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Societal savings by "fast tracking" lower acuity patients in an urban pediatric emergency department.

To evaluate the cost-effectiveness of a "fast track" system for diverting lower acuity patients away from the pediatric emergency department (ED), 4,060 patients triaged to the fast track area of an urban pediatric ED with the 10 most common discharge diagnoses from 1/1/94 through 12/31/94 were retrospectively evaluated. Patients triaged as having nonurgent concerns qualified for treatment in a separate fast track area for 8 hours per day (fast track patients). These patients were compared with 5,199 seen in the main pediatric ED for the same concerns during the remaining hours when the fast track was not in operation (ED patients). Computer records were reviewed for demographics, acuity levels, diagnosis, and collection ratios (revenues/charges). The societal savings was calculated as sigma $ [(delta mean revenue of diagnosis1-10 in the main ED - mean revenue of diagnosis1-10 in the fast track) x the number of patients seen in fast track for diagnosis1-10] stratified by acuity. Collection ratios were comparable between groups (57% v 62%), but the average charges (physician and facility) were significantly less for patients seen in the fast track by a ratio of 1:2.4 (P < .0001). The average net revenue was also significantly less for all patients seen in the fast track by a ratio of 1:2.6 (P < .0001). When stratified by diagnosis and acuity, the savings to society was $101,313, or an average of $25/patient seen in the fast track ($101,313 per 4,060). A fast track is an effective system for maintaining patient flow at a cost savings to society. It can help the hospital in its negotiations with payors because it curtails charges. It is also a potential means for maintaining overall departmental revenues as payors increasingly deny traditional pediatric ED visits for patients with lower acuity concerns.

Child↗

Differential effect of esmolol on the fast and slow AV nodal pathways in patients with AV nodal reentrant tachycardia.

INTRODUCTION: AV nodal reentrant tachycardia (AVNRT) usually involves anterograde conduction over a slowly conducting ("slow") pathway and retrograde conduction over a rapidly conducting ("fast") pathway. A variety of drugs, such as beta blockers, digitalis, and calcium channel blockers, have been reported to prolong AV nodal refractoriness in both the anterograde and retrograde limbs of the circuit. However, few data are available that address whether the fast and slow pathways respond in a quantitatively different manner to drugs such as beta-adrenergic antagonists. In addition, it is not known whether the effects of these agents on refractoriness parallel the effects on conduction in the fast and slow pathways. The present study was performed to measure the effect of the intravenous beta-adrenergic agent, esmolol, on refractoriness and conduction in both the fast and slow AV nodal pathways in patients with AVNRT. METHODS AND RESULTS: Thirteen patients with discontinuous AV nodal conduction properties and typical AVNRT were studied. Anterograde and retrograde AV nodal functional assessment was performed at baseline and following steady-state drug infusion of intravenous esmolol at a dose of 500 micrograms/kg for 1 minute, 150 micrograms/kg per minute for the next 4 minutes, followed by a continuous maintenance infusion of 50 to 100 micrograms/kg per minute. The anterograde effective refractory period of the fast pathway increased from 381 +/- 75 msec at baseline to 453 +/- 92 msec during the infusion of esmolol (P = 0.003). The anterograde effective refractory period of the slow pathway was also prolonged by esmolol, from 289 +/- 26 msec to 310 +/- 17 msec (P = 0.005). However, the absolute magnitude of the change in the anterograde effective refractory period of the fast pathway (+72 +/- 59 msec) was significantly greater than the change in anterograde effective refractory period of the slow pathway (+21 +/- 16 msec, P = 0.01). The mean retrograde effective refractory period of the fast pathway increased from 276 +/- 46 msec to 376 +/- 61 msec during esmolol infusion (P = 0.03). Retrograde slow pathway conduction that could not be demonstrated at baseline became manifest in three patients during esmolol infusion. In contrast to the effects of esmolol on refractoriness, the AH interval during anterograde slow pathway conduction prolonged to a far greater extent (+84 msec) than the HA interval associated with retrograde fast pathway conduction (+5 msec, P = 0.04). CONCLUSION: The beta-adrenergic antagonist, esmolol, has a quantitatively greater effect on anterograde refractoriness of the fast than the slow AV nodal pathway. However, the effects on conduction intervals during AVNRT are greater in the anterograde slow pathway than in the retrograde fast pathway. These observations suggest that the fast and slow pathways may have differential sensitivities to autonomic influences. This difference in the response to beta-adrenergic antagonists may be exploited as a clinically useful method for demonstrating slow pathway conduction in some individuals with AVNRT.

