Biomedical subjects

Kate Ward

Publications and source records attributed to Kate Ward.

6 recordsLinked to original sources

PubMed2005

Quantification of metaphyseal modeling in children treated with bisphosphonates.

There has been recent concern in the literature that the treatment with bisphosphonates in children can have an adverse effect on metaphyseal modeling leading to "drug-induced osteopetrosis". We created a normal database called metaphyseal index in the distal femur so that we could quantify the inwasting modeling process in children on bisphosphonates. Radiographs of the distal femur of 468 normal children who had presented to our institution for orthopedic trauma were examined. A measurement of the distal femoral growth plate width (GPW) was recorded. The femoral width at an interval of 0.5 GPW proximal to the distal femoral growth plate was also recorded (0.5 W). The metaphyseal index was defined as a ratio of 0.5 W/GPW. A graph of the means, one and two standard deviations from the mean, was constructed using the data obtained from this cohort. We found this ratio to be constant with minimal variability regardless of the age or sex of the child. We plotted 20 patients at our institution given bisphosphonates for localized orthopedic complaints. Z scores for girls averaged 0.68 and boys 0.13. Three patients had Z scores >2.0, with values of 2.2, 2.9, and 3.2. Metaphyseal modeling in the distal femur is constant, with slight variation between sexes, resulting in a similar shape of the distal femur throughout childhood. Clinically relevant doses of bisphosphonates given for appropriate indications do not necessarily disturb this process, while the beneficial clinical effect is maintained.

Adolescent↗

PubMed2004

Bone mineral density in childhood survivors of acute lymphoblastic leukemia treated without cranial irradiation.

Adult survivors of childhood acute lymphoblastic leukemia (ALL) whose treatment included cranial irradiation (XRT) have reduced bone mineral density (BMD). Fifty-three survivors of ALL (aged 6-17 yr; 22 males and 31 females), who had completed their treatment without XRT, at least 1 yr previously, and 187 (5-19 yr; 86 males and 101 females) healthy controls were examined with dual energy x-ray absorptiometry of the total body and L1-L4 vertebrae and peripheral quantitative computer tomography at the distal and midradial sites. The total body and lumbar spine BMDs did not differ between the ALL survivors and controls. Distal radial trabecular BMD (difference, -0.080 mg/cm(3); 95% confidence interval, -0.139 to -0.020; P = 0.009), but not total BMD (difference, -0.006 mg/cm(3); confidence interval, -0.051 to 0.039; P = 0.80), was lower in ALL survivors compared with controls. At the midradial site, both endosteal (11% larger; P = 0.0001) and periosteal (4% larger; P = 0.001) circumferences were greater, and cortical thickness was thinner by 6% (P = 0.006) in the ALL subjects, leading to an increase in the axial moment of inertia in the ALL subjects (difference, 13%; P = 0.008). In conclusion, BMD, except at the radius, is normal in childhood survivors of ALL treated without XRT. At the midradial site, we speculate that ALL or its treatment resulted in endosteal bone loss and cortical bone thinning, but the axial moment of inertia and, hence, strength was maintained as a result of bone gain at the periosteal surface.

Adolescent↗

PubMed2004

Low magnitude mechanical loading is osteogenic in children with disabling conditions.

