The PA7100 CPU, the first precision-architecture, reduced-instruction-set-computer (PA-RISC) architecture implementation to combine an integer core and floating-point coprocessor into a single-chip ...format, is described. It incorporates superscalar execution and supports clock rates of up to 100 MHz in standard 0.8- mu m CMOS. Features such as a flexible primary cache organization and multiprocessing capability allow the device to be scaled to a variety of system applications, price ranges, and performance levels. The microprocessor instruction execution pipeline, cache design, translation look-aside buffer (TLB) for virtual address translation, floating-point unit, and system interface bus are discussed. The design, test, and verification methods used in the development of the PA7100 are reviewed.< >
Just as the awareness of incest and childhood sexual abuse has grown in recent years, so too has knowledge of sexual exploitation of patients by psychotherapists and other mental health ...professionals. Almost no one, however, has discussed the prevalence of this problem in the hospital setting. The authors were members of a study group that thoroughly reviewed reported incidents in their own institution, leading to the recommendation that education is the best preventive measure currently available. The authors discuss fundamental issues involved in such a study, summarize profiles of patients and staff members who may be vulnerable to sexual involvement, and describe the main components of a preventive educational approach.
Spinal cord injury causes damage to ascending and descending tracts, as well as to local circuits, but relatively little is known about the effect of such injury on sensory neurons located within ...adjoining ganglia. We have therefore used immunocytochemistry for activating transcription factor-3 (ATF3), a sensitive marker of axonal damage, in order to examine the effects of spinal cord injury in rats on dorsal root ganglion (DRG) neurons. A 50-g static compression injury applied to the dorsal surface of the T12 thoracic spinal cord led to an up-regulation of ATF3 that was maximal at 1 day and affected 12-14% of DRG neurons in ganglia caudal to the injury (T13-L3). A similar response was seen after a T12 hemisection that transected the dorsal columns except that compression injury, but not hemisection, also evoked ATF3 expression in ganglia just rostral to the injury (T10, T11). ATF3 was up-regulated exclusively in DRG neurons that were of large diameter and immunoreactive for heavy neurofilament. Small-diameter cells, including the population that binds the lectin Grifffonia simplicifolia IB4, did not express ATF3 immunoreactivity. A similar pattern of ATF3 expression was induced by dorsal rhizotomy. The data show for the first time that ATF3 is up-regulated after spinal cord and dorsal root injury, but that this up-regulation is confined to the large-diameter cell population.
A single dose of ethane dimethane sulphonate (EDS) given to adult male rats has a specific destructive effects on Leydig cells, which are removed from the intertubular area by macrophages. This is ...associated with a decrease in testosterone (T) and a rise in serum FSH and LH for 21-28 days after EDS. Recovery of Leydig cells occurs from connective tissue precursors. This study uses the bilaterally cryptorchid rat to investigate the influence of local factors from the seminiferous tubules on the restoration of Leydig cell morphology and function. Morphometric data of intertubular tissue, hCG binding, serum T, FSH and LH levels all indicate that the Leydig cell population in cryptorchid testes is more rapidly restored from connective tissue cells when compared to the normal situation. The precise mechanism for this faster recovery will require further study.
The effects of glial cell line-derived neurotrophic factor on axonal outgrowth and apoptosis were studied in vitro using explanted dorsal root ganglia-peripheral nerve preparations of adult mice. In ...gels of matrigel or collagen type 1, glial cell line-derived neurotrophic factor increased both the numbers and lengths of axons growing out of explanted preparations, although less effectively than nerve growth factor. Stimulation of axonal outgrowth by glial cell line-derived neurotrophic factor was unaffected by K252a, a protein kinase inhibitor which blocks the effects of nerve growth factor and other neurotrophins acting through trk receptors. To determine the phenotype of the axons responding to glial cell line-derived neurotrophic factor, preparations were stained using antibodies to trkA, calcitonin gene-related peptide, 200,000 mol. wt phosphorylated neurofilaments (monoclonal antibody RT97) and the lectin Bandeiraea simplicifolia 1B4. RT97 recognizes large diameter neurons whilst 1B4 labels small diameter neurons which broadly do not express neurotrophin receptors. In preparations cultured with glial cell line-derived neurotrophic factor, significant increases in the numbers of outgrowing axons labelled with RT97 and 1B4 were observed but the numbers of calcitonin gene-related peptide-positive axons were not significantly increased and their staining intensity was generally faint. In separate preparations it was found that in the presence of glial cell line-derived neurotrophic factor, the majority of the 1B4 labelled axons were trkA negative, indicating that this factor can stimulate axonal growth in this population of neurons which do not respond to the neurotrophins. Spontaneous apoptosis in neurons and satellite cells occurs in explanted preparations of the type used in the present investigations, but in cryostat sections of preparations cultured in the presence of glial cell line-derived neurotrophic factor, the incidence of apoptosis was lower than in control preparations which had been cultured in the absence of this factor. This suggests that glial cell line-derived neurotrophic factor may promote survival of some adult sensory neurons in vitro.
