The large vestibular aqueduct: A new definition based on audiologic and computed tomography correlation

Objective

The study goal was to determine the prevalence and clinical significance of a large vestibular aqueduct (LVA) in children with sensorineural hearing loss (SNHL).

Study Design and Setting

We conducted a retrospective review of a pediatric SNHL database. One hundred seven children with SNHL were selected and their radiographic and audiometric studies were evaluated. Radiographic comparisons were made to a group of children without SNHL.

Results

A vestibular aqueduct (VA) larger than the 95th percentile of controls was present in 32% of children with SNHL. Progressive SNHL was more likely to occur in ears with an LVA and the rate of progressive hearing loss was greater than in ears without an LVA. The risk of progressive SNHL increased with increasing VA size as determined by logistic regression analysis.

Conclusions

An LVA is defined as one that is ≥2mm at the operculum and/or ≥1 mm at the midpoint in children with nonsyndromic SNHL. An LVA appears to be more common than previously reported in children with SNHL. A linear relationship is observed between VA width and progressive SNHL.

Significance

The finding of an LVA in children with SNHL provides diagnostic as well as prognostic information. © 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Abstract P6-13-22: Pharmacodynamics and consequences of PI3K inhibition in ER+ breast tumors

PI3K inhibitors have shown promise for the treatment of anti-estrogen-resistant ER+ breast cancers. Current PI3K inhibitor treatment regimens may incompletely and transiently inhibit the pathway in carcinomas, and are accompanied by significant adverse effects in patients. We hypothesized that short-term, complete inhibition of PI3K will have a greater anti-tumor effect and reduce systemic toxicity compared to chronic, partial inhibition.

Pharmacokinetic analysis of the orally available pan-PI3K inhibitor GDC-0941 at low (100 mg/kg) and high (800 mg/kg) doses in mice revealed that plasma levels peaked after 15-30 min, and decreased below the limit of detection within 24 h (low dose) and 72 h (high dose), respectively. Administering 2 doses at 100 mg/kg 12 h apart provided continuous drug exposure. Drug pharmacokinetics in MCF-7 tumors was similar.

Mice bearing s.c. MCF-7 tumors were treated with the anti-estrogen fulvestrant (fulv; 5 mg/wk) three days before GDC-0941 treatment to assess pharmacodynamic effects. Phospho-AKT and -S6 levels (markers of PI3K and mTORC1 activities, respectively) were inversely correlated with tumor drug concentrations. Mice bearing MCF-7, fulv-resistant T47D/FR, or HCC-003 patient-derived xenografts were treated with vehicle, fulv, GDC-0941 (100 mg/kg QD 5 d/wk; 100 mg/kg BID 3 d on/4 d off; 800 mg/kg QW), or combinations. Tumor growth curves indicated that different schedules of PI3K inhibition with fulv similarly induced tumor regression. Molecular analysis of MCF-7 tumors showed that fulv plus GDC-0941 QW induced 30.14% apoptosis (assessed by TUNEL) at 48 h, which dropped to baseline (2.72%) at 72 h. Fulv plus GDC-0941 BID induced 18.27% apoptosis at 24 h, and maintained apoptosis rate near 10% until 96 h (when GDC-0941 washed out), which is a rate similar to that observed with fulv plus GDC-0941 QD. Fulv plus GDC-0941 QW decreased cell proliferation (assessed by geminin and Ki67 staining) from 34.89% (baseline) to 11.46%, which rebounded to 60.54% at the time of GDC-0941 washout (at 96 h). Fulv plus GDC-0941 QD or BID modestly decreased cell proliferation to 28.84% and 24.32%, respectively, after 24 h, which returned to baseline after 36 h and 72 h, respectively, then maintained the level for a week. Temporal analysis of PI3K signaling revealed that fulv plus GDC-0941 QW and BID maximally decreased phospho-AKT levels after 3 h, which returned to baseline within 48 h and 72 h, respectively. With fulv + GDC-0941 QD, phospho-AKT levels decreased after 3 h, but rebounded to baseline within 24 h. These results indicate that 2 approaches to PI3K inhibition provide similar anti-tumor efficacy: 1) complete/intermittent (QW) PI3K inhibition induces a burst of apoptosis with a rebound in cell proliferation after drug clearance; and 2) metronomic/repeated (QD) PI3K inhibition repeatedly induces a smaller amount of apoptosis without significantly affecting cell proliferation. These findings may inform clinical testing of PI3K inhibitors to maximize therapeutic index.

Citation Format: Yang W, Bean J, Hosford S, Lloye D, Liu S, Salphati L, Pang J, Zhang X, Nannini M, Miller TW. Pharmacodynamics and consequences of PI3K inhibition in ER+ breast tumors. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-13-22.

Oral risedronate sodium improves bone mineral density in non-ambulatory patients: a randomized, double-blind, placebo controlled trial

AIMS

Investigate the efficacy of risedronate sodium (Procter and Gamble, Cincinnati, USA) for treating reduced lumbar spine (LS) bone mineral density (BMD) in non-ambulatory patients.

METHODS

Nine (10-39 years, mean age 23.0 years, 7 males) in the risedronate arm and 10 (10-35 years, mean age 21.4 years, 8 males) in the placebo arm completed 24 months of therapy at baseline, 6, 12, 18, and 24 months. The primary outcome was change in LS BMD assessed by dual energy x-ray absorptiometry (DXA). Secondary outcomes included changes in serum bone markers, bone specific alkaline phosphatase, osteocalcin, and N-telopeptides. Mixed models examined group, time, and the group by time interaction for the 4 post-baseline time points.

RESULTS

The change in LS BMD score from baseline to 24 months was 0.069 (95% CI 0.014 to 0.124) in risedronate participants compared to -0.015 (95% CI -0.073 to 0.042) (t Value = -2.40, P > t=0.03) in the controls. When controlling for baseline scores, the difference was consistent across four post-baseline time points tested (F=5.67, Pr > F=0.03). No differences in serum bone markers were observed.

CONCLUSIONS

Risedronate increases LS BMD in non-ambulatory patients with minimal side effects.

Cognitive behavioral therapy for the treatment of juvenile fibromyalgia: a multisite, single-blind, randomized, controlled clinical trial

OBJECTIVE

Juvenile fibromyalgia syndrome (FMS) is a chronic musculoskeletal pain disorder in children and adolescents for which there are no evidence-based treatments. The objective of this multisite, single-blind, randomized clinical trial was to test whether cognitive-behavioral therapy (CBT) was superior to fibromyalgia (FM) education in reducing functional disability, pain, and symptoms of depression in juvenile FMS.

