Pharmacokinetics of intravenously administered cefmetazole and cefoxitin and effects of probenecid on cefmetazole elimination

Sixteen healthy male volunteers participated in a randomized, balanced, three-way crossover study comparing the pharmacokinetics of cefmetazole, cefoxitin, and cefmetazole with probenecid pretreatment. Single 2-g doses of cefmetazole sodium and cefoxitin sodium were given intravenously as a 5-min infusion. Concentrations of cefmetazole and cefoxitin were determined by using a specific semiautomated high-performance liquid chromatographic method. Concentration-time profiles of cefmetazole and cefoxitin declined in a biexponential manner from peak levels. Compared with cefoxitin, cefmetazole had a significantly (P less than 0.05) higher mean (+/- standard error of the mean) peak concentration in serum (290 +/- 11 versus 244 +/- 10 micrograms/ml), a longer terminal disposition half-life (1.50 +/- 0.14 versus 0.81 +/- 0.04 h), lower systemic clearance (111.7 +/- 4.7 versus 279 +/- 12 ml/min) and renal clearance (78.7 +/- 4.3 versus 221 +/- 14 ml/min) of intact drug, and a slightly smaller steady-state volume of distribution (10.3 +/- 0.21 versus 12.8 +/- 0.48 liters). Mean recoveries of cefmetazole and cefoxitin in urine were approximately 71 and 77%, respectively. Pretreatment of volunteers with probenecid (1 g orally) significantly (P less than 0.05) increased concentrations of cefmetazole in serum 1 h after drug administration without significantly increasing maximum concentrations in serum. Mean areas under the concentration-time curve (466 +/- 27 versus 295 +/- 13 micrograms.h/ml) and terminal disposition half-lives (2.27 +/- 0.13 versus 1.50 +/- 0.14 h) of cefmetazole increased. Systemic clearance (72.1 +/- 4.0 versus 111.7 +/- 4.7 ml/min) and renal clearance (47.4 +/- 4.0 versus 78.7 +/- 4.3 ml/min) of intact antibiotic decreased. Mean recoveries (65.9 +/- 3.7 versus 71.0 +/- 3.2%) of intact cefmetazole in urine were not significantly (P > 0.05) different. Elimination of cefmetazole in urine was also significantly prolonged by probenecid, with substantial concentrations of cefmetazole (>/= 20 micrograms/ml) found in the 12- to 24-h urine collection for 14 to 16 volunteers. The results show that cefmetazole remains at clinically relevant concentrations (1 to 2 micrograms/ml) approximately twice as long as cefoxitin, that serum cefmetazole can be maintained longer at clinically significant concentrations with preadministration of probenecid, and that cefmetazole is partially eliminated by renal tubule secretion.

Significance of serum type-IV collagen levels in various liver diseases. Measurement with a one-step sandwich enzyme immunoassay using monoclonal antibodies with specificity for pepsin-solubilized type-IV collagen

Serum type-IV collagen levels determined with a one-step sandwich enzyme immunoassay (EIA) using monoclonal antibodies with specificity for pepsin-solubilized type-IV collagen were compared with histologic changes in liver biopsy specimens from 107 patients with various liver diseases. Serum type-IV collagen levels were increased in the groups with liver diseases compared with controls. The serum type-IV collagen levels in the group with alcoholic cirrhosis showed significantly higher values than the other groups (P less than 0.05). A significant positive correlation was found between the serum type-IV collagen level and the degree of fibrosis or cell infiltration in 107 patients. Immunolocalization of type-IV collagen was observed around blood vessels and bile ducts increased in number in the portal tracts, with cell infiltration and fibrosis, increased around vessels in fibrous septa, and sinusoidal walls of areas with cell infiltration or necrosis in hepatic lobules, and along the boundary between fibrous septa and hepatocytes. The present data indicate that serum type-IV collagen may be a sensitive marker for active fibrosis and that the elevation of serum type-IV collagen level primarily reflects the enhancement of type-IV collagen synthesis and deposition in the liver tissue at the stage of active fibrosis in liver disease.

Trace element homeostasis during continuous sedation with propofol containing EDTA versus other sedatives in critically ill patients

OBJECTIVE

To evaluate changes in serum and urinary zinc, cobalt, copper, iron, and calcium concentrations in critically ill patients receiving propofol containing disodium edetate (disodium ethylenediaminetetraacetic acid [EDTA]) versus sedative agents without EDTA.

