Novel mRNA isoforms and mutations of uridine monophosphate synthetase and 5-fluorouracil resistance in colorectal cancer

The drug fluorouracil (5-FU) is a widely used antimetabolite chemotherapy in the treatment of colorectal cancer. The gene uridine monophosphate synthetase (UMPS) is thought to be primarily responsible for conversion of 5-FU to active anticancer metabolites in tumor cells. Mutation or aberrant expression of UMPS may contribute to 5-FU resistance during treatment. We undertook a characterization of UMPS mRNA isoform expression and sequence variation in 5-FU-resistant cell lines and drug-naive or -exposed primary and metastatic tumors. We observed reciprocal differential expression of two UMPS isoforms in a colorectal cancer cell line with acquired 5-FU resistance relative to the 5-FU-sensitive cell line from which it was derived. A novel isoform arising as a consequence of exon skipping was increased in abundance in resistant cells. The underlying mechanism responsible for this shift in isoform expression was determined to be a heterozygous splice site mutation acquired in the resistant cell line. We developed sequencing and expression assays to specifically detect alternative UMPS isoforms and used these to determine that UMPS was recurrently disrupted by mutations and aberrant splicing in additional 5-FU-resistant colorectal cancer cell lines and colorectal tumors. The observed mutations, aberrant splicing and downregulation of UMPS represent novel mechanisms for acquired 5-FU resistance in colorectal cancer.

HIV point-of-care testing pitfalls

When counselling patients for postexposure prophylaxis after sexual exposure, we may need to inform them that the efficacy may be low, especially if the patient also had risks prior to the 72 hours between exposure and treatment. The use of a point-of-care test, as well as fourth generation HIV tests and HIV RNA in combination, can still miss seroconversion in the 'eclipse' phase of the infection as these tests are not designed to detect the earliest phase of infection.

Acceptance of HIV testing in medical inpatients: a local acceptability study

Late diagnosis remains the most important factor related to death due to HIV in the UK. To reduce late diagnosis, the British HIV Association (BHIVA), the British Association for Sexual Health and HIV (BASHH), and the British Infection Society jointly released national guidelines for HIV testing in the UK in 2008. They recommend local evaluation of HIV testing for all medical admissions aged 15-59 years in areas where the local prevalence is above 2/1000. The local prevalence of HIV in Croydon is 4.17/1000. We carried out a local acceptability study at Mayday Hospital in Croydon and found that 84/101 medical patients agreed to have an HIV test. A previous audit showed that only 9/1047 medical admissions had been tested for HIV. This study shows that HIV testing is acceptable and that more patients could be tested.

Common association of haemolytic uraemic syndrome with invasive Streptococcus pneumoniae infection in five Chinese paediatric patients

Haemolytic uraemic syndrome is an important cause of acute renal impairment in childhood. We review the incidence, and clinical and laboratory features of haemolytic uraemic syndrome in a Chinese population. Five patients were identified from 2006 to 2008. All patients were young children with associated invasive Streptococcus pneumoniae pulmonary infection. Serotypes 3, 14, and 19A were confirmed in four patients. The classical post-diarrhoeal form associated with Escherichia coli (O157:H7) infection was not seen. One patient died of acute respiratory failure. Streptococcus pneumoniae infection, as an associated condition in haemolytic uraemic syndrome, is important and relatively common in Chinese patients, especially among children. The acute clinical picture is similar to that reported in the western literature, except for an uncommon association with meningitis. The medium-term renal outcome of the Chinese population appears to be more favourable than the Caucasians. Widespread vaccination against Streptococcus pneumoniae may have resulted in changes in bacterial epidemiology and clinicians should be continuously aware of this severe disease. The use of washed blood components for transfusion in the acute stage requires further study.

Quantitative Skin Blanching Assay of Corticosteroid Creams Using Tristimulus Colour Analysis

The potencies of four proprietary corticosteroid creams were ranked using blanching measured by a tristimulus colour analyser as an index. Intra-subject variation was measured in a trial using a single subject while in a second study inter-subject variation was quantified using six volunteers. Discriminative parameters were derived from the extended multiple-point chromaticity coordinates L* and a* recorded after application of the steroid creams under occlusion. Analysis of variance of the data using the linear regression model was followed by Tukey's multiple comparison tests. Ranking of the creams using parameters of the pharmacodynamic response corresponded with the generally accepted rank order of the potencies of the corticosteroid creams. It is proposed that this multiple-point skin blanching assay of topical corticosteroids using an internationally accepted clear measurement standard and the subsequent data analysis be adopted as a standard protocol.

