A PET imaging study of the vascular disruptive agent OXi4503 to confirm in vivo mechanism of action in a phase I trial

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Background: OXi4500, the active product of OXi4503, reversibly binds at the colchicine binding site on the ß subunit of tubulin. This study investigated its mechanism of action using PET molecular imaging Methods: OXi4503 was administered by 3 weekly IV infusions in a phase 1 trial (32 pts). Between 1.6 & 15.4 mg/m2 dose levels, PET imaging was performed with 15O-labelled water (measuring blood perfusion) pretreatment & at 90min & 24hr after first infusion (8pts) & at 28days (1 pt). [18F]fluorodeoxyglucose (FDG) (measuring proliferative activity) was performed pretreatment & at 28 days (9pts) Results: 9 pts (mean age 48.5yrs) were studied: CRC (2), pancreatic (1), MM (6). 2 pts with MM (3.8 & 6.5 mg/m2) achieved stable disease. Toxicity included pyrexia, lethargy & hypertension. There was a dose-dependent linear increase in peak plasma concentrations & AUC of OXi4503 & OXi4500. Sustained tumour blood perfusion reduction (50% at 90min & 24hr) was seen in all metastases in the CRC pt treated at 15.4 mg/m2 after just one dose & resulted in FDG reduction (23% in all 5 mets) & tumor marker response. Doses between 1.9 & 11.0 mg/m2 produced dose independent reductions in tumour perfusion which were more variable & less marked with 3/8 pts showing a reduction in tumour FDG uptake. The 1pt studied at 28 days (8.5 g/m2) showed further sustained reduction in tumour blood flow (40%). Variable dose independent changes in normal tissue perfusion were seen at all dose levels eg in 3/4 pt splenic perfusion showed a dose-independent decrease (20–30%) at 90min with recovery at 24hr Conclusions: OXi4503 shows significant activity at 15.4 mg/m2 in line with its proposed mechanism of action. Characterisation of the mixed tumour perfusion response at lower doses will aid planning & assessing combination studies. The MTD is now being identified. Sponsored by CRUK.

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Verifiable CPD paper: oral health of remand prisoners in HMP Brixton, London

OVERVIEW

This study investigated the general and oral health status and behaviours and the dental treatment requirements of remand prisoners. It makes recommendations on how their oral health care needs may be met.

METHOD

A convenience sample of 78 remand prisoners participated in the study within HMP Brixton. The study involved a structured interview, to establish health status and behaviours as well as perceived oral health needs, combined with an oral examination to establish normative treatment need.

RESULTS

Prisoners' general health was compromised. In particular, there were high levels of mental illness and infectious disease. Unhealthy behaviours such as tobacco smoking, alcohol use, drug dependency, and high sugar diets were commonplace. This affected the remand prisoners' oral health, which presented with high levels of decay and relatively low levels of both missing and filled teeth. Whilst prisoners made high use of prison dental services, they made little use of dental services outside of prison. The high turnover of remand prisoners and high demand for emergency care made the delivery of preventive and routine care difficult.

CONCLUSION

Remand prisoners have compromised general and oral health compared with the general population. They exhibit poor oral health, which is contributed to by their lifestyles and health behaviours.

Polarization Observations with the Cosmic Background Imager

Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum. This key agreement between the phase of the observed polarization spectrum and that predicted on the basis of the total intensity spectrum provides support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

A Meaningful Day Group approach to weight gain from antipsychotic medication

For clients who receive medical treatment for a severe and enduring mental health problem, antipsychotic medication is the first line of treatment. The adverse effects of these medications are well documented and can lead to discontinuation of therapy. The newer atypical antipsychotics would seem to have distinct advantages over more traditional substances but significant weight gain can be experienced. This group is an attempt to capitalize upon psychosocial approaches to this such that outcome may be enhanced. The following is a description of an attempt to implement such a group and to explore the outcome. The group has been devised by one of the manufacturers of atypical antipsychotic medication concerned by the side-effect to their product. The group is formatted on a computer disc ready to use by any mental health professional and freely available.

