We retrospectively analyzed the results of 75 living-related pediatric renal transplants performed at our center between January 1986 and December 1999. The major causes of end-stage renal disease (ESRD) were glomerulonephritis (26%) and nephrolithiasis (16%), while the etiology was unknown in 50%. The mean age of the recipients was 12 yr (range 6-17 yr) and that of the donors was 39 yr (range 20-65 yr). The majority (73%) of donors were parents. Eighty five per cent of donors were one-haplotype matched and the rest identical. Immunosuppression was based on a triple drug regimen. Thirty per cent of recipients were rapid metabolizers of cyclosporin A (CsA) (area under the curve [AUC]: < 6,000 ng/mL/h), while 16% were slow metabolizers (AUC: > 8,000 ng/mL/h). Forty three (57%) children encountered 59 rejection episodes, the majority of which (59%) were recorded in the first month post-transplant. Seventy-four per cent of the rejection episodes were steroid sensitive and the rest, except two, were resolved by therapy with antithymocyte globulin (ATG) or orthoclone thymocyte 3 (OKT3). After a mean follow-up of 37 months, 17 (22%) grafts had chronic rejection and 76% of these recipients had previously experienced acute rejection episodes. The overall infection rate was high, necessitating two hospital admissions/patient/year. The majority (53%) of the infections were bacterial. Urinary tract infections (UTIs) were seen in 17 (23%) recipients. Twelve of these had ESRD as a result of stone disease and eight grafts were lost because of UTIs. Eight per cent of recipients developed tuberculosis (TB), and extra-pulmonary lesions were seen in 50%. Surgical complications were encountered in eight patients. Free medication to all recipients and parental support ensured a compliance rate of 93%. Baseline growth deficit was seen in children of the two groups studied (the 6-12 yr and 13-17 yr age-groups), with Z-scores of - 2.39 and - 2.12, respectively. No growth catch-up was observed at 12 and 24 months in either group. Post-donation complications were seen most commonly in donors > 50 yr of age and included: proteinuria (> 300 mg/24 h, four patients), hypertension (three patients), and diabetes (one patient). Twenty-four grafts were lost, 54% as a result of immunological and the rest as a result of non-immunological causes, and 17 recipients died during the follow-up period. Infections were the main cause of patient and graft loss. Overall 1- and 5-yr graft and patient survival rates were 88% and 65%, and 90% and 75%, respectively.

This study presents a simplified two-phase flow model using the drift-flux approach to well orientation, geometry, and fluids. For estimating the static head, the model uses a single expression for liquid holdup, with flow-pattern-dependent values for flow parameter and rise velocity. The gradual change in the parameter values near transition boundaries avoids discontinuity in the estimated gradients, unlike most available methods. Frictional and kinetic heads are estimated using the simple homogeneous modeling approach. We present a comparative study involving the new model as well as those that are based on physical principles, also known as semimechanistic models. These models include those of Ansari et al, Gomez et al., and OLGA. Two other widely used empirical models, Hagedorn and Brown and PE- 2, are also included. The main ingredient of this study entails the use of a small but reliable dataset, wherein calibrated PVT properties minimizes uncertainty from this important source. Statistical analyses suggest that all the models behave in a similar fashion and that the models based on physical principles appear to offer no advantage over the empirical models. Uncertainty of performance appears to depend upon the quality of data input, rather than the model characteristics. Introduction Modeling two-phase flow in wellbores is routine in every-day applications. The use of two-phase flow modeling throughout the project life cycle with an integrated asset modeling network has rekindled interest in this area. Plethora of models, some based on physical principles and others based on pure empiricism, often beg the question which one to use in a given application. Although a few comparative studies (Ansari et al. 1994; Gomez et al. 2000; Kaya et al. 2001) attempt to answer this question, often reliability of the data base has left this issue unsettled. One of the main objectives of this paper is to present a simplified two-phase flow model, which is rooted in drift-flux approach. The drift-flux approach (Hasan and Kabir, 2002, pp. 21–62, Shi et al. 2005a, 2005b) has served the industry quite well, as exemplified by its simplicity, transparency, and accuracy in various applications. The second objective is to show a comparative study with a few models using a small but reliable data base to get a perspective on relative performance. Here, data reliability stems from two elements: rate and fluid PVT properties. Pressure data are typically gathered with permanent downhole and wellhead sensors while rate data are measured with surface flow meters or test separators. In each case, the black-oil fluid PVT model was conditioned with laboratory data to ensure reliability and consistency. Proposed Model Total pressure gradient during any type of fluid flow is the sum of the static, friction, and kinetic gradients, the expressions for which are given in Eq. A-1 in the Appendix. For most vertical and inclined wells, the static head component-which directly depends on the volume average-mixture density-dominates. Thus, in simple terms, two-phase flow modeling boils down to estimating density of the fluid mixture or gas-volume fraction. Because gas-volume fraction depends on whether the flow is bubbly, slug, churn, or annular, we individually model each flow regime. However, for all flow regimes the gas (or lighter) phase moves faster than the liquid (or heavier) because of its buoyancy and its tendency to flow close to the channel center. This allows us to express in-situ gas velocity as the sum of bubble rise velocity, v8, and channel center mixture velocity, Covm. However, in-situ velocity is the ratio of superficial velocity to volume fraction. Therefore, the generalized form of gas-volume fraction relationship with measured variables- superficial velocity of gas and liquid phases-can be written as Equation (1) For downflow, buoyancy acts in the direction opposite to flow. Thus, in Eq. 1, the negative sign in front of the rise velocity applies to downflow and the positive sign is meant for upflow. While Eq. 1 is universal in its application, the values of the flow parameter Co, and rise velocity v8, are dependent on the type of flow and flow pattern. Table 1 presents these values.

