PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Restrictive”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

Moderate food restriction abolishes the pregnancy-associated rise in serum growth hormone and decreases serum insulin-like growth factor-I (IGF-I) concentrations without altering IGF-I mRNA expression in rats.

Pregnancy-associated growth of maternal and fetal tissues is likely mediated by insulin-like growth factors (IGF). To study the effect of food restriction during pregnancy on the IGF system, pregnant rats either had free access to food (control) or were fed 60% of control food intake. Serum and liver samples were obtained throughout gestation. Serum IGF-I and growth hormone (GH) concentrations were measured by RIA, and IGF binding proteins (IGFBP) were characterized by Western ligand blotting and gel filtration chromatography. Weight gain of control dams was nearly twice that of restricted dams. Litter size was not significantly different; however, fetuses and placentas of restricted dams were 20% smaller than those of controls. Serum IGF-I concentrations on d 20 were 35 and 23% of d 5 concentrations in control and restricted pregnant rats, respectively. However, hepatic IGF-I mRNA did not differ between the treatment groups. A pregnancy-associated rise in serum GH was observed in control but not food-restricted dams. Insulin-like growth factor binding protein with apparent molecular retention of 38-42 kDa (IGFBP-3), 29-31 kDa and 24 kDa were apparent in serum of pregnant dams in early gestation; however, IGFBP-3 was no longer detected by Western ligand blot by d 15 of gestation. The decline in IGFBP-3 was accompanied by an increase in IGFBP-1 and -2, particularly in the serum of food-restricted dams. These data suggest that in food-restricted pregnant rats, serum IGF-I and IGF-I mRNA are insensitive to serum GH concentrations and are not regulated at the level of transcription.

Animals↗

Food restriction reduces sympathetic support of blood pressure in spontaneously hypertensive rats.

We tested the hypothesis that food restriction would attenuate the development of hypertension in spontaneously hypertensive rats (SHR). Furthermore, we hypothesized that food restriction would reduce the tonic sympathetic nervous system support of blood pressure in the SHR. Male SHR (Charles River, age 5 wk) were randomly assigned to ad libitum (ADLIB, n = 8) or food-restricted (FR, n = 9) groups. ADLIB rats were given free access to nonpurified diet and demineralized water. Food-restricted rats ate 60% of the amount of nonpurified diet consumed by rats in the ADLIB group. After 8 wk of treatment, ADLIB rats were heavier than FR rats (ADLIB = 318 +/- 4 g; FR = 193 +/- 5 g, P < 0.05). Blood pressure and heart rate (HR) were measured after chronic implantation of iliac arterial and jugular venous catheters. Food-restricted rats had lower mean arterial blood pressure (MAP) than ADLIB rats, measured in conscious, unrestrained state 4-6 h after catheterization (ADLIB = 162 +/- 3 mmHg; FR = 142 +/- 3 mmHg, P < 0.05) and measured on the day after surgery (ADLIB = 150 +/- 6 mmHg; FR = 130 +/- 3 mmHg, P < 0.05). There were no significant differences in resting HR on either day. Food-restricted rats exhibited augmented cardiac baroreflex-mediated bradycardia (bolus phenylephrine, 0.5-4.0 pg/kg intravenously) as assessed by linear slope of the AHR/AMAP relationship (ADLIB = -0.73 beats/(min x mmHg); FR = -1.62 beats/(min x mmHg), P < 0.05). Sympathetic support of blood pressure quantified by the depressor response to ganglionic blockade (hexamethonium 30 mg/kg; atropine 0.1 mg/kg intravenously), was greater in the ADLIB group (ADLIB: -59 +/- 8 mmHg; FR: -36 +/- 2 mmHg, P < 0.05). The results support the hypotheses that chronic food restriction reduces the development of hypertension and sympathetic support of MAP in spontaneously hypertensive rats.

Animals↗

Implanted tumor growth is suppressed and survival is prolonged in sixty percent of food-restricted mice.

