Prevalence and genotype distribution of JC polyomavirus in urine from patients with hematological malignancies in Vietnam.

JC virus (JCV) causes progressive multifocal leukoencephalopathy in immunocompromised patients. The prevalence and genotype patterns of JCV vary between different geographical regions. This study was done to investigate the prevalence and genotype distribution of JCV in patients with hematological malignancies in Vietnam. A total of 48 urine samples were collected from patients with hematological malignancies. DNA was extracted and detection of JCV was by nested-polymerase chain reaction. Sequence analysis was obtained and a phylogenetic tree was constructed for genotyping of JCV. Twenty-seven (56.25%) urine samples tested positive for JCV. JCV genotype 7 was only observed in this study. Subtype analysis showed that JCV subtype 7A was the most commonly prevalent, followed by 7B1 and 7C1. Other subtypes were not detected in this population. There were no significant differences associated with age, gender, and biochemical parameters between patients with JCV and without JCV excretion in urine. The present study showed a high prevalence of JCV in the urine of patients with hematologic malignancies. The most common genotype found in this population was JCV subtype 7A.

Effects of USDA quality grade and cooking on water-soluble precursors of beef flavor.

The objective of the current study was to determine the effects of three USDA quality grades and cooking on the water-soluble flavor precursors of beef Longissimus lumborum. Raw and cooked steaks from beef strip loins of USDA Prime (PR; n = 8), Low-Choice (LC; n = 8), and Standard (ST; n = 8) were analyzed for extractable free amino acids, reducing sugars, and other nitrogenous organic compounds (NOCs). Overall, two-way quality grade × cooking interactions were found for the contents of most water-soluble precursors (Pquality grade × cooking < 0.05), which were greater in raw LC and ST and were changed more in ST and LC steaks by cooking. The magnitude of those changes suggested that cystine, a dimer of cysteine, glucose, and glucose 6-phosphate might play more important roles in beef flavor development than previously thought.

Effects of market type and time of purchase on oxidative status and descriptive off-odors and off-flavors of beef in Vietnam.

The objective of the current study was to determine the effects of market type (super market - SM, indoor market - IM, open market - OM) and sampling time (at the opening - T0 and 4 h after the opening - T4) on antioxidant capacity, lipid oxidation, and descriptive sensory attributes of beef in Vietnam. Values of FC and TEAC were greater in OM beef than IM and SM (P < 0.001) and FC value was also greater at T4 than T0 (P = 0.038). The beef from SM had 7% greater TBARS than IM and OM (P = 0.003). Livery odor was less intense in raw beef from OM when compared to SM and IM (P ≤ 0.047). Sour odor in raw beef, and livery flavor in cooked beef was increased from T0 to T4 (P ≤ 0.035). Principal component analysis of descriptive sensory attributes indicated that FC and TEAC could predict partial livery flavor in cooked beef, but not off-odors in raw beef.

Body fat of stock-type horses predicted by rump fat thickness and deuterium oxide dilution and validated by near-infrared spectroscopy of dissected tissues.

Body condition score and percent body fat (BF; %) of horses are positively correlated with reproductive efficiency and are indicative of metabolic issues. However, BF in horses may be poorly predicted because current procedures are either subjective or dependent on one anatomical location. Therefore, the objectives of the current study were to compare 2 methods of predicting BF using rump fat thickness (RFT) and deuterium oxide (DO) dilution with actual tissue fat analysis by near-infrared spectroscopy (NIRS) in stock-type horses and to identify the relationship between BF and BCS. Twenty-four stock-type horses were selected to be humanely euthanized based on 3 primary criteria: geriatric, crippled, and/or unsafe. Approximately 20 h before slaughter, horses were weighed and BCS assessed to be 1 ( = 1; 433 kg), 2 ( = 1; 415 kg), 3 ( = 1; 376 kg), 4 ( = 7; 468 ± 13 kg), 5 ( = 10; 455 ± 11 kg), and 6 ( = 4; 493 ± 12 kg) and RFT was measured using ultrasonography. Blood samples were collected immediately before and 4 h after DO infusion (0.12 g/kg BW). Deuterium oxide concentration of plasma was determined by gas isotope ratio mass spectrometry. Horses were housed in a dry lot overnight before being individually sedated (1.1 mg xylazine/kg BW) and anesthetized using a jugular venipuncture (2.2 mg ketamine/kg BW), and potassium chloride (KCl) solution was administered to cease cardiac function before exsanguination. After euthanasia, horse carcasses were processed and dissected and tissues were collected for NIRS analysis. Body fat predicted by DO dilution was correlated with BF measured by NIRS analysis on various weight bases ( = 0.76 to 0.81, < 0.001), whereas no correlation was observed for BF predicted by RFT. A paired -test indicated that both DO dilution and RFT overestimated BF by 2.48 to 3.26% ( < 0.001) and 5.81 to 6.59% ( < 0.001), respectively, compared with NIRS analysis. Body condition scores affected BF measured by NIRS analysis ( ≤ 0.038) and predicted by DO dilution ( < 0.001) and RFT ( = 0.042). The current study provided evidence that DO dilution was a better prediction method for BF than RFT and that BCS may serve as a BF predictor in stock-type horses.

