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ABSTRACT: The surface structures of the cells of Pasteurella pneumotropica from mice and Pasteurella multocida from rabbits were examined by transmission electron microscopy after ruthenium red staining and polycationic ferritin labelling. P. pneumotropica strains ATCC 35149 and K 79114 had slight extracellular fibrous materials associated with cell walls with ruthenium red staining. Ferritin labelling method revealed thick strands or sparsely ferritin-labelled materials on the cell surface of the strains. P. multocida strains Pm-78 and P-2440 had ferritin-labelled capsules surrounded with the cell wall. Strain Pm-78, which was serotyped as A:12, had a thick capsule, whereas serotype -:3 strain P-2440 had a thin and irregular capsule.
Laboratory Animals 05/2007; 41(2):285-91. · 1.21 Impact Factor
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ABSTRACT: In this review, based primarily on work from our laboratory, but related to previous studies, we summarize what is known about the convergence of vestibular afferent inputs onto single vestibular neurons activated by selective stimulation of individual vestibular nerve branches. Horizontal semicircular canal (HC), anterior semicircular canal (AC), posterior semicircular canal (PC), utricular (UT), and saccular (SAC) nerves were selectively stimulated in decerebrate cats. All recorded neurons were classified as either projection neurons, which consisted of vestibulospinal (VS), vestibulo-oculospinal (VOS), vestibulo-ocular (VO) neurons, or non-projection neurons, which we simply term "vestibular'' (V) neurons. The first three types could be successfully activated antidromically from oculomotor/trochlear nuclei and/or spinal cord, and the last type could not be activated antidromically from either site. A total of 1228 neurons were activated by stimulation of various nerve pair combinations. Convergent neurons were located in the caudoventral part of the lateral, the rostral part of the descending, and the medial vestibular nuclei. Otolith-activated vestibular neurons in the superior vestibular nucleus were extremely rare. A high percentage of neurons received excitatory inputs from two nerve pairs, a small percentage received reciprocal convergent inputs and even fewer received inhibitory inputs from both nerves. More than 30% of vestibular neurons received convergent inputs from vertical semicircular canal/otolith nerve pairs. In contrast, only half as many received convergent inputs from HC/otolith-nerve pairs, implying that convergent input from vertical semicircular canal and otolith-nerve pairs may play a more important role than that played by inputs from horizontal semicircular canal and otolith-nerve pairs. Convergent VS neurons projected through the ipsilateral lateral vestibulospinal tract (i-LVST) and the medial vestibulospinal tract (MVST). Almost all the VOS neurons projected through the MVST. Convergent neurons projecting to the oculomotor/trochlear nuclei were much fewer in number than those projecting to the spinal cord. Some of the convergent neurons that receive both canal and otolith input may contribute to the short-latency pathway of the vestibulocollic reflex. The functional significance of these convergences is discussed.
Experimental Brain Research 08/2005; 164(3):271-85. · 2.39 Impact Factor
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ABSTRACT: A suitable medium for the transport of Pasteurella multocida in nasal specimens from rabbits was investigated by using pure cultures of the organism and nasal swabs from infected rabbits. First, the ability of eight transport media to preserve the viabilities of P. multocida strains isolated from rabbits was studied. Cary-Blair medium and Leibovitz medium no. 15 (L-15) were found to be superior to the other six media tested, enabling survival of the organism for more than 14 days at room temperature. Second, the survival of P. multocida in nasal specimens was evaluated on both Cary-Blair medium and L-15. The recovery rate of the organism from these two media was more than 80 to 90% during 4 days of storage and decreased gradually with increasing preservation time. There were no significant differences (P > 0.05) in recovery rates of the organism between Cary-Blair medium and L-15. On the basis of these results, we recommend the use of Cary-Blair medium for the transport of P. multocida in rabbit nasal specimens because of the ease of transport of nasal swabs by mail.
Journal of Clinical Microbiology 08/1997; 35(8):1948-51. · 4.15 Impact Factor
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ABSTRACT: The effect of topical 0.5% timolol on the microcirculation in albino rabbit optic nerve head (ONH) tissue was examined using a laser speckle microcirculation analyser. In the first experiment, normalized blue (NB) in ONH, a quantitative index of peripheral blood flow in ONH, intraocular pressure (IOP), blood pressure (BP) and pulse rate (PR) were measured under general anesthesia before, and 30, 60, 90 and 120 minutes after a 20 microliters instillation of timolol in one eye and a placebo in the other eye in a masked randomized manner. In the second experiment, one eye of another group of rabbits received timolol twice daily for 20 days and a placebo in the fellow eye in a randomized masked manner. The NB in ONH and IOP were measured before treatment and 2 hours after the last instillation on the 20th day. After a single instillation of timolol, PR showed a maximum reduction of 11% and the IOP in the timolol-treated eyes showed a maximum decrease of 18%, but the NB in ONH and BP did not show any significant change during the experiment. After the 20-day treatment, IOP showed a maximum decrease of 28% in the timolol-treated eyes and 17% in the placebo-treated eyes. The NB in the timlol-treated eyes increased significantly (p < 0.01), but in the placebo-treated eyes it showed no significant change. Thus, the long-term use of topical timolol may increase peripheral blood flow in ONH tissue in the living rabbit eye.