To examine the effect of food restriction on immune functions in the tumor-bearing state, mice were divided into a control group (fed 5.0 g diet/d; 71 kJ/d) and a 60% food-restricted group (fed 3.0 g diet/d; 43 kJ/d) at 8-wk of age, and 4 wk later, L1210 tumor cells were inoculated intradermally. In the food-restricted mice, tumor growth was significantly suppressed, and mean survival time after the tumor inoculation was prolonged (P < 0.05). The plasma concentrations of two antitumor cytokines, interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), were greater in the food-restricted group before tumor inoculation (P < 0. 05). Furthermore, the food-restricted mice had significantly higher plasma levels of IFN-gamma and TNF-alpha after tumor inoculation, although the treatment significantly increased these cytokine levels in both groups. Splenic natural killer cell cytotoxicity was also higher in the tumor-bearing food-restricted mice than in controls (P < 0.05). Food-restricted mice have strong antitumor immunity, and as a result, tumor growth is suppressed and survival time is prolonged in these mice.

Analysis of Variance↗

Maternal and perinatal magnesium restriction predisposes rat pups to insulin resistance and glucose intolerance.

According to the fetal programming hypothesis, impaired intrauterine development results in insulin resistance and associated metabolic disturbances. Recently, we reported increased body fat, a forerunner of insulin resistance, in the pups of mineral-restricted rat dams. To identify the causative mineral(s), the effect of magnesium restriction was assessed. Female weanling WNIN rats (n = 21) consumed ad libitum for 9 wk a 70% magnesium-restricted diet or were pair-fed a control (C) diet (n = 7). After 9 wk, they were mated with control males. Control dams and pups were fed the control diet throughout, whereas 7 Mg-restricted dams were switched to the control diet at parturition and their pups weaned onto the control diet (RP). Pups of the remaining 14 restricted dams were weaned onto the control diet (RW) or the Mg-restricted diet (R). All groups had 8 male pups from weaning. Pups were studied on postnatal d 90 and 180. R pups weighed less than C pups at weaning, but both RP and RW pups caught up with controls by d 90. At this time, R pups were neither insulin resistant nor glucose intolerant, but had a higher percentage of body fat and plasma triglycerides and lower lean body and fat-free mass than C pups. These variables were partially corrected in both RP and RW pups. On postnatal d 180, R, RP, and RW pups were insulin resistant and had a lower insulin response to a glucose challenge than C pups; however, glucose tolerance was impaired only in RW pups. Thus, maternal magnesium restriction irreversibly increases body fat and induces insulin resistance in pups by 6 mo of age, whereas additional perinatal Mg deficiency impairs glucose tolerance.

Animals↗

Ligation-mediated PCR amplification of specific fragments from a class-II restriction endonuclease total digest.

A method is described which permits the ligation- mediated PCR amplification of specific fragments from a Class-II restriction endonuclease total digest. Feasibility was tested using Bcl I and phage lambda DNA as a model enzyme and amplicon system, respectively. Bcl I is one of many widely used restriction enzymes which cleave at palindromic recognition sequences and leave 5'-protruding ends of defined sequence. Using a single pair of universal primers, a given fragment can be specifically amplified after joining the fragments to adaptors consisting of a duplex primer region and a 9-nucleotide protruding single-stranded 5'-end containing the sequence complementary to the cleaved restriction site and a 4-nucleotide 'indexing sequence.' The protruding strand anneals to a restriction fragment by displacing its corresponding strand in the same fragment-specific indexing sequence located juxtaposed to the restriction site. The adaptor is covalently linked to the restriction fragment by T4 DNA ligase, and amplification is carried out under conditions for long-distance PCR using the M13 forward and reverse primers. The technique discriminated robustly between mismatches and perfect matches for the 16 indexing sequences tested to allow individual lambda Bcl I fragments to be amplified from their respective adaptor pairs. A strategy is proposed enabling a non-cloning approach to the accession, physical mapping and sequencing of genomic DNA. The method could also have application in high-throughput genetic mapping and fingerprinting and should expand the enzyme base for ligation- mediated indexing technology which has previously been limited to the Class-IIS and IP restriction endonucleases.

