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91.
Sanjana VM; Johnston PA; Robertson CR; Jamison RL 《The American journal of physiology》1976,231(2):313-318
92.
WSJM, a simple chemically defined medium for growth of Neisseria gonorrhoeae 总被引:13,自引:1,他引:13 下载免费PDF全文
The growth requirements of 135 clinical isolates of Neisseria gonorrhoeae and six American Type Culture Collection reference strains were examined by using a simple chemically defined medium known as Wong-Shockley-Johnston medium, WSJM. The simple liquid medium supported growth of gonococci from an inoculum of 2 X 10(6) colony-forming units ml-1 and yielded 10(10) colony-forming units ml-1 in 10 h in the absence of CO2. Scale-up experiments with the complete medium yielded 5 to 10 g, wet weight, of cells per liter. The complete medium was stable upon storage at 5 degrees C and after lyophilization. 相似文献
93.
Fisher JP Lalani Z Bossano CM Brey EM Demian N Johnston CM Dean D Jansen JA Wong ME Mikos AG 《Journal of biomedical materials research. Part A》2004,68(3):428-438
In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion. To test this hypothesis, healing bone was investigated within a rabbit incisor extraction socket, a subcritical size bone defect that resists significant soft tissue invasion by virtue of its conformity. After removal of the incisor teeth, one tooth socket was left as an empty control, one was filled with crosslinked polymer networks formed from the hydrophobic polymer poly(propylene fumarate) (PPF), and one was filled with a hydrogel formed from the hydrophilic oligomer oligo(poly(ethylene glycol) fumarate) (OPF). At five different times (4 days as well as 1, 2, 4, and 8 weeks), jaw bone specimens containing the tooth sockets were removed. We analyzed bone healing by histomorphometrical analysis of hematoxylin and eosin stained sections as well as immunohistochemically stained sections. The proposed hypothesis, that a hydrophilic material would hinder bone healing, was supported by the histomorphometrical results. In addition, the immunohistochemical results reflect molecular signaling indicative of the early invasion of platelets, the vascularization of wound-healing tissue, the differentiation of migrating progenitor cells, and the formation and remodeling of bone tissue. Finally, the results emphasize the need to consider biomaterial properties and their differing effects upon endogenous growth factors, and thus bone healing, during the development of tissue engineering devices. 相似文献
94.
Sigmundsdóttir H Johnston A Gudjónsson JE Valdimarsson H 《Clinical immunology (Orlando, Fla.)》2004,111(1):119-125
At both cutaneous and mucosal sites, interleukin (IL)-10, IL-12 and transforming growth factor (TGF)-beta are important regulators of chronic inflammatory disease, where cutaneous lymphocyte-associated antigen (CLA) and alphaE integrin (CD103) may be expressed. Stimulation with streptococcal pyrogenic exotoxin C (SpeC) increased the expression of CD103 by CD8+ but not CD4+ T cells. While adding IL-12 augmented the expression of CLA, superantigen-induced expression of CD103 was markedly suppressed by IL-12, which could be reversed by TGF-beta. Antibodies against TGF-beta inhibited, and a combination of anti-TGF-beta and IL-12 completely abrogated the induced CD103 expression. IL-10 strongly decreased the frequency of CLA+ and although not increasing the frequency of CD103+CD8+ T cells, the amount of CD103 expressed per cell was markedly increased. Thus, the expression of CLA and CD103 may be antagonistically regulated by IL-10 and IL-12 and the balance between these cytokines could influence the T cell migration of inflammatory cells into epithelial tissues. 相似文献
95.
Janine L. Johnston James A. Sharpe 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1994,99(2):302-308
The gain (ratio of eye velocity to head velocity) of the initial horizontal vestibulo-ocular reflex (VOR) was calculated in 12 normal subjects over 350 ms during impulsive, unpredictable whole body rotation under three conditions: (1) darkness; (2) visual enhancement of the VOR, while the subjects fixated a stationary target; and (3) visual cancellation of the reflex, while subjects fixated a target that rotated with the head. The gain of the initial 80 ms of compensatory eye movement increased significantly during visual fixation in 5 subjects and decreased during attempted VOR cancellation in 3 subjects, when compared with VOR gain in darkness. Compensatory vestibular smooth eye movements were slowed, becoming curved at the onset of VOR cancellation, at mean latencies ranging from 78 to 149 ms in individual subjects (group mean 128 ms). At about 190 ms, quick phases moved the eyes in the same direction as head and target motion. The subsequent vestibular eye movements were about 50% slower than the initial smooth eye movements, indicating more effective cancellation. Visual enhancement of the VOR can occur prior to the onset of pursuit, providing evidence that fixation and smooth pursuit are distinct ocular motor systems. Visual cancellation of the VOR also begins prior to smooth pursuit initiation and becomes more effective after the latency of smooth pursuit. 相似文献
96.