Nippon Ganka Gakkai zasshi 07/1995; 99(6):653-8.
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ABSTRACT: A new apparatus has been developed using the laser speckle phenomenon for non-contact, two-dimensional analysis of tissue circulation in the choroid and optic nerve head (ONH). The fundus was illuminated by a diode laser spot and its image speckle was detected by an image sensor. The difference between the average of the speckle intensity (Imean) and the speckle intensity for successive scannings was calculated, and the ratio of Imean to this difference was defined as normalized blur (NB), which is a quantitative index of blood velocity. The results were displayed on color graphic monitors showing the two-dimensional variation of the NB level in the measurement field. In the rabbit, this apparatus was used to study the relationship between the results of NB measurement and the choroidal blood flow determined by the microsphere technique, the relationship between NB obtained from the ONH tissue free of visible surface vessels and the ocular perfusion pressure (OPP) after a lethal injection of pentobarital, and the effect of intraocular pressure (IOP) on the NB in the choroid or in the ONH. A stepwise reduction in the OPP was introduced by elevating the IOP manometrically. The relative decrease in the average NB over the field measured, NBav, in the choroid with the reduction in OPP showed a significant correlation with the relative change in the blood flow rate determined using the microsphere technique (r = 0.60, P < 0.001). NBav in the ONH had a good correlation with the OPP after a lethal injection of pentobarbital (r = 0.98, P < 0.001). NBav in the choroid decreased with reduction in the OPP. Although NBav in the ONH was little affected by OPP change when OPP was above 40 mmHg, at OPP levels below 40 mmHg, NBav in the ONH decreased along with a reduction in the OPP. These results suggest that by using the present apparatus, the blood velocity in the choroid or ONH under various conditions can be studied non-invasively in the living eye.
Experimental Eye Research 05/1995; 60(4):373-83. · 3.26 Impact Factor
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ABSTRACT: To report a new apparatus for noncontact, two-dimensional measurement of retinal microcirculation using the laser speckle phenomenon and to demonstrate that this apparatus can document known or expected changes in retinal blood flow.
The rabbit fundus was illuminated by an argon (blue) laser spot (0.62 x 0.62 mm), and its image speckle was detected with an image sensor. The difference between the average of the speckle intensity (Imean) and the speckle intensity for successive scannings was calculated, and the ratio of Imean to this difference was defined as normalized blur (NB), a quantitative index of blood velocity in the retinal microcirculation. The results were displayed on a color monitor showing the two-dimensional variation of the NB level in the measurement area. Using this apparatus in the rabbit, the NB in the retinal field free of visible surface vessels was determined and compared with the retinal blood flow rate measured using the microsphere technique in the same eye simultaneously. In addition, the effect of the ocular perfusion pressure (OPP) on NB was studied. In the above experiments, a stepwise reduction in OPP was introduced by elevating the intraocular pressure manometrically.
The relative decrease in the average NB (NBav) over the field measured, with the reduction in OPP, showed significant correlation with the relative change in the blood flow rate determined using the microsphere technique (r = 0.59, P < 0.001). Although NBav in the retina was little affected by OPP change when OPP was greater than 50 mm Hg, NB decreased along with OPP at levels less than 50 mm Hg.
The NBav showed significant correlation with the retinal blood flow rate determined with microsphere technique. Retinal microcirculation under various conditions can be studied two dimensionally and noninvasively in the living eye with the present apparatus.
Investigative Ophthalmology & Visual Science 10/1994; 35(11):3825-34. · 3.60 Impact Factor
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ABSTRACT: The effect of intravenous administration of a calcium antagonist on the retinal microcirculation in rabbit eyes was examined with a laser speckle retinal microcirculation analyzer. Under general anesthesia, 40 micrograms/kg of nicardipine, a calcium antagonist, was injected intravenously in the nicardipine group, and 0.4 ml/kg of saline in the control group. A quantitative index of blood flow velocity, the normalized blur (NB) value, in a retinal area (0. 62 x 0.62 mm) free of visible vessels, was recorded at 1-minute intervals for the first 5 minutes and at 5 minute-intervals for the next 85 minutes. The retinal NB value in the nicardipine group was significantly greater than in the control group, averaging 119%, 115%, 111%, 112%, and 116% of the initial value at 65, 75, 80, 85, and 90 minutes after injection, respectively. The blood pressure in the nicardipine group decreased significantly from 1 to 20 minutes after injection. The pulse rate, arterial pH, partial CO2 pressure, partial oxygen pressure, body temperature and intraocular pressure did not show significant change during the experiment. These results suggest, for the first time, that nicardipine increases the blood flow velocity in the retinal microvasculature in the living eye.