Bacteriophage lambda↗

Restrictive tissue in the area of perimembranous ventricular septal defect. Cross-sectional and Doppler echocardiographic study.

This study using pulsed and continuous wave Doppler echocardiography was designed to achieve a cross-sectional echocardiographic categorization of the fibrous tissues in the environs of perimembranous ventricular septal defects, to determine the mechanism involved in its formation and for qualitative and quantitative evaluation of the anomalies associated with the entity. A total of 67 patients was studied, 23 presented cross-sectional echocardiographic evidence of perimembranous ventricular septal defect in isolation, 12 associated with tissue 'tags' and 32 combined with 'restrictive' tissue in the area of the defect. Four echocardiographic features of the 'restrictive' tissue were observed. In 23 of these 32 patients, it was possible to identify the exact anatomic origin of the 'restrictive' tissue (in seven complete and, in 15, partial involvement of the septal leaflet of the tricuspid valve; in one, prolapse of the aortic valve with a partial involvement of the tricuspid septal leaflet) while in nine the origin remained undetermined. In 20, the 'restrictive' tissue simultaneously protruded into the right atrium and ventricle; only in 12 did it extend exclusively into the right ventricle. Tricuspid insufficiency was detected by pulsed Doppler in 78% of the patients with 'restrictive' tissue and in 23% of the remaining patients. Tricuspid incompetence was severe in only two patients of the first group. Three patients with 'restrictive' tissue (9%) had obstruction to the outlet of the right ventricle and four (13%) patients presented aortic insufficiency. Five patients (16%) with 'restrictive' tissue closing the defect did not present pulsed Doppler evidence of a shunt at the ventricular level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Quantitative and qualitative feed restriction on growth characteristics of male broiler chickens.

Four experiments were conducted to evaluate the quantitative and qualitative feed restriction on the performance of male broiler chickens. In the first experiment, broilers fed identical pelleted diets were feed-restricted from 5 to 42 d by giving 95, 90, or 85% of the feed consumed ad libitum by control birds the previous day. In a second experiment, broilers were fed pellet or mash diets from 1 to 7 wk. In Experiments 3 and 4, broilers were feed-restricted to 90% of the ad libitum intake of a control group during different intervals. Results from Experiment 1 indicated that live body weight at 42 d was significantly different between unrestricted and restricted broilers (P < 0.01). A reduction in mortality was noted when feed intake was reduced (P < 0.05). In the second experiment, broilers fed mash had lower body weights and breast meat yields at 42 and 49 d (P < 0.05). Cumulative mortality at 42 and 49 d was reduced in broilers fed mash (P < 0.05). Results from Experiment 3 indicated that body weight and mortality were not significantly different (P > 0.05) at 42 d across treatments. There was a significant (P < 0.01) linear improvement on feed conversion at 42 d due to duration of feed restriction. Breast meat yield at 42 d was less in broilers subjected to mild feed restriction (P > 0.05) (Experiments 3 and 4). Broilers appeared able to recover from mild feed restriction, and there was always an associated reduction in mortality.

Animal Feed↗

Effects of qualitative feed restriction during rearing on the performance of broiler breeders during rearing and lay.

To prevent health and fertility problems associated with excessive weight gain, broiler breeders are severely feed restricted during rearing, which may affect welfare. We compared the effects of an experimental ad libitum feeding regimen based on qualitative restriction of food intake with conventional quantitative food restriction on the performance of female broiler breeders during rearing and lay. During rearing up to 20 wk of age, control birds were fed restricted amounts of standard broiler breeder mash once daily. Experimental birds had ad libitum access to the same standard mash mixed with 400 g of oat hulls/kg of feed and increasing concentrations of Ca propionate, an appetite suppressant. Mean total mash intake during rearing was 8.12 kg and did not differ between treatments. Both control and experimental birds showed an almost linear growth curve, treatment mean body weights were always within 100 g of the target weight line, and treatments did not differ for body weight uniformity. Groups were subjected to the same quantitative feed restriction from during lay. Feeding regimen during rearing did not affect number of eggs produced, egg weight, or egg quality up to 46 wk of age. We concluded that it may not be necessary to subject chicks to severe quantitative feed restriction to achieve desirable growth curves and body weight uniformity during rearing. Qualitative restriction of feed intake can achieve desirable growth curves in ad libitum fed chicks during rearing, and such a feeding regimen does not have negative effects on hen performance during lay.