Cord lining progenitor cells: potential in vitro adipogenesis model

OBJECTIVE

To investigate the effect of glucose and insulin concentrations on differentiation of umbilical cord lining progenitor cells to adipocyte-like cells (ALCs).

METHODS

Cord lining mesenchymal cells (CLMCs) were isolated from the explant of human umbilical cord amniotic membrane. CLMCs were subjected to differentiation under various culture conditions for 20 days. Lipid droplets were confirmed with Oil Red O staining. Gene expressions of adipsin and peroxisome proliferator-activated receptor gamma (PPARγ) were analyzed using reverse transcription-PCR. Leptin and adiponectin secretions were detected using enzyme-linked immunosorbent assay kit.

RESULTS

CLMCs became irregular, cuboidal-shaped cells that resemble adipocytes, and Oil Red O staining showed the presence of lipid droplets. The gene expressions of PPARγ and adipsin were upregulated. Leptin and adiponectin secretions by naive CLMCs were below the limits of detection. Matured ALCs cultured in low-glucose medium significantly secreted leptin and adiponectin, whereas those in high-glucose medium significantly secreted only leptin. Insulin concentration affects leptin but not adiponectin secretion.

CONCLUSIONS

Under different culture conditions, CLMCs can differentiate into ALCs that resemble adipocytes in either normal-weight or obese individuals. Hence, these ALCs have the potential to be used as an in vitro model to study adipogenesis and obesity, and possibly as a drug discovery model for metabolic disorders.

Monocarboxylate transporter 8 in neuronal cell growth

Thyroid hormones are essential for the normal growth and development of the fetus, and even small alterations in maternal thyroid hormone status during early pregnancy may be associated with neurodevelopmental abnormalities in childhood. Mutations in the novel and specific thyroid hormone transporter monocarboxylate transporter 8 (MCT8) have been associated with severe neurodevelopmental impairment. However, the mechanism by which MCT8 influences neural development remains poorly defined. We have therefore investigated the effect of wild-type (WT) MCT8, and the previously reported L471P mutant, on the growth and function of human neuronal precursor NT2 cells as well as MCT8-null JEG-3 cells. HA-tagged WT MCT8 correctly localized to the plasma membrane in NT2 cells and increased T(3) uptake in both cell types. In contrast, L471P MCT8 was largely retained in the endoplasmic reticulum and displayed no T(3) transport activity. Transient overexpression of WT and mutant MCT8 proteins failed to induce endoplasmic reticular stress or apoptosis. However, MCT8 overexpression significantly repressed cell proliferation in each cell type in both the presence and absence of the active thyroid hormone T(3) and in a dose-dependent manner. In contrast, L471P MCT8 showed no such influence. Finally, small interfering RNA depletion of endogenous MCT8 resulted in increased cell survival and decreased T(3) uptake. Given that T(3) stimulated proliferation in embryonic neuronal NT2 cells, whereas MCT8 repressed cell growth, these data suggest an entirely novel role for MCT8 in addition to T(3) transport, mediated through the modulation of cell proliferation in the developing brain.

Stability of morphine sulphate in saline under simulated patient administration conditions

OBJECTIVE

To study the stability of morphine sulphate solutions under simulated administration conditions in a patient-controlled analgesic device.

METHOD

Concentrations of 1 mg/ml and 10 mg/ml morphine sulphate in saline were monitored over 16 days under slow continuous delivery from Deltec Medication cassettes kept in the dark at a controlled temperature of 32 degrees C and a humidity between 36 and 38%. The morphine concentrations in the samples, collected at 0, 1, 2, 5, 6, 7, 9, 12, 14 and 16 days, were measured by a stability indicating high-performance liquid chromatographic method.

