Lower moiety heminephroureterectomy in the duplex refluxing kidney: the accuracy of isotopic scintigraphy in functional assessment

OBJECTIVE: To estimate the incidence of dysplasia in patients with Papanicolaou smears showing atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesions (SIL) and to identify clinical predictors of dysplasia in these patients. METHODS: Patients referred for ASCUS and low-grade SIL were reviewed retrospectively. All patients were evaluated with immediate colposcopy. A multivariate logistic regression analysis was performed to identify clinical predictors of histologic SIL and histologic high-grade SIL. RESULTS: One hundred thirty-seven (34%) of 406 consecutive patients had histologic SIL. Regression analysis identified age (under 35 versus 35 years or above) and initial smear (low-grade SIL versus ASCUS) as statistically significant predictors of histologic SIL and high-grade SIL (P < .001). When patient outcomes were analyzed by age and initial Papanicolaou smear results, the subgroup of patients 35 years or older with ASCUS had low incidences of histologic SIL (14%) and high-grade SIL (1%). The other subgroups (under 35 years with ASCUS, under 35 years with low-grade SIL, and 35 years or older with low-grade SIL) had incidences of histologic SIL and histologic high-grade SIL of at least 28% and 14%, respectively. CONCLUSION: The high incidence of dysplasia in patients with minimally abnormal Papanicolaou smears suggests that immediate colposcopy might be appropriate for many of these patients. Age and initial Papanicolaou smear are predictive of dysplasia and might be used to select patients who have low incidence of dysplasia and might not require immediate colposcopy.     

Simulation of welding flows in a slit. Part I: Kinematics

The kinematics of ideal welding flows generated by a thin-plate divider, a cylinder, or a slab in a slit channel are studied by using a finite element analysis. The analysis includes simulations of Newtonian and Carreau fluids. There are two flow configurations. First, a single plate-divider or an obstacle was positioned symmetrically in a slit channel with no-slip at the walls. In the second, an infinite number of plate-dividers or obstacles were positioned in parallel, and the boundary walls were infinitely far away. It was found that extensional flow dominates the region near the stagnation points of obstacles and plate-dividers, and that the fluid elements near the weld interfaces have a strain history of both high stretching and shearing. The thickness of the elongated region is reduced as the thickness of the plate-divider increases. Shear-thinning tends to increase the rate of extension. However, its influence on the flow field tends to lessen as the width of the flow channel or the obstacle size increases. A no-slip condition at walls causes slightly stronger elongational flow in the weld interface than does the symmetric condition of perfect slip at walls.     

Determination of fat in infant formula by robotic automated method

A method has been developed for the determination of fat in infant formula using a commercially available robotic system. The procedure and chemistry at large are the same as the manual method,Official Methods of Analysis 16.064, by the Association of Official Analytical Chemists (AOAC). Both liquid and powder forms of milk-protein-based and soy-protein-based matrices were analyzed in this study. The robotic operations are described in detail. The evaluation of the accuracy is accomplished by comparing the data obtained by the robotic automated method to those obtained by the official manual method. The analysis of variance does not indicate a statistically significant difference (p-value 0.0620, mean difference 0.0056%) between the mean results of the two methods for the milk-protein-based infant formula. The results of other matrices tested by both methods agreed within 1% relative of each other. The precision of the robotic automated method is slightly better than the manual method as shown by the overall relative standard deviation (RSD) of 0.167% vs 0.269%. The ruggedness of the instrument has been satisfactory. The results of this study suggest that the robotic automated method is suitable for this application.     

Exchange of aspartate and alanine. Mechanism for development of a proton-motive force in bacteria

