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71.
Francesca Grassi Aldo Giovannelli Sergio Fucile Elisabetta Mattei Fabrizio Eusebi 《Pflügers Archiv : European journal of physiology》1993,425(1-2):117-125
The cholinergic responses of the human tumour cell line TE671/RD were examined using digital Ca2+ imaging fluorescence microscopy and patch-clamp measurements. In response to stimulation of the muscarinic acetylcholine (ACh) receptor (mAChR), the intracellular concentration of Ca2+ ([Ca2+]i) rose about two-fold, in parallel with inositol 1,4,5-trisphosphate accumulation, measured by chromatographic techniques. By contrast, there was no increment of [Ca2+]i upon stimulation of the nicotinic ACh receptor (nAChR), nor after caffeine application. Electrophysiological experiments showed that TE671/RD cells lack functional voltage-activated Ca2+ channels. The stimulation of the nAChR induced transient whole-cell currents (I
ACh). Little or no current was detected in isotonic extracellular Ca2+, with Cs+ in the patch pipette. Cell pretreatment with muscarine reduced I
ACh by about 20%, without consistent modifications of current kinetics. Muscarine applied to the extra-patch membrane under the cell-attached configuration had no obvious effect on ACh-evoked unitary events. In conclusion, in human TE671/ RD cells, muscarinic stimulation increases [Ca2+]i, while nicotinic stimulation does not. In addition, the nAChR exhibits peculiar ion permeability properties and is not functionally regulated by the breakdown of phosphoinositides. 相似文献
72.
Compartmental Analysis of Breathing in the Supine and Prone Positions by Optoelectronic Plethysmography 总被引:2,自引:0,他引:2
Aliverti A Dellacà R Pelosi P Chiumello D Gatihnoni L Pedoti A 《Annals of biomedical engineering》2001,29(1):60-70
Optoelectronic plethysmography (OEP) has been shown to be a reliable method for the analysis of chest wall kinematics partitioned into pulmonary rib cage, abdominal rib cage, abdomen, and right and left side in the seated and erect positions. In this paper, we extended the applicability of this method to the supine and prone positions, typically adopted in critically ill patients. For this purpose we have first developed proper geometrical and mathematical models of the chest wall which are able to provide consistent and reliable estimations of total and compartmental volume variations in these positions suitable for clinical settings. Then we compared chest wall (CW) volume changes computed from OEP( V
CW) with lung volume changes measured with a water seal spirometer (SP) ( V
SP)in 10 normal subjects during quiet (QB) and deep (DB) breathing on rigid and soft supports. We found that on a rigid support the average differences between V
SP and V
CW were –4.2% ± 6.2%, –3.0% ± 6.1%, –1.7% ±7.0%, and –4.5% ± 9.8%, respectively, during supine/QB, supine/DB, prone/QB, and prone/DB. On the soft surface we obtained –0.1% ± 6.0%, –1.8% ± 7.8%, 18.0% ± 11.7%, and 10.2% ± 9.6%, respectively. On rigid support and QB, the abdominal compartment contributed most of the V
CW in the supine (63.1% ± 11.4%) and prone (53.5% ± 13.1%) positions. V
CW was equally distributed between right and left sides. In the prone position we found a different chest wall volume distribution between pulmonary and abdominal rib cage (22.1% ± 8.6% and 24.4% ± 6.8, respectively) compared with the supine position (23.3% ± 9.3% and 13.6% ± 3.0%). © 2001 Biomedical Engineering Society.
PAC01: 8763Lk, 8719Uv 相似文献
73.
To investigate the genome of the aphidMegoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases.EcoRI digestion produced a highly repeated DNA fragment, about 600 bp long. The contribution of thisEcoRI element to the total genome ofM. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescentin situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained byin situ nick translation experiments carried out afterEcoRI digestion, and clearly demonstrate that a substantial amount ofM. viciae heterochromatin consists ofEcoRI fragments which are mainly located on the X chromosome. Using theEcoRI restriction fragment as a molecular probe may prove to be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.accepted for publication by J. S. (Pat) Heslop-Harrison 相似文献
74.
A randomized trial of methylprednisolone and chlorambucil in idiopathic membranous nephropathy 总被引:11,自引:0,他引:11
C Ponticelli P Zucchelli P Passerini L Cagnoli B Cesana C Pozzi S Pasquali E Imbasciati C Grassi B Redaelli 《The New England journal of medicine》1989,320(1):8-13
We conducted a controlled trial to investigate the long-term effects of treatment with methylprednisolone and chlorambucil in patients with idiopathic membranous nephropathy. We have previously reported that after a mean of 31 months, treated patients did better. We now report the results of a longer follow-up. Eighty-one patients with proteinuria (greater than or equal to 3.5 g per day) and biopsy-proved membranous nephropathy were randomly assigned to receive either supportive therapy alone or a six-month course of corticosteroids alternated with chlorambucil (0.2 mg per kilogram of body weight per day) every other month. Methylprednisolone was first given intravenously in three pulses (1 g per day) and was then given orally (0.4 mg per kilogram per day) for 27 days. The patients were followed for 2 to 11 years (median, 5). Two patients in the control group and one in the treatment group died. At the last follow-up visit, 9 of 39 patients assigned to the control group (23 percent) and 28 of 42 patients assigned to the treatment group (67 percent) did not have the nephrotic syndrome. At five years there were more remissions of the nephrotic syndrome in treated patients than in controls (22 of 30 vs. 10 of 25; P = 0.026). Compared with base-line values, the mean reciprocal of the plasma creatinine level declined significantly in the control group (33 percent; P = 0.0002) but not in the treatment group (6 percent; P not significant). Plasma creatinine increased by 50 percent or more in 19 controls (49 percent) and in 4 treated patients (10 percent). We conclude that a six-month course of methylprednisolone and chlorambucil can bring about sustained remission of the nephrotic syndrome and help to preserve renal function in patients with idiopathic membranous nephropathy. 相似文献
75.
