Unexpectedly high prevalence of posttransplant anemia in pediatric and young adult renal transplant recipients

BACKGROUND

Although posttransplant anemia (PTA) is recognized as a common problem in adult renal transplant recipients, few pediatric studies have been published.

METHODS

In this retrospective cohort study of 162 pediatric renal transplant recipients treated at Stanford University, the authors sought to determine the prevalence, severity, and the predictive factors of PTA. Anemia was defined as a hematocrit (HCT) level greater than 2 SD below published means for age or as erythropoietin dependency to maintain a normal HCT.

RESULTS

Sixty-seven percent of pediatric renal transplant recipients were anemic at the time of transplantation. The prevalence of anemia increased to 84.3% in the first month posttransplant. From 6 months to 60 months posttransplant, the prevalence of anemia remained high at 64.2% to 82.2%. Only 4 patients (2.5%) were never anemic. Iron depletion was detected in 19 of 26 and 23 of 23 anemic patients 12 and 60 months posttransplant, respectively. Serum erythropoietin levels were low relative to hematocrit levels in 38 of 56 anemic patients. Logistic regression at 3 months posttransplant showed that discharge hematocrit level (P < 0.0001), calcium (P = 0.0004), and cyclosporine dose (P = 0.0002) correlated with anemia. Creatinine clearance (P = 0.002) and white blood cell count (P = 0.004) correlated with anemia at 12 months posttransplant, but only creatinine clearance (P = 0.011) correlated with anemia 60 months posttransplant.

CONCLUSION

Nearly all pediatric renal transplant recipients experience PTA. However, few children less than 2 years of age were anemic during the first year posttransplant. Antirejection therapy, bone disease, iron depletion, and creatinine clearance appear to play pivotal roles in the development of PTA in children.

Assessment of low-flow CSF drainage as a treatment for AD: results of a randomized pilot study

OBJECTIVE

This prospective, randomized, controlled study was designed to investigate the safety, feasibility, and preliminary efficacy of long-term CSF drainage via a low-flow ventriculoperitoneal shunt in subjects suffering from AD.

METHODS

Twenty-nine subjects selected for probable AD (National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer's Disease and Related Dementias Association criteria) were screened to exclude normal pressure hydrocephalus or other etiologies of dementia and randomized to treatment (shunt) or no treatment groups. The study endpoint was the comparison of group performance on psychometric testing at quarterly intervals for 1 year. Shunted subjects had CSF withdrawn for MAP-tau and Abeta((1-42)) assays at the same time intervals.

RESULTS

There was no mortality from the surgical procedure, and no patient sustained a subdural hematoma. Five notable postoperative adverse events, which resolved without permanent neurologic deficit, were reported in the shunt group. Group mean Mattis Dementia Rating Scale total scores showed little change over the year in the shunt-treatment group, in contrast to a decline in the control group (p = 0.06). Mini-Mental State Examination mean scores supported a trend in favor of shunt treatment (p = 0.1). There was a concomitant decrease in ventricular CSF concentrations of AD biomarkers MAP-tau and Abeta((1-42)).

CONCLUSIONS

The surgical procedure and the device are reasonably safe. Adverse events were consistent with shunt procedures for hydrocephalus in this older population. The endpoint data show a trend in favor of the treated group. A larger, randomized, double-blinded, controlled, clinical trial is underway.

Lifestyle habits and compression of morbidity

BACKGROUND

There has been much debate regarding the degree to which healthy lifestyles can increase longevity and whether added years will be offset by increased morbidity at older ages. This study was designed to test the compression of morbidity hypothesis, proposing that healthy lifestyles can reduce and compress disability into a shorter period toward the end of life.

METHODS

Functional status in 418 deceased members of an aging cohort was observed between 1986 and 1998 in relationship to lifestyle-related risk factors, including cigarette smoking, physical inactivity, and under- or overweight. Three risk groups were created based on the number of these factors at study entry. Disability scores prior to death were modeled for each risk group to compare levels and rates of change, as well as to determine if and when acceleration in functional decline occurred.