RESULTS

Throughout the study period, the reservoir concentrations varied within 10% of their initial values and there was no chromatographic evidence of degradation. However, the pH of both reservoirs decreased with time, but morphine is expected to be stable within the observed pH range.

CONCLUSION

This study demonstrated that the concentrating effect due to evaporation under the storage conditions described, over 16 days, was not of significance and the product was stable.

Syphilis causing hearing loss

An HIV-positive man with hepatitis B co-infection, naïve to highly active antiretroviral therapy, with a CD4 of 594 copies/mL and HIV-1 viral load of 140,070 copies, presented with right-sided facial weakness and hearing loss. He had been treated for secondary syphilis three months earlier when his rapid plasma reagin (RPR) result was 1:16, this had fallen to neat. At presentation, his RPR had risen to 1:16 again. A magnetic resonance imaging scan showed enhancement of the internal auditory canal and right cochlea. His cerebrospinal fluid examination was normal. He was treated with acyclovir and prednisolone before the syphilis serology was known. He was then treated for syphilis with doxycycline. He made an excellent recovery.

Performance study of vegetated sequencing batch coal slag bed treating domestic wastewater in suburban area

A practical and affordable wastewater treatment system serving small community in suburban areas was studied. The system was a vegetated sequencing batch coal slag bed integrated with the rhythmical movement of wastewater and air like that of a sequencing batch reactor. The removal mechanisms capitalized on the pollutant removal process in conventional constructed wetland. Cyperus alternifolius was planted into the coal slag bed to form a novel plant-soil-microbial interactive system. Nutrients in the domestic wastewater, which cause environmental nuisance like eutrophication, were targeted to be eliminated by the process design. Operated with the contact time of 18 h, the treatment systems achieved around 60% removal efficiency for carbonaceous matters. The removals of ammonia nitrogen and phosphorus were about 50% and 40%, respectively, while the removal of total suspended solids was approaching 80%. From the current study, the construction cost of the vegetated sequencing batch coal slag bed was 256 RMB/m3 and the operation cost was 0.13 RMB/m3. With the advantages of ease of operation, low costs, desirable treatment efficiency and aesthetic value, the vegetated sequencing batch coal slag bed is proposed to be an alternative for onsite domestic wastewater treatment in suburban areas.

Targeting of Sp1 transcription factor: a novel therapeutic approach for keloids, an in vitro analysis

Keloid scars are fibroproliferative disorders characterized by the accumulation of extracellular matrix (ECM) components resulting in a fibrotic condition. Several ECM promoters are regulated by Sp1. Thus, our aim was to investigate the role of Sp1 in keloid pathogenesis and investigate the antiproliferative and antifibrotic effects of Wp631 and mitoxantrone, potent inhibitors of Sp1-activated transcription. An elevated level of Sp1 was observed in tissue extracts obtained from keloid tissue. Serum stimulation elevated Sp1 levels in keloid fibroblasts (KF). Under coculture conditions Sp1 seemed to be downregulated. Wp631 and mitoxanthrone in serum growth factors resulted in a reduced expression of ECM components in KF. Both Wp631 and mitoxanthrone were also able to inhibit the proliferation of normal and keloid keratinocytes and fibroblasts significantly. As Wp631 seems to be potent in downregulating the ECM components in KF and also inhibiting the proliferation of these cells it could be explored as a possible therapeutic agent in the treatment of keloids.

Can computerised tomography replace bone scintigraphy in detecting bone metastases from breast cancer? A prospective study

BACKGROUND

The aim of this study was to determine whether bone scans (BS) can be avoided if pelvis was included in CT thorax and abdomen to detect bony metastases from breast cancer.

MATERIALS AND METHODS

Results of 77 pairs of CT (thorax, abdomen, and pelvis) and BS in newly diagnosed patients with metastatic breast cancer (MBC) were compared prospectively for 12 months. Both scans were blindly assessed by experienced radiologists and discussed at multidisciplinary team meetings regarding the diagnosis of bone metastases.

RESULTS

CT detected metastatic bone lesions in 43 (98%) of 44 patients with bone metastases. The remaining patient had a solitary, asymptomatic bony metastasis in shaft of femur. BS was positive in all patients with bone metastases. There were 11 cases of false positive findings on BS.

