The use of melatonin as an alternative to sedation in uncooperative children undergoing an MRI examination

AIM

Children who are uncooperative, due either to their age or medical condition, usually require sedation or a general anaesthetic (GA) to ensure immobility during magnetic resonance imaging (MRI) examination. These procedures have a risk of respiratory compromise and loss of vital reflexes. Melatonin induces a natural sleep with no known complication or risk of respiratory compromise. We aimed to evaluate the use of melatonin in these uncooperative children.

MATERIAL AND METHODS

An unselected group of 40 children, who had been referred for an MRI examination of the brain under sedation or GA, were chosen to receive melatonin instead. They all received 10 mg of melatonin and 17 children additionally underwent some form of sleep deprivation. The number of children who went to sleep and had a successful MRI examination was recorded.

RESULTS

Twenty-six children (65%) went to sleep and of these 22 (55%) had a successful MRI examination. In the 17 children who underwent sleep deprivation, 13 (76%) went to sleep and had a successful MRI examination. There was no complication.

CONCLUSIONS

Melatonin may provide an alternative to conventional sedation regimes and GA for uncooperative children undergoing an MRI examination. The use of sleep deprivation improves the success rate and there is no risk of respiratory compromise.

In vitro and in vivo (SCID mice) effects of phytosterols on the growth and dissemination of human prostate cancer PC-3 cells

The dietary effect of phytosterols (PS) versus cholesterol on the growth and metastasis of the PC-3 human prostate cancer cells in SCID mice was studied. Also, their direct effect on the growth and migration of these cells in vitro was analysed. In the in vivo experiment, SCID mice were fed a diet containing 2% of either PS mixture or cholesterol plus 0.2% cholic acid and implanted with 2 x 10(6) tumour cells per mouse. Tumour growth was monitored for 8 weeks post inoculation. Animals fed the PS diet had tumours 40-43% smaller than those fed the cholesterol diet. Furthermore, the number of mice with lymph node and lung metastasis was almost one-half that of the cholesterol-fed group. In the in vitro studies, both beta-sitosterol and campesterol inhibited the growth of PC-3 cells by 70% and 14%, respectively, while cholesterol supplementation increased the growth by 18% when compared with controls. PS inhibited the invasion of PC-3 cells into Matrigel-coated membranes by 78% while cholesterol increased it by 43% as compared with the cells in the control media. Migration of tumour cells through 8 microm pore membranes was reduced by 60-93% when the PC-3 cells were in PS media, as compared with a 67% increase after cholesterol supplementation. PS supplementation reduced the binding of PC-3 cells to laminin by 15-38% and fibronectin by 23% while cholesterol increased binding to type IV collagen by 36%. It was concluded that PS indirectly (in vivo as a dietary supplement) and directly (in tissue culture media) inhibited the growth and metastasis of PC-3 cells. beta-Sitosterol was more effective than campesterol in offering this protection in most of the parameters studied.

Clinical standards for specialist community rehabilitation services in the UK

OBJECTIVE

To develop a set of clinical standards for specialist community rehabilitation services in the UK and to undertake a preliminary survey of consultants who provide those services.

DESIGN AND METHODS

The proposed set of standards was adapted from the previously published standards for inpatient services, by a working party of the British Society for Rehabilitation Medicine (BSRM). Consensus was then achieved by an iterative consultation process in five rounds. A postal survey was conducted on behalf of the BSRM amongst its consultant members providing community rehabilitation services in the UK, who were asked to assess their services in relation to these standards, and to comment on the standards themselves, their usefulness and applicability.

RESULTS

Fifty consultants who ran specialist community rehabilitation services agreed to participate, of whom 29 (58%) actually responded. Overall, the standards appeared to be acceptable to most, and mainly struck the right level, being attained by the majority of services. Twenty-five (89%) felt the standards were helpful and 26 (93%) felt that they covered the main aspects of specialist community rehabilitation services: 23 (79%) found them at least partially applicable to their own service.

CONCLUSIONS

Proposed clinical standards have been developed for specialist community rehabilitation services in the UK. It is likely that they will require further refinement with time, and modification is required to adapt them to different subspecialities and settings.