RESULTS

The risk-factor-free group showed average disability scores near zero 10-12 years before death, rising slowly over time, without evidence of accelerated functional decline. In contrast, those with two or more factors maintained a greater level of disability throughout follow-up and experienced an increase in the rate of decline 1.5 years prior to death. For those at moderate risk, the rate of decline increased significantly only in the last 3 months of life. Other differences between groups provided no alternative explanations for the findings.

CONCLUSIONS

These results make a compelling argument for the reduction and postponement of disability with healthier lifestyles as proposed by the compression of morbidity hypothesis.

Long-term followup of patients treated with total lymphoid irradiation for lupus nephritis

OBJECTIVE

To describe the long-term survival, renal condition, and morbidity outcomes in patients who received total lymphoid irradiation (TLI) for the treatment of lupus nephritis.

METHODS

Twenty-one patients with biopsy-proven, diffuse membranoproliferative glomerulonephritis and significant proteinuria of >2.5 grams/day received TLI from 1980 to 1987 at Stanford University Medical Center. All patients had previously failed to respond to treatment with high-dose corticosteroids or therapy with corticosteroids plus immunosuppressive agents (azathioprine, cyclophosphamide, or chlorambucil).

RESULTS

The mean duration of followup since TLI was 10.7 years. Fifteen of 21 patients (71%) remained alive at the time of this assessment. Nine of the 21 patients (43%) survived without developing end-stage renal disease (ESRD). The probability of long-term survival without ESRD and without need for additional immunosuppressive agents after TLI was 19% (4 of 21). Factors predicting renal failure at the time of TLI included elevated creatinine levels, increased interstitial fibrosis on renal biopsy, and increased fractional excretion of immunoglobulin and albumin. Malignancies were found in 4 patients, and opportunistic infections occurred in 7 patients.

CONCLUSION

Overall, patients with lupus nephritis treated with TLI do not appear to have better 10-year survival with lower incidence of ESRD compared with patients in published series treated with conventional immunosuppressive therapies. However, in this series of patients, treatment with conventional immunosuppressive therapies had been unsuccessful and given the limited number of adverse events and the efficacy seen in some patients, TLI appears to be a reasonable therapeutic option for the treatment of severe lupus nephritis among patients who fail to respond under standard cytotoxic regimens.

Fetal ear length measurement: a useful predictor of aneuploidy?

OBJECTIVE

To determine the usefulness of short ear length (EL) measurement in the prenatal detection of fetuses with chromosomal abnormalities.

DESIGN

Fetal EL measurements, routine biometry and complete anatomic survey for fetal abnormalities were prospectively performed by antenatal sonography.

SUBJECTS

One thousand eight hundred and forty-eight patients with singleton pregnancies undergoing genetic amniocentesis in the second or third trimester.

METHODS

Complete data for EL, biometry and anatomic survey for major structural abnormalities and minor sonographic markers of chromosomal abnormality were available in 1311 fetuses. Of these, 48 (3.7%) had an abnormal karyotype and 1263 (96.3%) had a normal karyotype. Using an EL measurement of < or = 10th percentile for corresponding gestational age in normal fetuses as abnormal cut-off values, detection rates for chromosomal abnormalities by short EL were determined.

RESULTS

Among the 48 abnormal karyotypes, 34 were considered significant, and 11 of these 34 (32.4%) fetuses had short EL. In 14 cases, the karyotypic abnormality was considered non-significant and fetal EL was normal in all cases. Of the 34 fetuses with significant chromosomal abnormalities, six (17.6%) on antenatal sonography had no detectable abnormal findings, other than short EL. An increased biparietal diameter (BPD)/EL ratio of > or = 4.0 was also noted in fetuses with an abnormal karyotype, but the sensitivity and predictive value of increased BPD/EL ratio alone or increased BPD/EL ratio in combination with short EL was no better than the sensitivity and predictive value of short EL alone. A combination of short EL and abnormal ultrasound, however, gave a much higher positive predictive value (46%) for significant chromosomal abnormalities.

CONCLUSIONS

Our findings suggest that in women at high risk for fetal chromosomal abnormality, a short fetal EL measurement on prenatal ultrasound, either alone or in combination with other sonographically detectable structural abnormalities, may be a useful parameter in predicting fetal aneuploidy.

