Labelfree fully electronic nucleic acid detection system based on a field-effect transistor device

The labelfree detection of nucleic acid sequences is one of the modern attempts to develop quick, cheap and miniaturised hand-held devices for the future genetic testing in biotechnology and medical diagnostics. We present an approach to detect the hybridisation of DNA sequences using electrolyte-oxide-semiconductor field-effect transistors (EOSFETs) with micrometer dimensions. These semiconductor devices are sensitive to electrical charge variations that occur at the surface/electrolyte interface, i.e. upon hybridisation of oligonucleotides with complementary single-stranded (ss) oligonucleotides, which are immobilised on the oxide surface of the transistor gate. This method allows direct, time-resolved and in situ detection of specific nucleic acid binding events without any labelling. We focus on the detection mechanism of our sensors by using oppositely charged polyelectrolytes (PAH and PSS) subsequently attached to the transistor structures. Our results indicate that the sensor output is charge sensitive and distance dependent from the gate surface, which pinpoints the need for very defined surface chemistry at the device surface. The hybridisation of natural 19 base-pair sequences has been successfully detected with the sensors. In combination with nano-transistors a PCR free detection system might be feasible in future.

Living arrangements and place of death of older people with cancer in England and Wales: a record linkage study

The main objectives of the study were to (1) see whether the household circumstances of people aged 50 years and over with cancer, and trends in these, differ from those of the rest of the population and (2) whether living arrangements and presence and health status of a primary coresident are associated with place of death among older people dying of cancer and those dying from other causes. The design included prospective record linkage study of people aged 50 years and over included in a 1% sample of the population of England and Wales (the Office for National Statistics Longitudinal Study). The main outcome measures comprised family and household type, and death at home. The household circumstances of older people with cancer were very similar to those of the rest of the population of the same age and both showed a large increase in living alone, and decrease in living with relatives, between 1981 and 1991. The primary coresident of cancer sufferers who did not live alone was in most cases a spouse, with much smaller proportions living with a child, sibling or other person. In all, 30% of spouse, and 23% of other, primary coresidents had a limiting long-term illness. Compared with people who lived alone in 1991, odds of a home death among those dying of cancer between 1991 and 1995 were highest for those who lived with a spouse who had no limiting long-term illness (odds ratio (OR) 2.52, 95% confidence interval (CI) 2.15–2.97) and raised for those living with a spouse with a long-term illness (OR 2.14, CI 1.79–2.56) and those living with someone else who was free of long-term illness (OR 2.13, CI 1.69–2.68). Higher socioeconomic status, both individual and area, was positively associated with increased chance of a home death, while older age reduced the chance of dying at home. The changing living arrangements of older people have important implications for planning and provision of care and treatment for cancer sufferers.

Depth of word processing in Alzheimer patients and normal controls: a magnetoencephalographic (MEG) study

Effects related to depth of verbal information processing were investigated in probable Alzheimer's disease patients (AD) and age matched controls. During word encoding sessions 10 patients and 10 controls had either to decide whether the letter "s" appeared in visually presented words (alphabetical decision, shallow encoding), or whether the meaning of each presented word was animate or inanimate (lexical decision, deep encoding). These encoding sessions were followed by test sessions during which all previously encoded words were presented again together with the same number of new words. The task was then to discriminate between repeated and new words. Magnetic field changes related to brain activity were recorded with a whole cortex MEG.5 probable AD patients showed recognition performances above chance level related to both depths of information processing. Those patients and 5 age matched controls were then further analysed. Recognition performance was poorer in probable AD patients compared to controls for both levels of processing. However, in both groups deep encoding led to a higher recognition performance than shallow encoding. We therefore conclude that the performance reduction in the patient group was independent of depth of processing. Reaction times related to false alarms differed between patients and controls after deep encoding which perhaps could already be used for supporting an early diagnosis. The analysis of the physiological data revealed significant differences between correctly recognised repetitions and correctly classified new words (old/new-effect) in the control group which were missing in the patient group after deep encoding. The lack of such an effect in the patient group is interpreted as being due to the respective neuropathology related to probable AD. The present results demonstrate that magnetic field recordings represent a useful tool to physiologically distinguish between probable AD and age matched controls.

