Dynamic gadolinium-enhanced MRI in early ischaemia of the proximal femoral epiphysis--a preliminary study

AIM

To compare the sensitivities of dynamic Gadoteridol (Gd)-enhanced magnetic resonance imaging (MRI) and conventional Gd-enhanced spin-echo (SE) T1-weighted imaging (WI) in the detection of decreased perfusion of early epiphyseal ischaemia, and to determine the contribution of metaphyseal vascularity to physeal perfusion in epiphyseal vascular occlusion by dynamic Gd-enhanced MRI.

MATERIALS AND METHODS

Twenty-eight 2-week-old piglets were divided evenly into four groups: control groups A and B, and ischaemic groups A and B (seven animals in each). In the ischaemic groups, MRI was performed bilaterally on hips in persistent hyperabduction for 30 min. In the control and ischaemic group A the piglets underwent dynamic Gd-enhanced MRI, and in control and ischaemic group B the piglets were subjected to Gd-enhanced SE T1WI.

RESULTS

In ischaemic group A, the enhancement ratio (ER) and enhancement speed (ES) of the various tissues (except the metaphysis) were significantly lower than those in control group A on dynamic Gd-enhanced MRI (p<0.05). However, in ischaemic group B, no significant decrease in the ER of each tissue was found, compared with the ER in control group B as viewed using Gd-enhanced SE T1WI (p>0.05). On dynamic Gd-enhanced MRI, the ER and ES of the physis were less than those of metaphysis in the ischaemic group A (p<0.05); however, the ER and ES of the physis were similar to those of metaphysis in control group A (p>0.05).

CONCLUSION

Dynamic Gd-enhanced MRI is more sensitive than conventional Gd-enhanced SE T1WI in the detection of early epiphyseal ischaemia. Physeal perfusion might be from the metaphysis in epiphyseal vascular occlusion.

Uterine artery Doppler at 11 + 0 to 13 + 6 weeks and 21 + 0 to 24 + 6 weeks in the prediction of pre-eclampsia

OBJECTIVE

To evaluate the performance of screening for pre-eclampsia by uterine artery pulsatility index (PI) at 11 + 0 to 13 + 6 weeks' gestation and the change in uterine artery PI between 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks.

METHODS

In 3107 singleton pregnancies attending for routine care at 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks' gestation we recorded maternal characteristics and medical and obstetric history, and measured uterine artery PI. The distributions of uterine artery PI were made Gaussian after logarithmic transformation and the log of the ratio of uterine artery PI at 21 + 0 to 24 + 6 weeks to that at 11 + 0 to 13 + 6 weeks was calculated. Multiple regression analysis was used to determine which of the maternal variables and Doppler findings were significant predictors of early and late pre-eclampsia. The performance of screening was described by receiver-operating characteristics curves.

RESULTS

Pre-eclampsia developed in 93 (3.0%) pregnancies, including 22 (0.7%) in which delivery was before 34 weeks (early pre-eclampsia) and 71 (2.3%) with delivery at 34 weeks or more (late pre-eclampsia). Seventy-three (2.3%) women developed gestational hypertension, 346 (11.1%) delivered small-for-gestational-age (SGA) babies with no hypertensive disorders and 2595 (83.5%) were unaffected by pre-eclampsia, gestational hypertension or SGA. Multiple regression analysis demonstrated that maternal variables, uterine artery PI at 11 + 0 to 13 + 6 weeks and the change in uterine artery PI between 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks' gestation provided significant independent contributions to the prediction of pre-eclampsia. For a false positive rate of 5% the predicted detection rates of early and late pre-eclampsia were 90.9 and 31.0%, respectively. The same performance of screening was achieved by reserving second-trimester testing for only the 20% of women at the highest risk after first-trimester screening.

CONCLUSION

The decrease in uterine artery PI between 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks is steeper in pregnancies with a normal outcome than in those developing pre-eclampsia. Effective screening for pre-eclampsia can be achieved by the Doppler measurement of uterine artery PI at 11 + 0 to 13 + 6 weeks and the change in PI between 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks.

Laparoscopic radical prostatectomy: single centre experience after 5 years

OBJECTIVE

To summarise our experience of laparoscopic radical prostatectomy in a single centre in Hong Kong over 5 years.

DESIGN

Retrospective study.

SETTING

Urology Division, Department of Surgery, Tuen Mun Hospital, Hong Kong.

PATIENTS

A total of 87 patients who underwent laparoscopic radical prostatectomy from March 2002 to May 2007.

MAIN OUTCOME MEASURES

Peri-operative data and follow-up information.