Postural balance in children with cerebral palsy

Postural control deficits have been suggested to be a major component of gait disorders in cerebral palsy (CP). Standing balance was investigated in 23 ambulatory children and adolescents with spastic diplegic CP, ages 5 to 18 years, and compared with values of 92 children without disability, ages 5 to 18 years, while they stood on a force plate with eyes open or eyes closed. The measurements included center of pressure calculations of path length per second, average radial displacement, mean frequency of sway, and Brownian random motion measures of the short-term diffusion coefficient, and the long-term scaling exponent. In the majority of children with CP (14 of 23) all standing balance values were normal. However, approximately one-third of the children with CP (eight of 23) had abnormal values in at least two of the six center of pressure measures. Thus, mean values for path length, average radial displacement, and diffusion coefficient were higher for participants with CP compared with control individuals with eyes open and closed (p<0.05). Mean values for frequency of sway and the long-term scaling exponent were lower for participants with CP compared with control participants (p<0.05). Increased average radial displacement was the most common (nine of 23) postural control deficit. There was no increase in abnormal values with eyes closed compared with eyes open for participants with CP, indicating that most participants with CP had normal dependence on visual feedback to maintain balance. Identification of those children with impaired standing balance can delineate factors that contribute to the patient's gait disorder and help to guide treatment.

One-sided tests in clinical trials with multiple endpoints

Treatment comparisons in clinical trials often involve several endpoints. For example, one might wish to demonstrate that a new treatment is superior to the current standard for some components of the multivariate response vector and is not inferior, modulo biologically unimportant difference to the standard treatment for all other components. We introduce a new approach to multiple-endpoint testing that incorporates the essential univariate and multivariate features of the treatment effects. This approach is compared with existing methods in a simulation study and applied to data on rheumatoid arthritis patients receiving one of two treatments.

Electrogenic proton transfer in Rhodobacter sphaeroides reaction centers: effect of coenzyme Q(10) substitution by decylubiquinone in the Q(B) binding site

An electrometric technique was used to investigate the effect of coenzyme Q(10) (UQ), substitution by decylubiquinone (dQ) at the Q(B) binding site of reaction centers (UQ-RC and dQ-RC, respectively) on the electrogenic proton transfer kinetics upon Q(B) reduction in Rhodobacter sphaeroides chromatophores. Unlike dQ-RC, the kinetics of the second flash-induced proton uptake in UQ-RC clearly deviated from the mono-exponential one. The activation energy (about 30 kJ/mol) and the pH profile of the kinetics in dQ-RC were similar to those in UQ-RC, with the power law approximation used in the latter case. The interpretation of the data presumed the quinone translocation between the two binding positions within the Q(B) site. It is proposed that the native isoprenyl side chain (in contrast to decyl chain) favors the equilibrium binding of neutral quinone at the redox-active 'proximal' position, but causes a higher barrier for the hydroquinone movement from 'proximal' to 'distal' position.

A meta-analysis comparing buprenorphine to methadone for treatment of opiate dependence

BACKGROUND

The unique pharmacological properties of buprenorphine may make it a useful maintenance therapy for opiate addiction. This meta-analysis considers the effectiveness of buprenorphine relative to methadone.

METHODS

A systematic literature search identified five randomized clinical trials comparing buprenorphine to methadone. Data from these trials were obtained. Retention in treatment was analyzed with a Cox proportional hazards regression. Urinalyses for opiates were studied with analysis of variance and a common method of handling missing values. A meta-analysis was used to combine these results.

RESULTS

Subjects who received 8-12 mg/day buprenorphine had 1.26 times the relative risk of discontinuing treatment (95% confidence interval 1.01-1.57) and 8.3% more positive urinalyses (95% confidence interval 2.7-14%) than subjects receiving 50-80 mg/day methadone. Buprenophrine was more effective than 20-35 mg/day methadone. There was substantial variation in outcomes in the different trials.

CONCLUSIONS

The variation between trials may be due to differences in dose levels, patient exclusion criteria and provision of psychosocial treatment. The difference in the effectiveness of buprenorphine and methadone may be statistically significant, but the differences are small compared to the wide variance in outcomes achieved in different methadone treatment programs. Further research is needed to determine if buprenorphine treatment is more effective than methadone in particular settings or in particular subgroups of patients.