The midbrain periaqueductal grey matter (PAG) has numerous functional roles that include mediating nociceptive inhibition and integrating behavioural and physiological responses to potentially ...threatening or stressful stimuli. Underlying these behaviours is the diverse interconnectivity of this region, and it is possible that neurochemical subdivisions within the PAG reflect the functional properties of the different PAG regions. In this study, using in situ hybridization, we have investigated the distribution in the rat PAG of the messenger ribonucleic acids (mRNAs) encoding seven neuropeptides: enkephalin (ENK), substance P (SP), somatostatin (SST), galanin (GAL), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP). Each peptide mRNA had a distinct topographical distribution in the PAG. Preproenkephalin A (ENK) mRNA-expressing cells were found at all levels of the PAG in three distinct longitudinal columns. Preprotachykinin A (SP)-expressing cells were found at all levels of the PAG, principally in the Edinger-Westphal nucleus and the lateral and dorsal PAG. There was a column of neurons producing mRNA-encoding somatostatin that extended along the rostrocaudal extent of the ventrolateral PAG; there were also labelled cells in the dorsal and dorsolateral subdivisions at some levels of the PAG. Galanin mRNA-producing neurones were limited to the dorsal raphe nucleus and to a second population in the ventral border of the aqueduct. VIP mRNA-producing neurones were found in very localized regions of the PAG, including the cell-sparse region immediately ventral to the aqueduct and the ventral part of the dorsal raphe nucleus. NPY mRNA-producing neurones were localized mainly in some cells of the Edinger-Westphal nucleus and dorsal raphe nucleus. CGRP mRNA-expressing neurons were limited to the oculomotor and trochlear nucleus. The results showed a topographical distribution of neuropeptides over the rostrocaudal extent of the PAG that is compatible with the emerging theory that the anatomical and functional specificity of the PAG is expressed in the form of longitudinally arranged neuronal columns that extend for varying distances along the rostrocaudal axis of the midbrain PAG.
In August 1927 the Chinese Communist Party (CCP) in Jiangxi seemed moribund, yet by the end of 1930 the movement was larger and more active than ever before. How did this occur? Past studies have ...especially emphasized Mao Zedong's famous rural guerrilla strategy, but this was only part of the story. Equally significant was the little-studied success of members of the Jiangxi hill-country elite who were also in the CCP in using established schools and educational societies, time-honored traditions of local strongman behavior, and existing bandit–secret society gangs to build many localized base areas. Such techniques were congenial to CCP leaders and essential to the movement's survival in the early days when its prestige and material resources were at a very low ebb, and when radical reforms would almost certainly have failed. Nevertheless, this strategy also fostered parochial attitudes and organizational weaknesses that clashed with the later efforts of Mao and his allies to carry out mass mobilization and fundamental land reform. Only after a prolonged and violent crisis within the base areas did the “Maoist” policies vital for the revolution's long-term growth begin to overcome the policies of elite coalition building that had been necessary for the movement to obtain its initial foothold in the Jiangxi hill country.
The alpha(1) subunit provides both the voltage-sensing mechanism and the ion pore of voltage-dependent calcium channels. Of the six classes of alpha(1) subunit cloned to date, alpha)1A) is the ...subject of debate in terms of its functional correlate, although it is generally thought to encode voltage-dependent calcium channels of the omega-agatoxin IVA-sensitive, P/Q type. In the present study, an alpha(1A)-specific riboprobe and antibody were used with in situ hybridisation and immunohistochemical techniques to localise alpha(1A) messenger ribonucleic acid transcripts and subunit protein throughout the mature rat brain. Dual localisation of alpha(1A) protein and markers for acetylcholine, catecholamines, and 5-hydroxytryptamine have also been performed in a number of discrete areas. Abundant and widespread distribution of alpha(1A) protein was found, with immunoreactivity occurring both in cell bodies and as punctate staining in areas of neuronal processes. Several associations were noted across alpha(1A) localisation, defined neuroanatomical regions, and neurotransmitter systems. However, alpha(1A) expression was not confined to loci corresponding to any one neurotransmitter type, although a high level of expression was observed in cholinergic neurones. The distribution of the alpha(1A) subunit in the rat corresponded well with the limited human mapping data that are available.