DESIGN

This was a randomised, open-label, parallel-group study with randomisation stratified by baseline Acute Physiology and Chronic Health Evaluation (APACHE II) scores.

SETTING

Intensive care units (ICU) in 23 medical centres.

PATIENTS

Medical, surgical, or trauma ICU patients 17 years of age or older who required mechanical ventilator support and sedation.

INTERVENTIONS

A total of 106 patients received propofol containing 0.005 % EDTA (propofol EDTA), and 104 received other sedative agents without EDTA (non-EDTA). Only the first 108 patients were assessed for urinary trace metal excretion. Twenty-four-hour urine samples were collected on days 2, 3, and 7 and every 7 days thereafter for determination of zinc, cobalt, copper, iron, and calcium excretion; EDTA levels; urine osmolality; albumin levels; and glucose levels. The first 143 patients were assessed for serum concentration of zinc, cobalt, copper, iron, and calcium; creatinine; blood urea nitrogen; and albumin at baseline and once during each 24-hour urine collection.

MEASUREMENTS AND RESULTS

For the assessment of trace metals, patients receiving propofol EDTA demonstrated increased mean urinary excretion of zinc, copper, and iron compared with the normal range. All patients receiving sedatives demonstrated increased urinary excretion of zinc and copper above normal reference values. Compared with the non-EDTA sedative group, the propofol EDTA group demonstrated increased urinary excretion of zinc and iron. Mean serum concentrations of zinc and total calcium were decreased in both patient groups. Serum zinc concentrations increased from baseline to day 3 in the non-EDTA sedative group but not in the propofol EDTA group. Renal function, measured by blood urea nitrogen, serum creatinine, and creatinine clearance, did not deteriorate during ICU sedation with either regimen.

CONCLUSION

This study showed that critical illness is associated with increased urinary losses of zinc, copper, and iron. Propofol EDTA-treated patients had greater urinary losses of zinc and iron and lower serum zinc concentrations compared with the non-EDTA sedative group. No adverse events indicative of trace metal deficiency were observed in either group. The clinical significance of trace metal losses during critical illness is unclear and requires further study.

Fetal renal volume in normal gestation: a three-dimensional ultrasound study

To establish a reference chart of fetal kidneys in normal pregnancy, we performed a prospective and cross-sectional study. A total of 152 singleton fetuses ranging between 20 and 40 weeks' gestation and meeting the criteria of normal pregnancies were included. Three-dimensional ultrasound (3-D US) was used to measure the fetal renal volume. Our results revealed that both renal volumes are highly correlated with the fetal gestational age. Using gestational age (GA) as the independent variable and right renal volume (RRV) as the dependent variable, the best-fit regression equation was RRV (mL)=0.74053xGA (week)-13.318 (r = 0.89, p < 0.001). Similarly, the best-fit equation for the left renal volume (LRV) was LRV (mL)=0. 76093xGA (week)-13.421 (r = 0.86, p < 0.001). The normal growth centiles of both kidneys were established based on these two equations. There were no significant differences of the volumes between bilateral kidneys. In conclusion, our data of fetal renal volumes assessed by 3-D US may serve as a reference in evaluating fetal renal growth.

Radioimmunoassay of minoxidil in human serum

A simple, sensitive, and specific radioimmunoassay for determining minoxidil was developed. Antiserums to two minoxidil haptens were compared for cross-reactivity and assay levels on human serums. One antiserum had little cross-reactivity with minoxidil metabolites. The radioimmunoassay is specific for determining minoxidil directly in serum without extraction. Human serum minoxidil levels were determined from a single oral dose.

Correcting for measurement error in individual-level covariates in nonlinear mixed effects models

The nonlinear mixed effects model is used to represent data in pharmacokinetics, viral dynamics, and other areas where an objective is to elucidate associations among individual-specific model parameters and covariates; however, covariates may be measured with error. For additive measurement error, we show substitution of mismeasured covariates for true covariates may lead to biased estimators for fixed effects and random effects covariance parameters, while regression calibration may eliminate bias in fixed effects but fail to correct that in covariance parameters. We develop methods to take account of measurement error that correct this bias and may be implemented with standard software, and we demonstrate their utility via simulation and application to data from a study of HIV dynamics.