METHODS

Participants were 114 adolescents (ages 11-18 years) with juvenile FMS. After receiving stable medications for 8 weeks, patients were randomized to either CBT or FM education and received 8 weekly individual sessions with a therapist and 2 booster sessions. Assessments were conducted at baseline, immediately following the 8-week treatment phase, and at 6-month followup.

RESULTS

The majority of patients (87.7%) completed the trial per protocol. Intent-to-treat analyses showed that patients in both groups had significant reductions in functional disability, pain, and symptoms of depression at the end of the study, and CBT was significantly superior to FM education in reducing the primary outcome of functional disability (mean baseline to end-of-treatment difference between groups 5.39 [95% confidence interval 1.57, 9.22]). Reduction in symptoms of depression was clinically significant for both groups, with mean scores in the range of normal/nondepressed by the end of the study. Reduction in pain was not clinically significant for either group (<30% decrease in pain). There were no study-related adverse events.

CONCLUSION

In this controlled trial, CBT was found to be a safe and effective treatment for reducing functional disability and symptoms of depression in adolescents with juvenile FMS.

The effects of an intensive behavior and nutrition intervention compared to standard of care on weight outcomes in CF

Inadequate intake and suboptimal growth are common problems for patients with CF and a critical target for intervention. The purpose of this study was to compare the growth outcomes of children with CF who participated in a randomized clinical trial to improve energy intake and weight to children with CF receiving standard of care during the same time period. Our primary outcome was change in body mass index z-score (BMI z-score) over 2 years. An exploratory outcome was forced expiratory volume at 1-sec (FEV(1) ) over 2 years. Participants were children ages 4-12 with CF, who participated in a randomized clinical trial of behavior plus nutrition intervention versus nutrition education alone, and a matched Comparison Sample receiving standard of care drawn from the Cystic Fibrosis Foundation (CFF) Registry. Children in the Clinical Trial Group (N=67) participated in a 9-week, nutrition intervention and were followed at regular intervals (3, 6, 12, 18, and 24 months) for 2 years post-treatment to obtain anthropometric and pulmonary function data. For each child in the Comparison Sample (N=346), these measures were obtained from the CFF Registry at matching intervals for the 27-month period corresponding to the clinical trial. Over 27 months, children in the Clinical Trial Group (the combined sample of the behavior plus nutrition and the nutrition alone) demonstrated significantly less decline in BMI z-score, -0.05 (SD=0.68, CI= -0.23 to 0.13), as compared to children in the Comparison Sample, -0.21 (SD=0.67, CI= -0.31 to -0.11). No statistically significant differences were found for decline in FEV(1) between children in the Clinical Trial Group and the Comparison Sample. The key implication of these findings is that intensive behavioral and nutritional intervention is effective and needs to be adapted so that it can be broadly disseminated into clinical practice.

Review of Florida Red Tide and Human Health Effects

This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.

The impact of early nutrition on incidence of allergic manifestations and common respiratory illnesses in children

OBJECTIVE

To investigate the incidence of allergic and respiratory diseases through age 3 years in children fed docosahexaenoic acid (DHA)- and arachidonic acid (ARA)-supplemented formula during infancy.

STUDY DESIGN

Children who completed randomized, double-blind studies of DHA/ARA-supplemented (0.32%-0.36%/0.64%-0.72% of total fatty acids, respectively) versus nonsupplemented (control) formulas, fed during the first year of life, were eligible. Blinded study nurses reviewed medical charts for upper respiratory infection (URI), wheezing, asthma, bronchiolitis, bronchitis, allergic rhinitis, allergic conjunctivitis, otitis media, sinusitis, atopic dermatitis (AD), and urticaria.

RESULTS

From the 2 original cohorts, 89/179 children participated; 38/89 were fed DHA/ARA formula. The DHA/ARA group had significantly lower odds for developing URI (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.08-0.58), wheezing/asthma (OR, 0.32; 95% CI, 0.11-0.97), wheezing/asthma/AD (OR, 0.25; 95% CI, 0.09-0.67), or any allergy (OR, 0.28; 95% CI, 0.10-0.72). The control group had significantly shorter time to first diagnosis of URI (P = .006), wheezing/asthma (P = .03), or any allergy (P = .006).

CONCLUSIONS

DHA/ARA supplementation was associated with delayed onset and reduced incidence of URIs and common allergic diseases up to 3 years of age.

Baseline BMI is a strong predictor of nadir BMI after adolescent gastric bypass

OBJECTIVE

Surgical treatment of extreme obesity may be appropriate for some adolescents. We hypothesized that surgical weight loss outcomes may differ by preoperative level of extreme obesity (body mass index [BMI] > or=99th percentile).

STUDY DESIGN

A longitudinal assessment of clinical characteristics from 61 adolescents who underwent laparoscopic Roux-en-Y gastric bypass at a single pediatric center from 2002 until 2007 was performed. Patients were categorized into 1 of 3 preoperative BMI groups: group 1, BMI = 40.0 to 54.9 (n = 23); group 2, BMI = 55.0 to 64.9 (n = 21); group 3, BMI = 65.0 to 95.0 (n = 17). Changes in BMI and cardiovascular risk factors between baseline and year 1 were evaluated using repeated-measures mixed linear modeling.

RESULTS

BMI in the overall cohort at baseline (60.2 +/- 11 kg/m(2)) decreased by 37.4% at 1 year after surgery (P < .001). Percent BMI change varied little by preoperative BMI groups (-37.2%, -36.8%, and -37.7% for groups 1, 2, and 3 respectively; P = .8762). The rate of change in absolute BMI units significantly varied by preoperative BMI class (group x time interaction, P < .0001), with 1-year nadir BMI values for groups 1, 2, and 3 falling to 31 +/- 4 kg/m(2), 38 +/- 5 kg/m(2), and 47 +/- 9 kg/m(2), respectively. One year after surgery, only 17% of patients achieved a nonobese BMI (<30 kg/m(2)). Significant improvements in systolic and diastolic blood pressure (P < .0001), fasting insulin (P < .0001), total cholesterol (P = .0007), and triglyceride levels (P < .0001) were seen after surgery irrespective of baseline BMI class. Mean albumin levels remained normal despite significant caloric restriction and weight loss.

CONCLUSIONS

Laparoscopic gastric bypass resulted in improvement or reversal of cardiovascular risk factors and resulted in a decrease in BMI of approximately 37% in all patients, regardless of starting BMI, 1 year after surgery. The timing of surgery for adolescent extreme obesity is an important consideration, because "late" referral for bariatric surgery at the highest of BMI values may preclude reversal of obesity.

