Identification and isolation of a BTB-POZ-containing gene expressed in oocytes and early embryos of the zebrafish Danio rerio

In this report, we describe the cloning of a cDNA from the zebrafish Danio rerio encoding a protein containing a BTB-POZ domain closely resembling the BTBD1 and BTBD2 proteins previously identified in mammals. However, unlike other BTB-POZ-containing genes, expression of this gene in adults is most abundant in oocytes, where the RNA can be detected at all stages of oogenesis examined. The presence of the RNA persists through early cleavage, but is decreased significantly by gastrulation. Although the function of this gene has yet to be determined, its resemblance to the BTB-POZ family of genes coupled with its expression pattern suggests that it may have an important function in oogenesis and (or) early zebrafish development.

A simple, reproducible method for monitoring the treatment of tumours using dynamic contrast-enhanced MR imaging

Dynamic contrast-enhanced MR imaging (DCE-MRI) may act as a biomarker for successful cancer therapy. Simple, reproducible techniques may widen this application. This paper demonstrates a single slice imaging technique. The image acquisition is performed in less than 500 ms making it relatively insensitive to respiratory motion. Data from phantom studies and a reproducibility study in solid human tumours are presented. The reproducibility study showed a coefficient of variation (CoV) of 19.1% for K^trans and 15.8% for the initial area under the contrast enhancement curve (IAUC). This was improved to 16 and 13.9% if tumours of diameter less than 3 cm were excluded. The individual repeatability (the range within which individual measurements are expected to fall) was 30.6% for K^trans and 26.5% for IAUC for tumours greater than 3 cm diameter. This approach to DCE–MRI image acquisition can be performed with standard clinical scanners, and data analysis is straightforward. For treatment trials with 10 patients in a cohort, the CoV implies that the method would be sensitive to a treatment effect of greater than 18%. The individual repeatability is well inside the 40% change shown to be important in clinical studies using this DCE–MRI technique.

The elective use of oxytocin infusion during labour in nulliparous women using epidural analgesia: a randomised double-blind placebo-controlled trial

The obstetric outcome following the elective use of oxytocin infusion was determined in a randomised, double-blind placebo-controlled trial. 93 nulliparous women in a London hospital, who had requested epidural analgesia in labour (</= 6 cm.), were given an infusion of oxytocin (n = 46) or placebo (n = 47). The initial epidural dose was 15 ml of 0.125% bupivacaine, followed by an infusion at 10 ml per h, with 15 ml top-ups if required. When oxytocin was used electively there was a reduction in the length of the first stage of labour from 696 min to 578 min, (P < 0.05) even though more than half of the control group (53%) required oxytocin augmentation. There was no significant difference between the number of operative deliveries (34 [74%] vs 35 [74%]). The rotational delivery rate was less in the study group (2 [4%] vs 5 [11%]), though this did not reach significance. There were no adverse effects on the fetus, as judged by cord pH measurement, Apgar score, admission to the special care baby unit and neonatal jaundice. The prophylactic use of oxytocin in nulliparous women with epidurals reduces the length of the first stage of labour and appears to be safe. It does not reduce the operative delivery rate.

Assessment of infant physiology and neuronal development using magnetic resonance imaging

Previous work has demonstrated both that there are substantial individual differences in the rate of physiological development,and that infants with risk factors for Sudden Infant Death Syndrome (SIDS) develop more slowly, suggesting that their increased vulnerability may be due to delayed neuronal development associated with compromised development in fetal or early neonatal life. This project aims to test the hypothesis that individual differences in the rate of physiological development of infants correlate with measurable differences in the rate of brain development as assessed by magnetic resonance imaging (MRI). Sixty infants were recruited to this study in three different groups that are known to have differing rates of physiological development. MRI was performed successfully in 49 cases at 6 weeks of age without sedation. Forty-one of these cases had full follow-up (15 normal; 19 IUGR; 11 'high risk'). Postnatal physiological development was assessed by measuring age-related deep body temperature patterns during sleep. Neuronal development was assessed by subjective analysis of MRI images and objective measurements relating to myelination using T1 and diffusion weighted (23 cases) MRI images. As expected the normal group acquired the adult temperature pattern earlier, but this was not statistically significant. All MRI scan appearances were within normal limits. Ranking cases subjectively in order of maturity revealed no significant pattern. The normal group had a significantly higher myelination score than the IUGR and 'high risk' groups (P = 0.001). This trend was also shown by the diffusion weighted myelination score but did not reach statistical significance. No significant differences were seen in both the subjective and objective MRI measurements and development of nocturnal temperature patterns. The results suggest there may be differences in neurodevelopment between the different groups at 6 weeks of age but these are not linked to late development of temperature patterns. It is therefore unlikely that this related to a global delay in maturation.