Manufacture of antithymocyte globulin (ATGAM) for clinical trials

Methods are described for preparing large amounts of horse anti-human thymocyte globulin (ATG, ATGAM; The Upjohn Company) for clinical use. These methods have been used since 1968 to provide material for clinical trials. Characteristics of 40 lots of ATG are summarized.

NOX1 is essential for TNFα-induced intestinal epithelial ROS secretion and inhibits M cell signatures

OBJECTIVE

Loss-of-function mutations in genes generating reactive oxygen species (ROS), such as NOX1, are associated with IBD. Mechanisms whereby loss of ROS drive IBD are incompletely defined.

DESIGN

ROS measurements and single-cell transcriptomics were performed on colonoids stratified by NOX1 genotype and TNFα stimulation. Clustering of epithelial cells from human UC (inflamed and uninflamed) scRNASeq was performed. Validation of M cell induction was performed by immunohistochemistry using UEA1 (ulex europaeus agglutin-1 lectin) and in vivo with DSS injury.

RESULTS

TNFα induces ROS production more in NOX1-WT versus NOX1-deficient murine colonoids under a range of Wnt-mediated and Notch-mediated conditions. scRNASeq from inflamed and uninflamed human colitis versus TNFα stimulated, in vitro colonoids defines substantially shared, induced transcription factors; NOX1-deficient colonoids express substantially lower levels of STAT3 (signal transducer and activator of transcription 3), CEBPD (CCAAT enhancer-binding protein delta), DNMT1 (DNA methyltransferase) and HIF1A (hypoxia-inducible factor) baseline. Subclustering unexpectedly showed marked TNFα-mediated induction of M cells (sentinel cells overlying lymphoid aggregates) in NOX1-deficient colonoids. M cell induction by UEA1 staining is rescued with H2O2 and paraquat, defining extra- and intracellular ROS roles in maintenance of LGR5+ stem cells. DSS injury demonstrated GP2 (glycoprotein-2), basal lymphoplasmacytosis and UEA1 induction in NOX1-deficiency. Principal components analyses of M cell genes and decreased DNMT1 RNA velocity correlate with UC inflammation.

CONCLUSIONS

NOX1 deficiency plus TNFα stimulation contribute to colitis through dysregulation of the stem cell niche and altered cell differentiation, enhancing basal lymphoplasmacytosis. Our findings prioritise ROS modulation for future therapies.

Disposition of cefmetazole in healthy volunteers and patients with impaired renal function

The disposition of cefmetazole was studied in 25 subjects with various degrees of renal function after a 1,000-mg, constant-rate, 30-min intravenous infusion of cefmetazole sodium. In six subjects with creatinine clearance (CLCR) of greater than 90 ml/min per 1.73 m2 (group 1), the terminal elimination half-life (t1/2 beta) was 1.31 +/- 0.54 h (mean +/- standard deviation), cefmetazole total body clearance (CLP) was 132.8 +/- 25.1 ml/min per 1.73 m2, and volume of distribution at steady state was 0.165 +/- 0.025 liter/kg. The fraction of dose excreted unchanged in the urine was 84.0% +/- 26.1%. Subjects with CLCRS of 40 to 69 (group 2, n = 6) and 10 to 39 (group 3, n = 6) ml/min per 1.73 m2 demonstrated prolongation of the t1/2 beta (3.62 +/- 1.06 and 5.93 +/- 1.81 h, respectively) and significant reductions in cefmetazole CLP (52.8 +/- 14.3 and 30.2 +/- 10.2 ml/min per 1.73 m2, respectively), compared with group 1. In seven subjects on chronic hemodialysis (group 4) studied during an interdialytic period, the cefmetazole t1/2 beta was increased to 24.10 +/- 8.12 h and the CLP was reduced to 6.8 +/- 2.1 ml/min per 1.73 m2. Cefmetazole CLP correlated positively with CLCR (r = 0.951, P less than 0.001): CLP = (1.181 . CLCR) -- 0.287. The disposition of cefmetazole was also assessed in six group 4 subjects during an intradialytic period. The t1/2 beta during hemodialysis (2.09 +/- 0.69 h) was significantly shorter than that observed during the interdialytic period. The hemodialysis clearance of cefmetazole was 86.1 +/- 20.1 ml/min, and the fraction of cefmetazole removed during hemodialysis was 59.8% +/- 5.9%. It is recommended that patients with renal insufficiency received standard doses of cefmetazole at extended intervals and patients on maintenance hemodialysis received standard doses after hemodialysis.