Chemical and biological integration of a mouldable bioactive ceramic material capable of forming apatite in vivo in teeth

Chemically bonded ceramics have several advantages compared with conventional ceramics to be used as biomaterials. Especially the possibilities to harden the material at room temperature and to control the rheology are very beneficial. This paper investigates the interface formed in vivo between a calcium aluminate based dental filling material and teeth. Class 1 occlusal fillings were made in wisdom teeth and extracted after up to four weeks. Polished cross-sections of the teeth were studied with scanning electron microscopy (SEM), focused ion beam microscopy (FIB) and transmission electron microscopy (TEM). In order to analyse the distribution of elements at the interface elemental mapping was performed using STEM and EDX. The results showed that a tight bond forms between the filling material and tooth and no gap could be found even at high magnification. A 100-200 nm wide zone with an increase in oxygen was detected in the enamel next to the filling. The zone was denser than the rest of the enamel. Elemental mapping indicated an increase of silicon and a decrease of Ca at the interface. Dark field imaging and EDX mapping showed that the calcium aluminate system formed apatite in situ during hardening through precipitation.

Improved artificial neural networks in prediction of malignancy of lesions in contrast-enhanced MR-mammography

The aim of this study was to evaluate the capability of improved artificial neural networks (ANN) and additional novel training methods in distinguishing between benign and malignant breast lesions in contrast-enhanced magnetic resonance-mammography (MRM). A total of 604 histologically proven cases of contrast-enhanced lesions of the female breast at MRI were analyzed. Morphological, dynamic and clinical parameters were collected and stored in a database. The data set was divided into several groups using random or experimental methods [Training & Testing (T&T) algorithm] to train and test different ANNs. An additional novel computer program for input variable selection was applied. Sensitivity and specificity were calculated and compared with a statistical method and an expert radiologist. After optimization of the distribution of cases among the training and testing sets by the T & T algorithm and the reduction of input variables by the Input Selection procedure a highly sophisticated ANN achieved a sensitivity of 93.6% and a specificity of 91.9% in predicting malignancy of lesions within an independent prediction sample set. The best statistical method reached a sensitivity of 90.5% and a specificity of 68.9%. An expert radiologist performed better than the statistical method but worse than the ANN (sensitivity 92.1%, specificity 85.6%). Features extracted out of dynamic contrast-enhanced MRM and additional clinical data can be successfully analyzed by advanced ANNs. The quality of the resulting network strongly depends on the training methods, which are improved by the use of novel training tools. The best results of an improved ANN outperform expert radiologists.

In vivo 2D J-resolved magnetic resonance spectroscopy of rat brain with a 3-T clinical human scanner

A clinical 3-T scanner equipped with a custom-made transmit/receive birdcage coil was used to collect 2D J-resolved single-voxel spectroscopy in vivo of rat brain. Four adult Wistar rats were scanned twice each, with a 2-week interval. Voxel size was approximately 5 x 10 x 5 mm(3). Total spectroscopic acquisition time was 14 min for collection of two 4:20 min water-suppressed acquisitions and one 4:20 min acquisition acquired in the absence of water suppression. The unsuppressed water data were used in post-processing to reduce residual water side bands, as well as for metabolite signal normalization to account for variations in coil loading and voxel size. Peak areas were estimated for resonances from N-acetyl aspartate (NAA), creatine, choline, taurine, glutamate, and combined glutamate and glutamine. T(2)-relaxation times were estimated for NAA and creatine. The average deviation from the mean of repeated measures for glutamate, combined glutamate and glutamine, and taurine ranged from 7.6% to 18.3%, while for NAA, creatine, and choline, the deviation was less than 3%. The estimated T(2) values for NAA (mean +/- SD = 330 +/- 57 ms) and creatine (174 +/- 27 ms) were similar to those reported previously for rat brain and for human gray and white matter. These results indicate that reliable, small animal brain MR spectroscopy can be performed on a human clinical 3-T scanner.