Effects of combined ozone and air pollution particle exposure in mice

Epidemiologic studies indicate that ozone (O3*) and air pollution particles can exacerbate asthma symptoms. We investigated whether coexposure to inhaled particles and O3 causes a synergistic effect on airway responsiveness and allergic inflammation in a murine (BALB/c) model of ovalbumin (OVA)-induced asthma. Half of the mice were sensitized by intraperitoneal injection of OVA and then exposed to OVA aerosol on 3 successive days to create the asthmatic phenotype; the other half were sensitized to OVA and exposed to phosphate-buffered saline (PBS) to create the nonasthmatic control group. On the same 3 days that the OVA or PBS challenge was administered, mice were further divided into groups that were exposed for 5 hours to concentrated ambient particles (CAPs; mass values ranging from 63 to 1,569 microg/m3 for 1 day's exposure), 0.3 ppm O3, both, or neither (n > or = 61 total mice per exposure group for all 12 experiments). Whole-body plethysmography was used to measure airway responsiveness after challenge with aerosolized methacholine (MCh). Enhanced pause (Penh), an index that closely correlates with pulmonary resistance (Hamelmann et al 1997), was measured daily in each mouse immediately after pollutant exposure and, for 7 of the 12 experiments (n > or = 36/exposure group), beginning 24 hours after the final OVA or PBS challenge. Using several complementary statistical models, we found that exposure to CAPs alone caused a small but significant increase in Penh in both normal and asthmatic mice immediately after exposure (an increase of approximately 1% per 100-microg/m3 increase in CAPs). No increase in Penh was found in animals exposed to O3 alone or to filtered air. Compared with control animals, no combination of exposure atmosphere plus asthma produced a synergistic effect on Penh. By 24 hours after the last OVA or PBS challenge, any enhanced response induced by pollutant exposure had declined to control levels. The pollutant exposures did not significantly increase airway inflammation (assessed by bronchoalveolar lavage [BAL] fluid analysis beginning 24 or 48 hours after the final OVA or PBS challenge). Because CAPs are a heterogeneous mixture of particles, elemental analysis was conducted and associations between specific elemental groupings (present in daily samples) and airway responsiveness were analyzed. This analysis showed that increased Penh in asthmatic mice exposed to CAPs plus O3 was associated with the AlSi fraction of CAPs. No such association was found in control mice or in asthmatic mice not exposed to O3. We conclude that CAPs exposure causes an immediate, short-lived (< 24-hour), small increase in airway responsiveness in mice and that changes in airway physiology are correlated with specific elements found within the particle mixture.

An audit of hip radiographs performed for general practitioners

AIM

We carried out a prospective study of the GP referrals for hip radiographs to find out the proportion of radiographs falling within the RCR guidelines and to ascertain the reasons for not following the guidelines.

MATERIALS AND METHODS

One thousand two hundred and fifty six consecutive hip radiographs were performed for GPs over a 12-month period. Questionnaires were sent to GPs for 873 referrals during an audit period of 18 months Four hundred and fifty three questionnaires were returned with adequate information. The proportion of change in management between the patients falling within the guidelines and those outside the guidelines was compared using Fisher's Exact Test (SPSS Package Version 9) and the corresponding 95% confidence interval (CI) was calculated.

RESULTS

Only 194 (43%) of the 453 referrals were within RCR guidelines and 259 (57%) were outside guidelines. In the group where RCR guidelines were followed, 60% were normal, 34% had degenerative changes and 6% other diagnoses. The radiological reports changed management in 44%. In the group where guidelines were not followed 76% were normal, 18% had degenerative changes and 6% other diagnoses. The radiological reports changed management in 37%. There was no evidence of difference in the change in management between these two groups. Twenty per cent of the radiographs showed abnormalities other than hip changes. Of these, only 17% were abnormalities other than degenerative changes and considered significant.

CONCLUSIONS

This audit does not reveal why the majority of the requests fell outside guidelines. This may be due to lack of awareness amongst GPs about guidelines, patient pressure, medico-legal problems and the need for reassurance. However, the audit does not show any evidence that following guidelines would increase efficiency of referral.