Adrenergic beta-Antagonists↗

Action potential repolarization and a fast after-hyperpolarization in rat hippocampal pyramidal cells.

1. The repolarization of the action potential, and a fast after-hyperpolarization (a.h.p.) were studied in CA1 pyramidal cells (n = 76) in rat hippocampal slices (28-37 degrees C). Single spikes were elicited by brief (1-3 ms) current pulses, at membrane potentials close to rest (-60 to -70 mV). 2. Each action potential was followed by four after-potentials: (a) the fast a.h.p., lasting 2-5 ms; (b) an after-depolarization; (c) a medium a.h.p., (50-100 ms); and (d) a slow a.h.p. (1-2 s). Both the fast a.h.p. and the slow a.h.p. (but not the medium a.h.p.) were inhibited by Ca2+-free medium or Ca2+-channel blockers (Co2+, Mn2+ or Cd2+); but tetraethylammonium (TEA; 0.5-2 nM) blocked only the fast a.h.p., and noradrenaline (2-5 microM) only the slow a.h.p. This suggests that two Ca2+-activated K+ currents were involved: a fast, TEA-sensitive one (IC) underlying the fast a.h.p., and a slow noradrenaline-sensitive one (IAHP) underlying the slow a.h.p. 3. Like the fast a.h.p., spike repolarization seems to depend on a Ca2+-dependent K+ current of the fast, TEA-sensitive kind (IC). The repolarization was slowed by Ca2+-free medium, Co2+, Mn2+, Cd2+, or TEA, but not by noradrenaline. Charybdotoxin (CTX; 30 nM), a scorpion toxin which blocks the large-conductance Ca2+-activated K+ channel in muscle, had a similar effect to TEA. The effects of TEA and Cd2+ (or Mn2+) showed mutual occlusion. Raising the external K+ concentration reduced the fast a.h.p. and slowed the spike repolarization, whereas Cl- loading of the cell was ineffective. 4. The transient K+ current, IA, seems also to contribute to spike repolarization, because: (a) 4-aminopyridine (4-AP; 0.1 mM), which blocks IA, slowed the spike repolarization; (b) depolarizing pre-pulses, which inactivate IA, had a similar effect; (c) hyperpolarizing pre-pulses speeded up the spike repolarization; (d) the effects of 4-AP and pre-pulses persisted during Ca2+ blockade (like IA); and (e) depolarizing pre-pulses reduced the effect of 4-AP. 5. Pre-pulses or 4-AP broadened the spike less, and in a different manner, than Ca2+-free medium, Cd2+, Co2+, Mn2+, TEA or CTX. The former broadening was uniform, with little effect on the fast a.h.p., whereas the latter affected mostly the last two-thirds of the spike repolarization and abolished the fast a.h.p.(ABSTRACT TRUNCATED AT 400 WORDS)

4-Aminopyridine↗

Anechoic stripe size influences accuracy of FAST examination interpretation.

OBJECTIVES: Accurate and precise interpretations of Focused Assessment with Sonography for Trauma (FAST) findings are important factors in managing trauma patients. The objectives were to analyze the influence of anechoic stripe (AS) size on interpretation accuracy by emergency physicians (EPs) and to assess the precision of FAST examination interpretation as a function of EP FAST experience. METHODS: A prospective comparison study of FAST examination interpretation by 11 emergency medicine faculty (FAC), nine community attending EPs (ATT), and nine senior emergency medicine residents (RES) was conducted; these physicians were then divided into more experienced and less experienced cohorts to assess precision. Participants interpreted video recordings of the four standard views from five FAST examinations (20 total video clips); each examination contained views with various AS sizes. Accuracy of FAST examination interpretation was calculated for each group stratified by size of AS. Precision (reproducibility) of FAST examination interpretation was assessed by calculating kappa values. RESULTS: With large, moderate, or no AS, no significant differences in accuracy were found between groups. For small AS, significant differences in accuracy were found between the ATT and RES groups and between the combined FAC + ATT group and the RES group. Kappa was good to excellent when the nth and the (n + 1)th experienced physicians in the more experienced cohort were compared. kappa values reflected that the more experienced cohort was more precise than the less experienced cohort. CONCLUSIONS: AS size visible on FAST examinations and EP experience level with FAST examination interpretation exerted a significant influence on the interpretation accuracy of videotaped FAST examinations. In addition, precision was enhanced by increased EP experience with FAST.