Dental Development in Children with Growth Hormone Insensitivity Syndrome: Demirjian Analysis of Serial Panoramic Radiographs

Objective:

This study evaluates the effects of 8 years of insulinlike growth factor-I therapy on tooth development in patients with growth hormone insensitivity syndrome.

Methods:

Forty-nine panoramic radiographs were evaluated from eight patients (six boys, two girls). Seven teeth in the mandibular left region were graded according to the Demirjian system. Radiographs were taken at the start of insulinlike growth factor-I therapy and were continued at approximately yearly intervals for 8 years.

Results:

Three of six boys and one of two girls who began treatment with insulinlike growth factor-I at earlier ages experienced an increase in the rate of tooth development. One of six boys who began treatment with insulinlike growth factor-I at a later age had a slower rate of dental development. The patients had more rapid tooth maturation during the beginning of treatment. By the end of treatment, all patients had normal dental maturity for their age.

Conclusions:

Treatment of growth hormone insensitivity syndrome with insulinlike growth factor-I appears to lead to an increase in dental maturation, particularly in younger patients. After 8 years all patients had achieved normal dental development.

Reversal of type 2 diabetes mellitus and improvements in cardiovascular risk factors after surgical weight loss in adolescents

OBJECTIVES

Type 2 diabetes mellitus is associated with obesity, dyslipidemia, and hypertension, all well-known risk factors for cardiovascular disease. Surgical weight loss has resulted in a marked reduction of these risk factors in adults. We hypothesized that gastric bypass would improve parameters of metabolic dysfunction and cardiovascular risk in adolescents with type 2 diabetes mellitus.

PATIENTS AND METHODS

Eleven adolescents who underwent Roux-en-Y gastric bypass at 5 centers were included. Anthropometric, hemodynamic, and biochemical measures and surgical complications were analyzed. Similar measures from 67 adolescents with type 2 diabetes mellitus who were treated medically for 1 year were also analyzed.

RESULTS

Adolescents who underwent Roux-en-Y gastric bypass were extremely obese (mean BMI of 50 +/- 5.9 kg/m(2)) with numerous cardiovascular risk factors. After surgery there was evidence of remission of type 2 diabetes mellitus in all but 1 patient. Significant improvements in BMI (-34%), fasting blood glucose (-41%), fasting insulin concentrations (-81%), hemoglobin A1c levels (7.3%-5.6%), and insulin sensitivity were also seen. There were significant improvements in serum lipid levels and blood pressure. In comparison, adolescents with type 2 diabetes mellitus who were followed during 1 year of medical treatment demonstrated stable body weight (baseline BMI: 35 +/- 7.3 kg/m(2); 1-year BMI: 34.9 +/- 7.2 kg/m(2)) and no significant change in blood pressure or in diabetic medication use. Medically managed patients had significantly improved hemoglobin A1c levels over 1 year (baseline: 7.85% +/- 2.3%; 1 year: 7.1% +/- 2%).

CONCLUSIONS

Extremely obese diabetic adolescents experience significant weight loss and remission of type 2 diabetes mellitus after Roux-en-Y gastric bypass. Improvements in insulin resistance, beta-cell function, and cardiovascular risk factors support Roux-en-Y gastric bypass as an intervention that improves the health of these adolescents. Although the long-term efficacy of Roux-en-Y gastric bypass is not known, these findings suggest that Roux-en-Y gastric bypass is an effective option for the treatment of extremely obese adolescents with type 2 diabetes mellitus.

The combined approach to lysis utilizing eptifibatide and rt-PA in acute ischemic stroke: the CLEAR stroke trial

BACKGROUND AND PURPOSE

Multiple approaches are being studied to enhance the rate of thrombolysis for acute ischemic stroke. Treatment of myocardial infarction with a combination of a reduced-dose fibrinolytic agent and a glycoprotein (GP) IIb/IIIa receptor antagonist has been shown to improve the rate of recanalization versus fibrinolysis alone. The combined approach to lysis utilizing eptifibatide and recombinant tissue-type plasminogen activator (rt-PA) (CLEAR) stroke trial assessed the safety of treating acute ischemic stroke patients within 3 hours of symptom onset with this combination.

METHODS

The CLEAR trial was a National Institutes of Health/National Institute of Neurological Disorders and Stroke-funded multicenter, double-blind, randomized, dose-escalation and safety study. Patients were randomized 3:1 to either low-dose rt-PA (tier 1=0.3 mg/kg, tier 2=0.45 mg/kg) plus eptifibatide (75 microg/kg bolus followed by 0.75 microg/kg per min infusion for 2 hours) or standard-dose rt-PA (0.9 mg/kg). The primary safety end point was the incidence of symptomatic intracerebral hemorrhage within 36 hours. Secondary analyses were performed regarding clinical efficacy.

RESULTS

Ninety-four patients (40 in tier 1 and 54 in tier 2) were enrolled. The combination group of the 2 dose tiers (n=69) had a median age of 71 years and a median baseline National Institutes of Health Stroke Scale (NIHSS) score of 14, and the standard-dose rt-PA group (n=25) had a median age of 61 years and a median baseline NIHSS score of 10 (P=0.01 for NIHSS score). Fifty-two (75%) of the combination treatment group and 24 (96%) of the standard treatment group had a baseline modified Rankin scale score of 0 (P=0.04). There was 1 (1.4%; 95% CI, 0% to 4.3%) symptomatic intracranial hemorrhage in the combination group and 2 (8.0%; 95% CI, 0% to 19.2%) in the rt-PA-only arm (P=0.17). During randomization in tier 2, a review by the independent data safety monitoring board demonstrated that the safety profile of combination therapy at the tier 2 doses was such that further enrollment was statistically unlikely to indicate inadequate safety for the combination treatment group, the ultimate outcome of the study. Thus, the study was halted. There was a trend toward increased clinical efficacy of standard-dose rt-PA compared with the combination treatment group.

CONCLUSIONS

The safety of the combination of reduced-dose rt-PA plus eptifibatide justifies further dose-ranging trials in acute ischemic stroke.

Sirolimus for angiomyolipoma in tuberous sclerosis complex or lymphangioleiomyomatosis

BACKGROUND

Angiomyolipomas in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis are associated with mutations in tuberous sclerosis genes resulting in constitutive activation of the mammalian target of rapamycin (mTOR). The drug sirolimus suppresses mTOR signaling.