Assessment of volatile compounds, neutral and polar lipid fatty acids of four beef muscles from USDA Choice and Select graded carcasses and their relationships with consumer palatability scores and intramuscular fat content.

Fatty acids (FA) in neutral and polar lipids (NL and PL) and volatile compounds were determined in Gluteus medius (GM), Longissimus lumborum (LL), Serratus ventralis (SV), and Semimembranosus (SM) muscles from upper 2/3 USDA Choice and Select quality grades (QG). Concentrations of NL FA (mg/g) were influenced by intramuscular fat (IMF) content being greater in upper 2/3 Choice compared with Select. The SV contained greater concentrations of NL FA; meanwhile, the SM contained the lowest quantities of NL FA. Percentages (g/100g of total FA) of NL SFA and MUFA were increased in beef with greater IMF content. Concentrations and percentages of PL FA had muscle specific differences between QG. Volatile compounds were primarily affected by muscle. Increases in SFA and MUFA were related with consumer liking, regardless of lipid fraction. Overall the influence of QG on SFA and MUFA was muscle specific. Therefore, each muscle may require specific considerations when considering FA, volatile compounds, and ultimately consumer liking.

Consumer palatability scores, sensory descriptive attributes, and volatile compounds of grilled beef steaks from three USDA Quality Grades.

Consumer palatability scores, sensory descriptive attributes, and volatile compounds were assessed for beef Longissimus lumborum steaks of USDA Prime, Low Choice, and Standard grades. Overall and flavor liking was greater (P<0.05) for Prime and Low Choice. Initial flavor impact and fat-like attributes were greater (P<0.05) among Prime and Low Choice. Prime had greater (P<0.05) brown/roasted, beef identity, overall sweetness, and umami. Cardboard was greater (P<0.05) in Standard. Volatile compounds representing flavor development pathways were varied with quality grade. Standard had greater (P<0.05) abundances of n-aldehydes. Phenylacetaldehyde was greater (P<0.05) in Prime and Low Choice. Both 2,3-butanedione and 3-hydroxy-2-butanone were greatest (P<0.05) in Prime. Overall liking was positively correlated with many descriptive attributes, 3-hydroxy-2-butanone, and phenylacetaldehyde, and negatively correlated with cardboard, green, and n-aldehydes. While the measured attributes and volatiles may not be causative of flavor, this data indicates potential for prediction of flavor through their measurement.

Zinc Methionine Supplementation Impacts Gene and Protein Expression in Calf-Fed Holstein Steers with Minimal Impact on Feedlot Performance.

Providing cattle a more bioavailable zinc (Zn) source prior to administering a beta adrenergic agonist (ßAA) may enhance the metabolic pool of primary nutrients that will influence the magnitude of the ßAA response. Calf-fed Holstein steers were supplemented with a Zn methionine supplement (ZnMet; ZINPRO(®); Zinpro Corporation, Eden Prairie, MN) for 115 ± 5 days prior to harvest along with zilpaterol hydrochloride (ZH; Zilmax(®); Merck Animal Health, Summit, NJ) for the last 20 days with a 3-day withdrawal to evaluate the effects on growth and carcass performance together with gene and protein expression of skeletal muscle, adipose tissue, and fatty acid composition of polar and neutral lipid depots. Steers (n = 1296; initial weight = 468.5 ± 0.5 kg) were sorted by weight, blocked by harvest date, and randomly assigned to pens (n = 12) and treatments: control (90 ppm Zn from ZnSO4) and ZnMet (Control plus 720 mg Zn from ZnMet/hd/d). There were no differences (P > 0.05) in growth performance or carcass characteristics. The ZnMet-fed cattle had reduced (P < 0.05) abundance of myosin heavy chain (MHC)-IIX, ß1-adrenergic receptor (ßAR), peroxisome proliferator-activated receptor gamma, and stearoyl-CoA desaturase mRNA in skeletal muscle tissue. The ZnMet cattle had greater (P < 0.05) abundance of MHC-II protein, increased MHC-IIA and IIX cross-sectional areas (P < 0.05), an increased percentage of MHC-I fibers (P < 0.05), and a decreased percentage of MHC-IIX fibers (P < 0.05). The combination of ZnMet and ZH had positive biological effects on musculoskeletal tissue; however, these molecular effects were not significant enough to impact overall feedlot and carcass performance.

