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21.
Sulfates and glucuronides of 2,4-dinitrobenzyl alcohol 1a and 2,6-dinitrobenzyl alcohol 1b, which are major or putative metabolites of 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT), were synthesized from 1a and 1b by reaction with pyridinium sulfonate and methyl (2,3,4-tri-O-acetyl-alpha-D-glucopyranosyl)uronate bromide 3, respectively, as their pyridinium salts (2a, 2b) and potassium salts (6a, 6b). These conjugates are important for the study of the carcinogenicity of 2,4-DNT and 2,6-DNT.  相似文献   
22.
Nitric oxide (NO) has been implicated in the establishment of precise synaptic connectivity throughout the neuroaxis in several species. To determine the contribution of NO to NMDA receptor-dependent dendritic growth in motor neurons, we administered the NMDA antagonist MK-801 to wild-type mice and neuronal nitric oxide synthase (nNOS) knock-out mice between postnatal days 7 and 14. Compared to saline-treated wild-type animals the number of dendritic bifurcations was significantly reduced in nNOS knock-out animals and MK-801-treated wild-type animals. There was no significant difference in dendritic bifurcation between MK-801-treated wild-type, MK-801-treated nNOS knock-out, and saline-treated nNOS knock-out animals, suggesting that nNOS knock-out and NMDA receptor block had similar effects. The path of the longest dendrite and the number of primary dendrites was the same in all treatment groups, indicating an effect specific to bifurcation. Sholl analysis revealed that differences in bifurcation numbers occurred between 160 and 320 micrometers from the cell body, the distance at which second, third, and fourth order dendrites are most prevalent. Dendrite order analyses confirmed a significant reduction in numbers, but not lengths, of third and fourth order dendrites in nNOS knock-out and drug-treatment groups. Finally, immunohistochemical examination of the developing spinal cord indicated that NMDA receptors and nNOS are colocalized within interneurons surrounding the motor neuron pool. These results support the view that at least part of NMDA receptor-dependent arborization of motor neuron dendrites is mediated by the local production of NO within the developing spinal cord.  相似文献   
23.
Erb's type limb-girdle muscular dystrophy (LGMD) was identified and clinically studied in detail in a small community living in the Reunion Island (RI). It was linked to chromosome 15q and related to mutations in the muscle specific calpain 3 gene. A series of cases were afterwards clinically and genetically identified in the French metropolitan community. The phenotype was identical to the RI type in the great majority of cases, although clinical differences were noticed in a few cases. Six different mutations were identified in the RI families, whereas a series of 39 mutations were detected in the French metropolitan families, all different from those present in the RI patients. Phenotype-genotype correlations were attempted in both communities.  相似文献   
24.
OBJECTIVE: to investigate whether there are differences between the cost of intrapartum care for women at low obstetric risk in a midwife-managed labour and delivery unit and that in a consultant-led labour and delivery ward. DESIGN: cost analysis based on the findings of a randomised controlled trial comparing two alternative types of intrapartum care. SETTING: Aberdeen Maternity Hospital, Grampian. SUBJECTS: the number of women 'booked' for care in the Midwives' Unit in a standard year and a comparable group of women cared for in the consultant-led labour ward. PRIMARY OUTCOME MEASURE: the cost 'outcome' is the extra (or reduced) cost per woman resulting from the introduction of a midwife-managed delivery unit. FINDINGS: the baseline extra cost of the introduction of the Midwives' Unit was found to be 40.71 pounds per woman. Depending on the scenario used, this ranged from a cost saving of 9.74 pounds per woman to an additional cost of 44.23 pounds per woman. CONCLUSIONS: this study has shown that, in terms of costs incurred during the intrapartum period, the marginal cost of caring for women at low obstetric risk alongside women at high obstetric risk in a standard labour ward is small. However, the impact of establishing a separate midwife-managed delivery unit, requiring an increase in midwifery staffing levels, can be significant.  相似文献   
25.