Abdominal Injuries↗

Complex fiber-type-specific expression of fast skeletal muscle troponin I gene constructs in transgenic mice.

We analyzed, in transgenic mice, the cellular expression pattern of the quail fast skeletal muscle troponin I (TnIfast) gene and of a chimeric reporter construct in which quail TnIfast DNA sequences drive expression of E. coli beta-galactosidase (beta-gal). Both constructs were actively expressed in skeletal muscle and specifically in fast, as opposed to slow, muscle fibers. Unexpectedly, both constructs showed a marked differential expression among the adult fast fiber subtypes according to the pattern IIB > IIX > IIA. This expression pattern was consistent in multiple lines and differed from the endogenous mouse TnIfast pattern, which shows approximately equal expression in all fast fibers. These observations indicate that distinct regulatory mechanisms contribute to high-level expression of TnIfast in the various fast fiber subtypes and suggest that the outwardly simple pattern of equal expression in all fast fiber types shown by the endogenous mouse TnIfast gene is based on an intricate system of counterbalancing mechanisms. The adult expression pattern of the TnIfast/beta-gal construct emerged in a two-stage developmental process. Differential expression in fast versus slow fibers was evident in neonatal animals, although expression in fast fibers was relatively weak and homogeneous. During the first two weeks of postnatal life, expression in maturing IIB fibers was greatly increased whereas that in IIA/IIX fibers remained weak, giving rise to marked differential expression among fast fiber types. Thus at least two serially acting (pre- and post-natal) fiber-type-specific regulatory mechanisms contribute to high-level gene expression in adult fast muscle fibers. Unexpected similarities between TnIfast transgene expression and that of the myosin heavy chain gene family (which includes differentially expressed IIB-, IIX- and IIA-specific members) suggest that similar mechanisms may regulate adult fast muscle gene expression in a variety of unrelated muscle gene families.

Animals↗

Effects of fast-food consumption on energy intake and diet quality among children in a national household survey.

BACKGROUND: Fast food has become a prominent feature of the diet of children in the United States and, increasingly, throughout the world. However, few studies have examined the effects of fast-food consumption on any nutrition or health-related outcome. The aim of this study was to test the hypothesis that fast-food consumption adversely affects dietary factors linked to obesity risk. METHODS: This study included 6212 children and adolescents 4 to 19 years old in the United States participating in the nationally representative Continuing Survey of Food Intake by Individuals conducted from 1994 to 1996 and the Supplemental Children's Survey conducted in 1998. We examined the associations between fast-food consumption and measures of dietary quality using between-subject comparisons involving the whole cohort and within-subject comparisons involving 2080 individuals who ate fast food on one but not both survey days. RESULTS: On a typical day, 30.3% of the total sample reported consuming fast food. Fast-food consumption was highly prevalent in both genders, all racial/ethnic groups, and all regions of the country. Controlling for socioeconomic and demographic variables, increased fast-food consumption was independently associated with male gender, older age, higher household incomes, non-Hispanic black race/ethnicity, and residing in the South. Children who ate fast food, compared with those who did not, consumed more total energy (187 kcal; 95% confidence interval [CI]: 109-265), more energy per gram of food (0.29 kcal/g; 95% CI: 0.25-0.33), more total fat (9 g; 95% CI: 5.0-13.0), more total carbohydrate (24 g; 95% CI: 12.6-35.4), more added sugars (26 g; 95% CI: 18.2-34.6), more sugar-sweetened beverages (228 g; 95% CI: 184-272), less fiber (-1.1 g; 95% CI: -1.8 to -0.4), less milk (-65 g; 95% CI: -95 to -30), and fewer fruits and nonstarchy vegetables (-45 g; 95% CI: -58.6 to -31.4). Very similar results were observed by using within-subject analyses in which subjects served as their own controls: that is, children ate more total energy and had poorer diet quality on days with, compared with without, fast food. CONCLUSION: Consumption of fast food among children in the United States seems to have an adverse effect on dietary quality in ways that plausibly could increase risk for obesity.