Aging↗

The frequency of restricted range of movement in individuals with self-reported shoulder pain: results from a population-based survey.

Prevalence studies suggest that shoulder pain is very common (7-20%) in the adult population, though little is known about the severity and impact of such pain. Disability results, in part, from the restriction of movement and we therefore determined the frequency of restricted shoulder movement in individuals in a general population sample reporting shoulder pain and associated disability. In all, 232 individuals were interviewed about shoulder pain and related disability, and their range of shoulder movement in the following planes was measured: elevation, forward flexion, backward flexion, external rotation and internal rotation, together with the minimum difference achieved between the tip of a thumb and the spinous process of C7. In total, 48 (21%) subjects reported current pain and disability in one or both shoulders. Using receiver operating characteristic (ROC) analysis, cut-offs for restricted movements were selected at the point of maximal discrimination between painful and pain-free shoulders. There was considerable overlap in the distribution of range of movement, at all six sites, between these two groups. The highest positive predictive value for pain was observed in restriction of the thumb to cervical spine movement (53%), but this also had the lowest negative predictive value. By contrast, the highest negative predictive value was observed for restriction of external rotation (96%). Restriction in any plane was observed in 77% of those individuals with pain, but was also present in half of those without pain. In summary, most people with self-reported shoulder pain in the community do not have widespread restriction of movement. Reduction in external rotation was the most discriminatory, but it is necessary to examine movement in multiple planes to assess the true burden of shoulder pain in the community.

Adolescent↗

Age modulates the effects of sleep restriction in women.

STUDY OBJECTIVES: To investigate how age influences the effects of 3 nights of sleep restriction in healthy women. DESIGN: After a baseline night, sleep was restricted to 4 hours during 3 consecutive nights. One recovery night followed the sleep restriction. SETTING: The sleep-restriction experiments were conducted under standardized conditions with continuous electroencephalographic ambulatory recordings. Before entering the study, the subjects underwent a polysomnographic recording for exclusion of sleep disorder and adaptation to the laboratory environment. PARTICIPANTS: Eleven young women (aged 20-30 years) and 10 older women (aged 55-65 years) were included in the study. INTERVENTION: The subjects were admitted to the sleep laboratory for 5 consecutive nights and days. After 1 baseline night, 3 nights of sleep restriction to 4 hours were performed and were followed by 1 recovery night of 8 hours. Continuous ambulatory electroencephalographic recordings were performed, as well as the Maintenance of Wakefulness Test (8:30 AM and 1:30 PM), the Stanford Sleepiness Scale, and the Psychomotor Vigilance Test. RESULTS: Young women were more affected by sleep restriction than were the older women. This was evidenced by more sleep onsets during the Maintenance of Wakefulness Test sessions in the young subjects, who also rated themselves more sleepy than the older women. CONCLUSIONS: Age influences the impact of sleep restriction on vigilance in women.

Adult↗

Effects of food restriction and restoration on gonadotropin and growth hormone secretion in immature male rats.

This experiment concerned the changing patterns in secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and growth hormone (GH) under conditions of food restriction and subsequent catch-up growth. Weanling male rats were given either restricted (4 g food/day) or unrestricted access to food until 60 days of age. At this age, food-restricted rats weighed only 25% as much as rats fed ad libitum. Food restriction resulted in a dramatic decrease in the frequency of LH and GH pulses, and in the amplitude of GH pulses. It also slightly but significantly decreased mean blood levels of FSH (which was not secreted in a pulsatile manner in 60-day-old controls fed ad libitum). When restricted rats were given unrestricted access to food, frequency of LH and GH pulses and mean levels of FSH increased significantly and simultaneously within 2 days in half of the animals. Only an additional 8-10% of their body weight decrement was recovered at this time. After 10 days of food restoration, when restricted rats still weighed 50% less than controls, their secretory patterns of all three hormones were not significantly different from those of controls. Thus, recovery of gonadotropin and GH secretion was relatively rapid. Except for the quantitatively lesser impact of food restriction on FSH secretion, there was no evidence of any priorities in the secretion of the three hormones. Under conditions of rapid catch-up growth, the secretory patterns of LH, FSH, and GH appeared to develop simultaneously.