Spirometer-triggered high-resolution computed tomography and pulmonary function measurements during an acute exacerbation in patients with cystic fibrosis

OBJECTIVE

To evaluate a high-resolution computed tomography (HRCT) scoring system, clinical parameters, and pulmonary function measurements in patients with cystic fibrosis (CF) before and after therapy for a pulmonary exacerbation.

STUDY DESIGN

Patients (n = 17) were evaluated by spirometer-triggered HRCT imaging, clinical parameters, and pulmonary function tests (PFTs) before and after treatment. HRCT scans were reviewed by 3 radiologists using a modified Bhalla scoring system.

RESULTS

Bronchiectasis, bronchial wall thickening, and air trapping were identified in all subjects on initial evaluation. The initial total HRCT score correlated significantly with the Brasfield score (r = -.91, P <.001) and several PFT measures. After treatment, there were improvements in the acute change clinical score (ACCS) (P <.001), most pulmonary function measurements, and total HRCT score (P <.05). Bronchiectasis, bronchial wall thickening, and air trapping did not significantly change. Mucus plugging subcomponent HRCT score, slow vital capacity (SVC), forced expiratory volume in 1 second (FEV(1)), and forced vital capacity (FVC) (percent predicted) and reversible and total HRCT scores were most sensitive to change by effect size analysis.

CONCLUSIONS

Improvements occurred with treatment in total and reversible HRCT scores, PFTs, and ACCS. Total and reversible HRCT scores and percent predicted SVC, FEV1, and FVC were the most sensitive to change. The greatest change was seen in the mucus plugging subcomponent HRCT score.

Pumping capacity of bacterial reaction centers and backpressure regulation of energy transduction

Transduction of free-energy by Rhodobacter sphaeroides reaction-center-light-harvesting-complex-1 (RCLH1) was quantified. RCLH1 complexes were reconstituted into liposomal membranes. The capacity of the RCLH1 complex to build up a proton motive force was examined at a range of incident light intensities, and induced proton permeabilities, in the presence of artificial electron donors and acceptors. Experiments were also performed with RCLH1 complexes in which the midpoint potential of the reaction center primary donor was modified over an 85-mV range by replacement of the tyrosine residue at the M210 position of the reaction center protein by histidine, phenylalanine, leucine or tryptophan. The intrinsic driving force with which the reaction center pumped protons tended to decrease as the midpoint potential of the primary donor was increased. This observation is discussed in terms of the control of the energetics of the first steps in light-driven electron transfer on the thermodynamic efficiency of the bacterial photosynthetic process. The light intensity at which half of the maximal proton motive force was generated, increased with increasing proton permeability of the membrane. This presents the first direct evidence for so-called backpressure control exerted by the proton motive force on steady-state cyclic electron transfer through and coupled proton pumping by the bacterial reaction center.

The AneuRx stent graft: four-year results and worldwide experience 2000

OBJECTIVE

The objective was to review the current results of endovascular abdominal aortic aneurysm repair with the AneuRx stent graft and to determine the effectiveness of the device in achieving the primary objective of preventing aneurysm rupture.

METHODS

The outcome of all patients treated during the past 4 years in the U.S. AneuRx clinical trial was determined, and the worldwide clinical experience was reviewed.

RESULTS

A total of 1192 patients were treated with the AneuRx stent graft during all phases of the U.S. Clinical Trial from June 1996 to November 1999, with follow-up extending to June 2000. Ten (0.8%) patients have had aneurysm rupture, with most ruptures (n = 6) occurring in 174 (3.4%) patients treated with an early stiff bifurcation stent graft design used in phase I and in the initial stages of phase II. Since the current, flexible, segmented bifurcation stent graft design was introduced, four (0.4%) ruptures have occurred among 1018 patients treated. Of these, one was during implantation, two were placed too far below the renal arteries, and one patient refused treatment of a type I endoleak. Kaplan-Meier analysis of all 1192 patients treated with the AneuRx stent graft including both stent graft designs revealed the patient survival rate to be 93% at 1 year, 88% at 2 years, and 86% at 3 years, freedom from conversion to open repair to be 98% at 1 year, 97% at 2 years, and 93% at 3 years, and freedom from secondary procedure to be 94% at 1 year, 92% at 2 years, and 88% at 3 years. Freedom from aneurysm rupture with the commercially available segmented bifurcation stent graft was 99.7% at 1 year, 99.5% at 2 years, and 99.5% at 3 years. The presence or absence of endoleak on contrast computed tomography scanning after stent graft placement was not found to be a significant predictor of long-term outcome measures. Worldwide experience with the AneuRx device now approaches 10,000 patients.