Adolescent↗

The effect of a 'fast-track' unit on the performance of a cardiothoracic department.

OBJECTIVE: The objective of this study was to describe the impact of a 'fast-track' unit, combined with a computerised system for information collection and analysis, on the clinical practice and finance of a cardiothoracic department over the first 12 month period of its application. METHODS: Within 12 months, starting December 1996, 642 major cardiothoracic cases were performed at the Cardiothoracic Department, St Mary's Hospital, London, after the establishment of a 3-bed 'fast-track' unit, which was supported by a computerised system for admission planning and a pre-admission clinic. The main outcome measures were operating numbers, financial income, patient recovery and operative mortality. RESULTS: The 'fast-track' unit resulted in an increase of the operating numbers (11.3% increase in major cardiac cases) and income (38%), as compared with the year before. Some 525 patients out of 642 (81.8%) were scheduled for the 'fast-track' unit and 492 (93.7%) were successfully 'fast-tracked'. Coronary artery bypass grafting operations had the lowest 'fast-track' failure and mortality rates. Re-do operations and complex coronary procedures presented a high 'fast-track' failure rate of approximately 20-25%. Low cardiac output, postoperative bleeding and respiratory problems were the most frequent causes for 'fast-track' failure. CONCLUSIONS: The development of a 'fast-track' unit, supported by a computerised system for information collection and analysis and a pre-admission clinic, has resulted in a substantial improvement of operating numbers and financial income, without adversely affecting the clinical results. This task demanded close collaboration between a dedicated list manager and a designated member of the medical team. Patient selection with appropriate 'fast-track,' criteria may improve further the efficiency of 'fast-track' units in the future.

Aged↗

Utilization of FAST (Focused Assessment with Sonography for Trauma) in 1999: results of a survey of North American trauma centers.

Although much has been written about FAST (Focused Assessment with Sonography for Trauma) in the last decade little is known about its present clinical utilization. The purpose of this study was to evaluate and characterize the contemporary utilization of FAST at trauma centers in the United States and Canada. In 1999 trauma directors or their delegates at Level I regional trauma centers in the United States and Canada were surveyed either by fax or phone regarding the present utilization and the future of FAST at their center. The overall survey response rate was 91 per cent with 96 of 105 centers completing the survey. Of the 96 centers surveyed 78 were in the United States and 18 were in Canada. Of the 78 U.S. centers surveyed 62 (79%) routinely use FAST, and it is done by surgeons in 39 per cent, surgeons and emergency departments in 21 per cent, emergency departments in 5 per cent, and radiologists in 35 per cent. Most centers (79%) thought that it sped up their workups, and 89 per cent said it was an advance in patient care. FAST is used in penetrating injury at 58 per cent of centers, and some centers use FAST to assess organ injury. The utilization of diagnostic peritoneal lavage and CT has markedly decreased at many centers. Almost all respondents thought that FAST should be a component of surgery resident training. The utilization of FAST is significantly less in Canada than in the United States (P < 0.05). Our conclusions are the following. FAST has become routinely used at the majority of the U.S. centers surveyed. FAST is performed by clinicians at 65 per cent of the trauma centers surveyed. The utilization of CT and diagnostic peritoneal lavage has changed. Many centers have broadened the scope of FAST to include the assessment of organ, pediatric, and penetrating injury.

Abdominal Injuries↗

[Advantages and disadvantages of fast fluid-attenuated inversion recovery sequence in the evaluation of brain infarction].

This study was performed to determine the advantages and disadvantages of fast fluid attenuated inversion recovery (fast FLAIR) images in diagnosing brain infarction compared with fast spin-echo (fast SE) images. Fast FLAIR and fast SE images were obtained in 32 patients with brain infarction. Infarctions close to the sulci were difficult to differentiate from the real sulci on fast SE images, but were clearly depicted on FLAIR images. Linear foci along with cortex were especially well demonstrated on FLAIR images. On the other hand, foci that showed high signal intensity on fast SE images were sometimes appeared as having low or iso signal intensity on FLAIR images. These foci, suspected of being cystic lesions, were sometimes difficult to identify on fast FLAIR images. For the above reasons, we concluded that fast FLAIR and fast SE each have advantages and disadvantages in the detection of brain infarctions.

