Technology evaluation in a US hospital: The role of clinical engineering

Appropriate deployment of technological innovation contributes to improvement in the quality of healthcare delivered, containment of cost, and an increased access to the healthcare system. Hospitals have been allocating a, significant portion of their resources to procuring and managing capital assets; they are continously faced with demands for new medical equipment and are, asked to manage existing inventory for which they are not well prepared. To objectively manage their investment, hospitals are developing medical technology management programmes that need pertinent information and methods for new equipment planning as well as for reduction in the ownership costs of existing equipment. Clinical engineers can identify new medical equipment, review their institution's technological position, develop equipment-selection criteria, supervise installations and monitor postprocurement performance to meet their hospital's programme's objectives. This programme, together with cost accounting analysis, will objectively guide the capital assets decisionmaking process. The result of systematic planning and execution, the programme will assure the lowest life-cycle costs at the best performance. The clinical engineer's skills and expertise are needed to facilitate the adoption of an objective methodology for implementing the programme, thus improving the match between the hospital's needs and budget projections, equipment performance and cost of ownership.     

Effect of iron on the surface, degradation and ion release properties of phosphate-based glass fibres

Phosphate-based glass fibres (PGF) have the unique characteristic of being completely soluble in an aqueous environment, releasing bioactive and biocompatible ions. They have been proposed as tissue engineering scaffolds for craniofacial skeletal muscle regeneration, where myoblasts are seeded directly onto the fibres. Studies have shown that these cells have a preference in their initial attachment to fibres of certain composition and size, which in turn control the rate of degradation. This study investigated the relationship between the surface properties, degradation properties and ion release (cationic and anionic species) by altering the chemical composition of the PGF. Iron oxide (Fe2O3) was incorporated into glasses containing P2O5 (50 mol%), CaO (30 mol%) and Na2O (20 mol%). Six glass compositions with Fe2O3 ranging from 0 to 5 mol% by replacing the equivalent Na2O mol% were investigated. Contact angle measurements showed that polar interactions occurring on the glass surfaces diminished with increasing Fe2O3 content. This behaviour was reflected in the estimated surface energies of the glasses, where the overall surface energy decreased with increasing Fe2O3 content due to the decrease in polar or acid/base component. The incorporation of up to 5 mol% Fe2O3 into PGF resulted in a significant reduction in the degradation rate (by two orders of magnitude), which can be related to the formation of more hydration resistant P-O-Fe bonds. However, the degradation rate increased with decreasing fibre diameter (comparing average diameters of 31.6 +/- 6.5 microm versus 13.1 +/- 1.3 microm) for a given mass of fibre, and this is related to the surface area to volume ratio. Taken together the results suggest that fibres with the larger diameters and containing 3-5 mol% Fe2O3 could initially be a more durable scaffold than ones with 1 or 2 mol% Fe2O3 for initial cell attachment.     

The cellular structure and lipid/protein composition of adipose tissue surrounding chronically stimulated lymph nodes in rats

To test the hypothesis that chronic immune stimulation of a peripheral lymph node induces the formation of additional mature adipocytes in adjacent adipose tissue, one popliteal lymph node of large male rats was stimulated by local injection of 10 microg or 20 microg lipopolysaccharide three times a week for 6 weeks. Adipocyte volumes in sites defined by their anatomical relations to the stimulated and homologous unstimulated popliteal lymph nodes were measured, plus adipocyte complement of the popliteal depot, and the lipid and protein content of adipocytes and adipose stroma. The higher dose of lipopolysaccharide doubled the mass of the locally stimulated lymph node and the surrounding adipose tissue enlarged by the appearance of additional mature adipocytes. Similar but smaller changes were observed in the popliteal adipose depot of the unstimulated leg and in a nodeless depot. The lipid content of the adipocytes decreased and that of the stroma increased dose-dependently in all samples measured but the changes were consistently greater in the depot surrounding the stimulated lymph node. The protein content of both adipocytes and stroma increased in samples surrounding the stimulated node. We conclude that chronic immune stimulation of lymphoid tissues induces the formation of more adipocytes in the adjacent adipose tissue. These findings suggest a mechanism for the selective hypertrophy of lymphoid-containing adipose depots in the HIV-associated adipose redistribution syndrome.     

Reproduction and thermoregulation in Peromyscus: Effects of chronic short days

Seven groups of laboratory reared Connecticut P. leucopus were exposed to a 9L:15D photoperiod for either 6, 9, 12, 20, 25, 32, or 36 weeks. An eighth group was maintained on 16L:8D. During the final 6 weeks all mice were cold exposed (13°C). Substantial reproductive regression occurred in females following 6 weeks exposure to 9L:15D relative to 16L:8D animals. In males, a slight decrease in testicular weight occurred following 6 weeks on 9L:15D; this effect was pronounced by 9 weeks, along with a decrease in seminal vesicle weight. Reproductive recrudescence occurred in females by week 32 and in males by week 36. Between 10 and 12 weeks on 9L:15D mice exhibited increases in nesting, incidence of daily torpor, and presence of the winter molt. These increases persisted through 36 weeks on 9L:15D. An increase in the interscapular brown fat pad occurred between 12 and 25 weeks. Reproductive and thermoregulatory characters respond differently to prolonged exposure to a short day photoperiod in this species.     