Effects of USDA beef quality grade and cooking on fatty acid composition of neutral and polar lipid fractions.

The effects of USDA beef quality grade (QG; Prime, Low Choice, and Standard; n=8) and cooking (RC) on fatty acid (FA) concentrations (mg/g dry matter) and percentages of neutral and polar lipid fractions (NL and PL, respectively)from strip steaks were explored. An increase in QG led to an accumulation of most FA, especially in the NL fraction (P < 0.001). Common effects on FA percentages were two-way interactions of either QG or RC with LF (P ≤ 0.019). Fatty acids were affected differently by QG and RC depending on their originating LF. Monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) percentages of the PL were dependent on QG (P ≤ 0.014). Cooking and QG had minimal impact on FA percentages of the NL, however, greatly influenced PL MUFA and PUFA percentages (P b 0.001). There was evidence indicating that dry heat cookery affected not only PUFA, as generally thought, but also the MUFA of PL fraction.

Sensory evaluation of tender beef strip loin steaks of varying marbling levels and quality treatments.

The palatability of tender [Warner-Bratzler shear force values <33.34N (3.4kg)] beef strip loins of 10 different treatments [USDA Prime, High Choice (upper 1/3 Choice), Low Choice (lower 1/3 Choice), Select, Standard, Australian Wagyu, American Wagyu, Holstein Select, Holstein Top Choice (upper 2/3 Choice) and Grass-finished] was evaluated by consumers and a trained flavor panel. In general, tenderness, juiciness, flavor, and overall liking ratings as well as acceptability percentage for each trait, increased with increased fat levels. Moreover, overall liking was highly correlated (P<0.01) with flavor liking (r=0.96) as well as fat percentage (r=0.79). Beef flavor scores were positively associated (P<0.01) with fat-like (r=0.67) and umami (r=0.59) flavors. Fat level was the primary driver of beef flavor acceptability in all samples when no undesirable off-flavors were present.

Circadian integration of sleep-wake and feeding requires NPY receptor-expressing neurons in the mediobasal hypothalamus.

Sleep and feeding rhythms are highly coordinated across the circadian cycle, but the brain sites responsible for this coordination are unknown. We examined the role of neuropeptide Y (NPY) receptor-expressing neurons in the mediobasal hypothalamus (MBH) in this process by injecting the targeted toxin, NPY-saporin (NPY-SAP), into the arcuate nucleus (Arc). NPY-SAP-lesioned rats were initially hyperphagic, became obese, exhibited sustained disruption of circadian feeding patterns, and had abnormal circadian distribution of sleep-wake patterns. Total amounts of rapid eye movement sleep (REMS) and non-REMS (NREMS) were not altered by NPY-SAP lesions, but a peak amount of REMS was permanently displaced to the dark period, and circadian variation in NREMS was eliminated. The phase reversal of REMS to the dark period by the lesion suggests that REMS timing is independently linked to the function of MBH NPY receptor-expressing neurons and is not dependent on NREMS pattern, which was altered but not phase reversed by the lesion. Sleep-wake patterns were altered in controls by restricting feeding to the light period, but were not altered in NPY-SAP rats by restricting feeding to either the light or dark period, indicating that disturbed sleep-wake patterns in lesioned rats were not secondary to changes in food intake. Sleep abnormalities persisted even after hyperphagia abated during the static phase of the lesion. Results suggest that the MBH is required for the essential task of integrating sleep-wake and feeding rhythms, a function that allows animals to accommodate changeable patterns of food availability. NPY receptor-expressing neurons are key components of this integrative function.