METHODS

We conducted a 24-month, nonrandomized, open-label trial to determine whether sirolimus reduces the angiomyolipoma volume in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. Sirolimus was administered for the first 12 months only. Serial magnetic resonance imaging of angiomyolipomas and brain lesions, computed tomography of lung cysts, and pulmonary-function tests were performed.

RESULTS

Of the 25 patients enrolled, 20 completed the 12-month evaluation, and 18 completed the 24-month evaluation. The mean (+/-SD) angiomyolipoma volume at 12 months was 53.2+/-26.6% of the baseline value (P<0.001) and at 24 months was 85.9+/-28.5% of the baseline value (P=0.005). At 24 months, five patients had a persistent reduction in the angiomyolipoma volume of 30% or more. During the period of sirolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 second (FEV1) increased by 118+/-330 ml (P=0.06), the forced vital capacity (FVC) increased by 390+/-570 ml (P<0.001), and the residual volume decreased by 439+/-493 ml (P=0.02), as compared with baseline values. One year after sirolimus was discontinued, the FEV1 was 62+/-411 ml above the baseline value, the FVC was 346+/-712 ml above the baseline value, and the residual volume was 333+/-570 ml below the baseline value; cerebral lesions were unchanged. Five patients had six serious adverse events while receiving sirolimus, including diarrhea, pyelonephritis, stomatitis, and respiratory infections.

CONCLUSIONS

Angiomyolipomas regressed somewhat during sirolimus therapy but tended to increase in volume after the therapy was stopped. Some patients with lymphangioleiomyomatosis had improvement in spirometric measurements and gas trapping that persisted after treatment. Suppression of mTOR signaling might constitute an ameliorative treatment in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. (ClinicalTrials.gov number, NCT00457808.)

Activity-adjusted 24-hour ambulatory blood pressure and cardiac remodeling in children with sleep disordered breathing

Questions remain as to whether pediatric sleep disordered breathing increases the risk for elevated blood pressure and blood pressure-dependent cardiac remodeling. We tested the hypothesis that activity-adjusted morning blood pressure surge, blood pressure load, and diurnal and nocturnal blood pressure are significantly higher in children with sleep disordered breathing than in healthy controls and that these blood pressure parameters relate to left ventricular remodeling. 24-hour ambulatory blood pressure parameters were compared between groups. The associations between blood pressure and left ventricular relative wall thickness and mass were measured. 140 children met the inclusion criteria. In children with apnea hypopnea index <5 per hour, a significant difference from controls was the morning blood surge. Significant increases in blood pressure surge, blood pressure load, and in 24-hour ambulatory blood pressure were evident in those whom the apnea hypopnea index exceeded 5 per hour. Sleep disordered breathing and body mass index had similar effect on blood pressure parameters except for nocturnal diastolic blood pressure, where sleep disordered breathing had a significantly greater effect than body mass index. Diurnal and nocturnal systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure predicted the changes in left ventricular relative wall thickness. Therefore, sleep disordered breathing in children who are otherwise healthy is independently associated with an increase in morning blood pressure surge, blood pressure load, and 24-hour ambulatory blood pressure. The association between left ventricular remodeling and 24-hour blood pressure highlights the role of sleep disordered breathing in increasing cardiovascular morbidity.

Psychosocial and health consequences of adolescent depression in Black and White young adult women

Depression in adolescent girls may result in negative consequences in young adulthood. The Center for Epidemiologic Studies Depression Scale (CES-D) was administered to 1,727 Black and White girls ages 16 to 18 years who participated in the National Heart, Lung, and Blood Institute's Growth and Health Study. Three years later, women in the depressed groups were more likely to be current smokers, had attained a lower level of education, and reported lower self-worth relative to the nondepressed group. Body dissatisfaction, eating concerns, and loneliness were greater in the depressed groups. Relative to Black women, White women who were moderately depressed during adolescence reported more health care services utilization in young adulthood. Prevention efforts for depressed adolescents should be broadly focused to improve young adult outcomes.

SAOZ measurements of NO2 at Aberystwyth

We present in this paper fifteen years' measurements, from March 1991 to September 2005, of stratospheric NO2 vertical columns measured by a SAOZ zenith-sky visible spectrometer. The instrument spent most of its time at Aberystwyth, Wales, with occasional excursions to other locations. The data have been analysed with the WinDOAS analysis program with low-temperature high-resolution NO2 cross-sections and fitting a slit function to each spectrum. Because of a change in detector in May 1998 there is some uncertainty about the relative changes before and after this date, which are partially constrained by the results of an intercomparison exercise. However, the effect of the Mt Pinatubo aerosol cloud is very evident in the data from 1991-94, with a decrease of 10% in NO2 in the summer of 1992 (the SAOZ was located in Lerwick, Scotland during the winter of 1991-92 and observed very low NO2 values but these cannot be directly compared to the Aberystwyth data). To focus more on interannual and long-term variations in NO2, a seasonal variation comprising an annual and semi-annual component was fitted to the morning and evening twilight separately from 1995 to the present. This fit yielded average NO2 columns of 4.08 x 10(15) cm(-2) and 2.68 x 10(15) cm(-2) for the evening and morning twilight, respectively, with a corresponding annual amplitude of +/-2.08 x 10(15) cm(-2) and +/-1.50 x 10(15) cm(-2). Departures from the fitted curve show a trend of 6% per decade, consistent with that reported elsewhere, for the period 1998-2003, but in the past two years a distinct interannual variation of amplitude of approximately 8% has emerged.

Defining the relationship between ovarian hormones and migraine headache

OBJECTIVE

(1) To determine whether the attack characteristics of migraine differ between different intervals of the menstrual cycle; (2) To ascertain whether the "rate of change,""magnitude of change," or "total burden" of urinary hormone metabolites correlates with headaches outcome measures during different intervals of the menstrual cycle.

BACKGROUND

The mechanisms through which migraines are influenced by ovarian hormones remain unclear. No previous studies until now have identified "hormonally defined" time intervals within the female menstrual cycle and compared headache outcome measures among these intervals in female migraineurs.

METHOD

Daily headache diary data were obtained from 21 female migraineurs during three native menstrual cycles. Daily urine samples were collected and later assayed for estrogen and progesterone metabolites. Seven 3-day time intervals were identified within each menstrual cycle based on urine hormone measurements. Primary (headache index) and secondary (disability index, headache severity, and headache frequency) outcome measures were compared between intervals using the mixed model approach. "Rates of change,""magnitude of change," and the "total burden" of ovarian hormones were estimated from urine hormone metabolites and correlated with headache outcome measures.

