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11.
Pied S; Voegtle D; Marussig M; Renia L; Miltgen F; Mazier D; Cazenave PA 《International immunology》1997,9(1):17-25
TCR V beta usage was examined in C57BL/6 mice infected with Plasmodium
yoelii. In addition to a polyclonal T cell activation, already described, a
superantigenic-like activity was observed during the acute infection. This
superantigenic activity induces a preferential deletion without prior
expansion of CD4+ and CD8+ T cells bearing the TCR V beta 9 segment. The
superantigen could be released by the parasite at different stages of its
development since the deletion of V beta 9+ T cells was observed in blood
and lymph nodes of mice infected either with sporozoites or with
erythrocytic stages. Injection of sporozoite or parasitized erythrocytes to
newborn mice led to a deletion and anergy of peripheral V beta 9+ T cells,
without affecting thymic T cell populations. These observations suggest
that the superantigen is released at very low concentrations during
parasite development. The role of such parasite superantigenic activity in
infectivity can be underlined by the observation that congenic BALB.D2
Mis1a mice lacking V beta 9 T cells are more susceptible to infection by P.
yoelii.
相似文献
12.
G. J. Wiener MD T. M. Morgan PhD J. B. Copper PA W.C. Wu MB BS D. O. Castell MD J. W. Sinclair PA Dr. J. E. Richter MD 《Digestive diseases and sciences》1988,33(9):1127-1133
If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate gastroesophageal reflux patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 53 subjects (14 healthy normals, 14 esophagitis patients, and 25 patients with atypical symptoms) with two ambulatory pH tests performed within 10 days of each other. Intrasubject reproducibility of 12 pH parameters to discriminate the presence of abnormal acid reflux was determined. As a group, the parameters of percent time with pH<4 (total, upright, recumbent) were most reproducible (80%). Therefore, a subject was defined as having gastroesophageal reflux disease if at least one of these three values were abnormal. Intrasubject reproducibility for the diagnosis of reflux disease was 89% for the entire sample. Among subsets, the reproducibility was 93% for the normals and esophagitis patients and 84% for the atypical symptom patients. Total percent time with pH<4 was the single most discriminate pH parameter (85%) and nearly equaled that of the three combined parameters (89%). The intrasubject variability of this parameter was determined by the mean ±2sd of the relative differences between the two test results for all 53 subjects. Total percent time with pH<4 may vary between tests by a factor of 3.2-fold or less (218% higher to 69% lower). We conclude: (1) ambulatory 24-hr esophageal monitoring is a reproducible test for the diagnosis of gastroesophageal reflux disease; and (2) the large intrastudy variability in 24-hr total acid exposure may limit this test's usefulness as a measurement of therapeutic improvement.Supported, in part, by Public Health Services Grant AM 34200-01A1 from NIADDIK. 相似文献
13.
In a prospective, randomized study of insemination with donor semen,
intracervical insemination by straw was compared with insemination using a
cervical cap with an intracervical reservoir. A total of 91 patients
completed 486 treatment cycles. There were no significant differences in
age, parity, indication for insemination by donor, or method of cycle
monitoring between women who became pregnant and those who did not conceive
with either insemination method. In 236 standard intracervical insemination
cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients
conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude
pregnancy rates and the cumulative pregnancy rates calculated by the
Kaplan-Meier life-table method were significantly different (chi(2)-test, P
< 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates
in artificial insemination with cryopreserved donor semen may be improved
by the use of a cervical cap when compared to cervical insemination by
straw. The use of the cervical cap may prolong the exposure of the
spermatozoa to the cervical mucus and prevent the backflow of semen into
the vagina.
相似文献
14.
Sanjana VM; Johnston PA; Robertson CR; Jamison RL 《The American journal of physiology》1976,231(2):313-318
15.
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17.
Diffusion in gel-enzyme-linked immunosorbent assay—a new serological test for leptospirosis 下载免费PDF全文
A new serological test, diffusion in gel-enzyme-linked immunosorbent assay (DIG-ELISA) was developed and compared with the microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis. The results suggest that DIG-ELISA is a viable alternative to the MAT because of its simplicity, sensitivity, versatility and potential for standardisation. 相似文献
18.