CONCLUSIONS

Endovascular management of abdominal aortic aneurysms with the AneuRx stent graft has markedly reduced the risk of aneurysm rupture while eliminating the need for open aneurysm surgery in 98% of patients at 1 year and 93% of patients at 3 years. The device was effective in preventing aneurysm rupture in 99.5% of patients over a 3-year period. The overall patient survival rate was 93% at 1 year and 86% at 3 years.

Response criteria for clinical trials on osteoarthritis of the knee and hip: a report of the Osteoarthritis Research Society International Standing Committee for Clinical Trials response criteria initiative

BACKGROUND

The domains of pain, function and patient's global assessment are identified as core variables and frequently measured in clinical trials of patients with osteoarthritis (OA) of the hip and knee.

OBJECTIVE

To develop response criteria for OA of hip and knee based on the domains of pain, function and patient's global assessment.

METHODS

A methodology was developed by an interaction of the Osteoarthritis Research Society International Standing Committee on Clinical Trials, biostatisticians, pharmaceutical company representatives and health agency representatives. Data from previously conducted placebo-controlled clinical trials were normalized and collated. Data were subset by location of OA (knee, hip), active agent used in the clinical trial (non-steroidal anti-inflammatory drug, other agent) and route of administration (oral, intra-articular). Statistical analysis identified response criteria which best discriminate active agent from placebo.

RESULTS

Based on the analysis of data from 14 studies (totaling 1886 patients) and consensus opinion, the optimal responder criteria set differed for location of OA, active agent to be used, and route of administration. Because of nearly identical statistical results, two sets of responder criteria are proposed: (1) 'high' pain response or, alternatively, a 'moderate' response for at least two of three domains: pain, function and patient's global assessment; (2) 'high' response for either pain or function or, alternatively, a 'moderate' response for at least two of three domains: pain, function and patient's global assessment. The sensitivity (i.e., the percentage of responders in the active group) ranged from 52 to 96% and the specificity (i.e., the percentage of nonresponders in the control group) from 47 to 73%.

CONCLUSION

Based on data from clinical trials, two sets of responder criteria have been developed that can categorize an individual's responses to treatment in a clinical trial. These responder criteria require validation in additional datasets.

Reliability of proxy-reported and self-reported household appliance use

Exposure assessment presents a major challenge for studies evaluating the association between household exposure to electric and magnetic fields and adverse health outcomes, especially the reliance on proxy respondents when study subjects themselves have died. We evaluated the reliability of proxy- and self-reported household appliance exposure. We recruited 92 healthy couples through either random-digit dialing or newspaper advertisements. Trained interviewers administered questionnaires to each member of a couple independently to assess the reliability of proxy-reported household appliance use. Eighty-five couples completed a second interview 2 months later to assess the reliability of self-reported appliance use. Reliability of proxy-reported appliance exposure was good when we inquired about having any exposure to each of the eight indicator appliances during the past year (range of kappa coefficients = 0.63-0.85; median = 0.76) but was lower with increased time to recall or increased detail. Reliability of self respondents reporting 2 months apart was excellent (range of kappa coefficients = 0.75-0.94; median = 0.87) for having any exposure to the eight indicator appliances during the past year, but reliability was again lower with increased detail. When we used self reports at the first interview as the standard, little systematic over- or underreporting occurred for proxy respondents or for self respondents reporting 2 months later. Because this study did not include cases of specific disease, these findings of no systematic differences in reporting do not refer to case or control status. In summary, reliability of self respondents' reports of appliance use is very good for recent time periods and good for broad aspects of exposure in distant time periods. Proxy respondents can provide information regarding broad aspects of appliance exposure in the past year, but detailed aspects of exposure or exposure in more distant time periods is not reliable.