RESULTS

The headache index was significantly different across different intervals of the menstrual cycle (P values <.001) and was higher during menstrual intervals (first 6 days of the menstrual cycle) than during mid-cycle and mid-luteal intervals (P < .002). Similarly, secondary outcome measures were highest during the menstrual intervals. "Higher burdens" of urinary progesterone metabolites were positively correlated with headache outcome measures during the luteal intervals of the menstrual cycle. "Rates of change" and the "magnitude of change" of urinary hormone metabolites did not correlate with headache outcome measures.

CONCLUSIONS

Migraine headache is more severe, disabling, and frequent during the menstrual intervals of the female reproductive cycle than during mid-luteal or mid-cycle intervals. Progesterone metabolites may play a role in modulating migraine headaches during luteal intervals of the menstrual cycle.

Symptoms of Premenstrual Syndrome and Their Association With Migraine Headache

OBJECTIVES

To determine the association between the severity of premenstrual (PMS) symptoms and headache outcome measures during natural menstrual cycles and after medical oophorectomy.

BACKGROUND

Premenstrual syndrome may occur in 64% of those with pure menstrual migraine and 33% of those with menstrually related migraine. Few past studies have examined the relationship between the severity of PMS symptoms and migraine headache.

METHODS

Data were obtained from a 6.5-month randomized-controlled trial examining the role of medical oophorectomy in the prevention of migraine headache and later divided into two data sets for analysis purposes. The menstrual cycle data set was composed of data from three natural menstrual cycles obtained from 21 participants during lead-in and placebo run-in phases. Each menstrual cycle was subdivided into seven 3-day intervals based on urine hormone metabolites. The medical oophorectomy data set included data from a 2-month treatment period in which a medical oophorectomy was induced by gonadotropin-releasing hormone agonists (GnRHa) and participants were randomized to transdermal estradiol or a matching placebo (GnRHa/estradiol and GnRHa/placebo groups, respectively). All participants completed a daily diary recording the severity of PMS symptoms and headache outcome measures. The primary outcome measures were the PMS index (mean of the daily PMS severity scores) and the headache index (mean of the headache severity scores). Pearson correlation coefficients were used to assess the degree of association between the outcome measures.

RESULTS

Menstrual Cycle Data Set.-The PMS index was significantly correlated with the headache index during native menstrual cycles (correlation coefficient of 0.47; P < .05) and during all seven intervals of the menstrual cycle (correlation coefficients of 0.39 to 0.65; all P values < .05). Medical Oophorectomy Data Set.-Correlation coefficients between the PMS and headache indices were 0.58 and 0.47 for the GnRHa/estradiol (n = 9) and GnRHa/placebo groups, respectively (P-values of <.05).

CONCLUSIONS

Moderate correlations exist within female migraineurs between the severity of PMS symptoms and headache outcome measures throughout natural menstrual cycles as well as after medical oophorectomy. Our data would suggest that the presence and severity of headache might modulate PMS symptoms in female migraineurs.

Self-reported symptoms of depression in late adolescence to early adulthood: a comparison of African-American and Caucasian females

The prevalence of depressive symptoms from adolescence through young adulthood was examined in 1,146 African-American adolescent girls and 1,075 Caucasian adolescent girls who completed the Center for Epidemiological Studies of Depression scale. Caucasian girls' scores decreased over time, whereas scores for African-American girls were fairly consistent. Future studies are needed to examine age-specific risk factors in adolescent girls.

The relationship between sleep disturbance and pulmonary function in stable pediatric cystic fibrosis patients

BACKGROUND

Cystic fibrosis (CF) is the most common inherited disease affecting northern European populations. It is characterized by a progressive clinical course that causes diurnal and nocturnal pulmonary and gastrointestinal symptoms.

OBJECTIVES

To determine whether clinically stable pediatric patients with CF have lower sleep efficiency than healthy control subjects, and to examine the relationship between sleep efficiency and pulmonary function.

METHODS

Forty-four CF patients and 40 control subjects completed 5 days of actigraphy recordings. Additionally, sleep questionnaires were independently completed by all study participants and their parents. Pulmonary function testing was performed in all patients with CF. Multiple regression analysis was used to measure the independent correlation between sleep variables and pulmonary function.

RESULTS

CF patients had significantly lower sleep efficiency than control subjects. The FEV1 of these patients correlated positively with sleep duration and efficiency, and negatively with the number and duration of nocturnal awakenings, age, and body mass index (BMI). The independent effect of FEV1 on sleep was first examined. Age and FEV1 were the only variables that predicted sleep duration (R2 = 0.3; p = 0.0007), while FEV1 was the only variable predicting sleep efficiency (R2 = 0.28; p = 0.0002). When the independent effect of sleep on FEV1 was analyzed, sleep efficiency, BMI percentile, and gender predicted FEV1 (R2 = 0.46; p < or = 0.0001). The frequency of nocturnal cough reported by patients and their parents was an independent predictor of FEV1.

CONCLUSIONS

Pediatric patients with CF and stable pulmonary function have lower sleep efficiency and more frequent nocturnal awakenings than do healthy control subjects. After adjustment for demographic characteristics, there was an independent and significant correlation between sleep parameters and FEV1, when either sleep variables or FEV1 were used as dependent variables. These findings suggest a bidirectional relationship between sleep disturbance and CF lung disease.

Frequency of abnormal carbohydrate metabolism and diabetes in a population-based screening of adolescents

OBJECTIVE

To document the frequency of glucose intolerance in adolescents in a population-based study of primarily African-American/Non-Hispanic whites in an urban-suburban school district.

STUDY DESIGN

Measurement of fasting and 2-hour post-glucose load plasma glucose concentrations.

RESULTS

Carbohydrate intolerance (either impaired fasting glucose, impaired glucose tolerance, or both) was identified in 8.0%, near-diabetes (1 fasting glucose > or = 126 mg/dL [7.0 mmol/L] and/or 2-hour glucose > or = 200 mg/dL [11.1 mmol/L]) in 0.3%, and diabetes in 0.36% (type 1A = 0.24%; type 2 = 0.08%; undiagnosed type 2 = 0.04%). A model for abnormal carbohydrate metabolism was constructed with regression analysis in the Carbohydrate Intolerance (CI)/near-diabetes group and with logistic regression in the entire study population. Risk factors for the development of CI/near-diabetes included having a 1 unit increase in body mass index (BMI) z-score and either being non-Hispanic white or in the pubertal group. Increased fasting glucose correlated with having puberty and decreased BMI z-score, whereas 2-hour glucose correlated with increased BMI z-score. By using National Health and Nutrition Survey (NHANES) III (1988-1994) definitions, impaired fasting glucose was present in 2.0% in this study versus 1.7% (NHANES III).

