A composite of exhaled LTB4 , LXA4 , FeNO, and FEV1 as an "asthma classification ratio" characterizes childhood asthma.

BACKGROUND: Aberrant generation of eicosanoids is associated with asthma, but the evidence remains incomplete and its potential utility as biomarkers is unclear. Major eicosanoids in exhaled breath condensates (EBCs) were assessed as candidate markers for childhood asthma. METHODS: Ten exhaled eicosanoid species was evaluated using ELISA in the discovery phase, followed by prediction model-building and validation phases. RESULTS: Exhaled LTB4 , LTE4 , PGE2, and LXA4 showed significant difference between asthmatics (N = 60) and controls (N = 20). For validation, an expanded study population consisting of 626 subjects with asthma and 161 healthy controls was partitioned into a training subset to establish a prediction model and a test sample subset for validation. Receiver operating characteristic (ROC) analyses of the training subset revealed the level of exhaled LTB4 to be the most discriminative among all parameters, including FeNO, and a composite of exhaled LTB4 , LXA4 , together with FeNO and FEV1 , distinguishing asthma with high sensitivity and specificity. Further, the Youden index (J) indicated the cut point value of 0.598 for this composite of markers as having the strongest discriminatory ability (sensitivity = 85.2% and specificity = 83.6%). The predictive algorithm as "asthma classification ratio" was further validated in an independent test sample with sensitivity and specificity being 84.4% and 84.8%, respectively. CONCLUSIONS: In a pediatric study population in Taiwan, the levels of exhaled LTB4 , LTE4 , LXA4, and PGE2 in asthmatic children were significantly different from those of healthy controls, and the combination of exhaled LTB4 and LXA4 , together with FeNO and FEV1 , best characterized childhood asthma.

Tobacco smoke exposure and multiplexed immunoglobulin E sensitization in children: a population-based study.

BACKGROUND: Although there is evidence that exposure to tobacco smoke is harmful to children's respiratory health, the effects of tobacco smoke exposure on the regulation of immunoglobulin E (IgE)-mediated immune responses to specific allergens remain unclear. This study aimed to investigate the relationship between objectively assessed tobacco smoke exposure and specific IgE profiles for a broad spectrum of allergens in a population setting. METHODS: Children aged 5-18 years (N = 1315) were assessed using serum cotinine measurement and microarray-based multiplexed detection of specific IgE against 40 allergens. RESULTS: Serum cotinine levels were positively associated with sensitization to foods (adjusted odds ratio [AOR] = 4.95; 95% CI: 1.59-15.34), cockroaches (AOR = 3.77; 95% CI: 1.49-9.51), and pollen (AOR = 2.84; 95% CI: 1.20-6.73) while the association was borderline significant for animals (AOR = 2.53; 95% CI: 0.92-6.93). No associations were found for sensitization against mites, mold, and latex. When considering the degree of allergic sensitization, serum cotinine levels were positively correlated to the number of sensitization to cockroaches (P = 0.004), pollen (P = 0.006), and foods (P < 0.001), with statistically significant positive dose-response relationships (all P < 0.01). Similar results were observed when summing up specific IgE concentrations for the aforementioned allergen categories. CONCLUSIONS: The association between tobacco smoke exposure and IgE sensitization to environmental allergens varies for different allergens among children. This study demonstrates that elevated serum cotinine levels are significantly associated with IgE sensitization to cockroaches, grass pollen, and certain foods, with potential dose-dependent relationships.

Associations of depression with impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in Chinese adults.

AIM: To examine the association between depression and impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in middle-aged and elderly Chinese people, and whether depression was associated with different treatment regimens or durations of diabetes. METHODS: A cross-sectional study was performed among 229,047 adults living in the community aged ≥ 40 years from 25 centres in China. The self-reported depression rating scale Patient Health Questionnaire 9 (PHQ-9) was used to diagnose probable and sub-threshold depression. Glucose metabolism status was determined according to World Health Organization 1999 diagnostic criteria. RESULTS: The numbers of participants with normal glucose regulation, impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes were 120,458, 59,512, 24,826 and 24,251, respectively. The prevalence of sub-threshold depression in the total sample of participants was 4.8% (4.8%, 4.8%, 4.4% and 5.6% from normal glucose regulation to previously diagnosed diabetes, respectively), and the prevalence of probable depression was 1.1% (1.1%, 1.0%, 0.9% and 1.8% from normal glucose regulation to previously diagnosed diabetes, respectively). Compared with participants with normal glucose regulation, those with previously diagnosed diabetes had increased odds of probable depression [odds ratio (OR) = 1.61, 95% confidence interval (CI) 1.39-1.87] and sub-threshold depression (OR = 1.14, 95% CI 1.06-1.24), after adjustment for multiple confounding factors. Newly diagnosed diabetes or impaired glucose regulation was not associated with depression. Among those with previously diagnosed diabetes, insulin treatment was associated with greater odds of depression compared with no treatment or oral anti-diabetic medicine. CONCLUSION: Previously diagnosed diabetes, but not newly diagnosed diabetes or impaired glucose regulation, was associated with a higher prevalence of depression. Patients receiving insulin were more likely to have depression than those not receiving treatment or being treated with oral anti-diabetic medicine.

