Genomic and gene expression profiling of minute alterations of chromosome arm 1p in small-cell lung carcinoma cells

Genetic alterations occurring on human chromosome arm 1p are common in many types of cancer including lung, breast, neuroblastoma, pheochromocytoma, and colorectal. The identification of tumour suppressors and oncogenes on this arm has been limited by the low resolution of current technologies for fine mapping. In order to identify genetic alterations on 1p in small-cell lung carcinoma, we developed a new resource for fine mapping segmental DNA copy number alterations. We have constructed an array of 642 ordered and fingerprint-verified bacterial artificial chromosome clones spanning the 120 megabase (Mb) 1p arm from 1p11.2 to p36.33. The 1p arm of 15 small-cell lung cancer cell lines was analysed at sub-Mb resolution using this arm-specific array. Among the genetic alterations identified, two regions of recurrent amplification emerged. They were detected in at least 45% of the samples: a 580 kb region at 1p34.2–p34.3 and a 270 kb region at 1p11.2. We further defined the potential importance of these genomic amplifications by analysing the RNA expression of the genes in these regions with Affymetrix oligonucleotide arrays and semiquantitative reverse transcriptase–polymerase chain reaction. Our data revealed overexpression of the genes HEYL, HPCAL4, BMP8, IPT, and RLF, coinciding with genomic amplification.

Time Domain Fluorescent Diffuse Optical Tomography: analytical expressions

Light propagation in tissue is known to be favored in the Near Infrared spectral range. Capitalizing on this fact, new classes of molecular contrast agents are engineered to fluoresce in the Near Infrared. The potential of these new agents is vast as it allows tracking non-invasively and quantitatively specific molecular events in-vivo. However, to monitor the bio-distribution of such compounds in thick tissue proper physical models of light propagation are necessary. To recover 3D concentrations of the compound distribution, it is necessary to perform a model based inverse problem: Diffuse Optical Tomography. In this work, we focus on Fluorescent Diffuse Optical Tomography expressed within the normalized Born approach. More precisely, we investigate the performance of Fluorescent Diffuse Optical Tomography in the case of time resolved measurements. The different moments of the time point spread function were analytically derived to construct the forward model. The derivation was performed from the zero order moment to the second order moment. This new forward model approach was validated with simulations based on relevant configurations. Enhanced performance of Fluorescent Diffuse Optical Tomography was achieved using these new analytical solutions when compared to the current formulations.

Synthesis and Synchrotron Light-Induced Luminescence of ZnO Nanostructures: Nanowires, Nanoneedles, Nanoflowers, and Tubular Whiskers

ZnO nanostructures, including single-crystal nanowires, nanoneedles, nanoflowers, and tubular whiskers, have been fabricated at a modestly low temperature of 550 degrees C via the oxidation of metallic Zn powder without a metal catalyst. Specific ZnO nanostructures can be obtained at a specific temperature zone in the furnace depending on the temperature and the pressure of oxygen. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) studies show that ZnO nanostructures thus prepared are single crystals with a wurtzite structure. X-ray excited optical luminescence (XEOL) from the ZnO nanostructures show noticeable morphology-dependent luminescence. Specifically, ZnO nanowires of around 15 nm in diameter emit the strongest green light. The morphology of these nanostructures, their XEOL, and the implication of the results will be discussed.

Merosin-deficient congenital muscular dystrophy in two siblings

Congenital muscular dystrophies are a group of heterogeneous inherited autosomal recessive disorders. The so-called 'pure' or 'occidental' form is further divided into merosin-positive and merosin-negative subgroups. Merosin is also expressed in the nervous system and its deficiency could affect development of the nervous system. The authors report two siblings with merosin-negative congenital muscular dystrophy. The clinical picture, biopsy findings, and abnormalities as detected by the magnetic resonance imaging of the two patients are presented.