Reduction and protonation of the secondary quinone acceptor of Rhodobacter sphaeroides photosynthetic reaction center: kinetic model based on a comparison of wild-type chromatophores with mutants carrying Arg-->Ile substitution at sites 207 and 217 in the L-subunit

After the light-induced charge separation in the photosynthetic reaction center (RC) of Rhodobacter sphaeroides, the electron reaches, via the tightly bound ubiquinone QA, the loosely bound ubiquinone Q(B) After two subsequent flashes of light, Q(B) is reduced to ubiquinol Q(B)H2, with a semiquinone anion Q-(B) formed as an intermediate after the first flash. We studied Q(B)H2 formation in chromatophores from Rb. sphaeroides mutants that carried Arg-->Ile substitution at sites 207 and 217 in the L-subunit. While Arg-L207 is 17 A away from Q(B), Arg-L217 is closer (9 A) and contacts the Q(B)-binding pocket. From the pH dependence of the charge recombination in the RC after the first flash, we estimated deltaG(AB), the free energy difference between the Q-(A)Q(B) and Q(A)Q-(B) states, and pK212, the apparent pK of Glu-L212, a residue that is only 4 A away from Q(B). As expected, the replacement of positively charged arginines by neutral isoleucines destabilized the Q-(B) state in the L217RI mutant to a larger extent than in the L207RI one. Also as expected, pK212 increased by approximately 0.4 pH units in the L207RI mutant. The value of pK212 in the L217RI mutant decreased by 0.3 pH units, contrary to expectations. The rate of the Q-(A)Q-(B)-->Q(A)Q(B)H2 transition upon the second flash, as monitored by electrometry via the accompanying changes in the membrane potential, was two times faster in the L207RI mutant than in the wild-type, but remained essentially unchanged in the L217RI mutant. To rationalize these findings, we developed and analyzed a kinetic model of the Q-(A)Q-(B)-->Q(A)Q(B)H2 transition. The model properly described the available experimental data and provided a set of quantitative kinetic and thermodynamic parameters of the Q(B) turnover. The non-electrostatic, 'chemical' affinity of the QB site to protons proved to be as important for the attracting protons from the bulk, as the appropriate electrostatic potential. The mutation-caused changes in the chemical proton affinity could be estimated from the difference between the experimentally established pK2J2 shifts and the expected changes in the electrostatic potential at Glu-L212, calculable from the X-ray structure of the RC. Based on functional studies, structural data and kinetic modeling, we suggest a mechanistic scheme of the QB turnover. The detachment of the formed ubiquinol from its proximal position next to Glu-L212 is considered as the rate-limiting step of the reaction cycle.

Ultrasonographic ear length measurement in normal second- and third-trimester fetuses

OBJECTIVE

We sought to develop a nomogram for fetal ear length measurements from a large population of healthy second- and third-trimester fetuses and to investigate the correlation of fetal ear length with other standard fetal biometry measurements, as follows: biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length.

STUDY DESIGN

Ear length measurement was obtained prospectively in 4240 singleton fetuses between 15 and 40 weeks' gestational age. Either complete data for normal karyotype on amniocentesis or normal infant examination at birth or both were available in 2583 cases. These constituted the final study population.

RESULTS

A nomogram was developed by linearly regressing ear length on gestational age (Ear length [in millimeters] = 1.076 x Gestational age [in weeks] - 7. 308). There was a high correlation between ear length and gestational age (r = 0.96; P =.0001).

CONCLUSION

The results of this study provide normative data on growth of fetal ear length from 15 to 40 weeks' gestation. Good correlation was also observed between ear length and other fetal biometric measurements (biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length).

Functional indices for sciatic, peroneal, and posterior tibial nerve lesions in the mouse

The sciatic functional index previously described in rats has proven to be a reliable index of functional recovery following sciatic nerve injury and repair. A similar functional assay of sciatic, peroneal, and posterior tibial nerve lesions was developed in a mouse model. Forty-eight C57/BL6 mice were randomly divided into 4 groups: sham surgery, sciatic nerve transection, peroneal nerve transection, and posterior tibial nerve transection. Preoperative and postoperative (48 hours) walking tracks were obtained. The pawprints were analyzed in a blinded fashion for measurements of print length (PL), toe spread (TS), intermediate toe spread (IT), and the orthogonal distance from the toe of one paw to the hind pad of the opposite paw (TOF). Multiple linear regression analysis was performed using these measurements to determine their significance and appropriate weighted contribution to the index formula for each nerve lesion. For the sciatic functional index, changes in the PL (P = 0.0092) and TS (P = 0.0008) were significant, resulting in an R2 value of 0.88. For the peroneal functional index, only TS (P < 0.0001) was significant with R2 = 0.83. For the posterior tibial index, only PL (P < 0.0001) was significant with R2 = 0.89. Formulas for a sciatic, peroneal, and posterior tibial functional index were created based on the coefficients derived from the multiple linear regression analysis. The indices that were developed will allow investigators to assess functional recovery following specific nerve lesions in mice.