Nippon Ganka Gakkai zasshi 04/1994; 98(3):240-4.
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ABSTRACT: We have recently developed an apparatus for noninvasive two-dimensional analysis of the retinal microcirculation using the laser speckle phenomenon. The fundus is illuminated by an argon laser spot and its image speckle is detected by an area sensor. The difference between the average of output data and the output data for successive scannings of the image speckles at the sensor plane is calculated to give the value of normalized blur (NB), which is a quantitative index of tissue blood flow velocity. In pigmented rabbit eyes, the coefficient of reproducibility was 8% when the same area of retina was measured twice at 5-minute intervals and 13% at 24-hour intervals. The NB values in the retina free of visible vessels were recorded under various levels of intraocular pressure ranging from 10 to 80 mmHg and the results were compared with the blood flow rate determined with the colored microsphere technique. A linear correlation was found between the former and the latter, which suggested that the NB value also parallels the tissue blood flow rate.
Nippon Ganka Gakkai zasshi 03/1994; 98(2):169-74.
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ABSTRACT: We have developed an apparatus using the laser speckle phenomenon for noninvasive two-dimensional measurements of the fundus microcirculation. The normalized blur of the speckle pattern (NB value) was adopted as an index of blood flow velocity in the tissue. The present study investigated whether the NB value can be also used as a quantitative index of the blood flow rate in the tissue. In experimental animals, an injection of a lethal dose of pentobarbital causes rapid reduction in the ocular perfusion pressure (OPP), which linearly correlates with blood flow rate in the ocular tissue. The NB in rabbit optic nerve head (ONH) tissue showed a linear correlation (r = 0.98, p < 0.001) with the OPP after injection of a lethal dose of pentobarbital, which suggested that the NB value parallels the blood flow rate in the ONH tissue. At various levels of OPP, the choroidal NB showed a good correlation (r = 0.60, p < 0.001) with the choroidal blood flow rate measured with microsphere technique. These results indicated that the NB value can be used as a quantitative index not only for the blood flow velocity but also for the blood flow rate in the tissue.
Nippon Ganka Gakkai zasshi 02/1994; 98(2):162-8.
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ABSTRACT: A new instrument using the laser speckle phenomenon for non-invasive two-dimensional analysis of the retinal microcirculation was developed. The fundus was illuminated with an argon laser spot and its image speckle was detected with an area sensor. The difference between the average of output data (Imean) and output data for successive scannings of the image speckles at the sensor plane was calculated and integrated to give Dmean, and Imean/Dmean is defined as normalized blur (NB), which is a quantitative index of blood flow velocity. The results were displayed in color graphics showing the two-dimensional variation of the NB level in the area of interest. The NB had a good correlation with the speed of rotation of the ground glass in a range between 5 and 120 mm/sec. Using this instrument, the effect of intraocular pressure (IOP) on the microcirculation of the rabbit retina was studied. The coefficient of reproducibility was 9.2% when measured in the same area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure (OPP) was introduced by elevating the IOP manometrically. The NB in the retina was little affected by OPP change when OPP was above 50 mmHg, but below this value the NB decreased as the OPP decreased.
Nippon Ganka Gakkai zasshi 02/1994; 98(1):47-54.
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ABSTRACT: Enzyme-linked immunosorbent assay (ELISA), gel-diffusion precipitin test (GDPT), and indirect haemagglutination test (IHAT) were evaluated for the detection of antibodies to Pasteurella multocida in both naturally and experimentally infected rabbits. A total of 285 rabbit serum samples from 7 rabbit colonies were tested by ELISA, GDPT, and IHAT, and nasal cultures were taken coincidentally to use as the standard in the serological tests. There was better correlation (98.0%) between the results of ELISA and positive nasal culture than between the GDPT (86.3%) or IHAT (23.5%) and positive nasal culture. In addition, ELISA and GDPT were positive in 26 (11.1%) and 21 (9.0%) of 234 serum samples from nasal culture negative rabbits, respectively. In experimentally infected rabbits, antibodies detected by the ELISA and GDPT began to rise one to 3 weeks post-inoculation. IHAT did not detect antibodies. These results are discussed in terms of value to serodiagnosis of rabbit pasteurellosis.