Transforming growth factor beta-1 and gene polymorphisms in oriental ankylosing spondylitis

OBJECTIVES

To study serum levels of transforming growth factor beta-1 (TGFbeta1) and the expression of TGFbeta1 in in vitro peripheral blood mononuclear cell (PBMC) cultures in oriental ankylosing spondylitis (AS) patients, and to determine their association with codon 10 and 25 TGFB1 gene polymorphisms.

METHODS

Serum levels of TGFbeta1 were measured by enzyme-linked immunosorbent assay (ELISA). The ability of PBMCs to synthesize TGFbeta1 and other cytokines was assessed by in vitro cultures stimulated with mitogen. Genomic DNA was extracted from PBMCs of AS patients (n=72) or unrelated healthy controls (n=96). The codon 10 and 25 polymorphisms in the TGFB1 gene were analysed using standard polymerase chain reaction-based methods.

RESULTS

AS patients had significantly higher serum TGFbeta1 levels than controls (P<0.001). There was no difference in the distribution of codon 10 and 25 TGFB1 genotypes between AS patients and controls. Incubation of AS and control PBMC with phytohaemagglutinin (PHA) led to upregulation of TGFbeta1, interleukin-10, tumour necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma) assessed by ELISA. Importantly, PHA-induced TGFbeta1 production was significantly enhanced in AS patients compared with normal controls whereas the production of the pro-inflammatory cytokines TNFalpha and IFNgamma was reduced.

CONCLUSIONS

Our results show that AS patients express significantly higher levels of serum TGFbeta1 independent of the codon 10 and 25 genotype. Activation of AS PBMCs led to enhanced TGFbeta1 production accompanied by reduction of TNFalpha and IFNgamma while the converse was observed in normal controls.

Features predicting adverse outcomes of status epilepticus in childhood

OBJECTIVE

To examine variables that might predict abnormal outcome of status epilepticus among children.

DESIGN

Retrospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

All children younger than 15 years who were admitted to the paediatric intensive care unit with status epilepticus between 1997 and 2002.

MAIN OUTCOME MEASURES

Neurodevelopmental outcomes.

RESULTS

Two of the 25 patients died, resulting in a mortality rate of 8%. No deaths were due to status epilepticus itself. No patient with febrile or idiopathic status epilepticus developed epilepsy. Neurological deterioration was observed in a quarter (six of 23) of the survivors. Symptomatic aetiology (acute or remote) and refractory status epilepticus were associated with adverse outcomes (P<0.05). Young age at status epilepticus (<12 months) and duration of status epilepticus (>60 minutes) tended to be more frequent among those who developed adverse outcome. Rectal diazepam was given before hospital arrival in only four patients.

CONCLUSIONS

Paediatric patients with status epilepticus who had normal neurodevelopmental status before the onset of an attack and who did not sustain an acute insult to the central nervous system or have progressive encephalopathy, had favourable outcomes. Prompt use of rectal diazepam or buccal midazolam administered by caretakers or paramedics should be encouraged.

A new algorithm for determining collimator angles that favor efficiency in MLC based IMRT delivery

A new algorithm to determine collimator angles that favor delivery efficiency of intensity modulated radiotherapy plans was developed. It was found that the number of segments and monitor units (MUs) were largely reduced with the set of collimator angles determined with the new algorithm without compromising plan quality. The improvement of delivery efficiency using the new algorithm depends on the size and shape of the target(s), the number of modulation levels, and the type of leaf-sequencing algorithm. In a typical prostate case, when a sweeping leaf-sequencer is used for Varian 120 leaf (0.5 x 0.5 cm2 beamlet), 80 leaf (1 x 1 cm2 beamlet) and Elekta 40 leaf (1 x 1 cm2 beamlet), the number of segments was reduced by 42%, 29%, and 5%, respectively. The number of MUs was reduced by 41%, 35%, and 10%. For the Siemens MLC (IMFAST leaf sequencer, 1 x 1 cm2 beamlet) the segment reduction was 32% and the MU reduction was 14%. Comparison of the plans using the new and Brahme algorithms, in terms of target conformity index and dose volume histogram of the organs at risk, showed that the quality of the plans using the new algorithm was uncompromised. Similar results were obtained for a set of head and neck treatment plans.

