Amplification of Antimicrobial Resistance in Gut Flora of Patients Treated with Ceftriaxone.

Although antibacterial therapy has an impact on human intestinal flora and the emergence of resistant bacteria, its role in the amplification of antimicrobial resistance and the quantitative exposure-effect relationship is not clear. An observational prospective study was conducted to determine whether and how ceftriaxone exposure is related to amplification of resistance in non-intensive care unit (non-ICU) patients. Serial stool samples from 122 extended-spectrum ß-lactamase-positive (ESBL+) hospitalized patients were analyzed by quantitative real-time PCR to quantify the resistant gene blaCTX-M Drug exposure was calculated for each patient by using a population pharmacokinetic model. Multi- and univariate regression and classification regression tree (CART) analyses were used to explore relationships between measures of exposure and amplification of blaCTX-M genes. Amplification of blaCTX-M was observed in 0% (0/11) of patients with no treatment and 33% (20/61) of patients treated with ceftriaxone. Stepwise regression analysis showed a significant association between amplification of blaCTX-M and the plasma area under the concentration-time curve from 0 to 24 h for the unbound fraction of the drug (fAUC0-24), the maximum concentration of drug in serum for the unbound fraction of the drug (fCmax), and the duration of ceftriaxone therapy. Using CART analysis, amplification of blaCTX-M was observed in 11/16 (69%) patients treated for >14 days and in 9/40 (23%) patients treated for ≤14 days (P = 0.0019). In the latter group, amplification was observed in 5/7 (71%) patients with an fAUC0-24 of ≥222 mg · h/liter and in 4/33 (12%) patients with lower drug exposures (P = 0.0033). A similar association was found for an fCmax of ≥30 mg/liter (63% versus 13%, P = 0.0079). A significant association was found between the amplification of blaCTX-M resistance genes and exposure to ceftriaxone. Both duration of treatment and degree of ceftriaxone exposure have a significant impact on the amplification of resistance genes. (The project described in this paper has been registered at ClinicalTrials.gov under identifier NCT01208519.).

Elimination of symbiotic Aeromonas spp. from the intestinal tract of the medicinal leech, Hirudo medicinalis, using ciprofloxacin feeding.

The use of the medicinal leech (Hirudo medicinalis) in promoting venous drainage in tissues whose vitality is threatened by venous congestion and obstruction, especially in plastic and reconstructive surgery, has been complicated by infections caused by Aeromonas spp. These are leech endosymbionts for which patients undergoing hirudotherapy frequently receive systemic chemoprophylaxis. In order to evaluate the possibility of rendering leeches safe for use on patients, H. medicinalis were fed artificially with a 2 g/L arginine solution (used as a phagostimulant) supplemented with ciprofloxacin (100 mg/L). Aeromonads were detected in 57 out of 80 control leeches (71.3%), but in none of the 56 leeches treated with ciprofloxacin (p <0.001). Treated leeches survived for up to 4 months. Tested weekly, 61% of these leeches took human blood for at least 4 weeks after treatment and all remained negative for aeromonads. All water samples in which leeches were kept before treatment were contaminated with Aeromonas spp.; none were detected in any of the NaCl/arginine solutions with which treated animals were fed. Molecular characterization of two phenotypically distinct isolates using gyrB sequencing showed that one clustered tightly with A. veronii and the other was closely related to A. media. Other environmental bacteria and fungi were isolated from 26.5% of treated leeches that had taken a blood meal 1-4 weeks after treatment. Ciprofloxacin reduced the number of leech-associated aeromonads to undetectable levels for extended periods. Most treated leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy.

Fate of heavy metals after application of sewage sludge and wood-ash mixtures to short-rotation willow coppice.

Short-rotation willow coppice (SRWC), grown on farmland in Sweden for energy-biomass production, was fertilised with sewage sludge and wood-ash mixtures on the basis of the permitted annual phosphorus supply. Two identical experiments were conducted in central Sweden, on two newly harvested commercial SRWC fields. The maximum legally permitted amount of the sludge-ash mixture, sludge only, ash only, and twice the maximum permitted sludge-ash amount, were applied. The aim was to assess the effect of pH changes following treatment, on the ability of SRWC to take up large amounts of Cd and other metals. The remediation effect of SRWC was also studied. Under the experimental conditions applied, uptake by SRWC was unaffected by pH changes. The differences between the amounts of metals experimentally applied, less the uptake by SRWC after a potential harvest, were broadly within the permitted limits. For Cd, a reduction of total amounts in soil was observed.

Ovarian hormone influences on the density of immunoreactivity for tyrosine hydroxylase and serotonin in the primate corpus striatum.