Konservative befundadaptierte Therapie von superinfizierten chronischen venös bedingten Ulcera cruris

Die erfolgreiche Therapie von venösen Ulzera stellt eine besondere klinische Herausforderung dar. Das im Folgenden beschriebene konservative Wundmanagement bei einem Hochrisikopatienten zeigt eine Alternative zur primären operativen Therapie auf. Ein 79-jähriger, multimorbider Patient in reduziertem Allgemeinzustand wird mit superinfizierten, nekrotisch veränderten und schmerzhaften Ulzera hospitalisiert. Aufgrund der Multimorbidität des Patienten ist die kausale operative Therapie der zugrunde liegenden venösen Insuffizienz, bestehend aus Stripping der Vena saphena magna mit Perforantenligatur, kontraindiziert. Es wird deshalb interdisziplinär die Indikation für eine konservative Therapie gestellt. Sie umfasst ein initiales lokales Debridement, Feuchtverbände, Kompressionstherapie, systemische Antibiose und analgetische Therapie, unterstützt durch die allgemeine Stabilisierung des Patienten. In regelmäßigen Abständen wird eine fotografische Wunddokumentation durchgeführt. Der Behandlungs- und Beobachtungszeitraum beträgt 63 Tage. Durch konservatives Wundmanagement wird eine deutliche Besserung der Wundverhältnisse sowie des Allgemeinzustandes des Patienten erzielt. Die Dauer des Verbandswechsels kann von 2 Stunden auf 30 Minuten verkürzt werden. Der Schmerzscore reduziert sich von 8/10 auf 4/10 bei abnehmendem Analgetikabedarf. Die fotografische Dokumentation zeigt eine deutliche Progredienz der Wundheilung innerhalb von 9 Wochen auf. Unter antibiotischer Therapie und konservativem Wundmanagement sind die erhöhten Entzündungsparameter rückläufig. Durch ein konservatives, befundadaptiertes Therapieregime werden superinfizierte, chronische venös bedingte Ulzera in einen stabilen Zustand überführt.

Survival from breast cancer among South Asian and non-South Asian women resident in South East England

Ethnic differences in breast cancer survival have been observed in the USA but have not been examined in Britain. We aimed to investigate such differences between South Asian (i.e. those with family roots in the Indian subcontinent) and non-South Asian (essentially British-native) women in England. Primary breast cancer cases incident in 1986 -1993 and resident in South East England were ascertained through the Thames Cancer and Registry and followed up to the end of 1997. Cases of South Asian ethnicity were identified on the basis of their names by using a previously validated computer algorithm. A total of 1037 South Asian and 50 201 non-South Asian breast cancer cases were included in the analysis; 30% of the South Asian (n=312) and 44% (n=22 201) of the non-South Asian cases died during follow-up. South Asian cases had a higher relative survival than non-South Asians throughout the follow-up period. The 10-year relative survival rates were 72.6% (95% confidence interval: 69.0, 75.9%) and 65.2% (64.5, 65.8%) for South Asians and non-South Asians, respectively. The excess mortality rates experienced by South Asians were 82% (72, 94%) of those experienced by non-South Asians (P=0.004). The magnitude of this effect was slightly reduced with adjustment for differences in age at diagnosis, but was strengthened with further adjustment for differences in stage at presentation and socioeconomic deprivation (excess mortality rates in South Asians relative to non-South Asians=72% (63, 82%), P&<0.001). These findings indicate that the higher survival from breast cancer in the first 10 years after diagnosis among South Asian was not due to differences in age at diagnosis, socioeconomic deprivation or disease stage at presentation.

Repair of abdominal aortic aneurysms with the Excluder bifurcated stent-graft

The design of the Excluder, which is considered a 3rd generation device for endovascular repair of abdominal aortic aneurysms, is described. Based on a literature search, clinical short- to mid-term results are reviewed. So far, efficacy and safety of the Excluder for elective and emergent aneurysm repair have been demonstrated. In none of the studies perioperative conversion to open surgery or late aneurysm rupture has been reported. The cumulative 30-day-mortality rate was below 1%. Compared to the other commercial devices, aneurysm shrinkage is less marked after repair with the Excluder. Whether this is inconvenient remains to be proven on long-term follow-up.

Progress in treatment and outcome for children with neonatal haemochromatosis

AIM

To evaluate the role of antioxidant treatment and liver transplantation in the management of neonatal haemochromatosis.