Cerebral Infarction↗

The effects of fasting on the acute oral toxicity of nine chemicals in the rat.

Nine chemicals, with a range from extremely to slightly toxic, were used to measure the oral LD50 in both fasted (24-h) and non-fasted rats. Each chemical was tested as a solution or suspension in corn oil, responses within 14 days post-treatment were evaluated, and LD50S were calculated. Hexachlorophene was more toxic in non-fasted rats. The LD50 values for tetraethyl lead, methomyl and hexamethylenediamine were essentially the same in both fasted and non-fasted rats. Adiponitrile, bromobenzene, caffeine, carbon tetrachloride and N-butyl-1,6-hexamediamine yielded lower LD50 values in fasted rats. The use of non-fasted rats in acute oral toxicity determinations allows both the establishment of relative potency and the estimation of dosage levels for further repeated dose oral studies. The LD50 values obtained were generally (7 of 9) higher in non-fasted rats, but the magnitude of the differences was not great enough to suggest routine use of both fasted and non-fasted rats in oral toxicity studies.

Administration, Oral↗

Prolonged fasting increases the response of the renin-angiotensin-aldosterone system, but not vasopressin levels, in postweaned northern elephant seal pups.

The 8- to 12-week postweaning fast exhibited by northern elephant seal pups (Mirounga angustirostris) occurs without any apparent deleterious effects on fluid and electrolyte homeostasis. However, during the fast the role of vasopressin (AVP) has been shown to be inconclusive and the involvement of the renin-angiotensin-aldosterone system (RAAS) has yet to be examined. To examine the effects of prolonged fasting on these osmoregulatory hormones, 15 postweaned pups were serially blood-sampled during the first 49 days of their fast. Fasting did not induce significant changes in ionic or osmotic concentrations, suggesting electrolyte homeostasis. Total proteins were reduced by day 21 of fasting and remained depressed, suggesting a lack of dehydration. Aldosterone and plasma renin activity exhibited a correlated, linear increase over the first 49 days of the fast, suggesting an active RAAS. Aldosterone exhibited a parabolic trend over the fast with a peak at day 35, suggesting a shift in the sensitivity of the kidney to aldosterone later in the fast. AVP was elevated at day 49 only, but concentrations were relatively low. RAAS was modified during the postweaning fast in pups and appears to play a significant role in the regulation of electrolyte and, most likely, water homeostasis during this period.

Aldosterone↗

Induction of cytochrome P450-dependent monooxygenases in hamster tissues by fasting.

The effects of fasting on liver, kidney, and lung monooxygenases were studied using hamsters starved for 4 days. Fasting treatment increased microsomal cytochrome P450 content and NADPH-cytochrome P450 reductase activity in kidney and lung. The treatment caused significant increases of aniline hydroxylation, N-nitrosodimethylamine demethylation, and 7-ethoxycoumarin O-deethylation activities in the liver, kidney, and lung. Fasting caused a threefold increase of benzphetamine N-demethylation activity in lung and a 25% increase in liver and had no effect in kidney. Benzo[a]pyrene hydroxylation activities in the fasted hamster liver, kidney, and lung were higher, lower, and similar to the controls, respectively. Gel electrophoresis of tissue microsomes from control and fasted hamsters revealed that fasting enhanced the intensity of protein band(s) in the P450 molecular weight region. Immunoblotting of the microsomal proteins showed that fasting induced a protein crossreactive with rabbit antibody raised against human P450 2E1 in hamster liver, kidney, and lung. Immunoblotting analysis using mouse monoclonal antibody 2-66-3 raised against rat P450 2B1 revealed that fasting induced an immunorelated protein preferentially in hamster lung, with minimal effects on liver and kidney. Protein blots probed with mouse monoclonal antibody 1-12-3 indicated that fasting induced a protein related to P450 1A1 in hamster liver, kidney, and lung. These results demonstrate that fasting causes a variety of inductive effects on the enzyme components and catalytic activities of monooxygenase systems as well as on the P450s 2E, 2B, and 1A in the hamster tissues.

7-Alkoxycoumarin O-Dealkylase↗

Liver glycogen in fasted rat livers does not improve outcome of liver transplantation.