Intramuscular fat and fatty acid composition of longissimus muscle from divergent pure breeds of cattle.

The objective of this study was to compare the fatty acid (FA) composition of intramuscular fat from the LM of 3 divergent breeds of cattle: Angus (AN, n = 9), Brahman (BR, n = 7), and Romosinuano (RM, n = 11). Cattle were blocked by breed and finished 129 d before slaughter in one year and 157 d in the next year. Longissimus muscle samples were collected from each carcass between the 10th and 13th ribs, trimmed of external fat, frozen in liquid nitrogen, homogenized, and used for fat extraction, using a modified Folch procedure. Extracted fat was analyzed for FA by using a GLC system with an HP-88 capillary column. Fatty acid composition was expressed using both a normalized percentage (%) and gravimetric calculation (mg/g of fresh muscle tissue) in relation to degree of saturation, which was determined using a saturation index (ratio of total SFA to total unsaturated FA). Crude fat determination revealed that LM from AN purebred cattle had the greatest amount of intramuscular fat (7.08%; P = 0.001). Although intramuscular fat of LM from RM contained a reduced percentage of total SFA (P = 0.002) compared with AN, it had the greatest percentage of total PUFA (P < 0.001 and P = 0.020). The percentages of total MUFA were similar among the 3 breeds (P = 0.675). The gravimetric calculation, a measure of actual FA concentration, showed significantly greater concentrations of SFA (26.67 mg/g), MUFA (26.50 mg/g), and PUFA (2.37 mg/g) in LM from AN cattle, as compared with LM from BR and RM cattle (P < 0.001). Interestingly, BR purebreds had the least PUFA concentration (1.49 mg/g; P

Glioblastoma of the optic chiasm.

Primary malignant gliomas of the optic nerve and chiasm are rare, and are usually rapidly fatal in adults. We report a 48-year-old woman with a glioblastoma multiforme arising from the optic chiasm. Following radiotherapy, our patient survived nearly 14 months, which is the longest survival reported in patients with this diagnosis. There have only been four other reports of glioblastoma multiforme arising from the optic chiasm as distinct from secondary involvement of the chiasm, in the last 40 years.

Immunotoxic catecholamine lesions attenuate 2DG-induced increase of AGRP mRNA.

Injections of the immunotoxin, saporin conjugated to anti-dopamine-beta-hydroxylase (DSAP), into the hypothalamic paraventricular nucleus (PVH) selectively destroy norepinephrine (NE) and epinephrine (E) terminals in the medial hypothalamus and abolish glucoprivic feeding. We utilized PVH DSAP injections to examine the role of NE/E neurons in the previously reported 2-deoxy-D-glucose (2DG)-induced increases in mRNA levels for the orexigenic peptides, AGRP and NPY. Northern blot analysis revealed that DSAP lesions elevated basal but blocked 2DG-induced increases in AGRP mRNA levels. Changes in NPY mRNA were not detectable. AGRP neurons may contribute to circuitry activated by NE/E neurons for elicitation of glucoregulatory responses.

Tissue characterization and calcification potential of commercial bioprosthetic heart valves.

BACKGROUND: Tissue properties may contribute to intrinsic calcification of bioprosthetic heart valves. Phospholipids have been proposed as potential nucleation sites for calcification. Other tissue properties might also be important in calcification. METHODS: Commercial and control bioprosthetic valve tissues were characterized by shrinkage temperature, moisture content, free amine content, phospholipid content, and calcification level after 90-day rat subcutaneous implantation as described. RESULTS: Shrinkage temperature, moisture content, and free amine content were typical for glutaraldehyde-cross-linked tissues. Phospholipid and calcium levels varied considerably among valve types. There was a significant correlation between phospholipid levels and calcification (r = 0.63, p = 0.04). Sulzer Carbomedics Mitroflow and Toronto SPV valve tissues had significantly more calcification than other commercial bioprostheses in this study (p < 0.01). Carpentier-Edwards Duraflex, CE SAV, and CE PERIMOUNT valve tissues had significantly less calcification than Medtronic Mosaic in this animal model (p < 0.02). CONCLUSIONS: Processes that reduce phospholipid levels are associated with reduced calcification in the rat subcutaneous model. Significant differences in calcification level were found among commercially available valves. The clinical significance of these results is unknown.

