How does long-term drought acclimation modify structure-function relationships? A quantitative approach to leaf phenotypic plasticity of barley.

Under drought conditions the growth and survival of a plant depend on its adaptive characteristics and acclimation ability. Adaptation refers to inherent morpho-physiological characters providing protection against water losses. Acclimation, however, is a special case of phenotypic plasticity: environment-dependent phenotypic expression resulting to a 'new' phenotype through drought-induced modulations in leaf morphology, anatomy and physiology. Given that phenotypic plasticity influences environmental tolerance, a multi-trait plasticity index could be of great importance. Therefore, we examined the acclimation processes of three different barley genotypes using a multi-trait plasticity assessment with emphasis on the leaf water economy-related traits. Our results showed that (i) the structure-function co-ordination during long-term drought acclimation follows the trade-off between carbon gain and water saving as well as the competition between investments in photosynthesis vs synthesis of protective compounds; (ii) the genotypes with smaller leaf area, narrower and denser veins, as well as smaller and denser stomata i.e. traits providing tolerance, exhibited less drastic adjustments under stress conditions, suggesting a trade-off between acclimation and tolerance-adaptation; and (iii) the slope values of a multi-trait 'reaction norm' based on regression analysis of PCA scores were indicative of the degree of plasticity for each genotype, providing an accurate representation of a complex set of data with single numeric results easily comparable.

Analyzing functional brain connectivity by means of commute times: a new approach and its application to track event-related dynamics.

There is growing interest in studying the association of functional connectivity patterns with particular cognitive tasks. The ability of graphs to encapsulate relational data has been exploited in many related studies, where functional networks (sketched by different neural synchrony estimators) are characterized by a rich repertoire of graph-related metrics. We introduce commute times (CTs) as an alternative way to capture the true interplay between the nodes of a functional connectivity graph (FCG). CT is a measure of the time taken for a random walk to setout and return between a pair of nodes on a graph. Its computation is considered here as a robust and accurate integration, over the FCG, of the individual pairwise measurements of functional coupling. To demonstrate the benefits from our approach, we attempted the characterization of time evolving connectivity patterns derived from EEG signals recorded while the subject was engaged in an eye-movement task. With respect to standard ways, which are currently employed to characterize connectivity, an improved detection of event-related dynamical changes is noticeable. CTs appear to be a promising technique for deriving temporal fingerprints of the brain's dynamic functional organization.

Multiple brown tumors of the ribs simulating malignancy.

Bone disease associated with primary hyperparathyroidism, known as osteitis fibrosa cystica, is now very rarely encountered, since the parathyroid disorder is most often diagnosed at the early stage of asymptomatic hypercalcemia. Here, we report the case of a patient with multiple pleural-based masses and hypercalcemia, which led to the presumptive diagnosis of malignancy. However, histological and laboratory data were consistent with the development of brown tumors of the ribs due to underlying severe hyperparathyroidism.

A case of insulin edema with inappropriate hyperaldosteronism.

Edema of variable severity is an uncommon complication of insulin treatment. Increased sodium reabsorption, transient proteinuria and hypoalbuminemia are the most frequently reported laboratory disorders at the time of edema formation. This case report describes a 44-yr-old man with a 4-month history of anorexia, polyuria, polydipsia and weight loss of 25 kg who presented with diabetic ketoacidosis. On admission, there were no clinical or laboratory signs of volume depletion. Following insulin treatment he developed marked insulin edema and a cluster of abnormalities, including decreased sodium excretion, hypokalemia, hypouricemia, proteinuria, hypoalbuminemia and anemia. The diagnostic work-up showed the presence of high renin and aldosterone values despite the absence of evident hypovolemia and no evidence of gastrointestinal, cardiovascular, renal, thyroid, hepatic or other endocrine disorder. Complement values were normal; autonomic neuropathy and venoocclusive intraabdominal lesions were excluded and no other drugs except insulin were administered. Initiation of spironolactone was associated with prompt resolution of the edema and gradual correction of the laboratory abnormalities. Our findings show that hyperaldosteronism may occur in patients with insulin edema, even in the absence of volume depletion, contributing to the development of increased sodium reabsorption and of other laboratory disorders.