The serotonergic and dopaminergic inputs to the corpus striatum in human and non-human primates participate in diverse sensorimotor, cognitive, and affective functions, are implicated in dysfunction in diseases such as Parkinson's disease and schizophrenia, and are targets for many of the drugs used to treat these disorders. Sex differences in the incidence and/or clinical course of these disorders and in the effectiveness of related dopaminergic and serotonergic drug therapies suggest that primate striatal indolamines and catecholamines are also influenced by gonadal hormones. However, while well studied in rats, relatively little is known about precisely how gonadal steroids modulate stratial dopamine and serotonin systems in primates. To begin to address this issue, the present studies explored the effects of ovarian steroids on the serotonergic and dopaminergic innervation densities of the caudate, putamen, and the nucleus accumbens in young adult rhesus monkeys. Using densitometry to quantify immunoreactivity for serotonin and for the catecholamine-synthesizing enzyme tyrosine hydroxylase, innervation densities were compared in identified, functionally specialized striatal subdomains across animals that were either ovariectomized or ovariectomized and supplemented with estradiol and/or progesterone, i.e. in a primate model of surgical menopause, with and without hormone replacement therapy. These analyses revealed clear examples of structure-, hemisphere-, and replacement regimen-specific effects of changes in circulating steroids on the densities of each afferent system examined. Further, the predominantly stimulatory effects observed occurred in striatal areas analogous to those suspected as sites of localized dopamine and/or serotonin compromise in Parkinson's disease and schizophrenia. Thus, the hormone actions identified in this study could hold relevance for some of the sex differences identified in relation to these disorders, including the findings of decreased incidence and/or symptom severity in women that have led to hypotheses of protective effects for estrogen.

Gonadectomy in adult life increases tyrosine hydroxylase immunoreactivity in the prefrontal cortex and decreases open field activity in male rats.

The prefrontal cortices in rats participate in a range of cognitive, emotional, and locomotor functions that are dependent on its rich catecholamine innervation. Sex differences identified in many of these functions suggest that the prefrontal cortex is also influenced by gonadal hormones. Previous studies have shown that prefrontal catecholamines can be modified by changes in the hormone environment in developing animals. The present analyses, carried out in male rats gonadectomized as adults, with and without supplementation with testosterone proprionate, and examined at intervals from two days to 10 weeks after surgery, revealed that both the anatomical organization of prefrontal catecholamine afferents, and a behavioral measure sensitive to their selective lesioning remain highly responsive to changes in testicular hormones in adulthood. Thus, gonadectomy in adult male rats rapidly led to a large but transient decrease in the density of tyrosine hydroxylase immunoreactivity in all layers of the dorsal anterior cingulate cortex. This was followed by a sustained period in which immunoreactivity in the supragranular layers returned to levels that were just below normal (between 72 and 79% of normal), and labeling in deep laminae stabilized at considerably elevated innervation densities (approximately 150% of normal). Neither the acute decrease nor the chronic over-innervation characteristic of gonadectomized animals was observed in rats that were gonadectomized and supplemented with testosterone proprionate. Open field activity assessed along a corresponding 10 week timeline showed that gonadectomized animals were significantly less active than hormonally intact controls, a behavioral pattern opposite to the hyperactivity which persists following prefrontal dopamine lesions. Gonadectomized animals supplemented with testosterone proprionate, on the other hand, had open field scores that were not significantly different from controls. Taken together, these findings indicate that the adult hormone environment provides a significant, and seemingly functionally significant influence over the catecholamine innervation of the rat prefrontal cortex. Such lifelong responsiveness of the prefrontal cortical catecholamines to circulating hormones suggests that gonadal steroids are an active component of the biology of normal adult cognition, and may also have relevance for cortical dysfunction in disorders such as schizophrenia which are not only strongly tied to the catecholamines, but exhibit considerable biases among men and women as well.

Does the use of topical lidocaine, epinephrine, and tetracaine solution provide sufficient anesthesia for laceration repair?

OBJECTIVE: To determine: 1) the effectiveness of lidocaine, epinephrine, and tetracaine (LET) solution in eliminating or reducing the pain experienced in suturing superficial lacerations in adult patients; and 2) the effectiveness of LET in reducing the pain of local anesthetic injection. METHODS: A prospective, randomized, double-blind study in which 60 adult patients with superficial lacerations were entered was conducted in the ED of a community-based teaching hospital affiliated with the University of Toronto. Following application of the LET or placebo (sterile water) solution to the laceration, a visual analog pain scale was recorded by the patient upon needle probing of the wound margin. If probing was painless, the laceration was repaired using LET alone. If injection of local anesthetic was required, an additional pain scale was elicited to quantify the attenuation of the pain of injection by the prior application of LET. RESULTS: Pain scale values on needle probing were significantly reduced in the LET group vs the placebo group (medians of 4.0 vs 5.0 cm, respectively; p < 0.05). Only 13 of the 30 patients in the LET group required additional anesthetic, while all 30 patients in the placebo group requested local anesthetic. Pain scale values on injection of local anesthetic were not significantly different between the LET and placebo groups (medians of 3.5 vs 5.0 cm, respectively; p = 0.09), although there was a trend for lower pain scale values for those patients who received LET. No adverse effects were noted after the application of either LET or placebo solution. Follow-up was achieved for 54 of 60 patients with only 1 complication (a wound infection) reported in the LET group. CONCLUSIONS: Significantly fewer patients require an injectable anesthetic when LET is applied. Those who do require an injection may experience less discomfort. These advantages should be balanced against the 20 to 30 minutes necessary for the LET to take effect.

Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men.

This study examined the effects of garlic and fish-oil supplementation (alone and in combination) on fasting serum lipids and lipoproteins in hypercholesterolemic subjects. After an initial run-in phase, 50 male subjects with moderate hypercholesterolemia were randomly assigned for 12 wk to one of four groups: 1) 900 mg garlic placebo/d + 12 g oil placebo/d; 2) 900 mg garlic/d + 12 g oil placebo/d; 3) 900 mg garlic placebo/d + 12 g fish oil/d, providing 3.6 g n-3 fatty acids/d; and 4) 900 mg garlic/d + 12 g fish oil/d. In the placebo group, mean serum total cholesterol, low-density-lipoprotein cholesterol (LDL-C), and triacylglycerols were not significantly changed in relation to baseline. Mean group total cholesterol concentrations were significantly lower with garlic+fish oil (-12.2%) and with garlic (-11.5%) after 12 wk but not with fish oil alone. Mean LDL-C concentrations were reduced with garlic+fish oil (-9.5%) and with garlic (-14.2%) but were raised with fish oil (+8.5%). Mean triacylglycerol concentrations were reduced with garlic+fish oil (-34.3%) and fish oil alone (-37.3%). The garlic groups (with and without fish oil) had significantly lower ratios of total cholesterol to high-density-lipoprotein cholesterol (HDL-C) and LDL-C to HDL-C. In summary, garlic supplementation significantly decreased both total cholesterol and LDL-C whereas fish-oil supplementation significantly decreased triacylglycerol concentrations and increased LDL-C concentrations in hypercholesterolemic men. The combination of garlic and fish oil reversed the moderate fish-oil-induced rise in LDL-C. Coadministration of garlic with fish oil was well-tolerated and had a beneficial effect on serum lipid and lipoprotein concentrations by providing a combined lowering of total cholesterol, LDL-C, and triacylglycerol concentrations as well as the ratios of total cholesterol to HDL-C and LDL-C to HDL-C.

Lower prevalence of impaired glucose tolerance and diabetes associated with daily seal oil or salmon consumption among Alaska Natives.

OBJECTIVE: To examine the association of seal oil and salmon consumption with impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) among Alaska Natives. RESEARCH DESIGN AND METHODS: Screening was performed on 666 Yup'ik Eskimos and Athabaskan Indians > or = 40 years old in 15 villages. Self-administered questionnaires were used to obtain partial food frequency data. A case was defined as IGT or NIDDM, either newly discovered or known. Newly discovered cases (11 patients with NIDDM and 17 with IGT) were determined by random blood glucose testing followed by a 2-h 75-g oral glucose tolerance test (OGTT) for those with values > or = 6.72 mmol/l or for subjects with unconfirmed histories of glucose intolerance. Known cases included 26 patients with NIDDM and 1 with IGT. Control subjects had random blood glucoses < 6.72 or normal OGTT results. RESULTS: Compared with less-than-daily consumption, both daily seal oil (odds ratio [OR] 0.2, 95% confidence interval [CI] 0.1-0.8) and daily salmon consumption (OR 0.5, CI 0.2-1.1) were associated with a lower prevalence of glucose intolerance, controlling for age, ethnicity, body mass index, and sex. The effects were similar when limited to newly discovered cases: OR 0.3, CI 0.1-1.3 for seal oil and OR 0.4, CI 0.1-1.3 for salmon. Consumption of seal oil at least five times per week was required to reduce risk. CONCLUSIONS: Consumption of seal oil and salmon, high in omega-3 fatty acids, appears to lower the risk of glucose intolerance and is a potentially modifiable risk factor for NIDDM in Alaska Natives.

Management of perioperative hypertension using sublingual nifedipine. Experience in elderly patients undergoing eye surgery.