The use of dilute Calogen as a fat density oral contrast medium in upper abdominal computed tomography, compared with the use of water and positive oral contrast media

AIM

Oral contrast media are commonly given prior to computed tomography (CT) examination of the upper abdomen. Although positive oral contrast media are normally used, there is increasing interest in using negative agents such as water and less commonly fat density products. The aim of this study was to compare a positive oral contrast medium, water, and a diluted emulsion of arachis oil Calogen, a fat density food supplement) for assessment of the upper abdomen.

MATERIALS AND METHODS

Seventy-one patients referred for upper abdominal CT were randomized to receive either 500 ml water, 2% sodium diatrizoate or a dilute suspension of Calogen. The CT images were scored independently by three radiologists. Distension and anatomical identification was assessed for the stomach, duodenum and jejunum; with anatomical identification recorded for the pancreas, retroperitoneum, liver, gallbladder and spleen.

RESULTS

Dilute Calogen produced a significant improvement (P < 0.01) in distension and anatomical visualization of the stomach and proximal duodenum. Only minimal differences were demonstrated between the three contrast media for visualization of more distal small bowel or identification of the other upper abdominal viscera. Significantly more artifacts were caused by positive contrast media than with the Calogen mixture.

CONCLUSION

A dilute suspension of Calogen as an oral contrast medium is recommended when disease is suspected within the stomach or proximal duodenum.

Induction of apoptosis in prostate carcinoma cells by BH3 peptides which inhibit Bak/Bcl-2 interactions

Interactions between proteins of the Bcl-2 family play an important role in the regulation of apoptosis. Anti-apoptotic family members can heterodimerize with pro-apoptotic family members and antagonize their function, thus protecting against death. In cells protected from death by overexpression of Bcl-2 much of the Bax is present in Bax/Bcl-2 hetero-multimers and its death signal is blocked as it cannot homodimerize. This led us to use the Bcl-2/Bax heterodimer as a target for new compounds which may provide a therapy particularly suited to tumour cells for which resistance to conventional therapy is associated with elevated expression of Bcl-2. We assessed whether apoptosis could be induced in prostate tumour cells by blocking this heterodimerization with synthetic peptide sequences derived from the BH3 domain of pro-apoptotic Bcl-2 family members. Prostate cells were found to undergo up to 40% apoptosis 48 h following the introduction of synthetic peptides from the BH3 domains of Bax and Bak. The caspase inhibitor z-VAD.fmk provided protection against apoptosis mediated by these peptides. Immunoprecipitation studies revealed that introduction of peptides derived from the BH3 regions of Bak and Bax into cells blocked Bak/Bcl-2 heterodimerization. These data suggest that by blocking the dimerization through which Bcl-2 would normally inhibit apoptosis the apoptotic pathway driven by Bak was re-opened.

Assessing Wolf motor function test as outcome measure for research in patients after stroke

BACKGROUND AND PURPOSE

The Wolf Motor Function Test (WMFT) is a new time-based method to evaluate upper extremity performance while providing insight into joint-specific and total limb movements. This study addresses selected psychometric attributes of the WMFT applied to a chronic stroke population.

METHODS

Nineteen individuals after stroke and with intact cognition and sitting balance were age- and sex-matched with 19 individuals without impairment. Subjects performed the WMFT and the upper extremity portion of the Fugl-Meyer Motor Assessment (FMA) on 2 occasions (12 to 16 days apart), with scoring performed independently by 2 random raters.

RESULTS

The WMFT and FMA demonstrated agreement (P<0.0001) between raters at each session. WMFT scores for the dominant and nondominant extremities of individuals without impairment were different (P</=0.05) from the more and less affected extremities of subjects after stroke. The FMA score for the more affected extremity of subjects after stroke was different (P</=0.05) from the dominant and nondominant extremities. However, the FMA score for the less affected upper extremity of individuals after stroke was not different (P>0.05) from the dominant and nondominant extremities of individuals without impairment. The WMFT and FMA scores were related (P<0.02) for the more affected extremity in individuals after stroke.

CONCLUSIONS

The interrater reliability, construct validity, and criterion validity of the WMFT, as used in these subject samples, are supported.

Novel non-peptide ligands for the somatostatin sst3 receptor

A series of imidazole derivatives has been prepared using high throughput parallel synthesis. Several compounds showed high affinity (Ki in 10(-6)-10(-8) M range) and selectivity at recombinant human somatostatin receptor subtype 3 (hsst3).