Intraoperative electron beam radiotherapy followed by moderate doses of external beam radiotherapy in the treatment of resected soft tissue sarcomas of the extremities.

PURPOSE: Soft tissue sarcomas (STS) have a high incidence of local recurrence. In an effort to improve the local control rate and the survival in patients with STS, treatment strategies employing intraoperative electron beam radiotherapy (IOERT) in combination with external beam radiotherapy (EBRT) and extensive surgical resection have been explored. This study assesses the rate of overall survival (OS), local control and toxicity of this multimodal approach for primary and recurrent STS of the extremities. PATIENTS AND METHODS: From 1999 to 2004, 36 patients were treated at Agios Savvas Cancer Hospital for primary or recurrent extremity STS with IOERT as a component of their treatment. All patients underwent surgical resection, IOERT, and most of them received postoperative EBRT with a median dose of 45 Gy. Chemotherapy was given to patients with high grade tumors. Thirteen patients were treated for primary disease and 23 for isolated local recurrence.The locations of the tumors were as follows: upper limbs n=19, lower limbs n=17. Tumor size was >5 cm in 16 (44%) patients and high-grade histology (II-III) was present in 24 (67%) patients. Six (17%) patients had positive surgical margins. RESULTS: With a median follow up of 24 months (range 6-48) OS was 72% (84.5% for patients with low grade lesions compared to 65% for high grade lesions, p=0.127, and 90% for tumors <5 cm compared to 50% for tumors >5 cm, p=0.0136). Overall local tumor control rate was 89% (92% in primary disease group versus 87% in isolated local recurrence group, p=0.136, and 93% for patients with negative surgical margins versus 67% for those with positive margins, p=0.0013). Distant metastases occurred in 10 patients (1 of 13 (8%) with primary disease, and 9 of 23 (39%) with isolated local recurrence). All distant metastases were to the lungs. Twelve (33%) patients developed moderate neurotoxicity. CONCLUSION: In selected patients, IOERT results in excellent local control and OS with acceptable toxicity.

OTE-TS--a new value-added telematics service for telemedicine applications.

A new telemedicine service denoted as the Hellenic Telecommunication Organization Telemedicine Service (OTE-TS), which addresses an open multidisciplinary group of medical care providers (users), is presented in this paper. OTE-TS is supported by the Hellenic Telecommunication Organization (OTE) and is the result of the close collaboration of engineers, medical doctors, and market analysts. Its architecture provides the user with an integrated electronic working domain handling diverse types of conversational audiovisual information and medical records. It includes a stack of functions, protocols, and interfaces for data acquisition, processing, and display, and for the composition of dial-up multiparty cooperation schemes (synchronous or asynchronous), suitable for the coordination and management of high-level consult, report, and review activities. The service provider (i.e., the OTE) performs the central administration and maintenance of the service, as well as the management of medical cases and reports that are exchanged among the users. The service has been extensively tested in real-world conditions.

A new concept toward computer-aided medical diagnosis--a prototype implementation addressing pulmonary diseases.

The original concept that led to the structuring of a computer-based medical decision support system (DSS) that is able to support a physician's diagnosis is introduced in this paper. The concept's implementation modeled a generic DSS, the core of which are an integrated knowledge/information base (KIB) along with the inference properties of a data evaluator. The KIB encapsulates the necessary medical knowledge and experience in the form of rules and constraints, preemptive tasks, and actual patients' clinical data. The data evaluator handles approved medical subjective and objective criteria for assessing the KIB's data. The data evaluator incorporates a medical standard data gathering and decision process, structured upon the principles of the clinical differential diagnosis methodology and has been integrated in the system by means of both algorithmic and artificial intelligence techniques. The novel model and the resulted computer-based package have been extensively tested under the Pulmonary Department, University Regional Hospital Patras, Patras, Greece.

Replacement of the pyloric sphincter with the ileocecal valve: an experimental study.