CONCLUSION

Our findings suggest routine BS of patients presenting with MBC is not required if CT (thorax, abdomen, and pelvis) is performed.

Treatment of odorous volatile fatty acids using a biotrickling filter

In this study, a novel fibrous bioreactor was developed for treating odorous compounds present in contaminated air. The first stage of this work was a preliminary study which aimed at investigating the feasibility of using the fibrous bioreactor for the removal of malodorous volatile fatty acids (VFA) that is a common odorous contaminant generated from anaerobic degradation of organic compounds. The kinetics of microbial growth and VFA degradation in the selected culture, and the performance of the submerged bioreactor at different VFA mass loadings were studied. Above 95% of VFA removal efficiencies were achieved at mass loadings up to 22.4 g/m(3)/h. In the second stage, the odour treatment process was scaled up with system design and operational considerations. A trickling biofilter with synthetic fibrous packing medium was employed. The effects of inlet VFA concentration and empty bed retention time (EBRT) on the process performance were investigated. The bioreactor was effective in removing VFA at mass loadings up to 32 g/m(3)/h, beyond which VFA started to accumulate in the recirculation liquid, indicating the biofilm was unable to degrade all of the VFA introduced. Although VFA accumulated in the liquid phase, the removal efficiency remained above 99%. This suggested that the biochemical reaction rather than gas-liquid mass transfer was the limiting step of the treatment process. In addition, the biotrickling filter was stable for long-term operation with relatively low and steady pressure drop, no clogging and degeneration of the packing material occurred during the four-month study.

The prevalence of cardiovascular risk factors in male patients who have lower urinary tract symptoms

OBJECTIVES

To assess the prevalence of cardiovascular risk factors in men presenting with lower urinary tract symptoms, and their possible correlation with the severity of such symptoms.

DESIGN

Retrospective cohort study.

SETTING

Specialty clinic, Hong Kong.

PATIENTS

A total of 617 men presenting with lower urinary tract symptoms between April 2005 and October 2006.

MAIN OUTCOME MEASURES

Presence of cardiovascular risk factors inferred from the prior and current medical and social history as well as physical examination and investigative findings, among patients with International Prostatic Symptom Scores of different severity.

RESULTS

Of 617 patients, 268 (43%) had known hypertension and 318 (52%) had a history of smoking. According to the World Health Organization criteria for Asian populations, 396 (64%) patients were considered to be overweight (body mass index > or =23 kg/m(2)). A total of 178 (29%) patients were either known to have or were diagnosed to have dysglycaemia during workup. For dyslipidaemia and hyperuricaemia, the corresponding figures were 331 (54%) and 191 (31%). In total, 264 (43%) patients were newly diagnosed as having dysglycaemia, dyslipidaemia, or hyperuricaemia. Logistic regression indicated that only hyperuricaemia and a smoking history were significant predictors of moderate-to-severe lower urinary tract symptoms (International Prostatic Symptom Score > or =8), with respective adjusted odds ratios of 2.20 (95% confidence interval, 1.12-4.31; P=0.022) and 2.11 (1.24-3.57, P=0.006). Patients with moderate-to-severe International Prostatic Symptom Scores had a statistically higher chance of having at least one cardiovascular risk factor during assessment (P=0.001).

CONCLUSIONS

Cardiovascular risk factors were prevalent in male patients who had lower urinary tract symptoms; a large portion of these cardiovascular risk factors were not recognised until their urological consultations. Patients with moderate-to-severe lower urinary tract symptoms (International Prostatic Symptom Score > or =8) had statistically higher chances of having more cardiovascular risk factors.

Separase, securin and Rad21 in neural cell growth

The key mitotic regulator securin is expressed at low levels in fetal brain compared with adult, and modulates the proliferation of human embryonic neuronal N-Tera2 (NT2) cells. We now examine the function and expression of securin's interacting partner separase, along with Rad21, the functional component of cohesin, which is cleaved by separase following interaction with securin. In contrast to securin, the cleaved forms of separase and Rad21 were highly expressed in human fetal cerebral cortex compared with adult. In a murine model of absent securin expression - the PTTG knock-out mouse - separase and Rad21 were over-expressed in multiple brain regions. In addition, cDNA array analysis of other key mitotic regulators additionally identified cyclin C and sestrin 2 to be induced in the brains of securin-null mice compared with wild type. Further, Rad21 mRNA expression was highly correlated with that of securin, separase, cyclin C and sestrin 2 in fetal brains. In embryonic neuronal NT2 cells, siRNA repression of separase failed to significantly alter cell turnover, whereas repression of securin expression resulted in increased levels of the activated forms of Rad21 and separase, and promoted cell proliferation. Our data suggest that the co-ordinated expression of separase, securin and Rad21 is fundamental for the developing brain.