We examined the idea that aspartate metabolism by Lactobacillus subsp. M3 is organized as a proton-motive metabolic cycle by using reconstitution to monitor the activity of the carrier, termed AspT, expected to carry out the electrogenic exchange of precursor (aspartate) and product (alanine). Membranes of Lactobacillus subsp. M3 were extracted with 1.25% octyl glucoside in the presence of 0. 4% Escherichia coli phospholipid and 20% glycerol. The extracts were then used to prepare proteoliposomes loaded with either aspartate or alanine. Aspartate-loaded proteoliposomes accumulated external [3H]aspartate by exchange with internal substrate; this homologous self-exchange (Kt = 0.4 mm) was insensitive to potassium or proton ionophores and was unaffected by the presence or absence of Na+, K+, or Mg2+. Alanine-loaded proteoliposomes also took up [3H]aspartate in a heterologous antiport reaction that was stimulated or inhibited by an inside-positive or inside-negative membrane potential, respectively. Several lines of evidence suggest that these homologous and heterologous exchange reactions were catalyzed by the same functional unit. Thus, [3H]aspartate taken up by AspT during self-exchange was released by a delayed addition of alanine. In addition, the spontaneous loss of AspT activity that occurs when a detergent extract is held at 37 degrees C prior to reconstitution was prevented by the presence of either aspartate (KD(aspartate) = 0.3 mm) or alanine (KD(alanine) > or = 10 mm), indicating that both substrates interact directly with AspT. These findings are consistent with operation of a proton-motive metabolic cycle during aspartate metabolism by Lactobacillus subsp. M3.     

Isolation as a restoration strategy for nutrient reduction in a small hypereutrophic lake

The restoration of a small hypereutrophic urban lake in Baton Rouge, Louisiana was accomplished by isolating the lake from its primary source of nutrient loading: a larger, connecting lake that was heavily contaminated by sewage. Restoration objectives were directed towards reducing phosphorus levels in the system to minimize chronic summer fish kills. Previous studies had identified a critical phosphorus level of 0.4 mg l⁻¹, below which no fish kills had been observed in this system. Above this level the kill frequency was a uniform 3.0%. Water quality data, consisting of 13 parameters, were collected over a four and one-quarter year period, representing conditions before, during and after the isolation. Evaluation of total phosphorus data indicated an approx. 90% reduction in estimated risk of summer fish kills as a result of the isolation. A general reduction in nutrient levels, as well as an increase in system stability, was also observed. Isolation of the lake proved to be a simple and economical means of attaining management objectives.     

Streptococcal preseptal cellulitis complicated by the toxic Streptococcus syndrome

BACKGROUND: After decades of decline in the incidence of severe infections secondary to group A streptococci, a dramatic increase in the frequency and severity of infections with these organisms has been reported since 1984, including a "toxic Streptococcus syndrome," resembling staphylococcal toxic shock syndrome. To the authors' knowledge, this entity has never been described after ocular infection. METHODS: In a previously healthy 3-year-old boy, preseptal cellulitis developed secondary to minor trauma to the eyelid, progressing rapidly to hypotension, respiratory distress, and an erythrodermic desquamating rash. Ocular and blood cultures grew group A beta-hemolytic streptococci. Appropriate antibiotic coverage and management of systemic manifestations led to rapid improvement, although necrosis developed in the right upper anterior eyelid, requiring skin grafts. RESULTS: More than 3 years since the incident, the patient is free of infection and has a good cosmetic result after skin grafting and revisions for scarring and adhesions. CONCLUSIONS: Streptococcal preseptal cellulitis is not unusual, particularly after trauma. Ophthalmologists must be aware of the re-emergence of more virulent organisms with increased potential for morbidity and mortality.     

Determining the relative amounts of positional isomers in complex mixtures of triglycerides using reversed-phase high-performance liquid chromatography-tandem mass spectrometry

A reversed-phase HPLC-tandem mass spectrometry (RP-HPLC-MS-MS) method was refined for the positional analysis of complex mixtures of TAG. This method has the advantages of speed, ease of automation, and specificity over traditional digestion-based methods for the positional analysis of TAG. Collision-induced dissociation (CID) of ammoniated TAG in an ion-trap mass spectrometer produced spectra that were dependent on the FA position. Dominant DAG fragments were formed from the loss of a FA moiety from the ammoniated TAG species. The loss of FA in the outer positions was favored over their loss in the central position. The combination of RP-HPLC and CID produced spectra that were free of the isotope effects that can complicate spectral interpretation in existing methods. The combination also provided selectivity based on the chromatographic fractionation of TAG, in addition to the selectivity inherent in the CID process. Proof-of-concept experiments were performed with binary mixtures of TAG from the SOS/SSO, OSO/OOS, and the PSO/POS/SPO positional isomer systems (where S is 18∶0, stearic acid; O is 18∶1 (cis-9), oleic acid; and P is 16∶0, palmitic acid). Plots of fractional DAG fragment intensities vs. fractional composition of the binary mixtures were linear. These plots were used to determine the fractional composition of each of these isomeric systems in a variety of vegetable oils and animal fats. Current limitations, future developments, and applications of this method are discussed.     