Multiplexed immunoglobulin E sensitization in relation to exhaled nitric oxide in a population sample of children.

This study investigated the relationship between the specific immunoglobulin E (IgE) profile for 40 allergens using a novel microarray technique (BioIC) and fraction of exhaled nitric oxide (FeNO) in a population sample of 1321 children. Significant positive associations were found between FeNO and sensitization to mites (P < 0.001), animals (P = 0.001), cockroaches (P < 0.001), and foods (P = 0.042), and furthermore, between FeNO and the number of sensitizations (all P < 0.05) or the sum of specific IgE (all P ≤ 0.01) against the aforementioned allergen categories. Specifically, sensitization to the following allergens was significantly related to higher FeNO: Dermatophagoides pteronyssinus, Dermatophagoides farina, Blomia tropicalis, cat, German cockroach, Oriental cockroach, codfish, crab, shrimp, and cheese (all P ≤ 0.01). In conclusion, IgE sensitization to mites, pets, cockroaches, seafood, and cheese, respectively, is significantly associated with elevated FeNO levels in a dose-dependent fashion in children. Our results provide new evidence that sensitization to certain food allergens may contribute to prompt inflammation in the airways.

Synthesis of La0.6Nd0.2Na0.2MnO3 nanowire and its magnetism.

The colossal magnetoresistance (CMR) manganite La0.6Nd0.2Na0.2MnO3 nanowires were synthesized in porous anodic alumina oxide (AAO) membrane via the sol-gel template route. X-ray diffraction (XRD) results of La0.6Nd0.2Na0.2MnO3/AAO composites verified the purity of the perovskite structure of La0.6Nd0.2Na0.2MnO3. Field emission scanning electron microscopy (FE-SEM) confirmed that the monodisperse cylindrical pores of alumina membrane were filled with manganite nanowire arrays. The nanowires were found to be essentially polycrystalline materials by high-resolution transmission electron microscope (HRTEM) images and selected electron diffraction (SAED) analysis. The Curie temperature of the La0.6Nd0.2Na0.2MnO3 nanowires determined by superconducting quantum interference device (SQUID) was much less than the the Curie temperature of the bulk material. According to our experimental results, we proposed the single domain size should be less than 50 nm conservatively. The result suggested that the finite size effect may play an important role in the reduction of the Curie temperature of the La0.6Nd0.2Na0.2MnO3 nanowires.

The Cuffless Blood Pressure Measurement with Multi-dimension Regression Model based on Characteristics of Pulse Waveform.

According to the advancement of wearable technology, many physiological monitoring instruments are gradually converted into wearable devices. But, the blood pressure monitor still is a cuff-type device in the consumer market, which also does not do the beat-by-beat continuous blood pressure measurement. Now, the cuffless blood pressure measurement has been developed based on the pulse transit time (PTT) but its accuracy is not better. According to the cardiac hemodynamic theorem, the blood pressure relates with the arterial characteristics. Therefore, the purpose of this study was to use the characteristics of the pulse wave measured by photoplethysmography (PPG) to estimate the blood pressure with a multi-dimension regression model. The contour of pulse wave includes some characteristics of the artery. There were 10 subjects participating the experiment, and the blood pressure of the subject was changed by the exercise. The results showed that the cumulate root mean square error of the estimated systolic and diastolic pressures with the multi-parameters were 69.3 mmHg and 39.8 mmHg were better than only using one parameter, PTT, 82.1 mmHg and 45.2 mmHg, respectively.

Ferromagnetism in CaMn(1-x)Ir(x)O(3).