CONCLUSION

The prevalence of CI/near-diabetes was 8.3%. Undiagnosed diabetes mellitus was rare. One third of adolescents with diabetes mellitus could be classified as having type 2 diabetes mellitus. The adult model of the progression of insulin resistance to type 2 diabetes mellitus in adolescents may be valid. Despite the increase in the overweight population since NHANES III, abnormalities in glucose metabolism have not changed significantly.

Neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker for acute renal injury after cardiac surgery

BACKGROUND

The scarcity of early biomarkers for acute renal failure has hindered our ability to launch preventive and therapeutic measures for this disorder in a timely manner. We tested the hypothesis that neutrophil gelatinase-associated lipocalin (NGAL) is an early biomarker for ischaemic renal injury after cardiopulmonary bypass.

METHODS

We studied 71 children undergoing cardiopulmonary bypass. Serial urine and blood samples were analysed by western blots and ELISA for NGAL expression. The primary outcome measure was acute renal injury, defined as a 50% increase in serum creatinine from baseline.

FINDINGS

20 children (28%) developed acute renal injury, but diagnosis with serum creatinine was only possible 1-3 days after cardiopulmonary bypass. By contrast, urine concentrations of NGAL rose from a mean of 1.6 microg/L (SE 0.3) at baseline to 147 microg/L (23) 2 h after cardiopulmonary bypass, and the amount in serum increased from a mean of 3.2 microg/L (SE 0.5) at baseline to 61 microg/L (10) 2 h after the procedure. Univariate analysis showed a significant correlation between acute renal injury and the following: urine and serum concentrations of NGAL at 2 h, and cardiopulmonary bypass time. By multivariate analysis, the amount of NGAL in urine at 2 h after cardiopulmonary bypass was the most powerful independent predictor of acute renal injury. For concentration in urine of NGAL at 2 h, the area under the receiver-operating characteristic curve was 0.998, sensitivity was 1.00, and specificity was 0.98 for a cutoff value of 50 microg/L.

INTERPRETATION

Concentrations in urine and serum of NGAL represent sensitive, specific, and highly predictive early biomarkers for acute renal injury after cardiac surgery.

Diet-induced weight loss is associated with decreases in plasma serum amyloid a and C-reactive protein independent of dietary macronutrient composition in obese subjects

Elevated levels of serum amyloid A (SAA) and C-reactive protein (CRP) have been associated with increased cardiovascular risk. Although levels of CRP decrease with weight loss, it is not known whether SAA decreases with weight loss or whether dietary macronutrient composition affects levels of either SAA or CRP. SAA and CRP levels were measured retrospectively on baseline and 3-month plasma samples from 41 obese (mean body mass index 33.63 +/- 1.86 kg/m2) women completing a randomized trial comparing a low-fat diet (n = 19) and a very low-carbohydrate diet (n = 22). For the 41 participants, there were significant decreases from baseline to 3 months in both LogSAA (P = 0.049) and LogCRP (P = 0.035). The very low-carbohydrate dieters had a significantly greater decrease in LogSAA (P = 0.04), but their weight loss also was significantly greater (-7.6 +/- 3.2 vs. -4.3 +/- 3.5 kg, P < 0.01). In this study, the decreases in inflammatory markers correlated significantly with weight loss (r = 0.44, P = 0.004 vs. LogSAA and r = 0.35, P = 0.03 vs. LogCRP). Also, change in LogSAA correlated with change in insulin resistance (r = 0.35, P = 0.03). Thus, in otherwise healthy, obese women, weight loss was associated with significant decreases in both SAA and CRP. These effects were proportional to the amount of weight lost but independent of dietary macronutrient composition.

Vitamin K, bone turnover, and bone mass in girls

BACKGROUND

Vitamin K has been suggested to have a role in bone metabolism, and low vitamin K intake has been related to low bone density and increased risk of osteoporotic fracture.

OBJECTIVE

The objective of this study was to determine whether phylloquinone (vitamin K(1)) intake and biochemical indicators of vitamin K status are related to bone mineral content (BMC) and markers of bone formation and bone resorption in girls.

DESIGN

Vitamin K status [plasma phylloquinone concentration and percentage of undercarboxylated osteocalcin (%ucOC)] was measured at baseline in a study of 245 healthy girls aged 3-16 y. Cross-linked N-telopeptide of type 1 collagen (NTx) breakdown, osteocalcin, and bone-specific alkaline phosphatase were measured to reflect bone resorption and formation. BMC of the total body, lumbar spine, and hip and dietary phylloquinone intake were measured annually for 4 y.

RESULTS

Phylloquinone intake (median: 45 microg/d) was not consistently associated with bone turnover markers or BMC. Better vitamin K status (high plasma phylloquinone and low %ucOC) was associated with lower bone resorption and formation. Plasma phylloquinone was inversely associated with NTx and osteocalcin concentrations (P < 0.05), and %ucOC was positively associated with NTx and bone-specific alkaline phosphatase concentrations (P < 0.05). Indicators of vitamin K status were not consistently associated with current BMC or gain in BMC over the 4-y study period.

CONCLUSIONS

Better vitamin K status was associated with decreased bone turnover in healthy girls consuming a typical US diet. Randomized phylloquinone supplementation trials are needed to further understand the potential benefits of phylloquinone on bone acquisition in growing children.

Prevalence of dementia in three ethnic groups: the South Florida program on aging and health

To determine the prevalence of cognitive impairment and dementia in a multi-ethnic community, we examined a population sample of 2,759 elderly (65 years of age and older) African American, Hispanic-Cuban and white non-Hispanic men and women of Dade County, Florida. The Short Portable Mental Status Questionnaire (SPMSQ) was used as a screening test. The prevalence of cognitive impairment for African American men was 17.0% and women 16.7%; Cuban men 9.4% and women 11.4%; and white non-Hispanic men 9.0% and women 8.5%. Participants with cognitive impairment were referred to two Memory Disorder Clinics for diagnosis of dementia/Alzheimer's disease (AD). SPMSQ cutpoints took account of race and education. The prevalence of dementia/AD was adjusted for sensitivity and specificity of the SPMSQ in each sex/ethnic group. The prevalence of dementia among African American men (20.9%) was twice that among white non-Hispanic men (11.6%). White non-Hispanic and Cuban women had a similar prevalence of dementia (12.1% vs. 12.9%). Low SPMSQ specificity for Cuban men and African American women gave unstable dementia prevalence estimates. More than two thirds of all dementia cases had AD, and among white non-Hispanics, women had double the prevalence of AD among men (10.9% vs. 5.4%). The prevalence of AD among African American men was more than two and a half times greater than the prevalence among white non-Hispanic men (14.4% vs. 5.4%). Age (p = 0.001), family history of AD (p = 0.02) and African American (p = 0.0001) or Cuban (p = 0.006) ethnic group were directly and independently associated with the prevalence of AD.

