numbers, sizes and spatial distribution of pre- and post-synaptic markers on cochlear inner hair cells, in guinea pigs surviving from 1 day to 6 months after a synaptopathic exposure, shows dramatic synaptic re-organization during the recovery period in which synapse counts recover from 16 to 91% of normal in the most affected regions. Synaptic puncta move all over the hair cell membrane during recovery, translocating far from their normal positions at the basolateral pole, and auditory-nerve terminals extend towards the hair cell’s apical end to re-establish contact with them. These observations provide stronger evidence for spontaneous neural regeneration in a mature mammalian cochlea than can be inferred from synaptic counts alone.

scholarly journals TOXIC SUBSTANCES PRODUCED BY PNEUMOCOCCUS

1912 ◽  
Vol 16 (5) ◽  
pp. 644-664 ◽  
Author(s):  
Rufus Cole
Keyword(s):  
Blood Serum ◽  
Salt Solution ◽  
Guinea Pigs ◽  
Bile Salts ◽  
Considerable Proportion ◽  
Toxic Substances ◽  
Bacterial Cells ◽  
Bacterial Protein ◽  
Dilute Solutions ◽  
Peritoneal Washings

1. The filtered blood serum of rabbits infected with pneumococci is not toxic. 2. Extracts of pneumococci prepared by keeping emulsions of the bacteria in salt solution at 37° C. for varying periods of time may be toxic, and when injected intravenously into guinea pigs, may produce a train of symptoms followed by acute death resembling that seen in acute anaphylaxis. Such extracts, however, are not uniformly toxic and it has been impossible to discover the exact conditions under which such extracts become toxic. 3. When the centrifugalized peritoneal washings of guinea pigs infected with pneumococci are injected into the circulation of normal guinea pigs, these animals very frequently exhibit symptoms like those seen in acute anaphylaxis, and a considerable proportion of the animals die acutely. 4. When pneumococci are dissolved in dilute solutions of bile salts and the solution resulting is injected intravenously into rabbits and guinea pigs, these animals show with great constancy the same symptoms that are seen in acute anaphylaxis. The solution of pneumococci in bile may occur in ten minutes at 37° C. or in half an hour on ice. This is considered evidence that the toxicity of the solution does not result from digestion of the bacterial protein, but is due to substances preformed in the bacterial cells and set free on their solution. The toxicity of the solution is diminished or destroyed by heating to 55° C. or over.

scholarly journals Dietary calcium and phosphate restriction in guinea-pigs during pregnancy: fetal mineralization induces maternal hypocalcaemia despite increased 1α,25-dihydroxycholecalciferol concentrations

2000 ◽  
Vol 84 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Katrien Rummens ◽  
Erik Van Herck ◽  
Rita van Bree ◽  
Roger Bouillon ◽  
F. André Van Assche ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Plasma Concentrations ◽  
Dual Energy ◽  
Whole Body ◽  
Hydroxylase Activity ◽  
Mineral Density ◽  
X Ray ◽  
Highly Correlated ◽  
Stimulation Of

Guinea-pig fetuses at term are mineralized to a degree comparable with human fetuses, which makes the guinea-pig an attractive animal model to study maternal–fetal interactions with regard to Ca and phosphate (P) homeostasis. We studied non-pregnant and pregnant (day 57) vitamin D-replete guinea-pigs, fed either a normal guinea-pig chow with 9·6 g Ca/kg and 4·9 g P/kg or a study diet with 2 g Ca/kg and 1 g P/kg (low-Ca–P diet) for 7–8 weeks. Both pregnancy and the low-Ca–P diet decreased plasma concentrations of 25-hydroxycholecalciferol (25(OH)D3), but increased total and free 1α,25-dihydroxycholecalciferol (1,25(OH)2D3), strongly suggesting an additive stimulation of 1α-hydroxylase activity. Maternal and fetal 25(OH)D3and 1,25(OH)2D3levels were highly correlated (r0·82 and 0·92 respectively, P<0·001). Dual-energy absorption X-ray absorptiometry (DXA) showed that both pregnancy and the low-Ca–P diet decreased bone mineral density (BMD) of the maternal femur, particularly at the distal metaphysis. Despite higher 1,25(OH)2D3concentrations and lower BMD, pregnant animals on the low-Ca–P diet were hypocalcaemic; blood Ca2+levels were inversely correlated with the number of fetuses in this group (r-0·93, P<0·001). Fetal growth as well as mineralization (assessed by whole-body and femoral DXA, bone histomorphometry and plasma–bone osteocalcin measurements) were unaltered in the low-Ca–P group. In conclusion, fetal mineralization proceeds normally but induces maternal hypocalcaemia in guinea-pigs with dietary restriction of Ca and P.

scholarly journals A RICKETTSIAL INFECTION IN CANADIAN VOLES

1946 ◽  
Vol 84 (1) ◽  
pp. 37-50 ◽  
Author(s):  
James A. Baker
Keyword(s):  
Guinea Pigs ◽  
Scrub Typhus ◽  
Living Cells ◽  
Rickettsial Infection ◽  
Contact Points ◽  
Inapparent Infection ◽  
On This Island ◽  
The Relationship ◽  
Lethal Doses ◽  
Infective Agent

From apparently normal voles captured on Grosse Isle, Province of Quebec, Canada, an infective agent has been grown in embryonated eggs, and by inoculation an inapparent infection was established in voles, mice, guinea pigs, hamsters, and rats. No growth of the agent was obtained in the absence of living cells, and the manner of its development in the yolk sac of embryonated eggs, as well as morphological, epidemiological, and pathogenic features, indicates a rickettsial nature. The inability to transmit infection by either cage or intrauterine contact points to a vector, and mites are shown to have a probable part in the epidemiology. Mice infected with the vole agent resist lethal doses of the Karp strain of scrub typhus, and certain epidemiological, morphological, and immunological features support the relationship indicated by the mouse tests. It is therefore concluded that voles on this island have an inapparent infection due to a rickettsia that may be related to the rickettsia of scrub typhus.

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