The crystallographic, magnetic, and electric properties of CaMn(1-x)Ir(x)O(3) (0≤x≤0.6) were investigated. The lattice constants increase with increasing content of Ir. Specimens of 0.05≤x≤0.2 show antiferromagnetic behavior; however, ferromagnetism is observed for specimens of 0.3≤x≤0.6. T(N) decreases as the Ir content increases. T(N) is superseded by T(C) without passing 0 K and T(C) continues to increase in the ferromagnetic composition range. The effective moment µ(eff) decreases as the Ir content increases. The Weiss temperature is negative for small x; however, it continues to increase while changing its sign at about x = 0.3. The results were explained by assuming a mixed valence state of Mn(3+), Mn(4+), Ir(4+), and Ir(5+) ions. The composition dependence of µ(eff) could be explained qualitatively using the ion fractions estimated from the Ir content dependence of the unit cell volume. Experimental results suggest the coexistence of antiferromagnetic and ferromagnetic phases. When the volume fraction of the ferromagnetic phase dominates that of the antiferromagnetic phase, the system seems to show ferromagnetism.

Longitudinal investigation of nasopharyngeal methicillin-resistant Staphylococcus aureus colonization in early infancy: The PATCH birth cohort study.

OBJECTIVES: The study aimed to determine the long-term Staphylococcus aureus colonization patterns and strain relatedness, and the association between maternal and infant colonization in infancy. METHODS: A birth cohort study was conducted from January 2012 to November 2014. Nasopharyngeal swabs for S. aureus detection were collected from infants at the age of 1, 2, 4, 6 and 12 months and from mothers when their children were 1-month-old. RESULTS: In total, 254 samples were collected at each planned visit during the first 12-month study. The prevalence of S. aureus colonization decreased in the first year of life, ranging from 61.0% (155/254) at the age of 1 month to 12.2% (31/254) at 12 months. Persistent colonization, defined as a positive culture on four or five occasions, was detected in only 13.8% (35/254) of carriers. Most of the persistent carriers were colonized with methicillin-resistant S. aureus (MRSA) only, and among persistent MRSA carriers, 61.1% (11/18) had indistinguishable genotypes. Of the mothers with MRSA colonization, 77.1% (27/35) had infants who were concomitantly colonized at the age of 1 month; 70.4% (19/27) of the infant-mother paired isolates belonged to indistinguishable or related subtypes, which suggests that surrounding carriers, probably their mothers, may be the possible source for MRSA acquisition in early infancy. CONCLUSIONS: Staphylococcus aureus colonization including MRSA was commonly observed in our cohort. Strains of persistent MRSA among infant-mother pairs were usually of indistinguishable genotypes. Therefore, horizontal spread within households is possibly an important factor related to infant MRSA colonization.

Cantonese-style salted fish as a cause of nasopharyngeal carcinoma: report of a case-control study in Hong Kong.

Two hundred fifty incident cases of nasopharyngeal carcinoma under age 35 years in Hong Kong Chinese and an equal number of age- and sex-matched friend controls were interviewed. Mothers of cases and controls were interviewed also, if available, to obtain information on childhood events concerning the study subjects. Consumption of Cantonese-style salted fish during all time periods was significantly associated with nasopharyngeal carcinoma; the association was especially strong during childhood. The relative risk for having Cantonese-style salted fish as one of the first solid foods during weaning was 7.5 (95% confidence limits, 3.9, 14.8), and the relative risk for consuming the food at least once a week compared to less than once a month at age 10 years was 37.7 (95% confidence limits, 14.1, 100.4). It is estimated that over 90% of young nasopharyngeal carcinoma cases in Hong Kong Chinese can be attributed to consumption of this food during childhood.

Urinary electrolytes and blood pressure in three Yi farmer populations, China.

The relation between blood pressure and urinary electrolytes, including sodium, potassium, calcium, and magnesium were examined in male farmers of the Yi nationality who live in three separate communities in Sichuan and Yunnan provinces in China, where the lifestyles, habits, and living conditions are very different. One of these three communities was unacculturated and had the lowest average blood pressure as well as the lowest prevalence rate of hypertension in China; one was acculturated and had the highest average blood pressure; and the third was moderately acculturated with its average blood pressure between the other two. Blood pressure was taken on each of 3 days and corresponding 24-hour urine specimens were collected to measure potassium, sodium, calcium, magnesium, urea nitrogen, and creatinine. Ecological and individual-based data correlation analyses were employed to study the relations among age, body mass index, some related indexes of electrolyte derivatives, and blood pressure. Multiple regression analyses were used to explore the relation of blood pressure to the above indexes, adjusted for age, body mass index, urea nitrogen and creatinine, and geographical differences. Statistically significant correlation analyses showed that systolic blood pressure was positively associated with sodium-creatinine, calcium-creatinine, sodium-potassium, calcium-magnesium, and urea nitrogen and creatinine ratios; negatively associated with potassium-creatinine and magnesium-creatinine ratios. The ridge regression analysis selected only calcium-magnesium ratio as a predictor of systolic blood pressure.