A series of 14 patients suffering from tuberculosis of the sternum with a mean follow-up of 2.8 years (2 to 3.6) is presented. All were treated with antitubercular therapy: ten with primary therapy, two needed second-line therapy, and two required surgery (debridement). All showed complete healing and no evidence of recurrence at the last follow-up. MRI was useful in making the diagnosis at an early stage because atypical presentations resulting from HIV have become more common. Early adequate treatment with multidrug antitubercular therapy avoided the need for surgery in 12 of our 14 patients.

The therapeutic alternatives available for use against ciprofloxacin-resistant enteric fever isolates in an endemic area are limited. The antibiotics currently available are the quinolones, thirdgeneration cephalosporins and conventional first-line drugs. In this study, the MICs of various newer drugs were determined for 31 ciprofloxacin-resistant enteric fever isolates (26 Salmonella enterica serovar Typhi and 5 S. enterica serovar Paratyphi A). MICs for ciprofloxacin, ofloxacin, gatifloxacin, levofloxacin, cefotaxime, cefixime, cefepime and azithromycin were determined using Etest strips and the agar dilution method. By Etest, all of the ciprofloxacin-resistant isolates had ciprofloxacin MICs ¢32 mg ml with the other quinolones (92-100 %) in S. Typhi. The rise in MIC levels of these antimicrobials is a matter for serious concern.

Summary The current method for estimating the static reservoir temperature from transient data gathered downhole after the cessation of mud circulation is a Horner-type approach. The reservoir temperature estimate so established generally turns out to be lower than the true temperature. This work shows that the temperature analog of the Horner method is limited to large circulation-time situations and is not applicable to cases where the mud circulation time is generally short (less than 30 hours). This study provides a general solution of the thermal diffusivity equation obtained with an appropriate inner-boundary condition to solve the early-time, transient heat-transfer problem. An analytical solution was developed to handle problems requiring a variable-rate heat transfer or the superposition effects. A simple graphical technique is used to interpret data with the superposition function. Three approximate solutions, reflecting different time domains, are also presented. These solutions are reliable as long as they are applied within the specified time bounds. Synthetic examples are used to validate the proposed method, and field examples from both oil and geothermal wells demonstrate application of the method. Introduction An accurate estimate of the formation temperature is required for a variety of applications. Some of these applications include design of cementing programs, evaluation of formation water resistivity for openhole log analysis, establishment of geothermal gradients for exploration mapping and cased-hole temperature logging, and estimation of heat content in geothermal reservoirs. These needs have prompted many researchers to estimate formation temperature during and after mud circulation. Mud circulated during drilling causes considerable cooling of the formation around the well. Hence, the temperature recorded after mud circulation has ceased is always lower than the static formation temperature. Depending on the contrast between the inlet mud and formation temperatures and thermal characteristics of the reservoir, several days may be required to attain complete thermal equilibrium. Such long waits are usually economically prohibitive for estimating formation temperature. Thus, practicality demands discerning undisturbed formation temperature from transient mud-temperature data after the cessation of mud circulation. In this process, the effects of thermal disturbances introduced earlier by the circulating mud need to be addressed.