Animals↗

Testicular regression in response to food restriction and short photoperiod in white-footed mice (Peromyscus leucopus) is mediated by apoptosis.

Short day lengths or reduced food availability are salient cues for small mammals that breed seasonally. Photoperiod-mediated gonadal regression in white-footed mice (Peromyscus leucopus) is a slow, orderly process that involves testicular apoptosis. Testicular regression in response to restricted caloric intake is relatively rapid, and it is generally reversed quickly by ad libitum (ad lib) feeding. To determine the contribution of apoptotic cell death during food restriction, and to examine possible interactions with photoperiod, mice housed in long (16L:8D) or short (8L:16D) photoperiods were fed either ad lib or 70% of their average ad lib intake. Testes were removed at 2, 4, 6, or 8 wk of experimental treatment. Apoptotic activity was determined by in situ TUNEL labeling and assessment of DNA laddering. Significant (P < 0.05) gonadal regression in response to short days was first detected at 8 weeks in mice fed ad lib. Food-restricted, long-day mice also showed significant testicular regression at 8 wk. Combined exposure to short day lengths and food restriction resulted in significant testicular regression at 6 wk (P < 0.05). TUNEL labeling was slightly, though significantly, elevated in germ cells at 2 and 4 wk in long-day food-restricted mice (P < 0.05). TUNEL labeling was also elevated in short-day food-restricted males at these early times but then increased nearly 5-fold at 6 and 8 wk in these mice (P < 0.001). DNA laddering confirmed elevated apoptosis. Overall apoptotic activity negatively correlated with paired testis mass, plasma testosterone, and spermatogenic index measurements in both ad lib and food-restricted males. Few histological markers of necrotic cell death were observed in any group. Taken together, these results suggest that testicular regression in response to limited caloric intake or short days is mediated by apoptosis.

Animals↗

Calorie restriction delays age-dependent loss in androgen responsiveness of the rat liver.

We have shown that restricted calorie intake retards age-associated loss in androgen responsiveness of the rat liver. Sustained androgen receptivity delays age-dependent decline in the synthesis of the androgen-inducible alpha 2u globulin and derepression of the androgen-repressible senescence marker protein (SMP-2). Quantitation of mRNAs for alpha 2u globulin and SMP-2 in the liver of animals of various ages maintained on either ad libitum or restricted diets revealed that, although the 27-month-old ad libitum-fed rat had only 5% as much alpha 2u mRNA as the 6-month-old rat, the mRNA level was as high as 45% in the 27-month-old food-restricted rat. Conversely, the 27-month-old food-restricted rat had a much reduced amount (45%) of SMP-2 mRNA compared to the age-matched control that was allowed unlimited access to food. Furthermore, we have correlated the effect of dietary restriction on age-dependent changes in specific gene expression with the hepatic level of the immunoreactive cytoplasmic androgen-binding (CAB) protein. We observed that senescence in the male causes a substantial decrease in the circulating level of testosterone. However, dietary restriction does not retard the rate of decline in the plasma level of the male hormone during aging. These results indicate that age-dependent changes in the expression of androgen-responsive genes (alpha 2u globulin and SMP-2) reflect changing androgen sensitivity and that food restriction may directly influence the androgen receptivity of the liver.

Aging↗

The combined effects of aerobic exercise and alcohol restriction on blood pressure and serum lipids: a two-way factorial study in sedentary men.