Human breast sarcoma and human breast implantation: a time trend analysis based on SEER data (1973-1990).

Since the demonstration in the 1940s of foreign body induction of sarcomas in rodents, the safety of artificial implants in humans has been a matter of concern. In this study, we assess the risk for the development of breast sarcomas in women with silicone breast implants. Our analysis is based on the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program database for the years 1973-1990 and on estimates of breast implantation rates from about 1960 onward. We have divided the SEER data into two equal time periods, 1972-1981 and 1982-1990. For each time period, we estimated the average annual number of women in the United States who had received breast implants 10 or more years earlier. This analysis allows for a 10 year latency period for the induction of breast sarcoma. We calculated that the average number of women in the U.S. 10 or more years post breast implantation was 55,000 for the 1973-1981 period and 509,000 for the 1982-1990 period. We then examined the SEER data to observe whether there was a concomitant rise in the female breast sarcoma incidence rates between these two time periods. We found the mean age-adjusted incidence rate of breast sarcomas was 0.13 per 100,000 women for the initial 9-year period, 1973-1981, and 0.12 per 100,000 women for the latter 9-year period, 1981-1990.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of a pyoderma outbreak caused by methicillin-susceptible Staphylococcus aureus in a nursery for newborns.

An outbreak of pyoderma caused by methicillin-susceptible Staphylococcus aureus occurred in a nursery for newborns over 26 days. During this period, six neonates were involved. The mother of the first case had trunk pyoderma before delivery, which was regarded as the source of the outbreak. Contamination of the environment and equipment were implicated as the reservoirs of further pathogen spread, as supported by pulsed-field gel electrophoresis (PFGE) results, which showed that some screening isolates were indistinguishable from the epidemic strain. Termination of the outbreak was achieved by the reinforcement of infection control practices and disinfection of environmental surfaces.

Risk factors in the acquisition of extended-spectrum beta-lactamase Klebsiella pneumoniae: a case-control study in a district teaching hospital in Taiwan.

A case-control study was performed to find the risk factors in the acquisition of extended-spectrum beta-lactamase (ESBL) Klebsiella pneumoniae. From 1 May 2001 to 30 September 2001, 422 isolates ofK. pneumoniae identified by the microbiological laboratory in Hsin-Chu hospital were collected, 59 of which were ESBL-producing strains. The prevalence rate was 14% (59/422). There were 43 case patients (ESBL-producing K. pneumoniae) and 86 controls (non-ESBL-producing K. pneumoniae). Tracheostomy, insertion of a Foley catheter, endotracheal tube, nasogastric tube and central venous catheter were found to be risk factors in the acquisition of K. pneumoniae with ESBLs by univariate analysis. Tracheostomy (odds ratio, 5.13; 95% CI, 1.24-21.1;P =0.023) and ceftazidime use (odds ratio, 13.40; 95% CI, 1.21-148.85; P=0.035) remained as risk factors by multivariate analysis with logistic regression. Other anti-pseudomonal agents should be used as empirical therapy to treat possible Pseudomonas aeruginosa infection in order to reduce ceftazidime use and thereby decrease the prevalence of ESBL producing strains of Enterobacteriaceae.

A novel local PCA-based method for detecting activation signals in fMRI.

A novel local principal component analysis (LPCA) technique is presented for activation signal detection in functional magnetic resonance imaging (fMRI) without explicit knowledge about the shape of the model activation signal. Unlike the traditional PCA methods, our LPCA algorithm is based on a measure of separation between two clusters formed by the signal segments in active periods and inactive periods, which is computed in an eigen-subspace. In addition, we only applied PCA to the temporal sequence of each individual voxel instead of applying PCA to the fMRI data set. In our algorithm, we first applied a linear regression procedure to alleviate the baseline drift artifact. Then, the baseline-corrected temporal signals were partitioned into active and inactive segments according to the paradigm used for the fMRI data acquisition. Principal components were computed from all these segments for each voxel by PCA. By projecting the segments of each voxel onto a linear subspace formed by the corresponding most dominant principal components, two separate clusters were formed from active and inactive segments. An activation measure was defined based on the degree of separation between these two clusters in the projection space. We show experimental results on the activation signal detection from various sets of fMRI data with different types of stimulation by using the proposed LPCA algorithm and the standard t-test method for comparison. Our experiments indicate that the LPCA algorithm in general provides substantial signal-to-noise ratio improvement over the t-test method.