Impaired diet-induced thermogenesis in brown adipose tissue from rats made obese with parasagittal hypothalamic knife-cuts

Two experiments were performed to determine if bilateral parasagittal hypothalamic knife-cuts (KCs), which produce long-term overeating and obesity, after biochemical indices of brown adipose tissue (BAT) reactivity to thermogenic stimuli. In the first study, responses to environmental cold were tested. Four weeks after surgery, KC rats had gained 4-5 times more weight than controls and were obese (increased Lee Obesity Index and weight of gonadal white fat). Before being sacrificed, groups of KC and control rats were exposed to 4 degrees C for 21 hr or remained at 28 degrees C. Interscapular BAT weighed 300% more in KC rats, due largely to increased white fat content. Functional indices of BAT thermogenic capacity (protein content, DNA content, cytochrome oxidase activity and mitochondrial guanosine diphosphate (GDP) binding) were normal at 28 degrees C. Exposure to 4 degrees C produced greatly enhanced responses but these were equivalent for both groups. This suggested an intact capacity for non-shivering thermogenesis in obese KC rats. In the second study, the same BAT responses were examined in other rats fed a palatable "cafeteria" diet (CAFE). One week after surgery, KC and control rats were subdivided into groups that received chow alone or chow plus four different palatable foods daily. Before sacrificing 4-5 weeks later, KC rats had gained 3-4 times more weight than controls and were obese. Interscapular BAT weighed 200-300% more in KC rats. CAFE feeding produced larger increments in all variables for KC vs. control rats. Most importantly, GDP binding was reduced in both KC groups, and significantly more so after CAFE feeding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Distribution of the [3H]-label from low doses of radioactive ochratoxin a ingested by rats,and evidence for DNA single-strand breaks caused in liver and kidneys

The distribution of a single low dose of [³H]ochratoxin A (OTA) in different tissues of male Wistar rats, after administration by intubation, was investigated after 5 h, 24 h and 48 h. This dose corresponds to concentrations encountered in naturally contaminated feed (4 ppm). The distribution of [³H]-label varied with the time elapsed after administration; at 5 h the highest specific label was found in the stomach contents and in decreasing order in: intestinal contents, lung, liver, kidney, heart, fat, intestine, testes, and the lowest in muscles, spleen and brain. With exception of brain, fat, stomach and lung, all tissues showed maximum levels at 24 h, after which time the label decreased steadily, whereas in fat it increased.After a 12-week feeding experiment, with doses of 288.8 g/kg corresponding to an intake of 4 ppm in feed each 48 h, the DNA in liver and kidneys was investigated for damage. By the alkaline elution method combined with micro-spectrofluorimetric determinations of DNA, evidence for DNA single-strand breaks was obtained. These findings support reports on the carcinogenic action of OTA.     

Chronic Intake of Energy Drinks and Their Sugar Free Substitution Similarly Promotes Metabolic Syndrome

Energy drinks containing significant quantities of caffeine, taurine and sugar are increasingly consumed, particularly by adolescents and young adults. The putative effects of chronic ingestion of either standard energy drink, Mother^TM (ED), or its sugar-free formulation (sfED) on metabolic syndrome were determined in wild-type C57BL/6J mice, in comparison to a soft drink, Coca-Cola (SD), a Western-styled diet enriched in saturated fatty acids (SFA), and a combination of SFA + ED. Following 13 weeks of intervention, mice treated with ED were hyperglycaemic and hypertriglyceridaemic, indicating higher triglyceride glucose index, which was similar to the mice maintained on SD. Surprisingly, the mice maintained on sfED also showed signs of insulin resistance with hyperglycaemia, hypertriglyceridaemia, and greater triglyceride glucose index, comparable to the ED group mice. In addition, the ED mice had greater adiposity primarily due to the increase in white adipose tissue, although the body weight was comparable to the control mice receiving only water. The mice maintained on SFA diet exhibited significantly greater weight gain, body fat, cholesterol and insulin, whilst blood glucose and triglyceride concentrations remained comparable to the control mice. Collectively, these data suggest that the consumption of both standard and sugar-free forms of energy drinks induces metabolic syndrome, particularly insulin resistance.     

Vitamin A Status Improvement in Obesity: Findings and Perspectives Using Encapsulation Techniques

The association between obesity and vitamin A has been studied. Some studies point to the anti-obesity activity related to this vitamin, carotenoids with provitamin A activity, and carotenoid conversion products. This performance has been evaluated in respect of adipogenesis, metabolic activity, oxidation processes, secretory function, and oxidative stress modulation, showing a new property attributed to vitamin A in preventing and treating obesity. However, vitamin A and its precursors are highly sensitive and easily degraded when subjected to heat, the presence of light, and oxygen, in addition to losses related to the processes of digestion and absorption. In this context, encapsulation presents itself as an alternative capable of increasing vitamin A’s stability in the face of unfavorable conditions in the environment, which can reduce its functionality. Considering that vitamin A’s status shows a strong correlation with obesity and is an innovative theme, this article addresses the associations between vitamin A’s consumption and its precursors, encapsulated or not, and its physiological effects on obesity. The present narrative review points out those recent studies that demonstrate that vitamin A and its encapsulated precursors have the most preserved functionality, which guarantees better effects on obesity therapy.     

干细胞治疗子宫内膜损伤的研究进展

感染因素或宫腔手术操作导致的子宫内膜损伤阻碍胚胎的着床和发育,严重影响妇女的身心健康与生育能力。但目前治疗手段有限且效果欠佳。干细胞具有自我更新和分化潜能,在病变损伤组织的修复过程中发挥重要作用。骨髓间充质干细胞、脐带间充质干细胞、子宫内膜干细胞、脂肪干细胞和人羊膜上皮细胞等多种干细胞治疗子宫内膜损伤已在动物模型和临床研究中开展,并展现出巨大的潜力。干细胞治疗可促进子宫内膜细胞再生,改善子宫内膜厚度和微血管密度,提高受孕率并改善生育结局。干细胞治疗从形态和功能上改善子宫内膜,促进月经和生殖功能的恢复,为治疗子宫内膜损伤提供一种新策略。