Controversy exists over how the nutritional condition of the donor liver affects transplant outcome. Some studies suggest that livers from fasted animals (liver glycogen-depleted) are more readily injured than livers from fed animals. Our previous study suggested the opposite, i.e., livers from donors fasted for 4 days were significantly more viable on orthotopic liver transplantation. Fasting may decrease the sensitivity of the liver to an inflammatory response or block Kupffer cell activation following transplantation. Thus, long-term fasting may be beneficial for reasons unrelated to liver glycogen content. In this study we attempted to separate out the roles of fasting and liver glycogen in liver transplant outcome by fasting donors for 2 days and then feeding them only glucose to elevate liver glycogen. Rats (Brown Norway) were fed (standard diet), fasted (4 days), or fasted 2 days and then fed glucose (in water) for 2 days. Livers were preserved for either 30 or 44 h in UW solution and transplanted. Four-day fasting of the donor improved the survival rate in liver transplantation (50%-100% in 30-h cold storage, 29%-83% in 44-h cold storage). However, feeding glucose for 2 days to fasted animals caused a decrease in survival in this series of transplants (40% in 30-h cold storage, 0% in 44-h cold storage). In the glucose-fed group, liver glycogen was 240% of that in the control group. This suggests that the presence of a high concentration of liver glycogen is not beneficial to the preserved and transplanted rat liver.

Animals↗

Fasting prevents acute pancreatitis induced by cerulein in rats.

We examined the effect of fasting on the course of experimental acute pancreatitis induced in rats by four subcutaneous injections of 20 micrograms/kg body weight of cerulein at hourly intervals. Rats were either fasted from 24 hr before to 9 hr after the first cerulein injection or fed ad libitum throughout the experiment. Twenty-four hours of fasting reduced cerulein-induced increases in serum levels of amylase and anionic trypsin(ogen) to 50 and 70% of those in fed rats, respectively. Increases in pancreatic wet weight after cerulein injections were also less in fasted rats than in fed rats. Pancreatic content of trypsin was significantly decreased after a 24-hr fast, and no further changes were induced by cerulein injections. The histological signs of acute pancreatitis were greatly alleviated by fasting. However, 24 hr of fasting did not alter the sensitivity and responsiveness of the exocrine pancreas to cerulein in both in vivo and in vitro. Plasma CCK bioactivity and immunoreactive secretin concentration in 24-hr-fasted rats were significantly lower than those in fed rats. Administration of CCK receptor antagonist, loxiglumide, 12 hr prior to the induction of acute pancreatitis reduced the increase in serum amylase activity in fed rats to nearly the same levels as that in fasted rats and alleviated histological signs of pancreatitis to some extent. These present observations suggest that fasting lessens the severity of cerulein-induced acute pancreatitis by reducing endogenous CCK release.

Acute Disease↗

Histoenzymatic and ultrastructural findings in the human gastric mucosa during fasting.

In this study the influence of fasting on the structures in the human gastric mucosa was followed using selective histoenzymological and electronmicroscopic method. The gastrobioptical material of 7 healthy volunteers was examined after 24 to 240 hour fasting. During fasting an increased acid phosphatase activity in the chief cells of the human fundal mucosa was observed. The activity of the nonspecific esterase (naphtyl esterase) in the chief cells decreased mainly after 240 hour fasting. In the electronmicroscopic examination of the chief cells during fasting a multiplication of lysosomes and narrowing of the granular endoplasmic reticulum was observed. In some chief cells during fasting an agglomeration of zymogen granules was seen while in others only a few granules were observed. In the parietal and other cells of the human gastric glands a steatosis, which attained excessive values, was seen after 72 and 240 hours of fasting. We believe that this steatosis occurred mainly on the strength fasting lipemia with the possible participation of other factors. The changes in the mitochondrial structure of the parietal and other cells of the human gastric mucosa were only slightly pronounced. "The decreased" activity of dehydrogenase in the steatotic parietal cells under a histochemical examination may represent only findings caused by the agglomeration of a large amount of lipid drops in the steatotic cells. After 72 and 240 hours of fasting the parietal cells contained collapsed, underdeveloped intracellular canaliculi and narrowed tubulovesicular profiles probably related to the decreased HCl production. Generally it can be said that the observed morphological changes are the consequences of the decreased function of human gastric mucosa cells during fasting and that these regressive changes are reversible and they are caused by an insufficiency of nutrition.