The prevalence of dentine hypersensitivity in a hospital clinic population in Hong Kong

OBJECTIVES

Dentine hypersensitivity is a common clinical finding with a wide variation in prevalence values. The aim of this study was to establish the prevalence of dentine hypersensitivity and to examine some associated aetiological factors in a cross-sectional study of patients visiting the Periodontology and Oral Hygiene Clinic at Prince Phillip Dental Hospital, Hong Kong over a three-week period.

METHODS

226 patients were examined over a three-week period using a triple syringe to administer a blast of cold air to confirm the diagnosis of dentine hypersensitivity. Additional factors such as smoking habits, initiating stimuli, gingival recession and cervical tooth surface loss were noted.

RESULTS

153 patients were diagnosed as having dentine hypersensitivity, giving a prevalence figure of 67.7%. The commonest teeth affected were the lower incisors and the commonest initiating factor was cold drinks.

CONCLUSIONS

The prevalence of dentine hypersensitivity in a hospital periodontology clinic population in Hong Kong was 67.7%.

Expression, immunolocalization, and functional activity of Na+/H+ exchanger isoforms in mouse endometrial epithelium

The luminal fluid microenvironment of the uterus is important for sperm capacitation and embryo development. In an attempt to understand the possible role of Na(+)/H(+) exchangers (NHEs) in uterine function, the mRNAs of different NHE isoforms as well as their subcellular localization (apical versus basolateral) and functional activity were investigated in mouse endometrial epithelial cells using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and intracellular pH (pH(i)) measurement techniques. The presence of NHE1, NHE2, and NHE4, but not NHE3 mRNAs were revealed by RT-PCR. Immunostaining showed that NHE1, NHE2, and NHE4 were present in both apical and basolateral membranes. The pH(i) recovery from intracellular acidification was Na(+)-dependent; however, the rate of pH(i) recovery depending on basolateral Na(+) was 12.4 times faster than that depending on apical Na(+). The Na(+)-dependent rate of pH(i) recovery was also inhibited by amiloride, indicating H(+) extrusion through NHEs; however, the amiloride sensitivity of the apical membrane was less than that of the basolateral membrane, suggesting the involvement of different types of NHEs in the two membranes. The results indicate that the basolaterally located NHE1, NHE2, and NHE4, in addition to participating in the homeostatic control of intracellular pH, may play a role in H(+) extrusion in order to achieve transepithelial HCO(3)(-) secretion. The apically located NHEs may be involved in mediating Na(+) absorption as alternatives of or complementary to epithelial Na(+) channels.

Non-accidental carbon monoxide poisoning from burning charcoal in attempted combined homicide-suicide

OBJECTIVE

To describe an emerging form of serious child abuse in combined homicide-suicide in Hong Kong.

METHOD

This is a retrospective hospital chart review in a regional hospital in Hong Kong from January to December 2000.

RESULTS

Eight children, with a mean age of 7.8 years (range 0.5-11 years), from four families were admitted to hospital because of non-accidental exposure to carbon monoxide when their parents attempted suicide by burning charcoal. A 7-year-old boy died on arrival. His 5.6-year-old sister and another 6-month-old boy had cerebral hypoxia on admission. Hyperbaric oxygen therapy was used in both cases, with rapid improvement, although there were persistent neurological deficits in the girl. The other children in the present study were asymptomatic and none had delayed neurological sequelae. Concomitant use of sedatives was also detected in three of the surviving patients.

CONCLUSIONS

Non-accidental poisoning with carbon monoxide appears to be a new means of child abuse with potentially serious consequences. Concomitant intoxication with psychotropic drugs is common in such cases. The reason for parents killing their own children under such circumstances was unclear, but a desire to exact revenge on an estranged partner was suggested.