Immunotoxic destruction of distinct catecholamine subgroups produces selective impairment of glucoregulatory responses and neuronal activation.

The toxin-antibody complex anti-d(beta)h-saporin (DSAP) selectively destroys d(beta)h-containing catecholamine neurons. To test the role of specific catecholamine neurons in glucoregulatory feeding and adrenal medullary secretion, we injected DSAP, unconjugated saporin (SAP), or saline bilaterally into the paraventricular nucleus of the hypothalamus (PVH) or spinal cord (T2-T4) and subsequently tested rats for 2-deoxy-D-glucose (2DG)-induced feeding and blood glucose responses. Injections of DSAP into the PVH abolished 2DG-induced feeding, but not hyperglycemia. 2DG-induced Fos expression was profoundly reduced or abolished in the PVH, but not in the adrenal medulla. The PVH DSAP injections caused a nearly complete loss of tyrosine hydroxylase immunoreactive (TH-ir) neurons in the area of A1/C1 overlap and severe reduction of A2, C2, C3 (primarily the periventricular portion), and A6 cell groups. Spinal cord DSAP blocked 2DG-induced hyperglycemia but not feeding. 2DG-induced Fos-ir was abolished in the adrenal medulla but not in the PVH. Spinal cord DSAP caused a nearly complete loss of TH-ir in cell groups A5, A7, subcoeruleus, and retrofacial C1 and a partial destruction of C3 (primarily the ventral portion) and A6. Saline and SAP control injections did not cause deficits in 2DG-induced feeding, hyperglycemia, or Fos expression and did not damage catecholamine neurons. DSAP eliminated d(beta)h immunoreactivity but did not cause significant nonspecific damage at injection sites. The results demonstrate that hindbrain catecholamine neurons are essential components of the circuitry for glucoprivic control of feeding and adrenal medullary secretion and indicate that these responses are mediated by different subpopulations of catecholamine neurons.

Localization of hindbrain glucoreceptive sites controlling food intake and blood glucose.

Feeding and blood glucose responses to local injection of nanoliter volumes of 5-thio-D-glucose (5TG), a potent antimetabolic glucose analogue, were studied at 142 hindbrain and 61 hypothalamic cannula sites. A site was considered positive if 5TG elicited at least 1.5 g more food intake or a hyperglycemic response at least 25 mg/dl greater than the respective responses elicited by vehicle injection in the same rat. Of 61 hypothalamic cannula sites tested, none were positive for blood glucose and only one was positive for feeding. Increasing the 5TG dose to 48 ug did not produce additional positive results at hypothalamic sites. In contrast, 66 hindbrain sites were positive for feeding and 49 were positive for blood glucose, with 33 of these being positive for both responses. The distribution of positive sites for feeding and hyperglycemia overlapped almost completely. Positive sites were concentrated in two distinct zones: one in the ventrolateral and one in the dorsomedial medulla. In both locations, the glucoreceptive areas extended approximately from the level of the area postrema (AP) to the pontomedullary junction. Glucoreceptive zones were co-distributed with epinephrine cell groups C1-C3, suggesting that epinephrine neurons may be important components of the neural circuitry for glucoregulation. Localization of glucoreceptive sites will facilitate positive identification of glucoreceptor cells and the direct analysis of the neural mechanisms through which they influence food intake and metabolic responses.

Competitive inhibition of a glutamate carboxypeptidase by phosphonamidothionate derivatives of glutamic acid.

Several N-thiophosphonyl-glutamates were found to be potent competitive inhibitors of a zinc-dependent glutamyl hydrolase, carboxypeptidase G (CPG). Weak inhibition exhibited by an analogous N-phosphonyl-glutamate suggests that the enhanced potency of the phosphonamidothioates is due to the presence of their sulfur ligand and its favorable interactions with active site features, presumably zinc(II).

