scholarly journals THE EPIDEMIOLOGY OF A RABBIT RESPIRATORY INFECTION

1924 ◽  
Vol 40 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Leslie T. Webster
Keyword(s):  
Respiratory Infection ◽  
Spontaneous Recovery ◽  
Rockefeller Institute ◽  
Large Numbers ◽  
Nasal Passages

The onset of spontaneous snuffles in rabbits at The Rockefeller Institute is preceded by the appearance in the nasal passages of Bacterium lepisepticum. The active stages of snuffles infection are associated with the presence in these passages of large numbers of this bacterium. Spontaneous recovery from snuffles is associated with a diminution in number or a disappearance of these bacteria from the nasal passages. Various experimental procedures reduce the resistance of rabbits to spontaneous snuffles.

scholarly journals THE EPIDEMIOLOGY OF A RABBIT RESPIRATORY INFECTION

1924 ◽  
Vol 39 (6) ◽  
pp. 843-856 ◽  
Author(s):  
Leslie T. Webster
Keyword(s):  
Respiratory Infection ◽  
Rockefeller Institute ◽  
Nasal Passages ◽  
Animal House

100 adult rabbits taken at random from The Rockefeller Institute animal house were examined clinically, anatomically, and bacteriologically for evidence of respiratory infection. 58 of these rabbits proved to have snuffles; 42 were free of the disease. Bacterium lepisepticum was the predominating organism in the nasal flora of 55 of the 58 rabbits showing snuffles. This organism was also cultured from the nasal passages of eight normal rabbits. Bacillus bronchisepticus was associated with Bacterium lepisepticum in the nasal flora of eight rabbits with snuffles. It was also cultured from the nares of twenty-two normal rabbits. Fifteen normal rabbits showed neither Bacterium lepisepticum nor Bacillus bronchisepticus.

scholarly journals THE EPIDEMIOLOGY OF A RABBIT RESPIRATORY INFECTION

1924 ◽  
Vol 39 (6) ◽  
pp. 857-877 ◽  
Author(s):  
Leslie T. Webster
Keyword(s):  
Respiratory Infection ◽  
Rockefeller Institute ◽  
Gram Negative ◽  
Nasal Passages

The bacteria constituting the nasal flora of rabbits at The Rockefeller Institute may be enumerated as follows in the order of their frequency: (1) Micrococcus catarrhalis group, 80 per cent; (2) Bacterium lepisepticum, 70 per cent; (3) Gram-negative cocci which ferment dextrose, lactose, saccharose, maltose, and mannite, but not salicin and Bacillus bronchisepticus, 40 per cent; (4) Staphylococci, streptococci, and various intestinal bacilli which probably are localized at the external nares, 10 per cent. Bacterium lepisepticum is the predominating organism in the nasal passages of the rabbits affected with snuffles.

scholarly journals THE TRANSMISSION AND TREATMENT OF INFECTIOUS OPHTHALMIA OF CATTLE

1924 ◽  
Vol 39 (6) ◽  
pp. 803-810 ◽  
Author(s):  
F. S. Jones ◽  
Ralph B. Little
Keyword(s):  
Nasal Passage ◽  
Large Numbers ◽  
Warm Weather ◽  
Short Period ◽  
Negative Findings ◽  
Fine Spray ◽  
Sporadic Cases ◽  
Nasal Passages ◽  
Set Up ◽  
Gain Access

The experiments in which transmission of the disease was attempted by flies hardly parallel the observations within the herd. It is not unusual to observe large numbers of flies feeding on the exudate. Slight disturbances may interrupt feeding and cause the flies to disperse and within a short period alight about the eyes of other cows. The experiments, however, bring out the fact that the bacterium will not remain viable for even a few minutes in the digestive tract of the fly. Its life on the external surfaces of the fly is extremely short and in our observations has not exceeded 3 hours. The latter fact strengthens the opinion that in the main the infection is not dust-borne since the bacterium soon dies when not in contact with the eye. Two other points are of considerable significance. The ability of the organism to maintain itself on the eye for considerable periods after the acute symptoms have subsided may explain the reappearance of cases during the warmer months. The organism can exist in the eye throughout the winter and with the warm weather flies may transmit it to other susceptible individuals and thus a nucleus of an epidemic may be established. The presence of the organism in the nasal passages in the incubation stage and early in the disease in two of our experimental animals affords an explanation for the appearance of the disease in sporadic cases in the colder months. It is assumed that nasal exudate as a fine spray may be forcibly expelled and directly reach the eyeball of a normal individual. It has been shown that small quantities of culture sprayed on the cornea are capable of giving rise to the characteristic disease. The irregularity of the elimination of the organism through the nostril may be explained by the effect of inflammation on the tear duct. In experimental cases a small quantity of bouillon containing the culture was dropped or sprayed on the cornea. Doubtless the bacilli are deposited on the mucosa of the tear duct. Here they may multiply and set up an inflammation and thus gain access to the nasal passage. To what degree the virus is spread by the forcible expulsion of nasal secretion containing lacrimal fluid cannot be determined. The elimination of the bacilli from the nasal passage in our experimental inoculations leads us to believe that in the main the phenomenon is associated with early infections. The examination of the nasal passages of a large number of well established cases with negative findings tends to corroborate this view. Of interest to those concerned with the treatment of animal diseases is the readiness with which the inflammation subsides when treated with 1:40 zinc sulfate.

