Potential of nanoemulsions for intravenous delivery of rifampicin

The aim of the present study was to develop, characterize and evaluate nanoemulsion formulations for intravenous delivery of rifampicin (RIF). Different oil-in-water (o/w) nanoemulsions were prepared by the aqueous phase titration method. Prepared nanoemulsions were subjected to thermodynamic stability tests for phase separation, creaming, cracking, coalescence or phase inversion and dispersibility test for dilution capacity. Nanoemulsion formulations which passed these tests were characterized in terms of droplet size, viscosity, entrapment efficiency, homogeneity and pH. The selected formulations were subjected to in vitro dissolution studies using a dissolution apparatus-XXIII in dialysis bag. Best results were obtained with the formulation which consisted of 150 mg of RIF, 15% w/w of Sefsol 218, 18.75% w/w of Tween 80, 6.25% w/w of Tween 85 and 60% w/w of normal saline. The optimized formulation was also subjected to stability studies according to the ICH guidelines. The formulation was found to be stable for more than19 months. These results indicated the potential of nanoemulsions for intravenous delivery of RIF.

Diabetes in post genomic era: promises to discover biomarkers and new drug targets

The complementary disciplines of genomics and proteomics offer better insights into the molecular mechanisms of diseases. Whilst genomics hunts for defining our static genetic substrate, proteomics explores the structure and function of proteins expressed by a cell or tissue type under specified conditions. In the past decade, proteomics has been revolutionized by the application of techniques such as two-dimensional gel electrophoresis (2-DGE), mass spectrometry and protein arrays. These techniques have tremendous potential for biomarker development, target validation, diagnosis, prognosis, and optimization of treatment in medical care, especially in the field of diabetes. This mini review will highlight the contributions of proteomic technologies towards the discovery of potentially new biomarkers for pathophysiological mechanisms and clinical outcome of diabetes.

Sequential induction chemotherapy followed by radical chemo-radiation in the treatment of locoregionally advanced head-and-neck cancer

We describe a retrospective series of patients with advanced head-and-neck cancer who were treated with induction chemotherapy followed by radical chemo-radiation. Patients treated with two cycles of induction chemotherapy followed by definitive chemo-radiation for squamous cell carcinoma of the head-and-neck region, from 2001 – 2006 at the Royal Marsden Hospital, formed the basis of this study. Cisplatin (75 mg m⁻²) on day 1 and 5-FU (1000 mg m⁻²) day 1 – 4 was the standard regimen used for induction treatment. Cisplatin (100 mg m⁻²) on day 1 and day 29 was used for concomitant treatment. The radiation was delivered using conformal technique. Tissues containing macroscopic and microscopic disease were treated to doses of 65 Gray (Gy) in 30 fractions and 50 Gy in 25 fractions, respectively. Data on patterns of relapse and acute toxicity (NCICTCv.3.0) were collected. A total of 129 patients were included, median age was 58 (range: 27 – 78). The site of tumour was: oropharynx 70 (54%), larynx 30 (23%), hypopharynx 24 (19%) and other 5 (4%). The median follow-up was 19 months (range: 4 – 58). Local control, disease-specific survival and overall survival at 2 years were 71%, 68% and 63%, respectively. The distant recurrence rate at 2 years was 9%. Ten patients required dose reduction during induction chemotherapy due to toxicity. The dose of 5-FU was reduced in six patients and that of cisplatin in four patients. The incidence of grade 3/4 toxicity was: neutropenia 5%, thrombocytopenia 1%, nausea and vomiting 3%. One cycle of concurrent cisplatin was omitted in 23 patients due to toxicity. Full-dose radiotherapy was administered to 98% of patients. The incidence of grade 3/4 toxicity was: skin 20%, dysphagia 65%, mucositis 60%, neutropenia 3%, anaemia 1%, nausea and vomiting 4%, nephrotoxicity 1%. Induction chemotherapy followed by radical chemo-radiation is a safe and tolerable regimen in the treatment of advanced head-and-neck cancer. Distant recurrence rates are lower with equivalent local control and survival compared to chemo-radiation alone (historical controls).