Lactols in hydrolysates of DNA treated with alpha-acetoxy-N-nitrosopyrrolidine or crotonaldehyde.

alpha-Acetoxy-N-nitrosopyrrolidine (alpha-acetoxyNPYR) is a stable precursor to alpha-hydroxyNPYR, the initial product of metabolism and proposed proximate carcinogen of N-nitrosopyrrolidine (NPYR). Crotonaldehyde (2-butenal) is a metabolite of NPYR and also a mutagen and carcinogen. Both alpha-acetoxyNPYR and crotonaldehyde form DNA adducts, but these reactions have not been completely characterized. In previous studies, we detected substantial amounts of unidentified radioactivity in hydrolysates of DNA that had been treated with radiolabeled alpha-acetoxyNPYR. In this study, we have characterized these products as 2-hydroxytetrahydrofuran, the cyclic form of 4-hydroxybutanal, and paraldol, the dimer of 3-hydroxybutanal. These products were identified by comparison to standards and by conversion to 2,4-dinitrophenylhydrazones. 2-Hydroxytetrahydrofuran is the major product in neutral thermal hydrolysates of alpha-acetoxyNPYR-treated DNA and is derived predominantly from N2-(tetrahydrofuran-2-yl)deoxyguanosine 8. Paraldol is present to a lesser extent than 2-hydroxytetrahydrofuran in these reactions and is formed from paraldol-releasing adducts, which in turn are produced in the reaction of crotonaldehyde, a solvolysis product of alpha-acetoxyNPYR, with DNA. Other products in hydrolysates of alpha-acetoxyNPYR-treated DNA are N7-substituted guanines 5 and 6, cyclic N7-C8 guanines 4, 11, and 12, and 1, N2-propanodeoxyguanosines 9 and 10. Paraldol is a major product in hydrolysates of crotonaldehyde-treated DNA, being present in amounts 100 times greater than those of previously identified adducts 9 and 10. The results of this study provide a more complete picture of the reactions of alpha-acetoxyNPYR with DNA and yield some new insights about possible endogenous DNA adducts formed from crotonaldehyde.

Subgroups of hindbrain catecholamine neurons are selectively activated by 2-deoxy-D-glucose induced metabolic challenge.

Glucose is a major fuel for body energy metabolism and an essential metabolic fuel for the brain. Consequently, glucose deficit (glucoprivation) elicits a variety of physiological and behavioral responses crucial for survival. Previous work indicates an important role for brain catecholamine neurons in mediation of responses to glucoprivation. This experiment was conducted to identify the specific catecholamine neurons that are activated by glucoprivation. Activation of hindbrain catecholamine neurons by the antimetabolic glucose analogue, 2-deoxy-D-glucose (2DG; 50, 100, 200 or 400 mg/kg, s.c.) was evaluated using double label immunohistochemistry. Fos protein was used as the marker for neuronal activation and the enzymes tyrosine hydroxylase (TH) and phenethanolamine-N-methyl transferase (PNMT) were used as the markers for norepinephrine (NE) and epinephrine (E) neurons. 2-Deoxy-D-glucose (200 and 400 mg/kg) produced selective activation of distinct hindbrain catecholamine cell groups. In the ventrolateral medulla, doubly labeled neurons were concentrated in the area of A1/C1 and were predominantly adrenergic in phenotype. In the dorsal medulla, doubly labeled neurons were limited to C2 and C3 cell groups. In the pons, some A6 neurons were Fos-positive. Neurons in rostral C1, ventral C3, A2, A5 and A7 did not express Fos-ir in response to 2DG. Our results identify specific subpopulations of catecholamine neurons that are selectively activated by 2DG. Previously demonstrated connections of these subpopulations are consistent with their participation in the feeding and hyperglycemic response to glucoprivation. Finally, the predominant and seemingly preferential activation of epinephrine neurons suggests that they may play a unique role in the brain's response to glucose deficit.

Single daily dosing of aminoglycosides in immunocompromised adults: a systematic review.

We examined the efficacy and toxicity of single daily dosing (SDD) of aminoglycosides for febrile, immunocompromised adults by systematically reviewing four randomized, controlled trials of SDD vs. standard dosing regimens. We assessed the methodological quality of each study and extracted data pertaining to efficacy and toxicity outcomes. Pooled risk ratios for the efficacy outcomes were bacteriologic cure, 1.00 (95% confidence interval [CI], 0.86-1.16); clinical cure, 0.97 (95% CI, 0.91-1.05); and mortality, 0.93 (95% CI, 0.62-1.41). The pooled nephrotoxicity risk ratio was 0.78 (95% CI, 0.31-1.94). Only one study assessed ototoxicity. Although our study was limited by the small number of trials available for review, the results suggest that SDD of aminoglycosides may be efficacious for febrile, immunocompromised patients. Additional studies are necessary for more precise quantification of the mortality and toxicity risk ratios.