BACKGROUND: Several surgical methods have been devised and applied to overcome the complications associated with the loss of the pyloric sphincter after distal gastrectomy. However, none of these methods creates an efficient sphincteric mechanism at the anastomotic site. The purpose of this experimental study in dogs was to replace the pylorus with the ileocecal valve and determine whether its sphincteric function would be preserved in its new location without affecting gastrointestinal motility and the health of the animals. METHODS: Thirteen dogs underwent surgical removal of the pyloric sphincter and a partial distal gastrectomy. The ileocecal valve, with a short segment of ileum, was then relocated so that the ileal segment was anastomosed to the stomach while the cecal segment was anastomosed to the duodenum. Intestinal continuity was reestablished by anastomosing the distal ileum with the ascending colon. Intraileal and intracolic pressures were measured in all animals prior to and following transposition of the ileocecal valve. In 3 of these animals, pre-pyloric (intragastric) and post-pyloric (intraduodenal) pressures were also measured before the pylorus was removed. Pressure measurements on both sides of the transposed ileocecal valve were performed again 4-6 months later. All pressure measurements were made directly with a water manometer. Radiographic and fluoroscopic studies were carried out on all animals to assess gastrointestinal motility, gastric emptying times, and the sphincteric competence of the transposed ileocecal valve. Hematological and biochemical studies intended to assess the nutritional status of all animals were carried out. Also, postoperative measurements were made of gastric basic acid output. RESULTS: All animals were alive and well 4-6 months after the initial operative procedure. Hematological studies and biochemical tests and studies of liver function remained normal. There was a slight reduction in serum B12 levels and, as expected, a significant postoperative reduction in gastric basic acid output. The intraluminal pressure measurements and the radiographic and fluoroscopic studies all showed that the sphincteric mechanism of the ileocecal valve was preserved in its new location, that gastrointestinal motility was not impaired, and that the healthy condition of the animals was maintained. Gross and histological examination of the transposed segments of the intestinal tract did not reveal any abnormalities. CONCLUSION: Because the anatomy and physiology of the human alimentary tract are similar to those of the dog, this technique may be applicable clinically, when indicated, to avoid and/or relieve complications resulting from gastrectomy, when those complications do not respond or have not responded to conservative management.

Low bone mineral density in adults with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis have several risk factors for the development of low bone mineral density (BMD). To identify the prevalence and clinical correlates of low BMD in adult patients with cystic fibrosis, densitometry was performed in 151 patients (83 men) aged 15-52 years. METHODS: BMD was measured in the lumbar spine (L1-4) using dual energy x ray absorptiometry (DXA) and quantitative computed tomography (QCT). It was also measured in the proximal femur (total hip and femoral neck) using DXA, and in the distal and ultra distal forearm using single energy x ray absorptiometry (SXA). Biochemical markers of bone turnover, vitamin D levels, parathyroid hormone levels, and a variety of anthropometric variables were also assessed. RESULTS: The mean (SD) BMD Z score was -0.73 (0.85) in the distal forearm, -0.31 (0.92) in the ultra distal forearm, -1.21 (1. 18) in the lumbar spine using DXA, -0.56 (1.36) in the lumbar spine using QCT, -1.25 (1.30) in the femoral neck, and -1.01 (1.14) in the total hip. 34% of patients had a BMD Z score of -2 or less at one or more skeletal sites. Body mass index (0.527, p = 0.01), percentage predicted forced expiratory volume in one second (0.388, p = 0.01), and physical activity (0.249, p = 0.05) were positively related to the mean BMD Z score. Levels of C reactive protein (-0.328, p = 0. 01), parathyroid hormone (-0.311, p = 0.01) and biochemical markers of bone turnover (osteocalcin -0.261 and bone specific alkaline phosphatase -0.249, p = 0.05) were negatively related to the mean BMD Z score. Vitamin D insufficiency (25-hydroxyvitamin D <15 ng/ml) was prevalent (53/139 patients, 38%) despite supplementation with 900 IU vitamin D per day. CONCLUSIONS: Low bone density is prevalent in adult patients with cystic fibrosis. Current levels of vitamin D supplementation appear to be inadequate.

A new perspective in learning pattern generation for teaching neural networks.