A familial case of pleuropulmonary blastoma

PURPOSE

Pleuropulmonary blastoma (PPB) is a rare intrathoracic neoplasm of early childhood arising in the lung or visceral pleura. Approximately 150 cases have been reported in the literature, with only one previously documented case of PPB in siblings.

PATIENTS AND METHODS

We present the case of two brothers diagnosed with PPB.

RESULTS

A two month-old boy with an abnormal breathing pattern was referred for evaluation of a cystic mass discovered on chest radiograph. Computed tomography (CT) of the chest was performed at our institution which revealed findings compatible with congenital cystic adenomatoid malformation (CCAM) of the right middle and lower lobes. The patient underwent urgent thoracic exploration one week later after developing severe respiratory distress. Histological examination revealed PPB type I (cystic). The patient's 15-month-old brother was presumed to have a CCAM noted radiographically months earlier during an asthma exacerbation. He underwent elective cyst resection and was also found to have type I PPB. The index patient was treated with adjuvant chemotherapy due to the large size of the PPB and intraoperative spillage of cystic fluid during the emergent surgery. In contrast, the brother is being followed without adjuvant chemotherapy, given the much smaller size of the PPB, wide margins of resection, and lack of spillage. Family history included an uncle diagnosed at age 11 with an unusual form of T cell acute lymphoblastic leukemia.

CONCLUSION

Although PPB is known to have a familial association with other neoplasms, this case represents only the second report of PPB occurring in siblings. The importance of thoroughly investigating and resecting pulmonary cystic masses in the pediatric population is highlighted by these cases.

Systemic lupus erythematosus in Saudi Arabia: morbidity and mortality in a multiethnic population

The objective of this study is to summarize the features of patients with Lupus erythematosus in Saudi Arabia. Racial differences of patients and predictors of mortality are assessed. Ninety-three patients treated for SLE at the University Hospital in Jeddah were reviewed. Frequencies of clinical manifestations, causes of admission and causes of death were analysed. Variables predicting mortality were assessed by logistic regression and survival probabilities were estimated by the Kaplan-Meier method. The most frequent presenting symptoms were arthritis (68%) and fever (58%). Renal involvement was seen in 61% of patients. The majority of patients (61%) showed ANA titers higher than 1:1280. C4 levels were significantly lower in patients who died during the observation period than in survivors. The overall five-year survival rate was 92%. Variables predicting early death (<2 years after diagnosis) were young age at diagnosis, male sex and skin involvement. Death after more than two years correlated with older age at diagnosis and renal involvement. Patients of African descent had higher rates of neurological involvement and renal failure. The mortality in this group was highest, though this was not statistically significant. The overall survival in our cohort compares with mortality rates reported from western countries. However, renal disease tends to be common and has a severe prognosis, and thus merits additional attention.

Assessment of manoeuvres required for successful blind tracheal intubation through the PAXpress

A PAXpress (Vital Signs Inc., Barnham, UK) airway device was placed in 50 adult ASA grade I and II patients undergoing elective surgery under general anaesthesia. The alignment of the PAXpress to the larynx was scored fibreoptically. The patients were then intubated blindly through the PAXpress and the adjusting manoeuvres required for successful intubation and complications of intubation observed. Insertion of the PAXpress was successful in all patients, and intubation was successful in 42 (84%) patients. Eleven patients were intubated in the neutral position, seven with a flexion manoeuvre and 24 with an extension manoeuvre. Intubation was successful in 17/20, 18/20, 6/8 and 1/2 of patients with a fibreoptic alignment score of 1, 2, 3 and 4, respectively. When the fibreoptic alignment score was between 2 and 4 intubation was achieved predominantly with the extension manoeuvre (20/30, 66%) rather than the flexion manoeuvre (1/30, 3%) or the neutral position (5/30, 16%). Blood staining was observed in 20 patients. We conclude that blind tracheal intubation through PAXpress has a moderately good success rate and a high incidence of mucosal trauma. 'Extension' is the predominant adjusting manoeuvre required for blind tracheal intubation, especially when the alignment of the PAXpress to the larynx is poor.