Acid Phosphatase↗

Fasting and post-prandial glycemia and their correlation with glycated hemoglobin in Type 2 diabetes.

OBJECTIVE: The relative contribution of fasting and post-prandial glucose to glycated hemoglobin (HbA1c) is controversial. In the present study, we assessed the relationship with HbA1c of fasting and post-prandial glucose measured in a more naturalistic setting, through home glucose self-monitoring or with a continuous glucose monitoring system (CGM). MATERIALS AND METHODS: A consecutive series of 300 patients with Type 2 diabetes were enrolled in the study, provided that they performed blood glucose self-monitoring. HbA1c and fasting plasma glucose (FPG) were measured at enrolment. RESULTS: Both fasting plasma and capillary glucose showed a significant correlation with HbA1c (r=0.66 and 0.61, respectively; p<0.001). When home glucose monitoring was considered, both mean fasting and post-prandial glucose showed a significant correlation with HbA1c (r=0.71 and 0.73, respectively). In patients in the lower tertile of body mass index (BMI), HbA1c showed a significant correlation at multivariate analysis with post-prandial glucose, but not with fasting glucose. In patients with HbA1c >7%, both fasting and post-prandial glucose showed a significant correlation, after adjustment for age and BMI, with HbA1c (both p<0.01); conversely, in those with HbA1c < or =7%, such a correlation could be observed for fasting (p<0.01), but not for post-prandial glucose. CONCLUSION: In conclusion, both fasting and post-prandial glucose contribute to the determination of HbA1c . Home glucose self-monitoring appears to provide a more accurate assessment of metabolic control than a single plasma glucose measurement in experimental conditions. Fasting glucose could provide a greater contribution to HbA1c in patients with lower HbA1c, while post-prandial glucose seems to play a major role in leaner Type 2 diabetic subjects.

Aged↗

Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck.

We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day x week(-1); nine male; nine female), or long fasts (4 day x week(-1); eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g x kg(-1) x week(-1)) but fasted females consumed more than unfasted females in January (363 g x kg(-1) x week(-1) vs. 225 g x kg(-1) x week(-1)). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

Adaptation, Physiological↗

Fasting limits the increase in intracellular calcium during ischemia in isolated rat hearts.

INTRODUCTION: Fasting has been shown to limit ischemic injury and improve functional activity after global ischemia. Because calcium overload is considered a mechanism of ischemic injury, we hypothesized that fasting would limit the accumulation of intracellular calcium [Ca]i during ischemia, potentially due to reduced accumulation of intracellular sodium [Na]i. METHODS: To address this hypothesis, hearts isolated from rats fed either a normal diet or fasted for 24 hours underwent 20 min of global ischemia at 37 degrees. In addition to functional parameters, [Na]i and [Ca]i were measured using 21Na and 19F spectroscopy using thulium-DOTP-5 and 5F-BAPTA, respectively. In vitro measurement of sarcoplasmic reticulum calcium uptake and release, as well as activity of the sarcolemmal Na-Ca exchanger, was performed in hearts from fed and fasted animals under baseline and ischemic conditions. RESULTS: Hearts from fasted animals showed greater recovery of developed pressure (37+/-9 vs. 11+/-6 cm H2O, p < 0.05) and less contracture (end-diastolic pressure 25+/-2 vs. 47+/-2 cm H2O, p < 0.05) by the end of the reperfusion period. [Na]i was similar in the 2 groups during the first half of the ischemic period, albeit with a higher concentration of [Na]i in hearts from fed compared to fasted animals at reperfusion. Fasting markedly limited calcium accumulation during ischemia, with end-ischemic calcium being 419+/-46 nM in the hearts from fasted animals and 858+/-140 nM in the hearts from fed animals (p < 0.01). There was no significant effect of fasting on calcium uptake or release by the SR, nor on sarcolemmal Na-Ca exchange activity. CONCLUSIONS: Fasting for 24 hours improves functional recovery and markedly limits [Ca]i accumulation during ischemia and early reperfusion. The mechanism for this phenomenon remains to be elucidated.

Animals↗