Breast cancer risk in relation to type of estrogen contained in oral contraceptives.

We report analyses designed to address the recent hypothesis that women who use combination-type OCs containing ethinylestradiol (EE) are at increased risk of breast cancer before age 45, if use of such OCs occurs prior to first term pregnancy (FTP). Our findings, based on data from 1679 cases and 1689 controls, 20-44 years of age, from the population-based Cancer and Steroid Hormone Study, are against the hypothesis. The relative risk of breast cancer by duration of exclusive use prior to FTP of OCs containing EE is estimated to be 1.0 (1-12 months EE use), 1.2 (13-48 months EE use), and 0.9 (49+ months EE use). There was no evidence of a latent effect. Among parous women with 49+ months exclusive use prior to FTP of EE-containing OCs, the relative risk of breast cancer was estimated as 0.9 (0-4 years after FTP) and 0.6 (5-9 years after FTP). Among nulliparous women with 49+ months exclusive use of EE-containing OCs, the relative risk of breast cancer was estimated as 1.0 (0-4 years since first use), 0.7 (5-9 years since first use), and 1.1 (10-14 years since first use). With regard to exclusive use of OCs containing mestranol, parous women who used such preparations long-term before their FTP showed no alteration of breast cancer risk, even 15 years or more after pregnancy. Nulliparous women with exclusive use of ME-containing OCs did show elevations in breast cancer risk, but the magnitude of risk in relation to duration of use and latent interval shows no pattern that suggests a cause-effect relationship.

PIP: This report present analyses addressing the recent hypothesis that women who use combination-type oral contraceptives (OC) containing ethinylestradiol (EE) are at increased risk of breast cancer before age 45, if they use OCs before the 1st term of pregnancy (FTP). Our findings, based on data from 1679 controls, 20-44 years of age, from the population-based Cancer and Steroid Hormone Study, are against the hypothesis. The relative risk of breast cancer by duration of exclusive use prior to FTP of OCs containing EE is estimated to be 1.0 (1-12 months EE use), 1.2 (13-48 months EE use), and 0.9 (49+ months EE use). There was no evidence of a latent effect. Among parous women with the 49+ months exclusive use prior to FTP of EE-containing OCs, the relative risk of breast cancer was estimated as 0.9 (0-4 years after FTP) and 0.6 (5-9 years after FTP). Among nulliparous women with 49+ months exclusive use of EE-containing OCs, the relative risk of breast cancer was estimated as 1.0 (0-4) years since 1st use), 0.7 (5-9 years since 1st use), and 1.1 (0-4 years since 1st use). With regard to exclusive use of OCs containing mestranol (ME); parous women who used such preparations long-term before their FTP showed no alteration of breast cancer risk, even 15 years or more after pregnancy. Nulliparous women with exclusive use of ME containing OCs did show elevations in breast cancer risk, but the magnitude of risk in relation to duration of use and latent interval show no pattern that suggests a cause-effect relationship.

Oral contraceptives and premenopausal breast cancer in nulliparous women.

Characteristics of women with potential for modifying the relationship between use of oral contraceptives (OCs) and the risk of premenopausal breast cancer were investigated using data from the Cancer and Steroid Hormone study, a population-based, case-control study conducted in eight geographic areas of the United States. Cases consisted of 2945 women who were premenopausal and 20-54 years of age when breast cancer was diagnosed between December 1, 1980, and December 31, 1982; controls consisted of 2646 women with no history of breast cancer who were also premenopausal and 20-54 years of age when selected during the same period. Results are presented with the cases and controls divided into eight groups on the basis of age at diagnosis on selection (20-44, 45-54), parity (0, greater than or equal to 1), and age at menarche (less than 13, greater than or equal to 13). Among nulliparous women who experienced menarche before age 13, the relative risk of developing breast cancer in the age interval 20-44 years is estimated to be 1.0 for never-users of OCs (reference), 1.3 for greater than 0-3 years of use (95% confidence intervals 0.7-2.4), 1.3 for 4-7 years (95% CI 0.7-2.6), 2.7 for 8-11 years (95% CI 1.2-6.3), and 11.8 for 12 years or longer (95% CI 1.4-95.7). OC use is not significantly related to the risk of breast cancer among women in any of the other seven groups. These findings suggest that prolonged OC use may accelerate the onset of breast cancer for a small group of susceptible women while having no appreciable impact on overall risk. The findings should be regarded as tentative, however, since they are based upon numerous comparisons and because age of menarche was stratified at 13 years to highlight the concentration of breast cancer risk apparent in our data.