Genome-wide expression analysis of Middle Eastern papillary thyroid cancer reveals c-MET as a novel target for cancer therapy

In an attempt to find genes that may be of importance in malignant progression of papillary thyroid carcinoma (PTC) in the Middle East, which therefore can be targeted in cancer therapy, we screened and validated the global gene expression in PTC using cDNA expression arrays and immunohistochemistry (IHC) on tumour tissue microarrays. Twenty-nine PTC tissue specimens were compared with seven non-cancerous thyroid specimens by use of cDNA microarray. Results for selected genes were confirmed by quantitative real-time PCR. Protein expression of selected genes was further studied using a tissue microarray consisting of 536 PTCs and compared with histologically non-cancerous tissue samples. One hundred and ninety-six genes were overexpressed in PTC tissues relative to non-cancerous thyroid tissues. The genes that were up-regulated in PTC were involved in cell cycle regulation, cell signaling, and oncogenesis. Among these genes, c-MET was identified by immunohistochemical methods as a protein that is overexpressed in 37% of PTCs and was significantly associated with more aggressive behaviour, eg higher stage, nodal involvement, and tall cell variant (p value = 0.01, 0.01 and 0.04, respectively). In this study, 55% of the PTC cases expressed activated AKT (P-AKT), which suggests that activated AKT may play an important role in PTC tumourigenesis. The fact that most of the PTC cases that had activated AKT showed overexpression of c-MET (p = 0.027) leads us to hypothesize that c-MET may be an alternative mechanism of AKT activation in Middle Eastern PTCs. Finally, our data suggest that c-MET dysregulation is associated with aggressive behaviour and may serve as a molecular biomarker and potential therapeutic target in this disease.

Torsion of gallbladder: a diagnostic predicament

A 69-year-old woman underwent an emergency laparotomy and cholecystectomy, revealed gangrene of the gallbladder secondary to torsion.

Widespread oral and oropharyngeal mucosal oedema induced by ecstasy (MDMA): A case for concern

We describe an unusual adverse reaction that was probably caused by taking ecstasy: the patient developed widespread oral and oropharyngeal mucosal oedema, which was triggered after he had taken ecstasy and alcohol. The reaction to this could have been fatal.

Prevalence and diagnostic significance of fluid–fluid levels in soft-tissue neoplasms

AIM

To report the prevalence of fluid-fluid levels (FFLs) in soft-tissue tumours as demonstrated by magnetic resonance imaging (MRI) and the potential diagnostic relevance of this finding.

MATERIALS AND METHODS

A retrospective analysis was performed of 726 consecutive patients (361 women, 365 men, mean age 47.6 years+/-20.1 SD) presenting with a soft-tissue mass over a 7-year period. All subjects underwent MRI and final diagnosis was based on biopsy/surgical resection, or clinical follow-up and characteristic imaging findings. The patients were divided according to the presence or absence of FFLs on T2-weighted (T2W) axial MRI and histological diagnosis (non-neoplastic, neoplastic benign, neoplastic malignant). Cases with FFLs were sub-categorized depending upon the proportion of tumour containing FFLs: <1/3, 1/3-2/3 and >2/3, in order to determine whether the proportion of FFLs was useful for differential diagnosis.

RESULTS

Twenty-four of the 726 (3.3%: confidence interval 2.1-4.9%) soft-tissue masses contained FFLs. One of the 24 (4.1%) was non-neoplastic (one ganglion), 12 (50.0%) were benign neoplasms (nine haemangiomas, two schwannomas, one hamartoma) and 11 (45.9%) were malignant neoplasms (one leiomyosarcoma, one liposarcoma, one malignant fibrous histocytoma, one mxyofibrosarcoma, two primitive neuroectodermal tumours, two synovial sarcomas, one spindle cell sarcoma, and two sarcomas not otherwise specified). The presence of FFLs did not help to differentiate benign from malignant neoplasms. Of the 12 benign neoplasms, 66.7% contained over two-thirds FFLs, the majority of which were haemangiomas. Of the 10 malignant neoplasms, all contained less than two-thirds FFLs: 20% had less than one-third, 80% had one to two-thirds FFLs.

CONCLUSIONS

The prevalence of FFLs in soft-tissue tumours referred to a specialist orthopaedic oncology unit is 3.3%. However, the presence of FFLs does not reliably distinguish benign from malignant neoplasms, although all lesions with more than two-thirds FFLs were benign.