Prevalence of pelvic Paget's disease of bone in the United States

The objective of this article was to estimate the prevalence of Paget's disease of bone in the United States from a statistically derived sample of the general population. Pelvic radiographs obtained in the First National Health and Nutrition Examination Survey (NHANES-I) were reviewed for the presence of Paget's disease. Age, sex, and geographic distribution of Paget's disease of the pelvic region were determined. The overall prevalence of Paget's disease in the United States was estimated. Pelvic Paget's disease is estimated to be present in 0.71 + 0.18% of the radiographs of the general population. The disease was higher in frequency in people who were in the older decades of life with the highest prevalence of 2.32 + 0.54% in the 65- to 74-year-old people. There is a slight male predominance in the 45- to 74-year age group. The regional distribution suggests the highest prevalence in the Northeast (1.48 + 0.52%) with the lowest prevalence in the South (0.26+0.25%). The prevalence was equal in white people and black people. An estimate of the overall prevalence of Paget's disease in the United States was at least 1% and perhaps as much as 2 % of the general population with near equal sex distribution and the highest prevalence in the northeastern United States.

Falls in older Mexican-American women

OBJECTIVE

To determine the frequency of falls and identify risk factors for falls among older Mexican-American women.

DESIGN

A prospective cohort study with an average follow-up of 2.7 years.

SETTING

A clinical center at the Palo Alto Veterans Affairs Medical Center, California.

PARTICIPANTS

152 community-dwelling Mexican-American Caucasian women aged 59 years or older.

OUTCOME MEASURES

Falls and injurious falls, as determined by monthly telephone interviews.

RESULTS

The rate of falls was 508 per 1000 person-years (95% confidence interval (CI), 440-577). Injurious falls requiring medical attention occurred at a rate of 79 per 1000 person-years (95% CI, 52-107). Factors that were associated independently with an increased risk of falling were older age, a history of arthritis or rheumatism, a history of high thyroid, having fainted at least once in the year before baseline, current use of psychotropic medications, and walking fewer than 5 blocks a day. Those persons with an average time for the chair stand test had a lower risk of falling than those with the slowest times or the fastest times.

CONCLUSIONS

The frequency of falls and injurious falls in this cohort of 152 relatively acculturated, healthy, older Mexican-American women was similar or slightly higher than previously reported rates for non-Hispanic Caucasian(s). Many of the factors associated with falls in this study were similar to those reported for non-Hispanic Caucasian women, suggesting that fall prevention measures tested mainly among non-Hispanic Caucasian women would also be appropriate for Mexican-American women.

DNA damage measured by the comet assay in head and neck cancer patients treated with tirapazamine

Tirapazamine (TPZ) [3-amino-1,2,4-benzotriazine 1,4-dioxide, SR4233, WIN 59075, and Tirazone] is a novel anticancer drug that is selectively activated by the low oxygen environment in solid tumors. By killing the radioresistant hypoxic cells, TPZ potentiates the antitumor efficacy of fractionated irradiation of transplanted tumors in mice. As this cell kill is closely correlated with TPZ-induced DNA damage, we investigated whether human head and neck cancers would show DNA damage similar to that seen in mouse tumors following TPZ administration. TPZ-induced DNA damage in both transplanted tumors in mice and in neck nodes of 13 patients with head and neck cancer was assessed using the alkaline comet assay on cells obtained from fine-needle aspirates. The oxygen levels of the patients' tumors were also measured using a polarographic oxygen electrode. Cells from the patients' tumors showed DNA damage immediately following TPZ administration that was comparable to, or greater than, that seen with transplanted mouse tumors. The heterogeneity of DNA damage in the patients' tumors was greater than that of individual mouse tumors and correlated with tumor hypoxia. The similarity of TPZ-induced DNA damage in human and rodent tumors suggests that tirapazamine should be effective when added to radiotherapy or to cisplatin-based chemotherapy in head and neck cancers.