OBJECTIVES: To determine whether vigorous exercise and alcohol restriction have additive and independent effects in reducing blood pressure in sedentary male alcohol drinkers. Also to assess whether 4 weeks of vigorous exercise could offset the fall in high-density lipoprotein cholesterol (HDL-cholesterol) usually observed after alcohol restriction. DESIGN: Seventy-five sedentary men were randomly assigned to drink low-alcohol beer or continue their normal drinking habits. Within these two groups subjects were further assigned either to a vigorous exercise programme of three 30-min sessions a week of cycling at 60-70% of maximum workload or to a control light-exercise programme. RESULTS: Seventy-two subjects completed the trial. Alcohol consumption fell by 85% in the low-alcohol group. Fitness increased by 10% following vigorous exercise, with a significant improvement in maximum oxygen uptake. After adjustment for weight loss, a significant effect of alcohol restriction in reducing both systolic and diastolic blood pressure was demonstrated. There was no effect of vigorous exercise on blood pressure. Serum total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B were not influenced by alcohol restriction or vigorous exercise. However, alcohol restriction significantly reduced triglyceride, HDL-cholesterol, its subfractions HDL2-cholesterol and HDL3-cholesterol, and its major apolipoproteins apo A-I and apo A-II. These reductions were unaffected by moderate exercise. CONCLUSIONS: This study provides further evidence that alcohol restriction results in reductions in blood pressure in men who are regular alcohol drinkers. However, a simultaneous increase in fitness did not lead to lower blood pressures than those achieved with alcohol restriction alone, and was unable to offset alcohol-related falls in HDL-cholesterol, its subfractions and its major apolipoproteins.

Adult↗

Intrauterine growth restriction.

PURPOSE OF REVIEW: Intrauterine growth restriction remains one of the major problems in obstetrics. Recent published literature on this problem is summarized in this review. RECENT FINDINGS: Intrauterine growth restriction contributes disproportionately to neonatal mortality and morbidity in both preterm and term babies, and is a predisposing factor to major psychiatric sequelae such as depression, suicide and suicidal attempts. More evidence is accumulating to show that fetal Doppler changes of the ductus venosus and umbilical vein are good surrogate markers for fetal academia. The timing of delivery remains controversial, however. The Growth Restriction Intervention Trial showed that delayed delivery in those up to 30 weeks may be associated with lower rates of cerebral palsy and Griffiths development quotient under 70. In dichorionic twins, selective fetocide of one severe intrauterine growth restriction fetus in midtrimester twin pregnancies complicated by severe preeclampsia may abort the disease process and prolong the pregnancy. For monochorionic twins, the finding of intermittent absent or reversed end diastolic flow in the umbilical artery may be a manifestation of the transmission of the bi-directional waveforms of arterio-arterial anastomosis, but has been shown to be associated with an increased risk of intrauterine death in the growth restricted fetus and brain damage in the larger fetus. SUMMARY: The timing of delivery of the preterm growth restricted fetus remains controversial. Intrauterine growth restriction with intermittent absent or reversed end diastolic flow in the umbilical artery of monochorionic twins poses difficulties in assessment.

Adrenal Cortex Hormones↗

Impact of duty hour restrictions on otolaryngology training: divergent resident and faculty perspectives.

OBJECTIVES: In 2003, the Accreditation Council for Graduate Medical Education (ACGME) passed a controversial mandate limiting resident work hours. We sought to examine the impact of these restrictions on otolaryngology programs and to explore faculty and resident perspectives. METHODS: Faculty and residents of all 102 ACGME-accredited otolaryngology residency programs were invited to participate in an anonymous online survey. RESULTS: The study population consisted of 460 respondents: 275 residents and 185 faculty (including 41 program directors) representing 57 otolaryngology programs. Sixty-five percent of programs implemented at least one change specifically to comply with duty-hour restrictions. Strategies included tracking work hours electronically (35.7%), utilization of "home call" (33.1%), and hiring additional healthcare professionals (23.1%). When asked if the restrictions have had a negative effect on patient care, 61% of respondents said no, but a surprising 33% said yes. Sixty-nine percent of faculty felt that the restrictions have actually had a negative effect on resident training compared with only 31% of residents (P<.001). Thirty-nine percent of participants felt resident workload was excessive before the restrictions. Opinions on whether duty-hour limits had fostered improvements in resident education, research, or examination scores varied, but most agreed that resident mental health had improved (67%). CONCLUSIONS: Otolaryngology programs have successfully restricted resident duty hours through significant infrastructural changes. Of concern, the majority of residents surveyed appeared to be in favor of the ACGME restrictions, whereas most program directors and faculty were opposed. Further studies are needed to establish whether limited work hours will enhance or hinder the residency training experience.

