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51.
14 severely burned patients were randomly assigned to receive one of three nasogastric feeds commencing after the resuscitation period and continuing for 15 days. Group A received a feed with a high leucine content (31% of protein as branched chain amino-acids, BCAA). Group B received a similar feed to Group A but 65% of the leucine was replaced by alpha-ketoisocaproate (KIC). Group C received a whole protein feed (16% of the protein content as BCAA), and acted as a control group. Targeted energy intake was twice the calculated Basal Metabolic Rate (BMR). Group A had significantly reduced urinary 3-methylhistidine (3-MEH) and serum urea, compared with the control group. Serum total protein, albumin and transferrin and apparent nitrogen balance were not significantly different. Group B's results did not vary significantly from controls. Leucine enrichment reduces muscle protein breakdown benefiting burn patients fed enterally when compared to a standard feed, whereas KIC enrichment does not. 相似文献
52.
Weiss C Knuttinen MG Power JM Patel RI O'Connor MS Disterhoft JF 《Behavioral neuroscience》1999,113(5):1100-1105
Trace eyeblink conditioning (EBC) parameters, with an airpuff unconditioned stimulus, were examined in male Fischer 344 X Brown Norway F1 rats. Integrated electromyographic activity from the upper eyelid was recorded. An 8-kHz tone was superior to white noise as a conditioning stimulus. Rats trained with 30 or 50 trials per session showed similar learning. Reversal of environmental lighting had no significant effect. Trace intervals of 0 and 250 ms yielded well-timed conditioned responses (CRs); intervals of 500 ms or more did not. These experiments provide parameters that reliably yield CRs and suggest limits on the temporal processing capabilities of the rat. EBC can thus be used as part of a comprehensive test battery for learning and memory in this species. Physiological recording and pharmacological manipulations may also be done easily. This combination of approaches should facilitate a more complete understanding of learning mechanisms and age-related memory impairments. 相似文献
53.
It has been shown previously that the antero-inferior cortex is subjected to maximal tensile stress during a fall onto the
greater trochanter. We have recently shown that in cases of femoral neck fracture, cortical thinning and porosity is greatest
in the anterior and antero-inferior region of the femoral neck. To investigate whether this is due to increased remodeling,
we have quantified surface-based parameters associated with Haversian remodeling in femoral neck biopsies from women with
intracapsular hip fracture and post-mortem controls. Cryostat sections of chilled biopsies were reacted for either tartrate-resistant
acid phosphatase (TRAP) or alkaline phosphatase (ALP) activity. Proportions of active canals were determined in each quadrant
(inferior, anterior, superior, posterior) of the femoral neck. The biopsies were then embedded in methacrylate to permit histomorphometry
using Goldner’s and Solochrome sections. In the cases there was no significant increase in the proportion of canals undergoing
remodeling in the cortex as a whole (p = 0.846), but the regional distribution of remodeling was markedly different from that in the controls. In the anterior cortex,
the proportion of canals undergoing remodeling was increased by 56% (p = 0.0087); in contrast there was a relative decrease of 35% in the superior region (p = 0.0047). In the anterior cortex of cases there were 76% and 42% increases in the proportions of eroded (p = 0.019) and osteoid-bearing (p = 0.041) canals, respectively. In the superior region, the decrease in the proportion of remodeling sites was due to a marked
decrease in canals with an osteoid surface (51%; p = 0.0031). Covariance analysis with cortical porosity as the dependent variable showed that porosity was significantly dependent
on the regional distribution of eroded (p = 0.033) but not on the distribution of forming (p = 0.153) canals (R
2adj = 0.51). Cellular levels of TRAP and ALP were significantly elevated in the anterior region of cases compared with the
controls (TRAP 55%, p = 0.006; ALP 36%, p = 0.003). For the posterior and inferior regions there were no marked differences in cellular TRAP and ALP levels compared
with control values. These data show that the increased cortical thinning and increased porosity we have previously observed
in the anterior cortex in cases of hip fracture are associated with increased indices of Haversian remodeling. These findings
are consistent with the hypothesis that, in cases of hip fracture, remodeling imbalance in the anterior cortex is a continuing
process up to the time of fracture and is due to increased osteoclastic cellular activity associated with an osteoblastic
response that is inadequate to prevent bone loss.