New strategies for the diagnosis and screening of malaria

Thin and thick blood film microscopy are the "gold standard" for malaria diagnosis. In recent years, there have been important developments in malaria diagnostic tests including fluorescence microscopy of malaria parasites stained with acridine orange, dipstick immunoassays that detect species-specific parasite antigens, and more recently, detection of parasite nucleic acids after amplification by PCR. With some of these methods, sensitivities and specificities approaching and even exceeding those of the thin and thick film can be attained. In particular, PCR-based tests for plasmodium DNA or RNA are more sensitive and specific than other tests for malarial parasites. A specific application for PCR diagnosis of malaria could be blood donor screening. Clinical trials of blood donor sreening for malarial parasites by PCR are being conducted, in which pooled donor samples are screened to increase efficiency and reduce costs. Some of the new diagnostic methods may have specific applications in particular settings, depending on the purpose and location of testing, and other factors such as cost, desired sensitivity and specificity, speed and ease of use.

Consensus statements from the Second International Lung Cancer Molecular Biomarkers Workshop: a European strategy for developing lung cancer molecular diagnostics in high risk populations

The Second Molecular Biomarkers Workshop was held at the Roy Castle International Centre for Lung Cancer Research in Liverpool, in June 2001 and it brought together experts in the clinical, epidemiological and molecular-pathology of lung cancer from Europe and the USA, to address issues surrounding the development of a European strategy for early lung cancer detection. The 2001 Workshop Breakout Groups concentrated on the current challenges in the early detection of lung cancer which need to be addressed in the light of the recent surge in interest in many countries for mounting new clinical trials to evaluate the utility of Spiral CT in early lung cancer detection. If population-based trials of CT screening are mounted it will also be a favorable clinical environment in which to evaluate efficiently recent advances in molecular screening and genotyping. The Workshop focused specifically on: a) clinical and molecular biomarkers, b) sputum as an early detection and diagnostic tool, c) validation of molecular markers prior to their use in early detection trials and d) ethical issues that have to be considered in early lung cancer detection trials. A distillation of the Workshop discussions is given in this article.

Postnatal hypoxemia increases angiotensin II sensitivity and up-regulates AT1a angiotensin receptors in rat carotid body chemoreceptors

In the present study, the effects of postnatal hypoxemia on the AT1 angiotensin receptor-mediated activities in the rat carotid body were studied. Angiotensin II (Ang II) concentration-dependently increased the chemoreceptor afferent activity in the isolated carotid body. Single- or pauci-fiber recording of the sinus nerve revealed that the afferent response to Ang II was enhanced in the postnatally hypoxic carotid body. To determine whether the increased sensitivity to Ang II is mediated by changes in the functional expression of Ang II receptors in the carotid body chemoreceptors, cytosolic calcium ([Ca2+]i) was measured by spectrofluorimetry in fura-2 acetoxymethyl ester-loaded type I cells dissociated from carotid bodies. Ang II (25-100 nM) concentration-dependently increased [Ca2+]i in the type I cells. The proportion of clusters of type I cells responsive to Ang II was higher in the postnatally hypoxic group than in the normoxic control (89 vs 66%). In addition, the peak [Ca2+]i response to Ang II was enhanced 2- to 3-fold in the postnatally hypoxic group. The [Ca2+]i response to Ang II was abolished by pretreatment with losartan (1 microM), an AT1 receptor antagonist, but not by PD-123177 (1 microM), an AT(2) antagonist. Double-labeling immunohistochemistry confirmed that an enhanced immunoreactivity for AT1 receptor was co-localized to the lobules of type I cells in the hypoxic group. In addition, RT-PCR analysis of subtypes of AT1 receptors showed an up-regulation of AT1a but a down-regulation of AT1b receptors, indicating a differential regulation of the expression of AT1 receptor subtypes by postnatal hypoxia in the carotid body. These data suggest that postnatal hypoxemia is associated with an increased sensitivity of peripheral chemoreceptors in response to Ang II and an up-regulation of AT1a receptor-mediated [Ca2+]i activity of the chemoreceptors. This modulation may be important for adaptation of carotid body functions in the hypoxic ventilatory response and in electrolyte and water homeostasis during perinatal and postnatal hypoxia.