RESULTS

The operative procedure used entailed Montsouris technique and its modifications, including the latest method involving the extraperitoneal descending technique. In all, 87 patients underwent the operation; in two, the procedure was converted to open surgery. Peri-operative parameters which showed improvement included: operating time, blood loss, resort to blood transfusions, and the complication rate. There was no operation-related mortality. In organ-confined disease, a clear surgical margin was achieved in 93% of the patients, but in those whose disease was not organ-confined, the positive margin rate was 87%. Among patients with organ-confined disease, 13% had evidence of biochemical recurrence. Hormonal therapy was started in five patients, none of whom died during the follow-up period (mean, 24 months). Continence recovered in 69% of the patients by 6 months and in 92% by 12 months post-surgery. Assessment of erectile function before and after the surgery was problematic and estimated to be 20% among patients having the nerve-sparing procedure performed.

CONCLUSION

Although Hong Kong has a relatively low incidence for prostate cancer, it was possible to develop laparoscopic radical prostatectomy with acceptable early results. Further follow-up is warranted before formulating definitive conclusions about this procedure.

In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein

Some natural health products (NHPs) affect drug metabolism enzymes and transport proteins, potentially affecting the safety and efficacy of the drug or other NHPs. This study was undertaken to characterize the effect of uva-ursi (Arctostaphylos uva-ursi) on cytochrome P450 isozyme (3A4, 3A5, 3A7, 2C19, and 19)-mediated metabolism and P-glycoprotein (P-gp) transport. Three bulk and 2 capsulated uva-ursi samples were obtained from commercial outlets. The capsules were batched, and herbal samples were ground to a common consistency. Aqueous and methanol extracts were freshly prepared. Cytochrome P450 isozyme-mediated metabolism was determined by using in vitro bioassays. P-gp transport function was determined by using a rhodamine 123 (Rh123) uptake test in human (THP-1) monocytes and human Caco-2 cells. All products were analyzed by HPLC for arbutin, gallic acid, myricitrin, and isoquercetin. A large variation was observed in the biomarkers found between the bulk and capsulated samples. Our data indicate that both the aqueous and methanol extracts of all 5 uva-ursi products showed high cytochrome P450 isozyme inhibition, with the exception of the methanol extracts against cytochromes P3A4 and P19, which had low to moderate activity. The aqueous extracts of uva-ursi showed an inhibitory effect on Rh123 efflux by P-gp at 1 h and an inductive effect at 18 h for both cell lines. Our results show that the uva-ursi herbal products tested here have pharmacological properties, including the potential capacity to affect drug safety and efficacy. Further studies are warranted against a wider range of cytochrome P450 isozymes and to determine whether these effects are clinically significant.

Effect of supervised exercise intervention on metabolic risk factors and physical fitness in Chinese obese children in early puberty

The aim of this paper was to study the effect of long-term supervised exercise-induced weight maintenance on metabolic risk factors and physical fitness in obese children in early puberty. A total of 49 obese children aged 12-14 years were divided into control and exercise groups. The children in the exercise group accepted exercise intervention supervised by a professional sports teacher for 9 of the 12 months. All participants in both groups received health education once every 3 months. Anthropometry and fasting serum lipids, glucose, insulin and homeostatic model assessment for insulin resistance (HOMA-IR) were measured at months 0, 3, 9, 12 of the intervention. Physical fitness was determined before and after intervention. After the intervention (i) BMI was reduced by 0.6 (P < 0.05) in the exercise group, but increased by 0.5 (P < 0.05) in the control group, compared with the pre-intervention level at the end of 9-month intervention; (ii) Triglyceride levels in the exercise group significantly decreased by 23.1% by 3 months (P < 0.05), and by 30.2% after 9 months (P < 0.05), but increased by 50% (P < 0.05) in the control group; high density lipoprotein-cholesterol (HDL-C) decreased more by 35% (P < 0.05) in the controls than in the exercise group (P < 0.05); (iii) Fasting serum glucose, insulin level and HOMA-IR decreased, respectively, by 23.1%, 36.6% and 48.5% in the exercise group at 9 months (P < 0.05), whereas glucose levels increased by 10.9% (P < 0.05) in the control group; (iv) Exercise performance, such as upper- and lower-limb strength, flexibility and endurance, were enhanced by 17.9%, 12.3%, 22.3% and 20.4% (P < 0.01), respectively and (v) At 12 months, i.e. 3 months after terminating the supervised exercise, serum triglycerides, glucose, insulin and HOMA-IR level all returned to the pre-intervention level. Supervised decrement exercise can effectively slow the progress of obesity, improve insulin sensitivity and metabolic risk factors, but once the supervised exercise is stopped, the health benefits weaken or vanish. The key to helping these obese children is for them to cultivate good exercise habits which are sustained throughout their lives.