Received: 16 November 1998 / Accepted: 17 February 1999 相似文献
54.
Lone mothers have been shown to have higher levels of psychological distress than married mothers, but it is not clear how this difference arises. Using data from the 1958 British birth cohort followed to age 33, we investigated alternative explanations for the excess distress of lone mothers. Logistic regression models were used to estimate odds ratios for distress (measured using the Malaise Inventory) in lone vs married mothers. Odds ratios were adjusted to assess the contribution of explanatory factors. At age 33, psychological distress was greater among lone than married mothers (OR 2.59, 95% CI 1.97, 3.41). The odds ratio decreased to 1.43 (95% CI 1.02, 2.01) after adjustment for all explanatory factors (prior psychological distress, age of youngest child and number of children in the household, and contemporary measures of financial hardship, employment, and social support). Attenuation of the odds ratio was most marked after taking account of financial hardship. Psychological distress was greater among divorced mothers than never married mothers, though not significantly (OR = 1.70, 95% CI 0.88, 3.28). This difference was not explained by the factors examined, and was not due to the immediate distress associated with a recent divorce. Elevated psychological distress of lone mothers appears to be related to financial hardship, while other explanations, including social support and selection, have a more modest impact. Not all of the elevated psychological distress among lone mothers was accounted for, particularly among divorced lone mothers. 相似文献
55.
A minority of injecting drug users engage in high risk injecting behaviours when in prison. In the United Kingdom between a quarter and a third of injectors who enter prison inject when in prison, and of these about three-quarters share needles and syringes. In the present study, 44 drug injectors who had been released from prison for no longer than 6 months were recruited and interviewed in three geographical areas in England. Interviewees were asked to recount their experiences of drug use during their most recent period of imprisonment. The majority of interviewees were male (38/44), had a mean age of 28 years, with a mean age of 16 years at first drug use, were primarily opiate users (39) and had multiple imprisonments. All respondents reported drug use when imprisoned and drug injecting was reported by 16 interviewees. Most injected at irregular intervals and at a reduced level, compared with injecting when in the community. Nine reported using needles and syringes that others had previously used. When considering other injecting equipment, more sharing occurred than was actually reported. Much re-use of equipment was viewed simply as “using old works”. The sharing of “cookers” and “filters”, and drug sharing by “backloading” and “frontloading” were common. The concept of “sharing” tended to be understood by respondents as related to the use of tools of injection (needles and syringes rather than other equipment); the use of tools in the act of injection (rather than for mixing drugs); proximity (multiple use of needles and syringes in the presence of others); temporality (shorter time elapse between consecutive use of needles and syringes previously used by another) and source (hired rather than borrowed or bought). We conclude that syringe sharing is an integral part of drug use and drug injecting in prison. Many of those interviewed displayed a restricted understanding of what denotes syringe sharing. Our data reinforce the need for interventions and initiatives to be developed within prisons to deal with the considerable risk posed by continued injecting drug use. 相似文献
56.
57.
Marrow regeneration after mechanical depletion 总被引:1,自引:0,他引:1
The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration. 相似文献
58.
59.
A 15 year old boy with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome suffered recurrent episodes of severe intractable diarrhoea, steatorrhoea, and hypocalcaemia. The only treatment modality, which controlled the malabsorption syndrome, was immunosuppression with intravenous high dose methylprednisolone and oral methotrexate maintenance therapy. 相似文献
60.
Transforming insurance coverage into quality health care: voltage drops from potential to delivered quality 总被引:6,自引:0,他引:6
Although the US health care system is often touted as one of the best in the world, disparities exist in quality of care received by different populations, in different regions, and across different institutions and clinicians. Initiatives to provide access to health insurance have been a major policy tool to ensure that Americans receive high-quality health care. However, availability of insurance coverage does not automatically lead to high-quality care. This article explores points of vulnerability in the US health care system at which the potential to achieve high-quality care can be lost: (1) access to insurance coverage; (2) enrollment in available insurance plans; (3) access to covered services, clinicians, and health care institutions; (4) choice of plans, clinicians, and health care institutions; (5) access to a consistent source of primary care; (6) access to referral services; and (7) delivery of high-quality health care services. Ensuring high-quality health care requires that each of these "voltage drops" be recognized and addressed. JAMA. 2000;284:2100-2107. 相似文献