A new variational shape-from-orientation approach to correcting intensity inhomogeneities in magnetic resonance images.

A new intensity inhomogeneity correction algorithm based on a variational shape-from-orientation formulation is presented. Unlike most previous methods, the proposed algorithm is fully automatic, widely applicable and very efficient. Since no prior classification knowledge about the image is assumed in the proposed algorithm, it can be applied to correct intensity inhomogeneities for a wide variety of medical images. In this paper, a finite-element method is used to model the smooth bias-field function. Orientation constraints for the bias-field function are computed at the nodal locations of the regular discretization grid away from the boundary between different class regions. The selection of reliable orientation constraints is facilitated by the goodness of fit of a first-order polynomial model to the neighborhood of each nodal location. The automatically selected orientation constraints are integrated in a regularization framework, which leads to minimization of a convex and quadratic energy function. This energy minimization is accomplished by solving a linear system with a large, sparse, symmetric and positive semi-definite stiffness matrix. We employ an adaptive preconditioned conjugate-gradient algorithm to solve the linear system very efficiently. Experimental results on a variety of magnetic resonance images are given to demonstrate the effectiveness and efficiency of the proposed algorithm.

Fast numerical algorithms for fitting multiresolution hybrid shape models to brain MRI.

In this paper, we present new and fast numerical algorithms for shape recovery from brain MRI using multiresolution hybrid shape models. In this modeling framework, shapes are represented by a core rigid shape characterized by a superquadric function and a superimposed displacement function which is characterized by a membrane spline discretized using the finite-element method. Fitting the model to brain MRI data is cast as an energy minimization problem which is solved numerically. We present three new computational methods for model fitting to data. These methods involve novel mathematical derivations that lead to efficient numerical solutions of the model fitting problem. The first method involves using the nonlinear conjugate gradient technique with a diagonal Hessian preconditioner. The second method involves the nonlinear conjugate gradient in the outer loop for solving global parameters of the model and a preconditioned conjugate gradient scheme for solving the local parameters of the model. The third method involves the nonlinear conjugate gradient in the outer loop for solving the global parameters and a combination of the Schur complement formula and the alternating direction-implicit method for solving the local parameters of the model. We demonstrate the efficiency of our model fitting methods via experiments on several MR brain scans.

A hierarchical neural network algorithm for robust and automatic windowing of MR images.

A novel hierarchical neural network based algorithm for automatic adjustment of display window width and center for a wide range of magnetic resonance (MR) images is presented in this paper. The algorithm consists of a feature generator utilizing both wavelet histogram and compact spatial statistical information computed from a MR image, a competitive layer based neural network for clustering MR images into different subclasses, two pairs of a radial basis function (RBF) network and a bi-modal linear estimator for each subclass, as well as a data fusion process using estimates from both estimators to compute the final display parameters. Both estimators can adapt to new kinds of MR images simply by training them with those images, which make the algorithm adaptive and extendable. The RBF based estimator performs very well for images that are similar to those in the training data set. The bi-modal linear estimator provides reasonable estimations for a wide range of images that may not be included in the training data set. The data fusion step makes the final estimation of the display parameters accurate for trained images and robust for the unknown images. The algorithm has been tested on a wide range of MR images and has shown satisfactory results.

Fatal retroperitoneal haemorrhage: an unusual complication of percutaneous endoscopic gastrostomy.

A 93-year-old lady with dementia, neurological dysphagia and aspiration pneumonia, died from massive retroperitoneal haemorrhage which developed as a rare and, it is believed, hitherto unreported, complication of percutaneous endoscopic gastrostomy (PEG), which was performed for feeding purposes. It is postulated that the initial, unsuccessful attempt at needle puncture of the stomach, under endoscopic guidance, had resulted in iatrogenic perforation and laceration of the splenic and superior mesenteric veins close to their confluence with the portal vein. It would also appear that dense fibrous adhesions between the pyloro-antral region of the stomach and the posterior hepatic surface had altered the immediate anatomical relations of the stomach in such a manner as to have predisposed to these events.