This article deals with the Learning Patterns (LPs)' generation, a major aspect of Feed-Forward Artificial Neural Networks (FANNs)' learning process. Currently, more work is done to understand the mechanisms and improve the speed, learning accuracy, and implementation features of FANNs' teaching algorithms, though little is done towards the development of enhanced techniques that would extract experts' knowledge (from examples, rules, etc.) and obtain standardised LPs that would improve this learning process. A new approach in generating LPs is thereby introduced, that is used to train a new Medical Decision Support System (MDSS) based on FANNs, and its performance is analysed and compared with previous methods. It can handle incomplete data archives, individually boost any particular dataum special characteristics, and its application induces the FANNs to show better convergent facets. The efficiency of the resulting MDSS was thoroughly tested by pulmonologists and haematologists using medical data archives of a regional hospital.

Coexistence of myelodysplastic syndrome and multiple myeloma.

We describe the simultaneous presentation of myelodysplastic syndrome (MDS) and multiple myeloma (MM). Our patient had MDS (RAEB type) and bone marrow infiltration (40% plasma cells), as well as biclonal paraprotein. Patients with MM, MDS have been reported after chemotherapy but few cases documenting the coexistence of MDS and MM at diagnosis have been reported in the literature.

A three-day octreotide-containing helicobacter pylori eradication therapy for cure of peptic ulcers.

BACKGROUND/AIMS: Octreotide is used to arrest peptic ulcer hemorrhage. Since it has anti-secretory properties, it could also be used in Helicobacter pylori eradication therapy, to cure peptic ulcer before discharging patients from hospital. The aim of this pilot study was to determine safety and efficacy of an ultra short quadruple octreotide containing H. pylori eradication therapy in patients with peptic ulcer. METHODOLOGY: Twenty-six consecutive symptomatic H. pylori-positive patients with duodenal (n = 20) or gastric ulcer (n = 6), were treated with a three-day course of octreotide 0.3 mg/day subcutaneously, amoxicillin plus metronidazole 2 g/day orally and colloid bismuth subcitrate 480 mg/day. CLO-test, culture and crush tissue smears were performed on admission to the study, at 4 and 8 weeks post treatment. The effect of octreotide on intragastric pH (n = 10) was also investigated. RESULTS: Octreotide significantly increased the mean 24-hour intragastric pH > 3 over 68.9% of the time (37.1%-99.5%). There were no treatment side effects. Ulcer pain was abolished at between 2-12 days. By intention-to-treat 24/26(92.3%, 95% CI 82%-100%) ulcers had healed at 4 weeks. H. pylori eradication rate at 8 weeks was 88.5% (23/26) (95% CI 76%-100%). CONCLUSIONS: Our ultra-short octreotide containing quadruple therapy is a safe and effective regime in eradicating H. pylori and healing peptic ulcers. It may be a suitable therapy for hospitalized patients with peptic ulcer hemorrhage.

Tuberculosis of the prostate.

We present five cases of tuberculous prostatitis. In all cases this was an incidental histologic finding after transurethral prostatectomy. The patients were all treated with an antituberculous drug regimen. A literature review of this rare condition is included.

Administration of high doses of recombinant human erythropoietin to patients with beta-thalassemia intermedia: a preliminary trial.

Four patients (1 male, 3 female, age range 16-56 yr) with beta-thalassemia intermedia were given high doses of recombinant human erythropoietin (rHuEpo), iron sulfate and folic acid in an attempt to improve their anemia. The dose schedule was: rHuEpo, 500 U/kg 3 times weekly, iron sulfate, 300 mg/d and folic acid, 5 mg/d. All patients were red blood cell transfusion-dependent. Hematological data and fetal hemoglobin (HbF) were assayed every 2 wk. XmnI polymorphism and beta-thalassemia mutations were identified by PCR. All patients showed a moderate to high increase in hemoglobin values (mean value: 2.5 g/dl) and in 1 patient HbF levels also increased; 3 patients became red blood cell transfusion-independent and 1 patient was able to extend the intervals between transfusions significantly. No side effects were observed during rHuEpo therapy.

Effect of growth hormone replacement on bone mass in adults with adult onset growth hormone deficiency.