Reversible effects of permeation enhancers on human skin

This study outlines a systematic approach for investigating a desired characteristic of chemicals used to facilitate the permeation of drugs across the skin that is, the reversibility of the permeation enhancement effect. This implies that the vital skin barrier function is restored and not permanently impaired after the application of these enhancers. The reversible effects of two terpene enhancers, (R)-(-)-carvone and eucarvone, on excised human skin were evaluated by in vitro permeation and extraction studies on normal (untreated) and enhancer-pretreated epidermis, respectively. For the permeation studies on normal epidermis, the donor solutions were the model drug, haloperidol (HP, 3mg/ml), in propylene glycol (PG) with or without 5% (w/v) enhancer and for the extraction studies using epidermis pretreated with enhancer, a solution of HP (3mg/ml) in PG was used. The solubilities of the enhancers in 0.03% lactic acid (receptor solution) and of HP in PG (donor solution) were determined to demonstrate that the sink and saturated conditions were maintained in the respective compartments of the flow-through cells throughout the in vitro experiments. (R)-(-)-Carvone cleared out of the skin faster than eucarvone. This could be due to the 4-fold higher skin permeability of (R)-(-)-carvone compared to that of eucarvone. The amount of HP deposited in the epidermis was much lower in the eucarvone-pretreated epidermis than that pretreated with (R)-(-)-carvone. The permeation profile of HP across the enhancer-pretreated skin was 4-fold greater than in the vehicle alone (control), but similar to that across untreated skin with enhancer present in the donor solution, indicating that permeation across the enhancer-pretreated skin did not change. The enhancing effects of both terpenes on the skin were found to be reversible and the permeability of the skin was left intact after the passage of the drug in the vehicle with these enhancers.

Assessing optimal fermentation type for bio-hydrogen production in continuous-flow acidogenic reactors

In this study, the optimal fermentation type and the operating conditions of anaerobic process in continuous-flow acidogenic reactors was investigated for the maximization of bio-hydrogen production using mixed cultures. Butyric acid type fermentation occurred at pH>6, propionic acid type fermentation occurred at pH about 5.5 with E(h) (redox potential) >-278mV, and ethanol-type fermentation occurred at pH<4.5. The representative strains of these fermentations were Clostridium sp., Propionibacterium sp. and Bacteriodes sp., respectively. Ethanol fermentation was optimal type by comparing the operating stabilities and hydrogen production capacities between the fermentation types, which remained stable when the organic loading rate (OLR) reached the highest OLR at 86.1kgCOD/m(3)d. The maximum hydrogen production reached up to 14.99L/d.

Formulation development of transdermal dosage forms: Quantitative structure-activity relationship model for predicting activities of terpenes that enhance drug penetration through human skin

Terpenes and terpenoids have been used as enhancers in transdermal formulations for facilitating penetration of drugs into human skin. Knowledge of the correlation between the human skin penetration effect (HSPE) and the physicochemical properties of these enhancers is important for facilitating the discovery and development of more enhancers. In this work, the HSPE of 49 terpenes and terpenoids were compared by the in vitro permeability coefficients of haloperidol (HP) through excised human skin. A first-order multiple linear regression (MLR) model was constructed to link the permeability coefficient of the drug to the lipophilicity, molecular weight, boiling point, the terpene type and the functional group of each enhancer. The Quantitative Structure-Activity Relationship (QSAR) model was derived from our data generated by using standardized experimental protocols, which include: HP in propylene glycol (PG) of 3 mg/ml as the donor solution containing 5% (w/v) of the respective terpene, the same composition and volume of receptor solution, similar human skin samples, in the same set of automated flow-through diffusion cells. The model provided a simple method to predict the enhancing effects of terpenes for drugs with physicochemical properties similar to HP. Our study suggested that an ideal terpene enhancer should possess at least one or combinations of the following properties: hydrophobic, in liquid form at room temperature, with an ester or aldehyde but not acid functional group, and is neither a triterpene nor tetraterpene. Possible mechanisms revealed by the QSAR model were discussed.