UNLABELLED: The osteogenic potential of short durations of low-level mechanical stimuli was examined in children with disabling conditions. The mean change in tibia vTBMD was +6.3% in the intervention group compared with -11.9% in the control group. This pilot randomized controlled trial provides preliminary evidence that low-level mechanical stimuli represent a noninvasive, non-pharmacological treatment of low BMD in children with disabling conditions. INTRODUCTION: Recent animal studies have demonstrated the anabolic potential of low-magnitude, high-frequency mechanical stimuli to the trabecular bone of weight-bearing regions of the skeleton. The main aim of this prospective, double-blind, randomized placebo-controlled pilot trial (RCT) was to examine whether these signals could effectively increase tibial and spinal volumetric trabecular BMD (vTBMD; mg/ml) in children with disabling conditions. MATERIALS AND METHODS: Twenty pre-or postpubertal disabled, ambulant, children (14 males, 6 females; mean age, 9.1 +/- 4.3 years; range, 4-19 years) were randomized to standing on active (n = 10; 0.3g, 90 Hz) or placebo (n = 10) devices for 10 minutes/day, 5 days/week for 6 months. The primary outcomes of the trial were proximal tibial and spinal (L2) vTBMD (mg/ml), measured using 3-D QCT. Posthoc analyses were performed to determine whether the treatment had an effect on diaphyseal cortical bone and muscle parameters. RESULTS AND CONCLUSIONS: Compliance was 44% (4.4 minutes per day), as determined by mean time on treatment (567.9 minutes) compared with expected time on treatment over the 6 months (1300 minutes). After 6 months, the mean change in proximal tibial vTBMD in children who stood on active devices was 6.27 mg/ml (+6.3%); in children who stood on placebo devices, vTBMD decreased by -9.45 mg/ml (-11.9%). Thus, the net benefit of treatment was +15.72 mg/ml (17.7%; p = 0.0033). In the spine, the net benefit of treatment, compared with placebo, was +6.72 mg/ml, (p = 0.14). Diaphyseal bone and muscle parameters did not show a response to treatment. The results of this pilot RCT have shown for the first time that low-magnitude, high-frequency mechanical stimuli are anabolic to trabecular bone in children, possibly by providing a surrogate for suppressed muscular activity in the disabled. Over the course of a longer treatment period, harnessing bone's sensitivity to these stimuli may provide a non-pharmacological treatment for bone fragility in children.

Bone Density↗

PubMed2003

Gallbladder polyps in children--classification and management.

Polypoid lesions of the gallbladder (PLG) are rare in childhood. The authors describe 2 additional cases. A 12 year-old-girl was found to have a 5-mm gallbladder polyp during an ultrasound examination for nonspecific abdominal pain. Investigation showed no other biliary tract abnormality. During the next 5 years, she was reviewed periodically with ultrasound scans and underwent cholecystectomy when the diameter of the polyp increased to 1 cm. Histology results showed a benign cholesterol polyp. A 12-year-old-boy was found to have an incidental gallbladder polyp, which 2 years later remained static in size for 10 months. The polyp had disappeared spontaneously. The authors suggest that PLGs in children may be either primary or secondary. Only 11 primary PLGs have been reported, and their histology is variable (adenoma, gastric heterotopia, and epithelial hyperplasia). Secondary PLGs may be found in association with metachromatic leukodystrophy, Peutz-Jeghers syndrome, or pancreato-biliary malunion. The pathologic spectrum of PLGs in children appears to be different from that in adults. For primary PLGs, cholecystectomy is advisable if there are biliary symptoms or if the polyp is > or =1 cm in size. Asymptomatic cases should be maintained under ultrasound surveillance.

Abdominal Pain↗

PubMed2002

Respiratory virus infections in transplant recipients after reduced-intensity conditioning with Campath-1H: high incidence but low mortality.

Respiratory virus infections can cause serious morbidity and mortality after conventional allogeneic stem cell transplantation. However, the incidence and outcome of these infections after reduced intensity conditioning has not been reported. Between 1997 and 2001, 35 episodes of respiratory virus infections were noted in 25 of 83 transplant recipients conditioned with fludarabine, melphalan and Campath-1H, and 80% of them received early antiviral therapy. Parainfluenza virus (PIV) 3 was the commonest isolate (45.7%) followed by respiratory syncytial virus (37%). Patients with myeloma were more susceptible to these infections [odds ratio (OR) 4.1, P = 0.01] which were often recurrent in patients with severe acute or chronic graft-versus-host disease (GVHD) (OR 10.6, P = 0.03). Infection within the first 100 d (OR 5.0, P = 0.05) and PIV 3 (OR 9.2, P = 0.01) isolation were risk factors for developing lower respiratory infection. Although more than half of the episodes progressed to lower respiratory infection, the mortality was only 8%. This could have been due to early initiation of antiviral therapy, but the attenuation of pulmonary damage due to the reduced-intensity conditioning, low incidence of GVHD and, paradoxically, the low CD4+ T-cell subset in this setting might also have been contributory factors.

Adolescent↗

PubMedDate not supplied

Malaria.

Explore the source record for details and available documents.

Animals↗