A mixture-model approach to linking ADHD to adolescent onset of illicit drug use.

Prior research findings have been mixed as to whether attention-deficit/hyperactivity disorder (ADHD) is related to illicit drug use independent of conduct problems (CP). With the current study, the authors add to this literature by investigating the association between trajectories of ADHD symptoms across childhood and adolescence and onset of illicit drug use, with and without controlling for CP. In a longitudinal panel study of a community sample of 754 girls and boys recruited in kindergarten, this research question was examined with a combination of growth mixture modeling (to model parent-reported ADHD symptom trajectories) and survival analysis (to model youth-reported initiation of illicit drug use). Results revealed a 3-class model of ADHD trajectories, with 1 class exhibiting no or minimal symptoms throughout childhood and adolescence, another class showing a convex shape (an increase, then a decrease in symptoms) across time, and a third class showing a concave shape (a decrease, then a slight increase in symptoms) over time. The concave-trajectory class demonstrated significantly earlier onset of illicit drug use than the minimal-problem class, with the convex-trajectory class falling between (but not significantly different from either of the other two classes). These results did not change when the authors added CP to the model as a covariate. Implications of findings for theory and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aggregation With Fragment Retransmission for Very High-Speed WLANs

In upcoming very high-speed wireless LANs (WLANs), the physical (PHY) layer rate may reach 600 Mbps. To achieve high efficiency at the medium access control (MAC) layer, we identify fundamental properties that must be satisfied by any CSMA-/CA-based MAC layers and develop a novel scheme called aggregation with fragment retransmission (AFR) that exhibits these properties. In the AFR scheme, multiple packets are aggregated into and transmitted in a single large frame. If errors happen during the transmission, only the corrupted fragments of the large frame are retransmitted. An analytic model is developed to evaluate the throughput and delay performance of AFR over noisy channels and to compare AFR with similar schemes in the literature. Optimal frame and fragment sizes are calculated using this model. Transmission delays are minimized by using a zero-waiting mechanism where frames are transmitted immediately once the MAC wins a transmission opportunity. We prove that zero-waiting can achieve maximum throughput. As a complement to the theoretical analysis, we investigate the impact of AFR on the performance of realistic application traffic with diverse requirements by simulations. We have implemented the AFR scheme in the NS-2 simulator and present detailed results for TCP, VoIP, and HDTV traffic. The AFR scheme described was developed as part of the IEEE 802.11n working group work. The analysis presented here is general enough to be extended to proposed schemes in the upcoming 802.11n standard. Trends indicated in this paper should extend to any well-designed aggregation schemes.     

Fiscal versus social responsibility: how Philip Morris shaped the public funds divestment debate

Calls for institutional investors to divest (sell off) tobacco stocks threaten the industry's share values, publicise its bad behaviour, and label it as a politically unacceptable ally. US tobacco control advocates began urging government investment and pension funds to divest as a matter of responsible social policy in 1990. Following the initiation of Medicaid recovery lawsuits in 1994, advocates highlighted the contradictions between state justice departments suing the industry, and state health departments expanding tobacco control programmes, while state treasurers invested in tobacco companies. Philip Morris (PM), the most exposed US company, led the divestment opposition, consistently framing the issue as one of responsible fiscal policy. It insisted that funds had to be managed for the exclusive interest of beneficiaries, not the public at large, and for high share returns above all. This paper uses tobacco industry documents to show how PM sought to frame both the rhetorical contents and the legal contexts of the divestment debate. While tobacco stock divestment was eventually limited to only seven (but highly visible) states, US advocates focused public attention on the issue in at least 18 others plus various local jurisdictions. This added to ongoing, effective campaigns to denormalise and delegitimise the tobacco industry, dividing it from key allies. Divestment as a delegitimisation tool could have both advantages and disadvantages as a tobacco control strategy in other countries.