Use of polymerase chain reaction for diagnosis of picornavirus infection in subjects with and without respiratory symptoms. 总被引:10,自引:13,他引:10 下载免费PDF全文
S L Johnston G Sanderson P K Pattemore S Smith P G Bardin C B Bruce P R Lambden D A Tyrrell S T Holgate 《Journal of clinical microbiology》1993,31(1):111-117
Rhinoviruses and enteroviruses are the major members of the picornavirus genus that cause human disease. We compared the polymerase chain reaction and viral culture for the identification of picornaviruses in nasal aspirates from children during episodes of respiratory symptoms and when asymptomatic and from asymptomatic adults. One hundred eight children, aged 9 to 11 years, completed a year-long study. Within 24 to 48 h of a report of respiratory symptoms, a nasal aspirate was taken in the home. Nasal aspirates were also taken from 65 of the children and from 33 normal adults when they had been free of respiratory symptoms for at least 2 weeks. Picornaviruses were isolated by culture for three passages in Ohio HeLa cells in rolling tubes at 33 degrees C and pH 7.0. For the polymerase chain reaction, duplicate 50-microliters samples were amplified with conserved primers from the 5' noncoding region. Picornaviruses generated approximately 380-bp bands in agarose gel electrophoresis; the specificity of these bands was confirmed by filter hybridization with a conserved internal probe. Picornaviruses were isolated by culture in 47 (46 rhinoviruses) of 292 symptomatic episodes (16%), whereas the polymerase chain reaction identified picornavirus genomic material in 146 episodes (50%), including all but one of the culture-positive episodes. As for asymptomatic samples, eight (12%) children and two (4%) adults were positive by the polymerase chain reaction, whereas only one child's specimen was positive by culture. This polymerase chain reaction assay represents a clear advance in the identification of picornavirus infection, with a detection rate threefold greater than the virus culture method. 相似文献
97.
Evaluation of an automated immunodiagnostic assay system for direct detection of herpes simplex virus antigen in clinical specimens. 下载免费PDF全文
S L Johnston S Hamilton R Bindra D A Hursh C A Gleaves 《Journal of clinical microbiology》1992,30(4):1042-1044
The Vitek ImmunoDiagnostic Assay System (VIDAS) is a 2 1/3-h automated qualitative enzyme-linked fluorescent immunoassay developed for the direct detection of herpes simplex virus (HSV) antigen in clinical specimens. A total of 356 clinical specimens submitted for HSV isolation were prospectively evaluated with the VIDAS, and the results of the technique were compared with those of both HSV isolation in cell culture and Herpchek, a nonautomated enzyme immunoassay. Compared to cell culture, VIDAS had a sensitivity of 91.6% and a specificity of 89.3%, with positive and negative predictive values of 82.6 and 95.0%, respectively. In comparison to Herpchek, VIDAS had a sensitivity of 93.7% and a specificity of 93.0%, with positive and negative predictive values of 89.4 and 95.9%, respectively. The results demonstrated that the VIDAS required minimal manipulation in order to produce results comparable to those of Herpchek and HSV isolation in cell culture. 相似文献
98.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
99.
P. Pala S. D. Message S. L. Johnston P. J. M. Openshaw 《Clinical and experimental allergy》2002,32(12):1739-1744
BACKGROUND: Asthma, atopy and some forms of respiratory syncytial virus (RSV) disease are thought to be caused by T cells making IL-4 (Th2 cells). However, not all patients with similar patterns of clinical disease have the same underlying pathogenesis and the ability to detect immunopathogenic T cells by examination of the peripheral blood remains in doubt. With the prospect of specific immunotherapy for diseases caused by T cell subsets, it is important to determine whether peripheral blood mononuclear cell (PBMC) reactivity can be used to establish the presence of immunopathogenic responses and therefore to predict therapeutic effects. OBJECTIVE: To detect IL-4 and IFN-gamma production as markers of Th1 and Th2 responses in the peripheral blood of atopic and asthmatic adults. METHODS: PBMC from 22 adult asthmatics (18 of whom were atopic) and 21 non-asthmatic volunteers (ten of whom were atopic) were stimulated with cat, birch and house dust mite allergens, human rhinovirus, RSV and recombinant chimaeric F/G protein from RSV in vitro. ELISPOT assays were used to enumerate cells producing IL-4 and IFN-gamma. RESULTS: Asthmatics had a sixfold increase in frequencies of IL-4-producing cells to cat and birch allergen (median values: 37 vs. 7 per million PBMC, P < 0.01 and 20 vs. 3 per million PBMC, P < 0.04, respectively) compared to non-asthmatics. By contrast, non-asthmatic atopics showed no specific increase in antigen-specific IL-4 responses and there was no evident correlation between skin prick test reactivity and ELISPOT results. Atopics had significantly more IFN-gamma-producing cells specific for FG than nonatopics. while IFN-gamma and IL-4 responses to other antigens were not significantly different. CONCLUSION: Enhanced IL-4 responses to non-viral aeroallergens are seen in adults with asthma, while enhanced IFN-gamma responses to viral antigen FG were see in atopics. In practical terms, ELISPOT assays for specific cytokines may provide a method that could be used to monitor antigen-specific T cell responses in peripheral blood. 相似文献
100.
A 22-year-old man with recurrent pharyngitis developed a peritonsillar abscess from which aspirated material yielded a pure culture of Nocardia asteroides. It is likely that the organism was introduced iatrogenically during a prior tonsillar incision. Although unusual, Nocardia species should be considered and microbiological specimens should be handled appropriately in pharyngeal abscesses that respond poorly to conventional therapy. 相似文献