Functional properties of an agouti signaling protein variant and characteristics of its cognate radioligand

Agouti signaling protein (ASIP), the human (h) homolog of agouti, is an endogenous melanocortin peptide antagonist. To date, characterization of this protein has been performed with recombinant protein only and without the availability of an ASIP/agouti radioligand. In this report we describe the functional characteristics of a chemically synthesized truncated ASIP variant, ASIP-[90-132 (L89Y)], and the binding characteristics of its cognate radioligand, (125)I-ASIP-[90-132 (L89Y)]. Similar to full-length recombinant ASIP/agouti, ASIP-[90-132 (L89Y)] was a potent inhibitor of alpha-melanocyte-stimulating hormone cAMP generation at the cloned human melanocortin receptor (hMCR) subtypes hMC1R and hMC4R. It also displayed a lesser degree of inhibition at the hMC3R and hMC5R. However, ASIP-[90-132 (L89Y)] was found to be less potent than full-length recombinant ASIP and, surprisingly, only exhibited weak inhibitory activity at the hMC2R. In competition binding assays with the radioligand (125)I-ASIP-[90-132 (L89Y)], ASIP-[90-132 (L89Y)] displayed a hierarchy of binding affinity that roughly paralleled its rank order of inhibitory potency at the various MCR subtypes, i.e., hMC1R approximately hMC4R > hMC3R approximately hMC5R > hMC2R. Structure-activity studies revealed that ASIP-[90-132 (L89Y)] possessed greater pharmacological potency than either the further truncated ASIP variants ASIP-(116-132) or cyclo(CRFFRSAC). Interestingly, the latter molecules were both weak agonists at the hMC1R. These studies further support the concept that ASIP/agouti inhibits melanocortin action by directly binding to target MCRs and provide additional insight into the structural requirements for maximal inhibitory potency.

Patterns of abnormal FDG uptake by various histological types of non-small cell lung cancer at initial staging by PET

The aim of this study was to identify useful patterns of abnormal fluorine-18 fluorodeoxyglucose (FDG) uptake by different types of non-small cell (NSC) lung cancer and to assess their clinical implications. One hundred and three sequential patients with newly diagnosed, pathology-proven NSC lung cancer were included. FDG positron emission tomography (PET) images were acquired using a dedicated PET scanner. There were 35 squamous cell carcinomas (SQC), 17 large cell cancers (LGC), 38 adenocarcinomas (ADC), 1 bronchioloalveolar carcinoma (BAC) and 12 non-classified NSC cancers. PET images were categorized into detectable patterns of necrotic center in the primary tumor, satellite lesions (T4), hilar lymph nodes (N1), and N2, N3, and M1 lesions by visual interpretation of PET images for SQC, LGC, and ADC (n=90; BAC and non-classified NSC cancers were excluded). The PET lesions were correlated with surgical pathology and with CT findings in inoperable cases. Necrosis was more commonly present in the primary tumors of LGC (53%) and SQC (43%) than in those of ADC (26%) (P<0.0001 and <0.01, respectively). The frequencies of nodal uptake in ADC, SQC and LGC were similar (71%, 60%, and 59%, respectively). However, M1 lesions were present significantly more often in LGC (41%) and ADC (34%) than in SQC (3%) (both P<0.0001). Significantly more surgically inoperable cases were found by PET (T4, N3, M1) in ADC (50%) and LGC (41%) than in SQC (26%) (P<0.001 and <0.02, respectively). Our results suggest a wide variation of PET findings for different types of NSC lung cancer. Identification of these patterns is useful in clinical PET interpretation, in that knowledge of the most probable association between the PET patterns and the histological types will facilitate initial staging and planning of management.

The role of acupuncture in controlling the gagging reflex using a review of ten cases

The gagging reflex is a physiological reaction which safeguards the airway from foreign bodies. In some people this response is exaggerated to the extent that the acceptance/provision of dental treatment is not possible. The aim of this paper is to review the role of acupuncture in controlling gagging as a safe, cheap, quick and relatively non-invasive technique.