Direct identification of propargyl radical in combustion flames by vacuum ultraviolet photoionization mass spectrometry

We have developed an effusive laser photodissociation radical source, aiming for the production of vibrationally relaxed radicals. Employing this radical source, we have measured the vacuum ultraviolet (VUV) photoionization efficiency (PIE) spectrum of the propargyl radical (C(3)H(3)) formed by the 193 nm excimer laser photodissociation of propargyl chloride in the energy range of 8.5-9.9 eV using high-resolution (energy bandwidth = 1 meV) multibunch synchrotron radiation. The VUV-PIE spectrum of C(3)H(3) thus obtained is found to exhibit pronounced autoionization features, which are tentatively assigned as members of two vibrational progressions of C(3)H(3) in excited autoionizing Rydberg states. The ionization energy (IE = 8.674 +/- 0.001 eV) of C(3)H(3) determined by a small steplike feature resolved at the photoionization onset of the VUV-PIE spectrum is in excellent agreement with the IE value reported in a previous pulsed field ionization-photoelectron study. We have also calculated the Franck-Condon factors (FCFs) for the photoionization transitions C(3)H(3) (+)(X;nu(i),i = 1-12)<--C(3)H(3)(X). The comparison between the pattern of FCFs and the autoionization peaks resolved in the VUV-PIE spectrum of C(3)H(3) points to the conclusion that the resonance-enhanced autoionization mechanism is most likely responsible for the observation of pronounced autoionization features. We also present here the VUV-PIE spectra for the mass 39 ions observed in the VUV synchrotron-based photoionization mass spectrometric sampling of several premixed flames. The excellent agreement of the IE value and the pattern of autoionizing features of the VUV-PIE spectra observed in the photodissociation and flames studies has provided an unambiguous identification of the propargyl radical as an important intermediate in the premixed combustion flames. The discrepancy found between the PIE spectra obtained in flames and photodissociation at energies above the IE(C(3)H(3)) suggests that the PIE spectra obtained in flames might have contributions from the photoionization of vibrationally excited C(3)H(3) and/or the dissociative photoionization processes involving larger hydrocarbon species formed in flames.

Computer modeling of the effect of perfusion on heating patterns in radiofrequency tumor ablation

PURPOSE

To use an established computer simulation model of radiofrequency (RF) ablation to further characterize the effect of varied perfusion on RF heating for commonly used RF durations and electrode types, and different tumor sizes.

METHODS

Computer simulation of RF heating using 2-D and 3-D finite element analysis (Etherm) was performed. Simulated RF application was systematically modeled on clinically relevant application parameters for a range of inner tumor perfusion (0-5 kg/m3-s) and outer normal surrounding tissue perfusion (0-5 kg/m3-s) for internally cooled 3-cm single and 2.5-cm cluster electrodes over a range of tumor diameters (2-5 cm), and RF application times (5-60 min; n = 4618 simulations). Tissue heating patterns and the time required to heat the entire tumor +/- a 5-mm margin to > 50 degrees C were assessed. Three-dimensional surface response contours were generated, and linear and higher order curve-fitting was performed.

RESULTS

For both electrodes, increasing overall tissue perfusion exponentially decreased the overall distance of the 50 degrees C isotherm (R2 = 0.94). Simultaneously, increasing overall perfusion exponentially decreased the time required to achieve thermal equilibrium (R2 = 0.94). Furthermore, the relative effect of inner and outer perfusion varied with increasing tumor size. For smaller tumors (2 cm diameter, 3-cm single; 2-3 cm diameter, cluster), the ability and time to achieve tumor ablation was largely determined by the outer tissue perfusion value. However, for larger tumors (4-5 cm diameter single; 5 cm diameter cluster), inner tumor perfusion had the predominant effect.

CONCLUSION

Computer modeling demonstrates that perfusion reduces both RF coagulation and the time to achieve thermal equilibrium. These results further show the importance of considering not only tumor perfusion, but also size (in addition to background tissue perfusion) when attempting to predict the effect of perfusion on RF heating and ablation times.