Ultrasound Detection of Liver Fibrosis in Individuals with Hepatic Steatosis Using the Homodyned K Distribution

Acoustic structure quantification (ASQ) based on the analysis of ultrasound backscattered statistics has been reported to detect liver fibrosis without significant hepatic steatosis. This study proposed using ultrasound parametric imaging based on the parameter α of the homodyned K (HK) distribution for staging liver fibrosis in patients with significant hepatic steatosis. Raw ultrasound image data were acquired from patients (n = 237) to construct B-mode and HK α parametric images, which were compared with the focal disturbance (FD) ratio obtained from ASQ on the basis of histologic evidence (METAVIR fibrosis score and hepatic steatosis severity). The data were divided into group I (n = 173; normal to mild hepatic steatosis) and group II (n = 64; with moderate to severe hepatic steatosis) for statistical analysis through one-way analysis of variance and receiver operating characteristic (ROC) curve analysis. The results showed that the HK α parameter monotonically decreased as the liver fibrosis stage increased (p < .05); concurrently, the FD ratio increased (p < .05). For group I, the areas under the ROC (AUROCs) obtained using the FD ratio and the α parameter (AUROC_FD and AUROC_α) were, respectively, 0.56 and 0.55, 0.68 and 0.68, 0.64 and 0.64 and 0.62 and 0.62 for diagnosing liver fibrosis ≥F1, ≥F2, ≥F3 and ≥F4. The values of AUROC_FD and AUROC_α for group II were, respectively, 0.88 and 0.91, 0.81 and 0.81, 0.77 and 0.76 and 0.78 and 0.73 for diagnosing liver fibrosis ≥F1, ≥F2, ≥F3 and ≥F4. As opposed to previous studies, ASQ was found to fail in characterizing liver fibrosis in group I; however, it was workable for identifying liver fibrosis in patients with significant hepatic steatosis (group II). Compared with ASQ, HK imaging provided improved diagnostic performance in the early detection of liver fibrosis coexisting with moderate to severe hepatic steatosis. Ultrasound HK imaging is recommended as a strategy to evaluate early fibrosis risk in patients with significant hepatic steatosis.

Quantitative assessment of media concentration using the Homodyned K distribution

The Homodyned K distribution has been used successfully as a tool in the ultrasound characterization of sparse media, where the scatterer clustering parameter α accurately discriminates between media with different numbers of scatterers per resolution cell. However, as the number of scatterers increases and the corresponding amplitude statistics become Rician, the reliability of the α estimates decreases rapidly. In the present study, we assess the usefulness of α for the characterization of both sparse and concentrated media, using simulated independent and identically distributed (i.i.d.) samples from Homodyned K distributions, ultrasound images of media with up to 68 scatterers per resolution cell and ultrasound signals acquired from particle phantoms with up to 101 scatterers per resolution cell. All parameter estimates are obtained using the XU estimator (Destrempes et al., 2013). Results suggest that the parameter α can be used to distinguish between media with up to 40 scatterers per resolution cell at 22 MHz, provided that parameter estimation can be performed on very large sample sizes (i.e., >10,000 i.i.d. samples).

Value of homodyned K distribution in ultrasound parametric imaging of hepatic steatosis: An animal study

Ultrasound is the first-line tool for screening hepatic steatosis. Statistical distributions can be used to model the backscattered signals for liver characterization. The Nakagami distribution is the most frequently adopted model; however, the homodyned K (HK) distribution has received attention due to its link to physical meaning and improved parameter estimation through X- and U-statistics (termed "XU"). To assess hepatic steatosis, we proposed HK parametric imaging based on the α parameter (a measure of the number of scatterers per resolution cell) calculated using the XU estimator. Using a commercial system equipped with a 7-MHz linear array transducer, phantom experiments were performed to suggest an appropriate window size for α imaging using the sliding window technique, which was further applied to measuring the livers of rats (n = 66) with hepatic steatosis induced by feeding the rats a methionine- and choline-deficient diet. The relationships between the α parameter, the stage of hepatic steatosis, and histological features were verified by the correlation coefficient r, one-way analysis of variance, and regression analysis. The phantom results showed that the window side length corresponding to five times the pulse length supported a reliable α imaging. The α parameter showed a promising performance for grading hepatic steatosis (p < 0.05; r² = 0.68). Compared with conventional Nakagami imaging, α parametric imaging provided significant information associated with fat droplet size (p < 0.05; r² = 0.53), enabling further analysis and evaluation of severe hepatic steatosis.