Synthesis of PHAs from waster under various C:N ratios

Polyhydroxyalkanoates (PHAs) production was carried out under various C:N ratios. A ratio of 100 resulted best polymer yield. C-source was an important factor in synthesis. For example, as the ratio of valeric acid (C5) to butyric acid (C4) in N-free medium was increased, the mole fraction of HV in the copolymer increased. When soy waste was used as a C-source a copolymer, a high HV mole fraction (HB:HV, 75:25) was produced while when malt waste was used, a much lower HV mole fraction (HB:HV, 90:10) was generated. It was concluded that activated sludge bacteria could be induced to produce PHAs using food wastes as C-sources and this could be the basis for production of biodegradable plastics.

Neoadjuvant chemotherapy in locally advanced primary breast cancers: the Nottingham experience

AIM

Of our study was to assess and compare the outcome of patients undergoing anthracycline based neoadjuvant chemotherapy in locally advanced primary breast cancers with patients receiving mitoxantrone, methotrexate and mitomycin (MMM) as neoadjuvant agents.

METHODS

Records of 50 consecutive patients receiving anthrcycline based chemotherapy for locally advanced breast cancers from July 1996 to July 2004 were analysed with regard to locoregional recurrence, metastasis and survival. The MMM group comprised of 56 consecutive patients receiving MMM chemotherapy between 1989 and 1994. The unit protocol for patients receiving multimodal therapy has been neoadjuvant chemotherapy followed by Patey's mastectomy, radiotherapy and endocrine treatment if ER-positive. Patients were followed-up in the clinic until either death or the last clinic visit on or before December 2005 in the anthracycline group and on or before December 1999 in the MMM group.

RESULTS

There was no significant difference between the two groups with regard to number of patients, tumour size, grade, ER positivity and median duration of follow-up from start of chemotherapy. Significantly more patients in the anthracycline group had complete clinical response and 44% of the patients in anthracycline group had node negative disease compared to 4% in the MMM group. Anthracycline group when compared to MMM group had a lower incidence of locoregional recurrence (6% vs 19%), distant metastasis (20% vs 55%) and survival (82% vs 45%) at the end of follow-up, which was statistically significant.

CONCLUSION

Anthracycline based neoadjuvant chemotherapy has better response and significantly better outcome compared to MMM chemotherapy.

Laser Ablation of Foetal Microcystic Lung Lesion: Successful Outcome and Rationale for Its Use

OBJECTIVE

A foetus with an echodense, microcystic lung lesion complicated by non-immune hydrops has a high mortality rate. Because of the limited treatment options available, laser ablation was offered in an attempt to reduce the size of the lesion and reduce hydrops fetalis.

METHODS AND RESULTS

A 25-year-old nulliparous woman presented at 21 weeks gestation. Ultrasound revealed a male foetus with a large microcystic right sided lung lesion that completely occupied the right hemithorax causing marked mediastinal deviation. The foetus was hydropic with polyhydramnios. Percutaneous laser ablation of the large microcystic lung lesion was performed under direct ultrasound control. At a power setting of 45 W, and using a 400 microm Nd:YAG laser fibre, the core of the lesion was photocoagulated in pulses lasting 5 s at 5 s intervals. The total target dose was 1683 J. This led to a marked but temporary reduction in amniotic fluid volume. The patient was commenced on sulindac and amniodrainage was performed at 27 weeks as reaccumulation of the polyhydramnios occurred. Pre-eclampsia complicated the pregnancy at 38 weeks gestation and an emergency caesarean section was performed. The baby underwent a thoracotomy and lobectomy at 48 h of age, made a good recovery, and is currently well 8 weeks post-delivery.

CONCLUSIONS

In cases of cystic lung lesion complicated by hydrops, laser ablation should be considered as a treatment option.