Sublingual nifedipine was administered perioperatively to 19 elderly (age, greater than or equal to 60 years) patients undergoing ophthalmologic surgery. All of the patients had blood pressures exceeding 200 mm Hg systolic or 110 mm Hg diastolic, and 18 of the patients had both. Average (mean +/- SD) systolic blood pressure fell from 224.9 +/- 13.9 mm Hg to 154.6 +/- 19.0 mm Hg, while average diastolic blood pressure was reduced from 121.5 +/- 12.2 mm Hg to 78.1 +/- 10.6 mm Hg. Mean time to onset of response to nifedipine was 9.47 +/- 3.9 minutes, while the maximum antihypertensive response occurred in 35.3 +/- 10.2 minutes. A prompt antihypertensive response was obtained without any serious side effects. To our knowledge, this is the first reported study demonstrating the efficacy and safety of using sublingual nifedipine for the management of perioperative hypertension.

Silicon metabolism. I. Some aspects of renal silicon handling in normal man.

Renal silicon handling was investigated in 23 healthy adults using electrothermal atomic absorption techniques. The mean urinary silicon excretion was 33.1 +/- 3.85 mg/day; the mean renal silicon clearance was 88.6 +/- 7.94 ml/min; the mean fractional excretion of silicon was 86.35 +/- 8.1%, and the mean urine silicon concentration was 0.265 micrograms/ml. Using multiple correlation analysis, the urinary silicon was found to be highly significantly correlated with the urine magnesium concentration (p less than 0.001) and also with urinary sodium and urinary osmolality (p less than 0.01). 24-hour urinary silicon excretion was highly significantly correlated with fractional excretion of silicon (p less than 0.001), sodium (p less than 0.001), phosphorus (p less than 0.001), magnesium (p less than 0.001), and osmolar load. In split urine studies in 7 subjects urinary silicon was correlated highly significantly with urinary magnesium in all 7 and with urinary osmolality, urine calcium, and urine creatine concentration in 6 of 7. There was a highly significant correlation between renal silicon clearance and fractional excretion of silicon (p less than 0.0005), with magnesium excretion (p less than 0.01), and with sodium excretion. It is suggested that ion pairing of orthosilicate and magnesium may explain some of these urinary findings.

Renal calcium and magnesium handling in water immersion in nephrotic patients.

The effect of water immersion to the neck on renal calcium and magnesium handling was studied in 11 nephrotic patients. There was an increase in the urinary excretion of both calcium and magnesium on immersion, and a return towards preimmersion control values in the hour following immersion. Clearances of calcium and magnesium, and fractional excretion of calcium and of magnesium all increased significantly during water immersion, and decreased in the postimmersion hour. However, magnesium excretion was 10-50 times greater than calcium excretion. Fractional excretion of sodium was highly significantly related to fractional excretion of calcium (p less than 0.001) and magnesium (p less than 0.001). The relationship between fractional excretion of phosphate and fractional excretion of calcium was statistically significant (p less than 0.05), as was that between fractional excretion of phosphate and that of magnesium (p less than 0.01). Magnesium and calcium fractional excretions were significantly correlated (p less than 0.01). It was concluded that the increase in calcium and magnesium excretion on immersion is likely to be related to the sodium diuresis caused by central hypervolemia due to immersion.

Inadequate clearance of small molecular weight solutes during hemofiltration using Cuprophan membranes.

In a study of four patients treated with one hour of hemofiltration using Cuprophan membranes, followed by three hours of dialysis, it was found that patients will have reduced clearances of small molecular weight solutes. This may be prevented by increasing blood flow rates to compensate for the time spent in hemofiltration. Cuprophan membranes do not clear middle molecular weight solutes as well as other membranes, but fluid removal is comparable to that reported by other investigators using more porous membranes.

Distribution of labeled lymph node cells in mice during the lymphocytosis induced by Bordetella pertussis.

The mechanism by which Bordetella pertussis organisms and their products induce lymphocytosis in mice was analyzed in terms of the localization of syngeneic Cr-51-labeled lymph node cells. Labeled lymphoid cells incubated in vitro with the supernatant of B. pertussis cultures and then injected intravenously into normal recipients, or labeled cells injected into pertussis-treated recipients were unable to "home" to lymphoid organs but persisted for long periods in the blood. In animals "equipped" with a population of Cr-51-labeled lymphoid cells, administration of B. pertussis organisms or culture supernatant effected a shift of radioactivity from lymph nodes and spleen into the peripheral blood, coincident with the lymphocytosis. In in vitro experiments it was found that the active principle could bind to both erythrocytes and lymphocytes and could spontaneously elute from these cells onto labeled lymphocytes which were then unable to home efficiently. The data suggest that Bordetella pertussis-induced lymphocytosis involves a reversible attachment of the pertussis factor onto the surfaces of lymphocytes which prevents their recirculation to lymphoid organs. Recirculating lymphocytes are presumably affected as they emerge from lymphoid organs to enter the blood.