A neuropsychological assessment, using computerized battery tests (CANTAB), in children with benign rolandic epilepsy before AED therapy

RATIONALE

Benign rolandic epilepsy (BRE) is a form of partial idiopathic epilepsy according to the International League Against Epilepsy (ILAE) syndromes classification (1989). Recent studies have identified cases of BRE that do not meet the initial definition of 'benign'; these included reports of cases with specific cognitive deficits. It is still a matter of debate, whether these deficits are due to epilepsy per se, to treatment or other associated factors.

OBJECTIVES

The aim of this study was to evaluate if BRE children have cognitive deficits at the onset of their seizures, prior to their participation in any anti-epileptic drug therapy (AED).

METHODS AND RESULTS

We performed a neuropsychological assessment of 18 BRE children compared with a corresponding age-matched control group. We used the Cambridge Neuropsychological Test Automated Battery (CANTAB). Subjects were at their first neurological evaluation, before any AED therapy. We assessed: visual memory, induction and executive functions. In our group, the BRE children performed comparably with the control children for the induction and executive functions. Substantial differences were identified for the visual memory subtests: PRM percent correct (t = -2.58, p = 0.01) and SRM percent correct (t = -2.73, p = 0.01). Age of seizure onset had a negative impact on the visual memory subtest performances (PRM mean correct latency). We found significant correlations between the different CANTAB subtests results and characteristics of the centrotemporal spikes (CTS).

DISCUSSION

Our results are consistent with the findings of other similar studies. This form of epilepsy is associated with subtle neuropsychological deficits, present at seizure onset. Neuropsychological deficits identified, suggest a more diffuse brain involvement in the epileptiform process.

[Liver transplantation--indications, surgical technique, results--the analysis of a clinical series of 200 cases]

INTRODUCTION

Initially considered experimental, liver transplantation (LT) has become the treatment of choice for the patients with end-stage liver diseases.

MATERIAL AND METHODS

Between April 2000 and October 2009, 200 LTs (10 reLTs) were performed in 190 patients, this study being retrospective. There were transplanted 110 men and 80 women, 159 adults and 31 children with the age between 1 and 64 years old (mean age--39.9). The main indication in the adult group was represented by viral cirrhosis, while the pediatric series the etiology was mainly glycogenosis and biliary atresia. There were performed 143 whole graft LTs, 46 living donor LTs, 6 split LTs, 4 reduced LTs and one domino LT RESULTS: The postoperative survival was 90% (170 patients). The patient and graft one-year and five-year survivals were 76.9%, 73.6% and 71%, 68.2%, respectively. The early complications occurred in 127 patients (67%). The late complications were recorded in 71 patients (37.3%). The intraoperative and early postoperative mortality rate was 9.5% (18 patients).

CONCLUSIONS

The Romanian liver transplantation program from Fundeni includes all types of current surgical techniques and the results are comparable with those from other international centers.

Effects of combined strength and sprint training on regulation of muscle contraction at the whole-muscle and single-fibre levels in elite master sprinters

AIM

This study aims at examining the effects of progressive strength and sprint training on regulation of muscle contraction at the whole-muscle and single-fibre levels in older sprint-trained athletes.

METHODS

Eleven men (52-78 years) were randomized to a training (EX, n = 7) or control (CTRL, n = 4) group. EX participated in a 20-week programme that combined sprint training with heavy and explosive strength exercises, while CTRL maintained their usual run-based training schedules.

RESULTS

EX improved maximal isometric and dynamic leg strength, explosive jump performance and force production in running. Specific tension and maximum shortening velocity of single fibres from the vastus lateralis were not altered in EX or CTRL. Fibre type and myosin heavy chain isoform distributions remained unchanged in the two groups. There was a general increase in fibre areas in EX, but this was significant only in IIa fibres. The 10% increase in squat jump in EX was accompanied by a 9% increase in the integrated EMG (iEMG) of the leg extensors but the 21-40% increases in isometric and dynamic strength were not paralleled by changes in iEMG.

CONCLUSION

Adding strength training stimulus to the training programme improved maximal, explosive and sport-specific force production in elite master sprinters. These improvements were primarily related to hypertrophic muscular adaptations.

Effects of ageing and gender on contractile properties in human skeletal muscle and single fibres

AIM

The objective of this study is to improve our understanding of the mechanisms underlying the ageing- and gender-related muscle weakness.