METHODS

A retrospective review was performed of eight infants with acute liver failure and raised ferritin levels between 1990 and 1998. From 1994, treatment with an antioxidant cocktail (vitamin E, N-acetylcysteine, selenium, prostaglandin E1, and desferrioxamine) was begun once the diagnosis was suspected. Pathological and other findings were reviewed, and outcome before and after antioxidant treatment was evaluated.

RESULTS

Median age at presentation was 4 days with median ferritin levels of 4180 micro g/l (range 1650-40 000 micro g/l; normal range 110-503 micro g/l). Three infants presented before 1994. One infant died before liver transplantation from acute liver failure and one from neurological damage after transplantation. The third patient underwent successful transplantation at day 13 and remains well on follow up 8 years later. From 1994, five patients received antioxidant treatment, of whom two responded: both responders started antioxidants earlier (by day 5) than non-responders and had lower peak ferritin levels (< 4200 micro g/l) and a milder phenotype. Treatment was continued until ferritin levels were < 500 micro g/l. Both children remain well with mean follow up of 42 months, with no recurrence of iron overload. One child showed a partial response to treatment and survived long enough for a liver transplant, but died from graft failure after the transplant. Two children did not respond to antioxidant treatment; both had multiorgan failure and were not listed for transplantation. Only three of the eight patients survived (37.5%) over this time period.

CONCLUSION

Neonatal haemochromatosis can be a fatal disease with > 60% mortality. Early treatment with antioxidant cocktail is beneficial and may be curative in those who present with milder phenotype. Liver transplantation should always be considered at an early stage in non-responders and in children with more severe acute liver failure.

Radiological imaging as the basis for a simulation software of ventilation in the tracheo-bronchial tree

The inhaled route is a promising new way for administering drugs to the human body. Flow and particle deposition in the human respiratory tract depends on the individual's anatomy as well as on the drug composition. A European Framework V Program supported project is currently developing a simulation tool for assessment of drug distribution and deposition. This tool relies heavily on the input of radiological data sets, which are obtained in humans. Both high temporal and spatial resolutions are required, and CT and MRI (including hyperpolarized helium-3 MRI) are applied. The radiological data are integrated into computation fluid dynamics software, which is capable of assessing air-flow profiles and compartmental behaviours. This is complemented by pharmacokinetic models, which should result in a simulation tool that will be of use for the theoretical design of new inhaled therapies. This article describes the special imaging requirements of each region of the respiratory tract and the feasibility of these sophisticated radiological techniques with a view of using these data in a simulation model of the lung.

Hemostatic problems before, during and after delivery

Normal pregnancy and childbirth are known to be associated with marked changes in the coagulation and fibrinolytic systems. Generally, enhancement of clotting activity persists to prevent the risk of major hemorrhage. Hemostatic problems, either associated with a specific complication of pregnancy and labor or due to a hereditary or acquired bleeding diathesis or thrombophilias, present a significant cause of maternal and neonatal morbidity and mortality. This article reviews hemostatic disorders in pregnancy and the peripartal period from the standpoint of the obstetrician.

Giant uterine leiomyoma devascularized by embolization prior to surgical removal

A 49-year-old woman presented a tumor of pelvic origin filling almost the whole abdominal cavity. Angiography confirmed that it arose from the uterus. Bilateral internal iliac artery embolization was performed prior to surgical removal. It was found to be a 25kg uterine leiomyoma.

Cortical responses to object-motion and visually-induced self-motion perception

We investigated the spatiotemporal cortical dynamics during the perception of object-motion and visually-induced self-motion perception in six normal subjects, using a 143-channel neuromagnetometer. Object-motion specific tasks evoked early transient activity over the right temporooccipital cortex, while self-motion perception, or vection, additionally was followed by sustained bilateral activity in the temporoparietal area. The specific signal distributions suggest to represent the different perceptual modes of object-motion and self-motion sensation.