scholarly journals THE FECAL FLORA OF VARIOUS STRAINS OF MICE. ITS BEARING ON THEIR SUSCEPTIBILITY TO ENDOTOXIN

1962 ◽  
Vol 115 (6) ◽  
pp. 1149-1160 ◽  
Author(s):  
Russell W. Schaedler ◽  
René J. Dubos
Keyword(s):  
Environmental Temperature ◽  
Bacterial Flora ◽  
Lethal Effect ◽  
Rockefeller Institute ◽  
Gram Negative ◽  
E Coli ◽  
The Past ◽  
Adult Mice ◽  
Large Numbers ◽  
Sanitary Conditions

Adult mice from seven different colonies were studied with regard to (a) the numbers and types of bacteria that could be cultivated from their stools; (b) their resistance to the lethal effect of endotoxins prepared from three strains of Gram-negative bacilli. See PDF for Structure In six of the seven colonies, the stools yielded large numbers of various types of lactobacilli, enterococci, and Gram-negative bacilli. Most animals in these colonies died within 48 hours following injection of endotoxin. The other mouse colony (NCS) has been maintained for the past three years at the Rockefeller Institute under exacting sanitary conditions; it is free of many types of common mouse pathogens. The stool flora of NCS mice yielded very large numbers of viable lactobacilli (109 per gm), representing at least three different morphological types. In contrast, it contained only few enterococci and Gram-negative bacilli (less than 106 per gm). Moreover, E. coli, Proteus sp., and Pseudomonas sp. could not be recovered from the stools under normal conditions. NCS mice proved resistant to the lethal effect of endotoxins. These characteristics of the NCS colony prevailed whether the animals were housed continuously in individual cages on wire grids, or grouped continuously in large cages with wood shavings as litter. However, the composition of the bacterial flora could be rapidly and profoundly altered by a variety of unrelated disturbances such as sudden changes in environmental temperature, crowding in cages, handling of the animals, administration of antibacterial drugs, etc. The first effect of the change was a marked decrease in the numbers of lactobacilli and commonly an increase in the numbers of Gram-negative bacilli and enterococci. When tested 3 weeks after these disturbances some NCS animals were found to have become susceptible to the lethal effects of endotoxin.

scholarly journals Experiments bearing on the susceptibility of the striped hamster ( Cricetulus griseus ) to Leishmania of Chinese Kala Azar

1926 ◽  
Vol 100 (704) ◽  
pp. 374-379 ◽  
Keyword(s):  
Experimental Study ◽  
Subcutaneous Injection ◽  
Laboratory Animal ◽  
Spontaneous Recovery ◽  
Good Health ◽  
The Other ◽  
Cricetulus Griseus ◽  
Intraperitoneal Route ◽  
Kala Azar ◽  
Large Numbers

The experimental study of Kala Azar has been greatly facilitated by the introduction of the use of the Chinese striped hamster ( C. griseus ) as a laboratory animal. Smyly and Young (1924) were the first to demonstrate the marked susceptibility of this animal to infection with Leishmania , and subsequently, in collaboration with Brown (Young, Smyly and Brown, 1926), they confirmed and extended their original observations. Utilizing large numbers of hamsters, they were able to show that the intraperitoneal route is the most certain method of infecting this rodent. Out of a total of 182 hamsters inoculated in this way, 129 were positive after intervals varying from 10 to 347 days; and they noted that the parasites originally inoculated into the peritoneum could persist there for about a month after they were introduced. Two hamsters were infected by intrapleural injection, and both became infected, one after 15 days, and the other after an interval of 67 days. The infection in each case was detected by liver puncture. With regard to subcutaneous injection of the parasites into hamsters, these authors only succeeded in infecting three hamsters out of a total of 14. In connection with all their experiments it should be noted that their animals were invariably inoculated with relatively large quantities of liver and splenic emulsion, rich in parasites. It is important to note that in spite of the fact that large numbers of parasites were usually present in the spleen and liver, and the former organ was greatly enlarged, the animals seemed to remain in good health for long periods; although no tendency to spontaneous recovery was ever observed.

Inoculum size, incubation period and severity of malaria. Analysis of data from malaria therapy records

Parasitology ◽  
1995 ◽  
Vol 110 (1) ◽  
pp. 7-19 ◽  
Author(s):  
J. R. Glynn ◽  
D. J. Bradley
Keyword(s):  
Spontaneous Recovery ◽  
Strong Relationship ◽  
Inoculum Size ◽  
Patent Period ◽  
Data Set ◽  
Single Strain ◽  
Malaria Therapy ◽  
Large Numbers ◽  
Unique Source ◽  
Source Of Information

The size of the infecting inoculum may influence the severity of malaria, but evidence is scarce. Malaria therapy records provide a unique source of information on induced malaria in people. The therapy was given to large numbers of neurosyphilis patients and the malaria was left untreated as long as possible. Data from patients treated at the Horton Hospital, Epsom 1923–60 with a single strain of vivax malaria were analysed to assess the influence of inoculum size on severity of disease. Malaria was induced by mosquito bite, blood inoculation or direct sporozoite inoculation. The different measures of inoculum size were inversely correlated with pre-patent period, as expected. Overall, information was available on a total of 563 non-immune patients who were not treated during the first 5 days of patent parasitaemia. No strong or consistent relationships were found between measures of inoculum size and any of the measures of severity used: neither parasitaemia levels, nor peak fevers, nor number of paroxysms of fever. In the largest data set, longer pre-patent periods were associated with tertian fever, spontaneous recovery and less use of modifying treatment. Difficulties in interpreting the results are discussed, particularly with respect to misclassification of both exposure and outcome variables. While an inoculum size-severity relationship cannot be ruled out, a strong relationship is very unlikely.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

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