METHODS

Ageing- and gender-related differences in regulation of muscle contraction have been studied in knee-extensor muscles at the whole muscle and single muscle fibre levels in young and old sedentary men and women. In vivo knee-extensor muscle function was measured at slow (30 degrees s(-1)) and faster (180 degrees s(-1)) speeds of movement. Maximum velocity of unloaded shortening (V(0)) and maximum force normalized to cross-sectional area (CSA) [specific tension (ST)] were measured in single 'skinned' skeletal muscle fibre segments.

RESULTS

Significant ageing- and gender-related differences were observed in muscle torque. A 33-55% ageing-related decline (P < 0.001) in maximum torque was observed irrespective of gender. At the single muscle fibre level, the ageing-related decline in knee-extensor muscle function was accompanied by a 20-28% decline in ST in muscle fibres expressing the type I MyHC isoform in both men and women, and a 29% decline in type IIa muscle fibre CSA, but the decreased fast-twitch fibre size was restricted to the men. Furthermore, in both men and women, V(0) decreased in muscle cells expressing the type I and IIa MyHC isoforms.

CONCLUSION

The present results provide evidence of specific ageing- and gender-related differences in regulation of muscle contraction at the cellular level. It is suggested that these cellular changes have a significant impact on muscle function and the ageing-related motor handicap.

Serological and histological correlations in celiac disease

The aim of this study was to compare the sensitivity of the serological markers in patients with non-treated celiac disease by determination of antiendomysium and anti-tissue-transglutaminase autoantibodies separately and together. At the same time we examined the correlation between the serum levels of the two antibodies and the severity of the histological lesions.

MATERIAL AND METHODS

The research included 26 persons (19 females, 7 males, age range 18-56 years) in whom the small bowel biopsy confirmed the villous atrophy. The sera of these patients were investigated by the determination of antiendomysium antibodies (AEA) and antitissue-transglutaminase antibodies (ATTG). For the morphological disorders we used the Marsh modified criteria. ATTG were determined by a sandwich-ELISA technique and AEA were dosed by indirect immunofluorescence technique.

RESULTS

6 patients presented with partial villous atrophy (PVA), 7 with subtotal villous atrophy (SVA) and 13 with total villous atrophy (TVA). 23 persons were seropositive, having at least one of the two antibodies tested. The sensitivity of the serological investigation increased at 88% using both AEA and ATTG determinations. In patients with TVA, the sensitivity of ATTG was 100% and of AEA was 92%. In patients with SVA and PVA, the sensitivity of these antibodies was lower. Among the patients with SVA, 43% were negative for AEA and 50% for ATTG. The determination of AEA and ATTG together reduced the seronegativity at 15% in patients with SVA and at 34% in patients with PVA.

CONCLUSIONS

Antitissue-transglutaminase antibodies testing in patients with non-treated celiac disease is more sensitive than antiendomysium antibodies. The efficiency of the serological diagnosis improves when both AEA and ATTG are determined. Serum antibodies levels correlated very well with the severe histological alterations (TVA), but the correlation is not so good with SVA and PVA. So, we can tell that high levels of AEA and/or ATTG are suggestive for severe histological disorders in celiac disease.

[Extracorporeal shock wave lithotripsy (ESWL) can be done for lithiasic patients with cardiac arrhythmias with a lithotriptor without ECG triggering system--the experience of Iaşi Urological Department]

The recommendations for spark gap lithotripters include that the shock waves must be delivered according to the ECG, avoiding the discharge during the refractory part of the heart activity. The lithotripters we have in our department does not have from the factory an ECG correlated triggering system. Observing that ESWL for patients without heart problems did not induced arrhythmias, we decide to perform this procedure under strict cardiologic supervision to the patients having arrhythmias (chronic fibrillation, chronic atrial fibrillation, supraventricular arrhythmias, supraventricular premature beats, ventricular premature beats, ventricular tachycardia). All the ESWIL sessions did not have any major incidents and all the patients return home safe, without any changes of the cardiac medication. Even we did not notice any aggravation of the cardiac arrhythmias during ESWL we consider that the careful monitoring of the patients by the cardiologist is necessary during the procedure, most of all when the spark gap lithotripter has not an ECG triggering system.

Finite-difference lattice Boltzmann model with flux limiters for liquid-vapor systems

In this paper we apply a finite difference lattice Boltzmann model to study the phase separation in a two-dimensional liquid-vapor system. Spurious numerical effects in macroscopic equations are discussed and an appropriate numerical scheme involving flux limiter techniques is proposed to minimize them and guarantee a better numerical stability at very low viscosity. The phase separation kinetics is investigated and we find evidence of two different growth regimes depending on the value of the fluid viscosity as well as on the liquid-vapor ratio.