A modified system to evaluate the potency of anti-oxidative compounds in different cell types in vitro

Common assays for evaluation of antioxidative capacity of different compounds are usually performed in cell-free systems. By this approach, cell-specific regulatory mechanisms upon distinct stimuli are not taken into account. Therefore, there is a need to measure anti-oxidative capacity in a cellular setting. - We now developed a valid method that provides monitoring of anti-oxidative capacities of compounds in different cell types. Oxidative stress, induced by 100 microM H subset2O subset2 in human microvascular endothelial cells (HMEC-1), was quantified by the generation of oxidized, fluorescent C-DCF from C-H subset2DCF-DA/AM. As DCF-production could be almost completely blocked by diethyldithiocarbamate (DEDTC), which inhibits intracellular Cu/Zn superoxide dismutase (SOD), mainly intracellular production of C-DCF was assumed. Preincubation with alpha-tocopherol resulted in a dose-dependent reduction of both spontaneous and H subset2O subset2-induced C-DCF-production (maximal inhibition by 41.6% at 75 microM). A synergistic effect was observed with co-incubation with vitamin C (maximal inhibition 46.8% at 10 microM vitamin C and 50 microM alpha-tocopherol). In this way compounds with different modes of action and subcellular localization can be evaluated concomitantly in respect of their anti-oxidative capacities. As this method was established on 24- and 48-well plates in other cell lines (Caco-2, HFP-1), too, screening of a large array of antioxidative compounds in different cell lines can be performed.

Successful treatment of alloimmune thrombocytopenia using corticosteroid therapy in a woman with two consecutive neonatal deaths--case report

Alloimmune thrombocytopenia is a serious fetal disorder resulting from platelet-antigen incompatibility between the mother and the fetus. In mild cases, the diagnosis is usually made upon detection of neonatal thrombocytopenia, but serious consequences such as fetal intracranial hemorrhage and/or unexplained fetal death may complicate the disorder. Various treatment modalities are suggested in the management of alloimmune thrombocytopenia, however, none has yet been confirmed as obviously superior. We report on the successful use of corticosteroids during pregnancy in a woman with a history of two consecutive neonatal deaths due to severe thrombocytopenia and HPA 5b platelet-specific antigen incompatibility.

Liver transplantation for polycystic liver disease

Polycystic liver disease (PLD) may provoke massive hepatomegaly and severe physical and social handicaps. Data on orthotopic liver transplantation (OLT) for PLD are rare and conflicting. Conservative surgery (resection or fenestration) is indicated for large single cysts, but its value for small diffuse cysts is questionable. In addition, conservative surgery is not devoid of morbidity and mortality. OLT offers the prospect of a fully curative treatment, but controversy remains because those patients usually have preserved liver function. Thus, we reviewed our experience with OLT for PLD. Sixteen adult women underwent OLT for small diffuse PLD between 1990 and 1999. Mean age was 45 years (range, 34 to 56 years). Fourteen patients had combined liver and kidney cystic disease, but only 1 patient required combined liver and kidney transplantation, whereas 13 patients underwent OLT alone. Two patients had isolated PLD. Indications for transplantation were massive hepatomegaly causing physical handicaps (n = 16), social handicaps (n = 16), malnutrition (n = 4), and cholestasis and/or portal hypertension (n = 5). OLT caused no technical difficulty in 15 of 16 patients (surgery duration, 6.8 hours; range, 5 to 8 hours), with blood transfusions of 7.9 units (range, 0 to 22 units). One patient who underwent attempted liver-mass reduction pre-OLT died of bleeding and pulmonary emboli. Native liver weight was 10 to 20 kg. Posttransplantation immunosuppression consisted of cyclosporine or FK506, azathioprine, and steroids (discontinued at 3 months). Morbidity included biliary stricture (2 patients), revision for bleeding and hepatitis (1 patient), pneumothorax and subphrenic collection (1 patient), and tracheostomy (1 patient). One patient died of lung cancer 6 years posttransplantation. Both patient and graft survival rates are 87.5% (follow-up, 3 months to 9 years). Of 15 patients who underwent OLT alone, only 1 patient needed a kidney transplant 4 years after OLT. Kidney function has remained satisfactory in the other patients despite the use of cyclosporine or FK506 (last follow-up creatinine level, 1.55 mg/dL; range, 0.80 to 2.85 mg/dL). OLT had a dramatic impact on daily quality of life, enabling these patients to go back to a fully active life style. OLT offers the chance of a definitive treatment in patients with extensive, small, diffuse PLD that has evolved into severely handicapping hepatomegaly. In contrast to previous studies, combined liver and kidney transplantation is rarely needed. Patient symptoms and chances of definitive palliation offered by OLT must be balanced against the risks of transplantation and lifelong commitment to immunosuppression.