Glutamate-loading stimulates metabolic flux and improves cell recovery following chemical hypoxia in isolated cardiomyocytes

The amino acid glutamate is used in cardioplegic solutions, yet evidence is conflicting as to whether or not exogenous glutamate is indeed cardioprotective. This controversy may be because increasing extracellular glutamate does not necessarily lead to an increase in intracellular glutamate. In this study we aimed to determine whether isolation of myocytes in the presence of glutamate resulted in glutamate-loading of the cells, and, if so, whether such loading protected myocytes from simulated (chemical) hypoxia. Single ventricular myocytes were isolated from rat hearts in the presence and absence of 6.4 mM glutamate. Levels of glutamate and ATP were determined using HPLC, and NADH/NAD(+) was determined from cell autofluorescence. Chemical hypoxia was induced by superfusion with a solution containing 2.5 mM cyanide and no glucose. Intracellular [Ca(2+)] was measured by loading cells with indo-1, and cell length was measured using an edge-tracking device. Isolation of myocytes in the presence of glutamate resulted in increased intracellular glutamate levels compared with cells isolated in the absence of glutamate, 1324+/-108 v 948+/-124 pmol/mg protein, respectively (P<0.05). Cells loaded with glutamate showed increased NADH/NAD(+), (0.384+/-0.032 v 0.281+/-0.029, P<0.05) and greater ATP levels (36.031+/-1.633 nmol/mg protein v 19.279+/-3.327 nmol/mg protein, P<0.005) compared to control cells. When subjected to chemical hypoxia, cells underwent rigor-contracture at various timepoints, and were then reperfused following 5 min in rigor. Cells loaded with glutamate showed better recovery of diastolic [Ca(2+)], Ca(2+) transient amplitude, and improved contractile function compared with cells isolated in absence of glutamate. This study demonstrates an efficient method for loading myocytes with glutamate during cell isolation, and myocytes loaded with glutamate showed increased metabolic flux, as indexed by a higher NADH/NAD(+) and ATP content. Myocytes also exhibited better recovery from chemical hypoxia in terms of both Ca(2+) handling and cell contraction.

Choreography of song, dance and beak movements in the zebra finch (Taeniopygia guttata)

As do many songbirds, zebra finches sing their learned songs while performing a courtship display that includes movements of the body, head and beak. The coordination of these display components was assessed by analyzing video recordings of courting males. All birds changed beak aperture frequently within a single song, and each individual’s pattern of beak movements was consistent from song to song. Birds that copied their father’s songs reproduced many of the changes in beak aperture associated with particular syllables. The acoustic consequences of opening the beak were increases in amplitude and peak frequency, but not in fundamental frequency, of song syllables. The change in peak frequency is consistent with the hypothesis that an open beak results in a shortened vocal tract and thus a higher resonance frequency. Dance movements (hops and changes in body or head position) were less frequent, and the distribution of dance movements within the song was not as strongly patterned as were changes in beak aperture, nor were the peaks in the distribution as strongly marked. However, the correlation between the positioning of dance movements within fathers’ and sons’ songs was striking, suggesting that the choreography of dance patterns is transmitted from tutor to pupil together with the song.

A QuickTime movie of a courtship display used in this study can be found at: http://www.williams.edu/Biology/ZFinch/zfdance.html.

Characteristics of L-aspartate transport and expression of EAAC-1 in sarcolemmal vesicles and isolated cells from rat heart

OBJECTIVE

L-Aspartate is an important intermediary metabolite in the heart and has also been implicated in myocardial protection, but little is known about its transport across the cardiac sarcolemma. In this study we have tested the hypothesis that the high affinity sodium-dependent aspartate transporter, EAAC-1 is expressed in heart and have also characterised aspartate transport into the myocardium.

METHODS

Characteristics of L-[14C]aspartate uptake into rat heart were investigated using sarcolemmal vesicles and isolated myocytes. The expression of EAAC-1 in the two preparations was also investigated by western blotting.

RESULTS

The K(m) and V(max) of L-aspartate uptake was 9.78+/-0.7 microM and 1.17+/-0.27 pmol/mg/s in vesicles compared to 6.53+/-1.24 microM and 13.65+/-1.0 pmol/microl/s in cells. In vesicles, L-aspartate uptake was dependent on external sodium and internal potassium, and was rheogenic. In cells, L-aspartate uptake was also dependent on external sodium. Addition of unlabelled L- and D-aspartate and L-glutamate significantly inhibited L-[14C]aspartate uptake in both preparations but D-glutamate had no effect. An antibody to the aspartate transporter, EAAC-1 recognised a protein of appropriate size in both vesicles and cells.

CONCLUSIONS

L-aspartate uptake in heart is mediated by a high affinity sodium-dependent transporter. This is accompanied by the expression in heart of EAAC-1. The physiological significance of this transporter with respect to aspartate utilisation in the heart is discussed.