Laboratory Animals 02/1994; 28(1):19-25. · 1.21 Impact Factor
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ABSTRACT: A new instrument using the laser speckle phenomenon for noninvasive 2-dimensional analysis of the choroidal microcirculation was developed. The fundus was illuminated with a diode laser spot and its image speckle was detected with an area sensor. The difference between the average of the output data (I-mean) and the output data from successive scannings of the image speckles at the sensor plane was calculated and integrated to give as D-mean, and I-mean/D-mean was defined as normalized blur (NB), which is a quantitative index of blood flow velocity. The results were displayed in color graphics showing the 2-dimensional variation of the NB level in the area of interest. The NB had good correlation with the speed measured on ground glass in the range between 2 and 130mm/sec. Using this instrument, the effect of intraocular pressure on the chroidal circulation of the rabbit was studied. The coefficient of reproducibility was 6.9% when measured in the same area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure was introduced by elevating the intraocular pressure manometrically. A linear correlation was found between the NB and the ocular perfusion pressure.
Nippon Ganka Gakkai zasshi 06/1993; 97(5):602-9.
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ABSTRACT: A new instrument using the laser speckle phenomenon for noninvasive 2-dimensional analysis of the microcirculation in the optic nerve head (ONH) was developed. The ONH was illuminated with a diode laser spot and its image speckle was detected by an area array sensor. The difference between a pair of output data for successive scannings of the image speckles at the sensor plane was calculated and integrated for each pixel to obtain the average difference (AD), which is a quantitative index of blood speed. The results were displayed in color graphics showing the 2-dimensional variation of the AD level in the area of interest. The AD had good correlation with the speed of ground glass in a range between 0 and 8 mm/sec. Using this instrument, the effect of intraocular pressure (IOP) on the circulation in the area of the rabbit ONH free from surface vessels was studied. The coefficient of reproducibility was 4.7% when measured in this area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure (OPP) was introduced by elevating the IOP manometrically. The AD was little affected by OPP change when OPP was above 40 mmHg, but with the OPP below 40 mmHg, a linear correlation was found between the AD and OPP.
Nippon Ganka Gakkai zasshi 05/1993; 97(4):501-8.
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ABSTRACT: A new instrument has been developed which uses the laser speckle phenomenon for noninvasive two-dimensional analysis of the microcirculation in the optic nerve head (ONH). The ONH is illuminated by a diode laser spot and its image speckle is detected by an area sensor. The difference between a pair of output data from successive scannings of the image speckles at the sensor plane is calculated and integrated for each pixel to obtain the average difference (AD) value, which is a quantitative index of blood flow velocity. The results are displayed in color graphics showing the two-dimensional variation of the AD value in the area of interest. In an in vitro model, the AD value correlated well with the speed of rotation of a ground glass in a range between 0 and 5 mm/second. Using this instrument, the effect of intraocular pressure (IOP) on the circulation was studied in the area of the rabbit ONH free of surface vessels. The coefficient of reproducibility was 4.7% when measured twice in this area at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure (OPP) was introduced by elevating the IOP manometrically. The AD value was little affected by a change in OPP when the OPP was above 40 mmHg; while when the OPP was below 40 mmHg, a linear correlation was found between the AD value and the OPP. This finding agreed well with those of previous studies where the effect of the OPP on the ONH blood flow were studied using various invasive methods.(ABSTRACT TRUNCATED AT 250 WORDS)
Japanese Journal of Ophthalmology 02/1993; 37(2):178-86. · 0.92 Impact Factor
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Nippon juigaku zasshi. The Japanese journal of veterinary science 01/1991; 52(6):1277-9.
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ABSTRACT: Prevalence and some properties of Pasteurella multocida in rabbits kept at laboratory animal facilities and commercial rabbitries, and in their environment were investigated. A total of 1,147 nasal swab samples from 1,147 rabbits and 126 samples from their environment were subjected to the isolation of P. multocida. The bacteria were isolated from 199 (29.8%) of 668 rabbits in laboratory animal facilities and from 1 (0.2%) of 479 rabbits in the rabbitries. Isolation rate of P. multocida was low (0.9%) or high (44.9%) in the facilities with or without the monitoring for the presence of the bacteria, respectively. The highest rate of the isolation from rabbits was recorded at 10 to 12 months of their housing time. Thirty-nine cultures (31.0%) of air and the surfaces of floors, tips of water bottles, and cages were positive for P. multocida and isolation rate of the bacteria was high (78.6%) in the air. Biological and biochemical properties of the isolates were identical except for indole production and raffinose fermentation. The isolates were susceptible to antibiotics tested except for clindamycin, serologically similar in the gel-diffusion precipitin test and weakly virulent for mice. The present results suggested that these P. multocida isolates were the causal agent of rabbits rhinitis (snuffles) in Japan.
Nippon juigaku zasshi. The Japanese journal of veterinary science 11/1990; 52(5):915-21.