OBJECTIVE: Previous studies of the effect of GH replacement on bone mass in adults with GH deficiency have produced conflicting results. We have studied the effect of 6 and 12 months of GH replacement on bone mass in adults with adult onset GH deficiency. DESIGN: Double blind placebo controlled study of GH replacement (0.125 IU/kg/week for the first month and 0.25 IU/kg/week thereafter) for 6 months and an open study for a further 6 or 12 months. PATIENTS: Twenty-two adults (10 men, 12 women), aged 41.5 +/- 2.1 years (mean +/- SE, range 23.6-59.5), with adult onset GH deficiency. MEASUREMENTS: Single-energy quantitative computed tomography was used to measure vertebral trabecular bone mineral density (BMD), single-photon absorptiometry (SPA) was used to measure forearm cortical and integral bone mineral content and BMD and dual-energy X-ray absorptiometry (DXA) was used to measure lumbar spine, femoral neck, trochanteric and Ward's triangle integral BMD. RESULTS: After 6 months of GH replacement (n = 21) there was a significant decrease in forearm cortical BMD (SPA: median change -0.009 g/cm2, P = 0.01), forearm integral BMD (SPA: median change -0.016 g/cm2, P = 0.03), lumbar spine BMD (DXA: median change -0.22 g/cm2; P = 0.003) and femoral neck BMD (DXA: median change -0.029 g/cm2, P = 0.006). After 12 months of GH replacement (n = 13) there was a significant decrease in lumbar spine BMD (DXA: median change -0.035 g/cm2, P = 0.002) from baseline. There was no significant increase in bone mass at any site after 6 or 12 months of GH replacement. Change in bone mass was not influenced by sex of the patient or by presence or absence of additional pituitary hormone deficiencies. CONCLUSION: The response of bone mass to 6 and 12 months of GH replacement in adults with adult onset GH deficiency is disappointing. Longer-term studies are required to determine whether prolonged GH replacement has a beneficial effect on bone mass.

Latency measurement improvement of P100 complex in visual evoked potentials by FMH filters.

The ensemble average of Pattern Shift Visual Evoked Potentials (PSVEP) signals is seriously affected by random latency variations encountered in each individual sweep which is modeled as a continuous signal with linear segments and well-shaped triangular peaks. This effect is causing the smoothed peaks of the averaged PSVEP waveforms. It is our objective to restore the degraded peaks and provide accurate information about their exact location. The method used is based on nonlinear filtering of the FIR-Median Hybrid (FMH) type and is recommended as a postfiltering process to the well-known averaging methods of recovering PSVEP signals from noise by time-locking to stimuli. The new technique, tested in signals from clinical observations, has proven very promising.

Further increase in forearm cortical bone mineral content after discontinuation of growth hormone replacement.

OBJECTIVE: Growth hormone replacement of adults with childhood onset GH deficiency results in an increase in bone mineral density (BMD) after 6-12 months of GH replacement. By measuring BMD 12 months after discontinuation of GH replacement we aimed to investigate whether there is an effect of GH replacement on BMD persisting after GH has been withdrawn. DESIGN: BMD was measured 13 +/- 1 (mean +/- SE, range 11-16) months after discontinuation of GH replacement. PATIENTS: Ten adults, age 23.2 +/- 1.4 (range 18.8-32.4) years, with childhood onset isolated GH deficiency (2 idiopathic, 8 irradiation induced) who had previously completed a study of the effect of 12 months of GH replacement on BMD. MEASUREMENTS: Forearm cortical bone mineral content (BMC) was measured using single-photon absorptiometry at the proximal site of the distal forearm. Forearm integral BMC at the ultradistal site of the forearm and bone width at both proximal and ultradistal sites of the distal forearm were measured by the same technique. Vertebral trabecular BMD was measured using quantitative computed tomography. RESULTS: Forearm cortical BMC was significantly greater than that measured at the time of discontinuation of GH (1.48 +/- 0.04 vs 1.44 +/- 0.05 g/cm). There was no significant change in forearm integral BMC or in vertebral trabecular BMD after discontinuation of GH. There was no significant change in bone width at proximal and ultradistal sites of the distal forearm after discontinuation of GH. CONCLUSION: After discontinuation of GH replacement the further increase in forearm cortical bone mineral content without a significant increase in forearm bone width suggests that the increase in cortical bone mineral content is due to a persisting effect of previous GH replacement, and not to further spontaneous attainment of bone mass before peak bone mass is reached. These findings emphasize the importance of continuing to monitor bone mass after the stimulus to increase bone turnover has been withdrawn.