Psychosocial factors and adherence to treatment advice in childhood atopic dermatitis

Poor adherence to maintenance treatment for atopic dermatitis and anxiety about using topical steroids are common features seen among children with atopic dermatitis and their mothers. No systematic study exploring factors associated with adherence to treatment advice on atopic dermatitis has been carried out to date. This study seeks to generate hypotheses regarding the relationship between a range of psychosocial factors and adherence to treatment advice on atopic dermatitis. An anonymous self-completed questionnaire containing adherence items, psychosocial items, some demographic items, and attitudes to steroid use was given to 258 mothers of atopic dermatitis follow-up patients who attended the National Children's Hospital, Tokyo. Responses from 205 families (80%) with complete data were then analyzed to explore the correlation between each factor and to build a structure equation model. The strongest predictor of adherence to skin-care treatment was a good doctor-patient (mother) relationship, followed by the severity of the disease as perceived by the mother. Surprisingly, the mother's anxiety about using topical steroids had no significant influence on reported use of topical steroids nor on adherence to skin-care treatment. This may have been overcome by the well-established doctor-patient (mother) relationship. Maternal personality, husband's cooperation, and social support were indirectly correlated with adherence via the doctor-patient relationship. Maternal self-efficacy of treatment was strengthened by good doctor-patient (mother) relationship.

The effects of ketamine-xylazine anesthesia on cerebral blood flow and oxygenation observed using nuclear magnetic resonance perfusion imaging and electron paramagnetic resonance oximetry

Ketamine-xylazine is a commonly used anesthetic for laboratory rats. Previous results showed that rats anesthetized with ketamine-xylazine can have a much lower cerebral partial pressure of oxygen (P(t)O(2)), compared to unanesthetized and isoflurane anesthetized rats. The underlying mechanisms for the P(t)O(2) reduction need to be elucidated. In this study, we measured regional cerebral blood flow (CBF) using nuclear magnetic resonance (NMR) perfusion imaging and cortical P(t)O(2) using electron paramagnetic resonance (EPR) oximetry in the forebrain of rats under isoflurane, ketamine, ketamine-xylazine and isoflurane-xylazine anesthesia. The results show that in ventilated rats ketamine at a dose of 50 mg/kg does not induce significant changes in CBF, compared to isoflurane. Ketamine-xylazine in combination causes 25-65% reductions in forebrain CBF in a region-dependent manner. Adding xylazine to isoflurane anesthesia results in similar regional reductions in CBF. EPR oximetry measurements show ketamine increases cortical P(t)O(2) while xylazine decreases cortical P(t)O(2). The xylazine induced reduction in CBF could explain the reduced brain oxygenation observed in ketamine-xylazine anesthetized rats.

Comparison of external dacryocystorhinostomy and 5-fluorouracil augmented endonasal laser dacryocystorhinostomy. A retrospective review

PURPOSE

To compare the success rates of external dacryocystorhinostomy (EXT-DCR) with 5-fluorouracil (5-FU) augmented endonasal laser dacryocystorhinostomy (ENL-DCR) and to record the complications associated with 5-FU augmented ENL-DCR MATERIALS AND METHODS: This was a retrospective non-randomised study. Forty-one patients with primary acquired nasolacrimal duct obstruction underwent an EXT-DCR (19 patients) or an ENL-DCR (22 patients) over a 3-year period. A Holmium YAG laser (Ho:YAG) was used in the latter group of patients. Silicone tubes intubated in all patients were removed at three months. 5-FU was applied intraoperatively at the site of the ostium in the ENL-DCR patients. The median follow-up was 12 months (range 3-24 months) for the ENL-DCR group and 22 months (range 6-28 months) for the EXT-DCR group. The patency of the lacrimal system and the severity of epiphora were assessed at a final-review.

RESULTS

The median age of the EXT-DCR group was 77 years (range 53-87) and that of the ENL-DCR group was 71 years (range 23 to 84). There were 12 female patients in the former group and 19 in the latter. The percentage of success in the EXT-DCR group was 94.7% (95% confidence interval (CI) = 75.4-99.1) = ), and 63.6% in the ENL-DCR group (95% CI= 43.0-80.3). The confidence interval for the difference of 31.1% was 5.6-52.2. There was a statistically significant difference between the two groups, p=0.024 (Fisher exact test).

CONCLUSIONS

These data suggest that EXT-DCR provides better results than 5-FU augmented ENL-DCR. However, ENL-DCR is the procedure of choice in certain circumstances such as in elderly, frail or medically unfit patients. Our results of 5-FU augmented ENL-DCR compare favourably with other published series.

Use of fluorescent Ca2+ dyes with green fluorescent protein and its variants: problems and solutions

We have studied the degree to which fluorescent Ca(2+) indicator dyes, and green fluorescent protein and its variants, can be used together. We find that the most commonly used fluorescent protein, enhanced green fluorescent protein (EGFP), seriously contaminates fura 2 signals. We suggest two alternative combinations for which there is no detectable contamination of the Ca(2+) indicator signal by the fluorescent protein. Blue fluorescent protein can be used with the Ca(2+) indicator Fura Red; EGFP can be used with the Ca(2+) indicator X-Rhod 1. The use of these combinations will permit the accurate measurement of Ca(2+) signals in cells transfected with fluorescent proteins.