Antiendomysial and antitissue transglutaminase antibodies in gluten-induced enteropathy

Although the gold standard for diagnosis of coeliac disease remains the small bowel biopsy, the broad spectrum and the non-specific nature of many of the clinical manifestations makes biopsy as the initial investigation impossible. So, much effort has been put into the identification of serological screening tests with adequate sensitivity and specificity. The aim of this study was to identify antiendomysial and antitissue-transglutaminase antibodies as serum markers of coeliac disease in a group of patients admitted in the 3rd Medical Clinic, 4th Medical Clinic and 1st Pediatric Clinic as well as in the general population. The study was made on serum samples collected from 64 persons, adults and children with or without documented coeliac disease. Antitissue transglutaminase (anti-tTG) antibodies were determined by the sandwich ELISA technique, using a commercial kit. Antiendomysium (EMA) antibodies were dosed by indirect immunofluorescence. Twenty-four subjects were positive for IgA anti-tTG and 23 for EMA. We found that IgA anti-tTG were 100% positive in patients with clinical suspicion of coeliac disease, the diagnosis being confirmed by biopsy. All, but two patients on a gluten-free diet had small or zero EMA levels. We also found that serum EMA levels correlated perfectly with the degree of histological alterations. A very good correlation was found between the serum concentrations of the two antibodies studied

[The ecological accident on the Siret River. A possible cyanide intoxication of children]

THE PURPOSE

Of our study is to assess the gravity of cyanide intoxication of children, in the ecological accident in January 2001.

MATERIAL AND METHODS

We included in our study 127 children aged between 2 months and 17 years. They were hospitalized in January and February 2001, in the "Sf. Maria" Children's Hospital. Case analysis was based on data of the emergency unit and units where the children were sent after primary care. We evaluated the patients from clinical and paraclinical point of view and we took samples of biological products in order to confirm the diagnosis.

RESULTS

Age distribution was 0-1 year (4%), 1-3 years (7.8%), 3-6 years (9.4%), 6-12 years (33.8%), and 12-18 years (42.5%). The lapse of time between the ingestion of contaminated fish and symptomatology was variable. Measures were taken: removal from toxic contact, hospitalization, antidote administration, and treatment of complications.

DISCUSSIONS

Although literature data shows that this intoxication appears after the age of three, we found that mother ingestion of contaminated fish, determined intoxication in nursings. Symptoms appeared at 3-12 hours after fish ingestion from the contaminated river and it was suggestive for the diagnosis. First aid measurements were necessary in specialized emergency unit and antidote administration sometimes only in clinical suspicion of intoxication. Correlation between clinical findings and toxic concentrations in urine samples confirm the diagnosis.

CONCLUSIONS

Our study tries to highlight those ecological accidents with cyanides present important consequences on people and animal's health. The therapeutic intervention must be fast in order to stop blood distribution of the toxic.

A micropopulational modelling of a viral epidemic by using a special neural network

A general forward neural network was adapted for a simulation of viral epidemics. This involves the introduction of a strongly dependence upon history, upon the cumulated values of the corresponding neuron (individual) activations (states of infection) specifying the activation (health) states of the contaminated individuals, represented by the activated neurons and the dynamic parameters of the neural network: the matrix of the synaptic connection and the vector of the activation thresholds (corresponding to the matrix of the viral transfers between the various individuals and to the vector of the minimal individual contamination doses of virus). The recurrence relations and the learning procedures were also adapted to these processes. This methodology was used for the study of the micropopulational spreading of viral epidemics in various epidemiological situations.

Immunological methods in the diagnosis of monoclonal gammopathies. The prognostic impact of the immunological data

Immunological data are extremely important for the diagnosis of monoclonal gammopathies (MG). During the 1977-1998 period, 160 MG cases were diagnosed in our laboratory. Out of the 130 multiple myeloma (MM) cases, 70 (53.85%) met the strictly immunological criteria; in the rest of the cases, the immunological data had to be corroborated with the bone marrow cytology and bone X-ray data. We tried to assess retrospectively the prognostic impact of the immunological data on the 60 cases that were treated and followed at the Hematology Dept. of the Cancer Institute, Cluj. The following parameters were found to have a favorable prognostic impact on survival: IgG monoclonal component, kappa light chains, response to therapy with plateau phase achievement, Salmon Durie stages I and II at diagnosis.