Identification of novel DKC1 mutations in patients with dyskeratosis congenita: implications for pathophysiology and diagnosis

Dyskeratosis congenita (DC) is characterised by the failure of those tissues that are rapidly dividing in the adult, particularly the skin and haemopoietic system. The X-linked form of the disease is caused by mutations in the DKC1 gene. To date the only DKC1 mutations detected result in alterations in the amino acid sequence of dyskerin. Dyskerin is the catalytic subunit of the H+ACA box small nucleolar RNA particles responsible for the site-specific pseudouridination of rRNA and in humans is also a component of the telomerase complex. In order to further characterise the disease at the molecular level, male DC patients from 25 families were screened for mutations in the DKC1 gene. Sequence variations were detected in 10 of these families. In five families, previously identified mutations were detected. Of the five novel sequence changes, three were coding changes: R158 W, S280R and P384L. A fourth sequence change was detected in the 5'-flanking region that disrupts a putative Spl transcription factor binding site. An intronic change was also detected that resulted in the partial incorporation of a portion of intron 1 into the mRNA. The identification of this mutation highlights the importance of screening for mutations that cause the partial aberrant splicing of mRNA. This is the first report of DKC1 mutations that are predicted to affect the level of expression of dyskerin. This suggests that a decrease in the amount of the normal protein may cause the disease.

Synthesis of substituted imidazopyrazines as ligands for the human somatostatin receptor subtype 5

A new preparation of trisubstituted imidazopyrazines and dihydroimidazopyrazines via parallel synthesis using aminoacids and bromoketones resulted in the discovery of non-peptidic sst5 selective agonists.

Inhibition of human tumor cell growth in vivo by an orally bioavailable inhibitor of human farnesyltransferase, BIM-46228

Oncogenic mutations of the ras gene leading to constitutive activation of downstream effectors have been detected in a wide spectrum of human cancers (pancreas, thyroid, colon, non-small-cell lung cancer). Membrane anchorage of Ras, required for functional activity in signal transduction, is facilitated by post-translational modifications resulting in covalent attachment of a farnesyl group to the cysteine in the C-terminal CAAX motif. This attachment is mediated by farnesyltransferase (FTase). Here, we report a novel FTase inhibitor, BIM-46228, which showed (i) specific inhibition of purified human FTase enzyme, (ii) inhibition of proliferation in vitro in a large spectrum of human tumor cell lines, (iii) inhibition of growth of human tumor xenografts in athymic nude mice treated by per os administration and (iv) the benefits of in vitro combination of its activity with chemotherapy or radiotherapy.

A comparison of dry powder inhaler dose delivery characteristics using a power criterion

A novel method is described that compares the in vitro drug delivery characteristics of different dry powder inhalers (DPIs) based on the power supplied by the air flow. Power is defined as the rate at which work is done by the air flow and is equal to the product of pressure gradient and air flow rate through the inhaler. Tests were conducted to compare the emitted dose and fine particle fraction of the total dose (FPFTD) of the Diskus, Diskhaler, and a proprietary powder dispersion device (PDD) containing fluticasone propionate/lactose powder blends. Three power levels were selected: 1, 2, and 3 W, representing a range of inspiratory efforts. The Diskus and PDD were independent of power, delivering consistent doses and fine particle fractions over the range of powers evaluated. Diskhaler was dependent on power, the emitted dose and FPFTD significantly decreasing at the lower power level (1W) (p < 0.005). Diskus and Diskhaler are trademarks of the Glaxo Wellcome group of companies.

Enzymatic kinetic resolution of piperidine atropisomers: synthesis of a key intermediate of the farnesyl protein transferase inhibitor, SCH66336

The resolution of secondary amines via enzyme-catalyzed acylation is a relatively rare process. The kinetic resolution of a series of intermediates of SCH66336 (1), by either enzymatic acylation of the pendant piperidine (4, 5) or hydrolysis of the corresponding carbamate 3, was investigated. In the case of 4, the molecule exists as a pair of enantiomers due to atropisomerism about the exocyclic double bond. The enzymatic acylation of (+/-)-4 was optimized in terms of acylating agent, solvent, and moisture content. The use of lipase, Toyobo LIP-300, and trifluoroethyl isobutyrate as acylating agent resulted in isobutyrylation of the (+)-enantiomer, which is easily separated from the unwanted (-)-4. Hydrolysis of the isobutyramide 6c yielded the desired (+)-4 in high enantiomeric excess. (-)-4 may be recovered from the resolution step, racemized, and resubjected to enzymatic acylation to increase material throughput.