Children's symptoms in the wake of Challenger: a field study of distant-traumatic effects and an outline of related conditions

OBJECTIVE

The Challenger space shuttle explosion in January 1986 offered an opportunity to determine what, if any, symptoms of posttraumatic stress disorder (PTSD) and bereavement normal latency-age children and adolescents would develop after a distant, horrifying event.

METHOD

With a structured interview, the authors assessed the symptoms of 153 randomly selected children from Concord, N.H., and Porterville, Calif. Responses were statistically compared between East Coast children, who saw the event on television and who generally cared more about the teacher aboard Challenger, and West Coast children, who heard about it first; between latency-age children and adolescents; and between children seen 5-7 weeks later and those same children seen 14 months later.

RESULTS

More than 60% of the subjects feared at least one stimulus related to Challenger within the first 5-7 weeks of the explosion. The East Coast and latency-age groups appeared significantly more symptomatic than did the West Coast and adolescent groups. Over the 14-month study period, most symptoms dramatically faded. However, adolescents' diminished expectations for the future in general increased, and latency-age children's changed approach to space careers held relatively steady. Three East Coast latency-age children met the DSM-III-R symptom requirements for PTSD in 1986; no children met these in 1987.

CONCLUSIONS

Children's symptomatic patterns after Challenger relate to the patterns for PTSD listed in diagnostic manuals and to three symptoms not in the DSM-IV list. To the authors, distant traumas appear to be one of a newly defined spectrum of trauma-related conditions that include relatively evanescent symptoms and a few longer-lasting ones. These symptoms may affect large numbers of normal children.

Capturing the patient's view of change as a clinical outcome measure

CONTEXT

Measurement of change in patients' health status is central to both clinical trials and clinical practice. Trials commonly use serial measurements by the patients at 2 points in time while clinicians use the patient's retrospective assessment of change made at 1 point in time. How well these measures correlate is not known.

OBJECTIVE

To compare the 2 methods in measurement of changes in pain and disability.

DESIGN

Longitudinal survey of patients starting new therapy for chronic arthritis in 1994 and 1995. Surveys were completed at baseline (before intervention) and at 6 weeks and 4 months.

SETTING

Community health education program and university medical and orthopedic services.

SUBJECTS

A total of 202 patients undertaking self-management education (n = 140), therapy with prednisone or methotrexate (n = 34), or arthroplasty of the knee or hip (n = 28).

MAIN OUTCOME MEASURES

Concordance between serial (visual analog scale for pain and Health Assessment Questionnaire for disability) and retrospective (7-point Likert scale) measures, sensitivities of these measures, and their correlation with patients' satisfaction with the change (7-point Likert scale).

RESULTS

When change was small (education group), serial measures correlated poorly with retrospective assessments (eg, r=0.13-0.21 at 6 weeks). With greater change, correlations improved (eg, r = 0.45-0.71 at 6 weeks). Average agreement between all pairs of assessments was 29%. Significant lack of concordance was confirmed in all 12 comparisons by McNemar tests (P = .02 to <.001) and by t tests (P = .03 to <.001). Retrospective measures were more sensitive to change than serial measures and correlated more strongly with patients' satisfaction with change.

CONCLUSION

The 2 methods for measuring health status change did not give concordant results. Including patient retrospective assessments in clinical trials might increase the comprehensiveness of information gained and its accord with clinical practice.

Plans, designs, and analyses for clinical trials of anti-cocaine medications: where we are today. NIDA/VA/SU Working Group on Design and Analysis

Increased interest in addiction psychopharmacology has raised unique methodologic issues in the design, conduct, and analysis of outcomes in clinical trials of therapeutic agents for drug dependence. This article summarizes issues raised at a meeting in Palo Alto, California, on November 4, 1996, that was sponsored by the Medication Development Division of the National Institute on Drug Abuse and the Department of Veterans Affairs Cooperative Studies Program to discuss the methodologic issues in clinical trials of cocaine pharmacotherapy.