Cellular immune responses to melanoma-associated Ags are the focus of ongoing studies aimed at developing immunotherapies for treatment of malignant melanoma. Melanoma predominantly affects Caucasians, a population in whom expression of HLA-A2 is prevalent. Among HLA-A2 subtypes, HLA-A*0201 is widely expressed, and HLA-A*0201-restricted, tumor-reactive CTL responses are well studied. We have observed in a group of melanoma patients an unexpectedly high frequency (approximately 20%) of non-HLA-A*0201 subtypes (*0202, *0204, and *0205), and little is known regarding antimelanoma response profiles in patients expressing such subtypes. We analyzed non-HLA-A*0201 peptide response profiles using HLA-A*0201-restricted epitopes from melanoma Ags MART-1/Melan A and glycoprotein 100. Most of these peptides bound to the majority of subtypes tested with 50% inhibitory concentrations less than 500 nM. Recognition of cells pulsed with different peptides (MART-1(27-35), G9(154), and G9(280) Flu M1(58-66)) and expressing different subtype molecules by HLA-A*0201-restricted CTL was limited to only a subset of non-HLA-A*0201 molecules, and the peptide/subtype complexes recognized varied among the effector populations tested. CTL responses elicited from PBL of patients and healthy donors expressing subtypes HLA-A*0202 and HLA-A*0205 suggested significant differences among HLA-A2 subtype function in the context of melanoma Ag presentation. These observations imply the necessity of subtyping patients considered for peptide-based protocols and highlight the need for further study of melanoma-directed cellular responses among patients expressing non-HLA-A*0201 subtypes.  相似文献   
26.
The intention of this review is to compare studies on the morphology and histology (light and electron microscopic) of ultimobranchial glands of various groups of reptiles. Moreover, experiments (including our investigations) on suppression or stimulation of the ultimobranchial gland are included. Adult reptiles possess one (on the left side) or two ultimobranchial glands (UBG). The UBG lie just anterior to the heart. Light as well as electron microscopically, the gland has been shown to contain follicles and cell cords (cell aggregates). The follicular epithelium is lined by simple cuboidal or pseudostratified columnar cells. Ciliated and goblet cells may be present in the follicular epithelia in some groups. The lumen may contain a colloid-like substance with desquamated cells or debris. The UBG of reptiles seem to be an active secretory organ with influence on calcium regulation. Other functions of calcitonin have also been suggested in reptiles for example in neurotransmission, in volume regulation, phosphate balance and promotion of bone calcification (at least in juveniles).  相似文献   
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The transient suppression of muscle contraction during the cutaneous silent period (CSP) could be produced either through postsynaptic inhibition of motoneurons or through presynaptic inhibition of the excitatory inputs to motoneurons that sustain voluntary contraction. We sought to delineate the mechanisms underlying the CSP in hand muscles by measuring changes in H-reflexes and motor-evoked potentials (MEPs) produced by transcranial magnetic stimulation (TMS) during the CSP in 10 healthy volunteers. H-reflexes and MEPs both measure the excitability of the motoneuron pool and activate similar subpopulations of motoneurons through different pathways. Inhibition of H-reflexes and MEPs of similar size was maximal at the midpoint of the CSP and gradually returned to baseline. The similar time course of recovery suggests that the H-reflex and MEP are affected by inhibition at a common site, most likely postsynaptic inhibition of the motoneurons.  相似文献   
30.
One of the main tasks of current cutaneous surgery is to completely eliminate the tumor while avoiding unnecessary normal tissue extirpation. This is especially important when removing facial tumors close to the external canthus, mouth angles and perialar regions. In all these areas we advise fusiform excision but with distal M-plasty in the nearest angle so as to avoid angle retraction. The same is true for mediofrontal tumors, as this often causes a drawing together of the eyebrows. We have reviewed all mediofrontal excisions carried out during the last six years. M-plasty following fusiform excision was always performed in the interglabellar area. The good results achieved allow us to recommend this technique in this location.  相似文献   
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