METHOD

Ten people agreed to try ear acupuncture to control gagging during dental treatment. Prior to treatment the severity of gagging was assessed. Acupuncture needles were inserted into a specific anti-gagging point on each ear, manipulated briefly and left in situ. Dental treatment was then carried out and the effectiveness of the acupuncture in preventing gagging was assessed. After treatment, the needles were removed and the patient discharged. All acupuncture was carried out by a dentist trained in its use.

RESULTS

Four people had a severe gag reflex which made treatment impossible and six had a very severe reflex which made treatment impossible and affected their dental attendance. Ear acupuncture completely controlled the gag reflex in eight cases (23 treatment episodes) and partially controlled the reflex in two cases (two treatment episodes). Dental treatment could be carried out in all cases and at all visits. The cost of materials was 0.2 pounds per person per visit. Additional clinical time was in the order of 2-3 minutes. There were no adverse reactions to the technique and, on all occasions, patients were fit to leave the surgery and travel home unaccompanied.

CONCLUSIONS

Ear acupuncture was successful in controlling the gag reflex. It is a safe, quick, inexpensive and relatively noninvasive technique. A controlled clinical trial is required to investigate any placebo effect.

The antenatal ward care delivery map: a team model approach

We begin by defining the concept of a 'CareMap', before briefly examining the context in which CareMaps emerged, as well as both their potential applications and the benefits arising from their implementation in health care services. We identify and discuss the history of, and critical aspects involved in, the development of the Antenatal Ward Care Delivery Map for the Mater Mothers' Hospital, Brisbane. We will address the multiple applications of, and specific benefits arising from, the formulation and implementation of the Antenatal Ward Care Delivery Map. Additionally, the relationship between the Care Delivery Map and other projects aimed at enhancing and maintaining high quality service delivery for patients across the continuum of care, will be explored. We examine the benefits of utilising the Care Delivery Map in professional education for clinical staff, as well as for health care consumers and their families. In conclusion, future projects enabled through the development of the Care Delivery Map are identified, as well as areas requiring further research.

Agouti-related protein-like immunoreactivity: characterization of release from hypothalamic tissue and presence in serum

A novel RIA was used to examine the release of agouti-related protein-like immunoreactivity (AGRP-LI) from perfused rat hypothalamic tissue slices and to characterize AGRP-LI in rat serum. A continuous low level basal AGRP-LI release was observed from hypothalami of rats fed ad libitum before the rats were killed. Basal AGRP-LI release was 3-fold greater in rats fasted 48 h. In fasted animals leptin dose-dependently suppressed basal AGRP-LI release. In fed animals no change in basal AGRP-LI release was detected in response to 10(-6) M alpha-MSH, orexin B, melanin-concentrating hormone, or serotonin. HPLC analysis of AGRP-LI in rat serum identified a single peak that eluted in close proximity to synthetic AGRP (87-132) and mouse [Leu127Pro]AGRP and that was identical to the peak seen in hypothalamic and adrenal tissue extracts. The serum concentration of AGRP-LI in rats fed ad libitum was 0.865+/-0.323 nmol/liter (mean +/- SE). Food deprivation resulted in a slow, but statistically significant rise in serum immunoreactivity at 48 h [1.174+/-0.118 nmol/liter (mean +/- SE)]. Bilateral adrenalectomy did not change serum levels of AGRP-LI. These studies demonstrate that in the rat there are different levels of basal hypothalamic AGRP-LI release in fed and fasted states and that in the fasted rat this release can be profoundly suppressed by leptin. These studies also suggest that AGRP is present in the systemic circulation of rats.

Toothbrush handle adaptation using silicone impression putty

Some patients suffer from conditions that make holding toothbrushes difficult, if not impossible. This article describes a quick, simple and flexible method of adapting toothbrush handles to allow patients the best possible chance of performing adequate oral care.