Medical oophorectomy with and without estrogen add-back therapy in the prevention of migraine headache

OBJECTIVES

To determine the preventive benefit of "medical oophorectomy" and transdermal estradiol in women with migraine.

BACKGROUND

Epidemiological studies have demonstrated that declines in serum estrogen levels occurring during normal menstrual cycles can trigger headache in women with migraine. Prior to this study, no randomized controlled trials have evaluated whether minimizing these hormonal changes pharmacologically can prevent headache.

METHODS

Twenty-one women with regular menstrual cycles and a diagnosis of migraine headache were enrolled. After a 2.5-month placebo run-in phase, all patients received a subcutaneous goserelin implant (a gonadotropin-releasing hormone agonist) to induce a medical oophorectomy. One month later, while continuing goserelin, participants were randomized to receive a transdermal patch containing 100 microg of estradiol-17beta (gonadotropin-releasing hormone agonist/estradiol group, n = 9) or a placebo patch (gonadotropin-releasing hormone agonist/placebo group, n = 12) during a 2-month treatment phase. The primary outcome measure was the headache index, which was defined as the mean of pain severity ratings (0 to 10 scale) recorded three times per day by daily diary. Secondary outcome measures included headache disability, headache severity, headache frequency, and the percentage of headaches with a pain severity rating of 7 or greater.

RESULTS

The headache index was significantly lower during the treatment period in the gonadotropin-releasing hormone agonist/estradiol group than in the gonadotropin-releasing hormone agonist/placebo group (P =.025). Similar improvements were observed in the gonadotropin-releasing hormone agonist/estradiol group for all secondary outcome measures with the exception of headache frequency, which was unchanged between the groups. Within the gonadotropin-releasing hormone agonist/estradiol group, there was a 33.7% reduction (95% confidence interval, -64.4 to -3.0) in the headache index during the treatment phase when compared with the placebo run-in phase; no difference was seen between those phases within the gonadotropin-releasing hormone agonist/placebo group.

CONCLUSIONS

Minimization of hormonal fluctuations with gonadotropin-releasing hormone agonist therapy alone is inadequate to prevent headache in women who are premenopausal with migraine. The addition of transdermal estradiol to existing gonadotropin-releasing hormone agonist therapy provides a modest preventive benefit.

Lack of benefit of intravenous synthetic human secretin in the treatment of autism

The objective of this study was to determine if an intravenous infusion of synthetic human secretin improves language and behavioral symptoms in children with autism. Forty-two children with the diagnosis of autism were randomized to one of two groups in this double-blind cross-over trial. One group received 2 IU/kg of intravenous synthetic human secretin at the first visit, followed by an equal volume of intravenous saline placebo at week 6. The other group received treatments in the reverse order. All children were evaluated at weeks 1, 3, 6, 9, and 12 with standardized assessments of language, behavior, and autism symptomatology. There were no significant differences in the mean scores on any measure of language, behavior, or autism symptom severity after treatment with secretin compared to treatment with placebo. The results of this study do not support secretin as a treatment for autism.

Randomized, controlled human challenge study of the safety, immunogenicity, and protective efficacy of a single dose of Peru-15, a live attenuated oral cholera vaccine

Peru-15 is a live attenuated oral vaccine derived from a Vibrio cholerae O1 El Tor Inaba strain by a series of deletions and modifications, including deletion of the entire CT genetic element. Peru-15 is also a stable, motility-defective strain and is unable to recombine with homologous DNA. We wished to determine whether a single oral dose of Peru-15 was safe and immunogenic and whether it would provide significant protection against moderate and severe diarrhea in a randomized, double-blind, placebo-controlled human volunteer cholera challenge model. A total of 59 volunteers were randomly allocated to groups to receive either 2 x 10(8) CFU of reconstituted, lyophilized Peru-15 vaccine diluted in CeraVacx buffer or placebo (CeraVacx buffer alone). Approximately 3 months after vaccination, 36 of these volunteers were challenged with approximately 10(5) CFU of virulent V. cholerae O1 El Tor Inaba strain N16961, prepared from a standardized frozen inoculum. Among vaccinees, 98% showed at least a fourfold increase in vibriocidal antibody titers. After challenge, 5 (42%) of the 12 placebo recipients and none (0%) of the 24 vaccinees had moderate or severe diarrhea (> or = 3,000 g of diarrheal stool) (P = 0.002; protective efficacy, 100%; lower one-sided 95% confidence limit, 75%). A total of 7 (58%) of the 12 placebo recipients and 1 (4%) of the 24 vaccinees had any diarrhea (P < 0.001; protective efficacy, 93%; lower one-sided 95% confidence limit, 62%). The total number of diarrheal stools, weight of diarrheal stools, incidence of fever, and peak stool V. cholerae excretion among vaccinees were all significantly lower than in placebo recipients. Peru-15 is a well-tolerated and immunogenic oral cholera vaccine that affords protective efficacy against life-threatening cholera diarrhea in a human volunteer challenge model. This vaccine may therefore be a safe and effective tool to prevent cholera in travelers and is a strong candidate for further evaluation to prevent cholera in an area where cholera is endemic.

Brace modification improves aerobic performance in Charcot-Marie-Tooth disease: a single-subject design

OBJECTIVE

Ankle-foot orthoses (AFOs) can lower energy expenditure in patients with hemiplegia by 10%-13%. Review of the lower motor injury literature reveals insufficient physiologic evidence supporting the use or modification of AFOs in patients with lower motor neuron injury and, specifically, progressive conditions such as Charcot-Marie-Tooth disease. We sought to test the hypothesis that optimal AFOs would improve submaximal aerobic performance and submaximal perceived exertion, while producing no change in maximal aerobic capacity.

DESIGN

In an individual with Charcot-Marie-Tooth disease, a single-subject design study was used. An A-B-A design was used, with "A" corresponding to use of the patient's old AFOs and "B" corresponding to the newly prescribed AFOs. The subject underwent treadmill exercise tolerance testing using a modified Balke protocol. Indirect calorimetry was used to measure oxygen consumption per unit time (VO2), and the Borg scale was used to measure perceived exertion.

RESULTS

At the same submaximal exercise intensities, VO2, rate-pressure product, and perceived exertion were all reduced when using the modified AFOs. Additionally, these conditions allowed the subject to conduct the treadmill exercise test 20% longer. Maximal VO2 remained constant under all conditions.