The importance of late pregnancy scans for renal tract abnormalities.

A 12-month prospective population study of antenatal patients was undertaken in a large district general hospital to assess ultrasound scanning in late pregnancy for the detection of non-lethal fetal renal abnormalities. The rate of false-negative antenatal scans during the study period was also assessed. Both 18-20 and 28-32 weeks' gestational scans were performed on 6497 pregnant women. Forty fetuses with a suspected abnormality were referred for postnatal examination and 29 neonates were found to have renal abnormalities. Of these, 21 were significant and eight were likely to be extrarenal pelves. In six, there was evidence of an abnormality at the early scan. Nine children, seven with reflux, presented within the study period, all with preceding normal antenatal scans. The incidence (0.46 per cent) of structural renal abnormalities is similar to that reported previously. A late scan is necessary for the antenatal detection of non-lethal renal abnormalities.

Reduced bone mineral density in patients with adult onset growth hormone deficiency.

We have demonstrated previously that adults with isolated GH deficiency of childhood onset have a reduced bone mineral density (BMD) of vertebral trabecular bone [quantitative computed tomography (QCT): median Z score -1.3, P < 0.01, n = 12] and of cortical bone in the forearm [single photon absorptiometry (SPA): median Z score -2.9, P = 0.001, n = 7]. We have now examined BMD in 26 patients (13 men, 13 women), aged between 23.6 and 59.5 (mean 42.4) yr, with adult onset GH deficiency, defined as a GH response of less than 5 micrograms/L to provocative testing, of at least two years duration. BMD was measured using QCT for vertebral trabecular bone, dual energy x-ray absorptiometry (DXA) in the lumbar spine and femoral neck, and SPA in the forearm. There was a highly significant reduction in QCT (median Z score -1.07, P < 0.00005), in DXA of the lumbar spine (median Z score -0.76, P = 0.0001) and in SPA of the forearm (median Z score -0.86, P = 0.0001) but not in DXA of the femoral neck (median Z score -0.38, P = 0.35). There were no significant differences in Z scores between those patients with isolated GH deficiency and those with GH and gonadotrophin deficiency. There was a significant positive correlation between age at which BMD was measured and Z score (the older the patient, the higher the Z score) for QCT (r = 0.38, P < 0.05) and SPA (r = 0.48, P < 0.01) with a trend to a positive correlation for DXA of the lumbar spine and femoral neck. Patients were grouped according to estimated duration of GH deficiency (less than 5 yr, n = 7; 5-10 yr, n = 10; greater than 10 yr, n = 9). These groups did not show a significant difference in BMD at any site. We conclude that patients with adult onset GH deficiency (isolated or in conjunction with other pituitary hormone deficiencies) have a reduced BMD. Age at development of GH deficiency may be more important than duration of GH deficiency in determining the degree of reduction in bone mass. The impact of GH treatment on BMD in adults with adult onset GH deficiency requires investigation.

Prognostic factors of gastric non-Hodgkin's lymphomas of the adult.

Sixteen patients, seven men and nine women, with a non-Hodgkin's lymphoma of the stomach (NHLS), have been managed in our institute during the past 15 years. Their median age was 68 years. Ten of them were classified, before treatment, at an early stage (I or II, Ann Arbor system) and six at an advanced one (III or IV). Ten patients were submitted to gastrectomy, and eight out of them had an adjuvant postoperative treatment (radiotherapy and/or chemotherapy). The remaining six patients were treated conservatively by radiotherapy and/or chemotherapy. Two patients that were followed less than 24 months were excluded from further study. In the remaining 14 patients, the 5-year actuarial and age-corrected survival rates were 42% +/- 28 and 53% +/- 35, respectively. In the gastrectomy subgroup, the corresponding rates were 77% +/- 22 and 93% +/- 24. The later ameliorated results also, reflect the effect of an earlier stage. The most important prognostic factors appeared to be the stage and the histologic type. Old age and female sex seem to predispose to a better outcome, but they are not independent prognostic factors. Finally, a bad nutritional status, at presentation, seems an ominous prognostic sign.