Massimiliano Valeriani Domenico Restuccia Vincenzo Di Lazzaro Domenica Le Pera Carmen Barba Pietro Tonali François Mauguiere 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1998,120(3):306-315
Brain electrical source analysis (BESA) of the scalp electroencephalographic activity is well adapted to distinguish neighbouring
cerebral generators precisely. Therefore, we performed dipolar source modelling in scalp medium nerve somatosensory evoked
potentials (SEPs) recorded at 1.5-Hz stimulation rate, where all the early components should be identifiable. We built a four-dipole
model, which was issued from the grand average, and applied it also to recordings from single individuals. Our model included
a dipole at the base of the skull and three other perirolandic dipoles. The first of the latter dipoles was tangentially oriented
and was active at the same latencies as the N20/P20 potential and, with opposite polarity, the P24/N24 response. The second
perirolandic dipole showed an initial peak of activity slightly earlier than that of the N20/P20 dipolar source and, later,
it was active at the same latency as the central P22 potential. Lastly, the third perirolandic dipole exaplaining the fronto-central
N30 potential scalp distribution was constantly more posterior than the first one. In order to evaluate the effect of an increasing
repetition frequency on the activity of SEP dipolar sources, we applied the model built from 1.5-Hz SEPs to traces recorded
at 3-Hz and 10-Hz repetition rates. We found that the 10-Hz stimulus frequency reduced selectively the later of the two activity
phases of the first perirolandic dipole. The decrement in strength of this dipolar source can be explained if we assume that:
(a) the later activity of the first perirolandic dipole can represent the inhibitory phase of a “primary response”; (b) two
different clusters of cells generate the opposite activities of the tangential perirolandic dipole. An additional finding
in our model was that two different perirolandic dipoles contribute to the centro-parietal N20 potential generation.
Received: 5 August 1997 / Accepted: 26 November 1997 相似文献
19.
George N Papanikolaou Maria S Baltogianni Despina G Contopoulos-Ioannidis Anna-Bettina Haidich Ioannis A Giannakakis John PA Ioannidis 《BMC medical research methodology》2001,1(1):3
Background
Guidelines published in major medical journals are very influential in determining clinical practice. It would be essential to evaluate whether conflicts of interests are disclosed in these publications. We evaluated the reporting of conflicts of interest and the factors that may affect such disclosure in a sample of 191 guidelines on therapeutic and/or preventive measures published in 6 major clinical journals (Annals of Internal Medicine, BMJ, JAMA, Lancet, New England Journal of Medicine, Pediatrics) in 1979, 1984, 1989, 1994 and 1999.Results
Only 7 guidelines (3.7%) mentioned conflicts of interest and all were published in 1999 (17.5% (7/40) of guidelines published in 1999 alone). Reporting of conflicts of interest differed significantly by journal (p=0.026), availability of disclosure policy by the journal (p=0.043), source of funding (p < 0.001) and number of authors (p=0.004). In the entire database of 191 guidelines, a mere 18 authors disclosed a total of 24 potential conflicts of interest and most pertained to minor issues.Conclusions
Despite some recent improvement, reporting of conflicts of interest in clinical guidelines published in influential journals is largely neglected.20.
Dal Zotto L; Quaderi NA; Elliott R; Lingerfelter PA; Carrel L; Valsecchi V; Montini E; Yen CH; Chapman V; Kalcheva I; Arrigo G; Zuffardi O; Thomas S; Willard HF; Ballabio A; Disteche CM; Rugarli EI 《Human molecular genetics》1998,7(3):489-499
We have recently reported isolation of the gene responsible for X- linked
Opitz G/BBB syndrome, a defect of midline development. MID1 is located on
the distal short arm of the human X chromosome (Xp22. 3) and encodes a
novel member of the B box family of zinc finger proteins. We have now
cloned the murine homolog of MID1 and performed preliminary expression
studies during development. Mid1 expression in undifferentiated cells in
the central nervous, gastrointestinal and urogenital systems suggests that
abnormal cell proliferation may underlie the defect in midline development
characteristic of Opitz syndrome. We have also found that Mid1 is located
within the mouse pseudoautosomal region (PAR) in Mus musculus , while it
seems to be X- specific in Mus spretus. Therefore, Mid1 is likely to be a
recent acquisition of the M. musculus PAR. Genetic and FISH analyses also
demonstrated a high frequency of unequal crossovers in the murine PAR,
creating spontaneous deletion/duplication events involving Mid1. These data
provide evidence for the first time that genetic instability of the PAR may
affect functionally important genes. In addition, we show that MID1 is the
first example of a gene subject to X-inactivation in man while escaping it
in mouse. These data contribute to a better understanding of the molecular
content and evolution of the rodent PAR.
相似文献