Thermal capsular shrinkage for shoulder instability

We present the short- and medium-term clinical results of thermal shrinkage in selected groups of patients with multidirectional or capsular stretch-type instability. We treated 56 patients (61 shoulders) by laser-assisted capsular shrinkage (LACS) and 34 patients (38 shoulders) by radiofrequency (RF) capsular shrinkage. The two groups were followed for mean periods of 40 months and 23 months, respectively.

In the LACS group the mean Walch-Duplay score improved to 90 points 18 months after the operation, but then declined to a plateau of about 80 points; 59% of patients considered their shoulders to be ‘much better’ or ‘better’ but there was a failure rate of 36.1%. For the RF group the mean Walch-Duplay and Constant scores were 80 points at the various follow-up times; 76.3% of patients considered their shoulder to be ‘much better’ or ‘better’. RF failed in nine shoulders (23.7%). These results match some clinical series of patients with multidirectional instability, undergoing open inferior capsular shift, with a similar rate of failure. We believe that the minimal morbidity involved makes thermal shrinkage a viable alternative to open capsular shift in this difficult group of patients.

Thermal capsular shrinkage for shoulder instability. Mid-term longitudinal outcome study

We present the short- and medium-term clinical results of thermal shrinkage in selected groups of patients with multidirectional or capsular stretch-type instability. We treated 56 patients (61 shoulders) by laser-assisted capsular shrinkage (LACS) and 34 patients (38 shoulders) by radiofrequency (RF) capsular shrinkage. The two groups were followed for mean periods of 40 months and 23 months, respectively. In the LACS group the mean Walch-Duplay score improved to 90 points 18 months after the operation, but then declined to a plateau of about 80 points; 59% of patients considered their shoulders to be 'much better' or 'better' but there was a failure rate of 36.1%. For the RF group the mean Walch-Duplay and Constant scores were 80 points at the various follow-up times; 76.3% of patients considered their shoulder to be 'much better' or 'better'. RF failed in nine shoulders (23.7%). These results match some clinical series of patients with multidirectional instability, undergoing open inferior capsular shift, with a similar rate of failure. We believe that the minimal morbidity involved makes thermal shrinkage a viable alternative to open capsular shift in this difficult group of patients.

Jet ventilation via a Univent tube for sleeve pneumonectomy

A 51-year-old man presented with a right upper lobe adenocarcinoma with carinal extension. He underwent a right sleeve pneumonectomy, which involved a carinal resection with anastomosis between the trachea and left main bronchus. This report describes the successful use of jet ventilation, administered via the lumen of the bronchial blocker of a Univent tube. During 15 min of carinal resection, oxygenation of his left lung was maintained with the bronchial blocker bridging the airway discontinuity.

Association analysis of NOTCH4 loci in schizophrenia using family and population-based controls

A genetic association between NOTCH4 and schizophrenia has previously been proposed. Unsing all markers previously shown to be associated, we found no evidence for such in three independent family-based samples (n=519 parent-offspring trios), and a case-control sample derived from the same ethnic background as the original observation. These data strongly suggest that NOTCH4 is not a significant susceptibility allele for schizophrenia.

Association of tumour necrosis factor alpha and interleukin 6 levels with cytomegalovirus DNA detection and disease after renal transplantation

Cytokines such as tumour necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) are thought to be important in the pathogenesis of post-transplant cytomegalovirus (CMV) disease. CMV infection increases the production of TNF-alpha and IL-6. Conversely, TNF-alpha switches on the replication of CMV. To study the association of these two cytokines with CMV activity and disease, TNF-alpha and IL-6 levels were assayed in plasma samples taken serially from three groups of renal transplant recipients. Group A (n = 12) had CMV disease and syndrome; Group B (n = 11) had detectable CMV DNA in plasma or peripheral blood leucocytes without disease, i.e., presumed asymptomatic CMV infection, and Group C (n = 11) had no detectable CMV DNA nor disease. The median peak TNF-alpha levels in patients with CMV disease (Group A) were significantly higher than that in Group B or Group C (P < 0.02) whereas the median peak IL-6 levels in group C patients were significantly lower than that in group A (P < 0.04) or group B (P < 0.03). A TNF-alpha level of above 100 pg/ml was significantly associated with CMV disease and high plasma CMV load (> 10,000 copies/ml). IL-6 levels above 15 pg/ml were significantly associated with CMV DNA detection, but not with CMV disease or elevated CMV load. High levels of TNF-alpha or IL-6 were not associated with CMV donor/recipient serostatus, HHV-6 or HHV-7 DNA detection, immunosuppressive regimen or rejection episodes. The role of TNF-alpha in the pathogenesis of CMV disease deserves further investigation.