Increase in NAD but not ATP and GTP concentrations in rat liver by dehydroepiandrosterone feeding

Dehydroepiandrosterone (5-androsten-3beta-ol-17-one; DHEA), the main circulating steroid in humans, has been described to exert varied beneficial effects including antiobesity, anti-aging and anticancer action when used at pharmacological doses in experimental animals. To elucidate the mechanism of the pleiotropic effects of DHEA, we studied the effect of this steroid on concentrations of NAD and adenine and guanine nucleotides in rat liver. Administration of DHEA at 0.3% in the diet for 7 consecutive days caused an increase in liver NAD and NADP, but was without effect on NADH concentrations. This indicates a shift of the redox couple (NAD/NADH) towards oxidation in the DHEA-treated rats. Moreover, there was no change in adenine and guanine nucleotide concentrations, which disproves the hypothesis that the DHEA anticancer actions are due to a decrease in the availability of nucleosides for DNA synthesis. The findings indicate that an increase in liver NAD pool and/or altered redox status, but no changes in adenine or guanine nucleotide content, may be involved in the pleiotropic effects of DHEA.

Dehydroepiandrosterone stimulates proliferation and gene expression in MCF-7 cells after conversion to estradiol

Dehydroepiandrosterone (DHEA) is a mitogen for estrogen-dependent MCF-7 breast cancer cells. Our aims were to determine whether DHEA required conversion to estrogens in order to stimulate cell proliferation and estrogen-dependent gene expression. After incubation of cells with 100 nM DHEA for 4 days, estradiol was present in the medium at a concentration of approximately 200 pM. Other compounds identified were testosterone ( approximately 300 pM) and estrone. Significant stimulation of cell proliferation by 1 nM estradiol and 100 nM DHEA was observed after 38 h and 4 days of incubation, respectively, indicating the necessity of DHEA conversion. DHEA doses > or = 10 nM induced estrogen-dependent reporter gene expression in MCF-7 cells transfected with a luciferase reporter gene under the control of the estrogen response element. DHEA-dependent stimulation of proliferation and luciferase induction could be inhibited by the anti-estrogens ICI182,780 and tamoxifen, respectively, and by the aromatase inhibitor 4-hydroxyandrostenedione. An androgenic effect of DHEA on proliferation and gene expression of MCF-7 cells was not observed. We conclude that conversion of DHEA to estrogens, particularly estradiol, is required to exert a mitogenic response.

Detection and quantification of protein phosphatase inhibitor-1 gene expression in total rat liver and isolated hepatocytes

The mRNA expression of protein phosphatase inhibitor-1 (inhibitor-1) in rat liver was demonstrated using highly sensitive semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Quantification by real-time RT-PCR (LightCycler technology) yielded the same copy number of inhibitor-1 mRNA in total rat liver and isolated hepatocytes (12 copies per cell). This novel finding shows that rat liver expresses indeed inhibitor-1 mRNA, albeit in low amounts. The low copy number explains why the mRNA had not been detected by Northern blotting so far. For comparison, about 425 copies/cell were detected in brain and 2500 copies/cell in skeletal muscle from rat. The full-length coding sequence of rat liver inhibitor-1 was cloned and sequenced, 100% homology with the muscle cDNA was obtained, indicating the expression of the same gene in liver and muscle. In vitro transcription and translation yielded a protein (Mr approximately 30 kDa) which could be detected with a specific antibody by immunoblotting. This indicates an intact open reading frame of inhibitor-1 in rat liver. Immunoblotting of liver extract yielded a very weak band which comigrated with the inhibitor-1 proteins from muscle and brain. It is concluded that mRNA expression of inhibitor-1 may have implications for the regulation of protein phosphatase-1 (PP1) in rat liver.