Adult↗

Night driving self-restriction: vision function and gender differences.

PURPOSE: The purpose of this study was to evaluate gender differences in the relationship between night driving self-restriction and vision function in an older population. METHODS: Night driving self-restriction patterns (assessed by questionnaire) were examined cross-sectionally in relation to age, gender, health and cognitive status, depression, and vision function in a sample of 900 elders (mean age, 76 years) living in Marin County, California. RESULTS: Of the total sample, 91% of men and 77% of women were current drivers. The mean age of the drivers was 73.3 years (range, 58-96 years). Among current drivers, women had slightly better vision function than men on most measures (low-contrast acuity, contrast sensitivity, low-contrast acuity in glare, low-contrast, low-luminance acuity, and glare recovery) but were twice as likely as men to restrict their driving to daytime. Men showed significant associations with avoidance of night driving on four spatial vision measures (high- and low-contrast acuity, low-contrast, low-luminance acuity, and contrast sensitivity). For women, in addition to these measures, a significant association was seen for low-contrast acuity in glare. Neither men nor women showed significant associations between driving restriction and performance on the other vision measures examined (glare recovery time, attentional field integrity, or stereopsis). The vision measures most predictive of self-restriction were contrast sensitivity for men and low-contrast acuity in glare for women. CONCLUSIONS: Including both cessation and self-restriction, men over age 85 years are 6.6 times more likely than women to be driving at night. For both genders, vision plays a significant role in the self-restriction decision. A higher percentage of men than women continue to drive at night with poor vision. Men's night-driving cessation was associated with contrast sensitivity and depression, whereas women's night-driving cessation was associated with low-contrast acuity in glare as well as age.

Accidents, Traffic↗

Is a restrictive transfusion strategy safe for resuscitated and critically ill trauma patients?

BACKGROUND: An analysis from the prospective multicenter randomized controlled trial (Transfusion Requirements in Critical Care Trial) compared the use of restrictive and liberal transfusion strategies with resuscitated critically ill trauma patients. METHODS: Critically ill trauma patients with a hemoglobin concentration less than 90 g/L within 72 hours of admission to the intensive care unit were randomized to a restrictive (hemoglobin concentration, 70 g/L) or liberal (hemoglobin concentration, 100 g/L) red blood cell transfusion strategy. RESULTS: The baseline characteristics in the restrictive (n = 100) and liberal (n = 103) transfusion groups were comparable. The average hemoglobin concentrations (82.7 +/- 6.2 g/L vs. 104.3 +/- 12.2 g/L; p < 0.0001) and the red blood cell units transfused per patient (2.3 +/- 4.4 vs. 5.4 +/- 4.3; p < 0.0001) were significantly lower in the restrictive group than in the liberal group. The 30-day all-cause mortality rates in the restrictive group were 10%, as compared with 9% in the liberal group (p = 0.81). The presence of multiple organ dysfunction (9.2 +/- 6.3 vs. 9.0 +/- 6.0; p = 0.81), the changes in multiple organ dysfunction from baseline scores adjusted for death (1.2 +/- 6.1 vs. 1.9 +/- 5.7; p = 0.44), and the length of stay in the intensive care unit (9.8 +/- 8.1 vs. 10.2 +/- 8.7 days; p = 0.73) and hospital (31.4 +/- 17.1 vs. 33.7 +/- 17.7 days; p = 0.34) also were similar between the restrictive and liberal transfusion groups. CONCLUSIONS: A restrictive red blood cell transfusion strategy appears to be safe for critically ill multiple-trauma patients. A randomized controlled trial would provide the appropriate level of evidence with regard to the daily use of blood in this population of patients.

Adult↗