CONCLUSION

Optimizing the AFO prescription in a patient with Charcot-Marie-Tooth disease can enhance physiologic performance and perceived exertion at submaximal activity levels. Larger controlled trials are necessary to further demonstrate such benefits in patients with progressive neuropathy and other causes of lower motor neuron injury.

Comorbidity of the nonmotor symptoms of Parkinson's disease

Many patients with Parkinson's disease (PD) have clinically significant anxiety, depression, fatigue, sleep disturbance, or sensory symptoms. The comorbidity of these nonmotor symptoms and their relationship to PD severity has not been extensively evaluated. Ninety- nine nondemented PD patients were evaluated with the following battery of tests: Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Fatigue Severity Scale (FSS), Pittsburgh Sleep Quality Index (PSQI), a sensory symptom questionnaire, Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr (H/Y) Stage, and the Schwab & England ADL scale (S/E). The comorbidity of the nonmotor symptoms and their relationship to PD severity was analyzed. Thirty-six percent of the study population had depression (BDI > or =10), 33% had anxiety (BAI > or =10), 40% had fatigue (FSS > 4), 47% had sleep disturbance (PSQI > 5), and 63% reported sensory symptoms. Only 12% of the sample had no nonmotor symptoms. Fifty-nine percent of the patients had two or more nonmotor symptoms, and nearly 25% had four or more. Increased comorbidity was associated with greater PD severity (P < 001). This study reveals that the nonmotor symptoms of PD frequently occur together in the same patients. Increased comorbidity of the five nonmotor symptoms was associated with greater PD severity. These results suggest that recognition of these diverse nonmotor symptoms may be enhanced by looking for others when one nonmotor symptom has been identified.

Randomized trial of supplemental beta-carotene to prevent second head and neck cancer

Beta-carotene has established efficacy in animal models of oral carcinogenesis and has been shown to regress oral precancerous lesions in humans. The purpose of this study was to see whether these effects extended to the prevention of oral/pharyngeal/laryngeal (head and neck) cancer in humans. The subject population for this randomized, placebo-controlled, double-blinded clinical trial included 264 patients who had been curatively treated for a recent early-stage squamous cell carcinoma of the oral cavity, pharynx, or larynx. Patients were assigned randomly to receive 50 mg of beta-carotene per day or placebo and were followed for up to 90 months for the development of second primary tumors and local recurrences. After a median follow-up of 51 months, there was no difference between the two groups in the time to failure [second primary tumors plus local recurrences: relative risk (RR), 0.90; 95% confidence interval (CI), 0.56-1.45]. In site-specific analyses, supplemental beta-carotene had no significant effect on second head and neck cancer (RR, 0.69; 95% CI, 0.39-1.25) or lung cancer (RR, 1.44; 95% CI, 0.62-3.39). Total mortality was not significantly affected by this intervention (RR, 0.86; 95% CI, 0.52-1.42). Whereas none of the effects were statistically significant, the point estimates suggested a possible decrease in second head and neck cancer risk but a possible increase in lung cancer risk. These effects are consistent with the effects observed in trials using intermediate end point biological markers in humans, in which beta-carotene has established efficacy in oral precancerous lesions but has no effect or slightly worsens sputum cytology, and in animal carcinogenicity studies, in which beta-carotene has established efficacy in buccal pouch carcinogenesis in hamsters but not in animal models of respiratory tract/lung carcinogenesis, with some suggestions of tumor-promoting effects in respiratory tract/lung. If our results are replicated by other ongoing/completed trials, this suggests a critical need for mechanistic studies addressing differential responses in one epithelial site (head and neck) versus another (lung).

Organization of junctional proteins in proliferating cat corneal endothelium during wound healing

PURPOSE

To evaluate for the first time cell junctional protein organization in proliferating corneal endothelial cells during in vivo wound healing.

METHODS

A total of 16 cats (32 eyes) were used in this study. A single 3-mm diameter (n = 24) or 1- to 2-mm diameter (n = 8) scrape injury was created in the central corneal endothelium of each eye. Twenty-four, 48, 72 hours or 5 days after scrape injury, eyes were collected for in situ double- or triple-labeling with phalloidin, anti-ZO-1, alpha-catenin, beta-catenin, and MIB-1 (monoclonal antibody to Ki67, a marker for actively cycling cells) and were imaged using confocal laser microscopy.

RESULTS

In 3-mm diameter injuries, endothelial cells completely resurfaced the wound 48 to 72 hours after scrape injury; smaller wounds resurfaced by 48 hours. Ki67 staining was negative 24 hours after scrape injury in all cases. Ki67-positive cells were observed in the central region of the wounds after 48 and 72 hours, and mitotic figures and pairs of postmitotic cells were observed. On day 5, Ki67-positive cells were rarely detected, and no mitotic figures were observed. In the wound area, a significant increase in cell area and a reduction in hexagonality were observed in cycling cells after 48 and 72 hours. Normal apical, pericellular staining of f-actin, ZO-1, alpha-catenin, and beta-catenin was partially maintained at all times during wound healing of small and large wounds. Double-labeling confirmed that these proteins were also present along the apical cell border in Ki67-positive cells.

CONCLUSIONS

After in vivo scrape injury, proliferation is limited temporally and spatially to spreading endothelial cells within the wound. Cell junctional connections appear to be maintained in actively cycling cells during healing.

High intensity strength training improves strength and functional performance after stroke

OBJECTIVE

To evaluate the effects of a progressive resistance strength training program on changes in muscle strength, gait, and balance in older individuals 1 yr after stroke, seven individuals were recruited who were greater than 60-yr-old, 1 yr after stroke, living at home, and able to follow verbal commands.

DESIGN

Subjects participated in a 12-wk 2x per wk resistance training program at 70% of 1 repetition maximum.

RESULTS

Lower limb strength improved 68% on the affected side and 48% on the intact side during training, with the largest increases observed for hip extension (affected side: 88%, P < 0.01; intact side: 103%, P < 0.001). Repeated chair stand time decreased 21% (P < 0.02). Motor performance assessed by the Motor Assessment Scale improved 9% (P < 0.04) and static and dynamic balance (Berg balance scale) improved 12% (P < 0.004). Progressive resistance training in individuals 1 yr after stroke improves affected and intact side lower limb strength and was associated with gains in chair stand time, balance, and motor performance.

CONCLUSIONS

These results support the concept that strength training is an appropriate intervention to improve the quality of physical function in older community dwelling stroke survivors.