Development and preliminary evaluation of culturally specific web-based intervention for parents of adolescents

WHAT IS KNOWN ON THE SUBJECT?: Problematic parent-child relationships have been identified as one of the main predictors of adolescents' mental health problems, but there are few existing interventions that address this issue. The format and delivery method of existing interventions for parents are relatively inaccessible for parents with full-time jobs and families living in rural areas. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: The newly developed 'Stepping Stone' culturally specific web-based intervention, which is intended to help Korean parents of adolescents to acquire both knowledge and communication and conflict management skills, was found to be feasible and well-accepted by parents. This study enabled us to identify areas for improvement in the content and format of the intervention and strategies. This will potentially increase effect sizes for the outcome variables of parents' perception and behaviours. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This web-based intervention could be delivered across diverse settings, such as schools and community mental health centers, to increase parents' knowledge of adolescent's mental health and allow for early detection of mental health problems. Mental health nurses working in schools may spend a significant amount of time addressing students' mental health issues; thus, this web-based intervention could be a useful resource to share with parents and children. In this way, the mental health nurses could facilitate parental engagement in the intervention and then help them to continue to apply and practice the knowledge and skills obtained through the program.

ABSTRACT

Introduction There is a need for accessible, culturally specific web-based interventions to address parent-child relationships and adolescents' mental health. Aims This study developed and conducted a preliminary evaluation of a 4-week web-based intervention for parents of adolescents aged 11 to 16 years in Korea. Methods We used a two-group, repeated measures, quasi-experimental study design to assess the feasibility of developing and implementing a web-based intervention for parents. Descriptive statistics, chi-square and t tests, and mixed effect modeling were used for data analysis. Results The intervention and 1-month follow-up survey were completed by 47 parents in the intervention group and 46 parents in the attention control (AC) group. The intervention was found to be feasible and well-accepted by parents. Discussion This culturally specific web-based intervention is a useful tool for knowledge dissemination among large numbers of parents. Areas for improvement in the content and format of the intervention and strategies to elicit significant parent-child interactions are provided. Implications for practice and conclusion The intervention could be disseminated in collaboration with mental health nurses working in schools to facilitate parents' participation.

A micropatterned elastomeric surface with enhanced frictional properties under wet conditions and its application

Engineered surfaces that have high friction under wet or lubricated conditions are important in many practical applications. However, it is not easy to achieve stable high friction under wet conditions because a layer of fluid prevents direct solid-solid contact. Here, we report a micropatterned elastomeric surface with superior wet friction. The surface has unique arch-shaped microstructures arrayed in a circle on the surface to provide high friction on wet or flooded surfaces. The arch-shaped micropatterned surface exhibits remarkably enhanced and stable friction under wet conditions, surpassing even the performance of the hexagonal patterns of tree frogs, owing to the large contact surface and the optimal shape of drainage channels. Robotic substrate transportation systems equipped with the micropatterned surfaces can manipulate a delicate wet substrate without any sliding in a highly stable and reproducible manner, demonstrating the superior frictional capabilities of the surface under wet conditions.

Pharmacokinetics of single-dose cefmetazole following intramuscular administration of cefmetazole sodium to healthy male volunteers