A new hydrogel, with scleroglucan using borax as a crosslinker, has been prepared. The physical gel has been loaded with a model molecule (theophylline) and the release of the drug from the gel was evaluated. The same system was used to prepare tablets and the delivery of theophylline in different environmental conditions (HCl and SIF) was determined. A recent theoretical approach has been applied to the dissolution profiles obtained from the tablets and a satisfactory agreement has been found with the experimental data. Furthermore, the diffusion coefficient of the model molecule was evaluated according to a suitable strategy that was tested on two set of data obtained with different set-ups (permeation and diffusion experiments). A simplified mathematical approach allows to reduce the two-dimensional problem of the Fick's second law in a one-dimensional system leading to a much easier handling of the data without loosing the accuracy of the original problem in two dimensions. The characterization of the gel has been also carried out following the kinetics of swelling in terms of water uptake. 相似文献
76.
Lack of association between angiotensin converting enzyme polymorphism and sporadic Alzheimer's disease 总被引:3,自引:0,他引:3
Monastero R Caldarella R Mannino M Cefalù AB Lopez G Noto D Camarda C Camarda LK Notarbartolo A Averna MR Camarda R 《Neuroscience letters》2002,335(2):147-149
Epidemiological and pathogenetic evidences suggest a strong association between vascular risk factors and sporadic Alzheimer's disease (sAD). In agreement with the vascular hypothesis of AD, the role of various candidate genes for atherosclerosis has been investigated, leading to conflicting results. In order to clarify the significance of angiotensin-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphism in a group of patients with sAD, we conducted a case-control study including 149 cases and 149 age and sex matched controls. All subjects were genotyped for ACE and Apolipoprotein E (APOE). There were no significant differences in ACE genotype or allele frequencies between cases and controls, even after stratification for APOE4 carrier status. Our data suggest that the ACE I/D polymorphism is not associated to genetic susceptibility in sAD patients. 相似文献
77.
Mario Cocco Cristiana Bellan Roxane Tussiwand Davide Corti Elisabetta Traggiai Stefano Lazzi Susanna Mannucci Lucio Bronz Nazzareno Palummo Chiara Ginanneschi Piero Tosi Antonio Lanzavecchia Markus G. Manz Lorenzo Leoncini 《The American journal of pathology》2008,173(5):1369-1378
Recent studies suggest that Epstein-Barr virus (EBV) can infect naïve B cells, driving them to differentiate into resting memory B cells via the germinal center reaction. This hypothesis has been inferred from parallels with the biology of normal B cells but has never been proven experimentally. Rag2−/− γc−/− mice that were transplanted with human CD34+ cord blood cells as newborns were recently shown to develop human B, T, and dendritic cells, constituting lymphoid organs in situ. Here we used this model to better define the strategy of EBV infection of human B cells in vivo and to compare this model system with different conditions of EBV infection in humans. Our results support the model of EBV persistence in vivo in cases that were characterized by follicular hyperplasia and a relatively normal CD4+ and CD8+ T-cell distribution. Intriguingly, in cases that were characterized by nodular and diffuse proliferation with a preponderance of CD8+ T cells, similar to infectious mononucleosis, EBV still infects naïve B cells but also induces clonal expansion and ongoing somatic mutations without germinal center reactions. Our results reveal different strategies of EBV infection in B cells that possibly result from variations in the host immune response. Future experiments might allow understanding of the mechanisms responsible for persistent EBV infection and provide targets for more highly tailored therapeutic interventions. 相似文献
78.
Davide Gibellini Paola Monari Monica Sassi Maria Carla Re 《Journal of clinical virology》2003,28(3):341-343
A hemi-nested PCR approach was adopted to detect HTLV-1 infection in clinical samples of peripheral blood mononuclear cells (PBMCs) from subjects with positive or indeterminate serological results. Our results showed that the hemi-nested PCR quickly solved the diagnostic query, detecting the presence of proviral HTLV-1 DNA in two of the 252 patients with inconclusive serological results. The main advantage of this method are the typology of DNA extraction, allowing a consistent DNA recovery without amplification problems, the rapidity (4-5 hours), the performance of the assay and its comparable or better sensitivity than other HTLV-1 PCR formats. 相似文献
79.
80.
Voltage-dependent GABA-induced modulation of calcium currents in chick sensory neurons 总被引:8,自引:0,他引:8
Externally applied gamma-aminobutyric acid (GABA) quickly and reversibly reduces by 60% voltage activated Ca2+ currents in chick dorsal root ganglion cells. This action is antagonized by depolarization, with characteristic time and voltage requirements. Intracellular perfusion with guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) or guanosine 5'-O-(2-thiodiphosphate) (GDP beta S) mimicks and blocks the GABA effect, respectively. A 3-state model describing the reactions involved is proposed. 相似文献