The tolerance and pharmacokinetics of cefmetazole were studied in healthy male volunteers who received a placebo (sterile saline) or a single dose of cefmetazole sodium intramuscularly. Drug-treated volunteers received one of four doses, 0.375, 0.750, 1, or 2 g. The drug was well tolerated, with no adverse medical events or laboratory changes observed during the study that could affect the pharmacokinetic interpretation of the data. Cefmetazole concentrations were determined by using a specific high-performance liquid chromatographic method. Serum cefmetazole concentrations were well described by a one-compartment open model with first-order absorption and elimination. Cefmetazole was rapidly absorbed in most volunteers, with a mean time to maximum concentration in serum of 1.24 +/- 0.12 h (+/- standard error of the mean), and the mean maximum concentration in serum increased from 17.0 +/- 1.6 to 74.2 +/- 9.5 micrograms/ml over the 0.375- to 2-g dose range. Maximum concentrations in serum, areas under serum concentration-time curve, and urinary excretion of intact drug increased in proportion to cefmetazole sodium dose. Times at which maximum concentrations in serum occurred, apparent volumes of distribution, steady-state volumes of distribution, absorption and elimination half-lives, and systemic clearances did not change significantly (P greater than 0.05) with drug dose. Although absorption and elimination half-lives were not significantly different in 10 of 40 volunteers (P greater than 0.05), in a majority of subjects elimination half-lives were approximately 10 times longer than absorption half-lives. The mean recovery of intact drug in urine ranged from 68.8 to 86.0% over the dose range studied, with a mean recovery over all doses of 77.1 +/- 2.4%. Rental clearances were significantly lower (P < 0.05) for the two lowest doses (93.0 and 84.3 versus 115.0 and 118.0 ml/min); these differences are not considered clinically important. The results of this study indicate that cefmetazole pharmacokinetics are linear after administration of single intramuscular doses ranging from 0.375 to 2 g, that clinically relevant concentrations of cefmetazole in serum (1 to 2 micrograms/ml) persist in a majority of volunteers for more than 8 h after administration of 0.750-g or higher doses, and that clinically relevant concentrations of cefmetazole continue to be excreted in urine 8 to 12 h after administration of 0.375- to 2-g doses.

Telangiectatic oncocytoma: a previously undescribed variant of renal oncocytoma

OBJECTIVES

To identify, describe, and investigate the clinical, radiologic, and pathologic features of 8 cases of telangiectatic oncocytoma.

METHODS

Fifty-three consecutive renal oncocytomas were reviewed for the telangiectatic pathologic features that were subsequently correlated with the demographic, clinical, and radiographic findings.

RESULTS

Telangiectatic oncocytoma accounted for 15% of the 53 renal oncocytomas collected in the past 7 years in our institution. On radiology, almost all presented as an enhancing mass and were suspicious for or consistent with a renal malignant tumor. Grossly, the tumors ranged from 2.4 to 6.0 cm (mean, 3.5 cm) and macroscopically were hemorrhagic spongy or multicystic masses without a central stellate scar. Microscopically, they were characterized by variably sized blood-distended spaces (<0.1-mm to 2- to 3-mm blood lakes) lined by typical oncocytoma cells and without evidence of degenerative changes.

CONCLUSIONS

With its unique radiologic and pathologic presentations in comparison with classic renal oncocytoma, it is important to recognize this new variant of renal oncocytoma.

Mild postischemic hypothermia is neuroprotective in the immature rat neocortex slice

Mild hypothermia as an intervention after perinatal asphyxia may prevent neurological damage in the newborn. We used stimulus-induced field potentials to monitor recovery from oxygen and glucose deprivation (OGD) in neocortex slices of 6-8-day-old wistar rats. OGD after a latency of 10.7+/-2.1 min (mean+/-S.E.) resulted in an anoxic depolarisation with an amplitude of 5.4+/-2.4 mV. Mild hypothermia of 31 degrees C (vs. 35 degrees C in the control group) was applied for 60 min after end of OGD. The 20, 40, 60 and 80% recovery of the field potential amplitude was significantly faster in the hypothermia group in comparison to the control group. These data indicate that mild postischemic hypothermia may have neuroprotective effects after perinatal asphyxia.

Uniform spatial pooling explains topographic organization and deviation from receptive-field scale invariance in primate V1

Receptive field (RF) size and preferred spatial frequency (SF) vary greatly across the primary visual cortex (V1), increasing in a scale invariant fashion with eccentricity. Recent studies reveal that preferred SF also forms a fine-scale periodic map. A fundamental open question is how local variability in preferred SF is tied to the overall spatial RF. Here, we use two-photon imaging to simultaneously measure maps of RF size, phase selectivity, SF bandwidth, and orientation bandwidth—all of which were found to be topographically organized and correlate with preferred SF. Each of these newly characterized inter-map relationships strongly deviate from scale invariance, yet reveal a common motif—they are all accounted for by a model with uniform spatial pooling from scale invariant inputs. Our results and model provide novel and quantitative understanding of the output from V1 to downstream circuits.

Two-photon imaging in macaque V1 captured maps of tuning selectivity for four spatial parameters, all of which correlated with peak spatial frequency. These inter-map relationships reveal a common motif—they are described by uniform spatial pooling from a family of scale invariant Gabor receptive fields.