Increased plasma levels of interleukin-8 in patients with unstable angina pectoris

Interleukin-8 is a proinflammatory cytokine with chemo-attractive and major activator properties on neutrophils. The very few studies in literature on the IL-8 behaviour in myocardial ischaemia refer only to acute myocardial infarction. This study investigates the IL-8 behaviour in stable angina pectoris after myocardial ischaemia induced by dipyridamole (14 patients) and in unstable angina pectoris, Braunwald's class III (35 patients). In stable exercise angina following dipyridamole-induced myocardial ischaemia, the plasma IL-8 levels did not increase. In unstable angina pectoris increased plasma IL-8 levels were evidenced in 25 of the 35 patients, after an average interval of 20 +/- 1.2 hours from the last spontaneous episode of angina pectoris. The IL-8 behaviour was different in class III B patients as compared to class III A: only 30% of the patients in class III A presented transient increase of IL-8, while 70% of the class III B presented increased IL-8 with a median value of 900 pg/ml within the first 24 hours from the last spontaneous episode of angina pectoris. The increased plasma IL-8 levels within the first 24 hours from the spontaneous episode could represent a marker of primary angina pectoris, Braunwald's class III B.

EEG differences between the opioid and adrenergic psyhoneuroendocrine rat types

Our work is based on the hypothesis of the existence of an opioid psychoneuroendocrine type named "O" type (Cristea, 1993), opposed to the well known adrenergic "A" type described by Roseman and Friedman in 1980. In the present study we tested the differences between the background EEG activity (BEA) of the "O" and "A" rat types during restrained wakefulness and anesthesia with Ether and chloral hydrate (CHL). The differentiation of the psyhoneuroendocrine rat types was made using the level of painful sensitivity. 13 hypersensitive "A" and 14 hyposensitive "O" rats were selected from a 91 adult (140 g) male Wistar population using the distribution of the tail retraction time (TRT) during a tail-flick test. The epidural EEG activity, was quantified within the 1-30 Hz band by six numerical parameters: root mean square (RMS), mean spectral frequency (MSF), spectral edge frequency at 95% (SEF95) and the relative spectral power (RSP) within the Theta (4.5-7.5 Hz), Alpha (7.5-12 Hz) and Beta (12.5-30 Hz) bands. The quantification method used was able to detect statistically significant differences between the two psyhoneuroendocrine rat types during consciousness and light ether anesthesia but failed to show any differences during the deep CHL anesthesia. The particularities were shown to be topographically related with the fronto-parietal regions were "O" type showed a higher SEF95 during the awake restrained state. The pain sensitive "A" type showed a significant intrahemispheric theta RSP asymmetry both during consciousness and ether anesthesia while no such theta gradient could be shown for the "O" type. The differences between the "A" and "O" types are enhanced under light Ether anesthesia to which the "A" type is more resistant. The EEG complementarity between the "A" and "O" types is discussed.

Removing irrelevant features in neural network classification using evolutionary computations

Evolutionary artificial neural networks (EANN) are a new paradigm that refers to a special class of artificial neural networks (ANN) in which evolution is another fundamental form of adaptation in addition to learning. Evolution can be introduced at various levels of ANN. It can be used to evolve weights, architectures and learning parameters. Evolutionary computations are population-based search methods that have shown promise in many similarly complex tasks. This paper presents an application of evolutionary programming for simultaneously inducing the input structure and weights evolving for multilayer feed-forward perceptrons (MLP) with standard sigmoidal activation function.

[The presence of nitrates and nitrites in the environment in different geographical areas of Moldova correlated with morbidity from methemoglobinemia]

It was studies the content of nitrates and nitrites in water sources and vegetables from different geographical regions, resulting high values of nitrates in colinae and plain regions, and low values in mountain and submountain region. The high value of nitrates are related with methaemoglobinaemia. The nitrites from edible water studied and from vegetables presented very low values in the order of ppm.

Empirical decompositions of overall AIDS epidemics in local epidemics using generalized neural networks

A generalized neural network was adapted for the simulation of processes strongly dependent upon the history, imposed by the inner own history of an individual neuronal activation. This involves the dependence of the neural network parameters upon the cumulated values of the corresponding neuron activations. When in the neural network weakly coupled blocks with strong inner couplings can be identified, the activation wave on the entire network (associated with the overall epidemic) can be decomposed into quasi-independent intra-block local activation waves, with characteristic delays between them (corresponding to the simultaneous and successive local epidemics). Special simulations on strongly connex neural network determine the typical local activation waves for various block parameters and the mentioned delays between two such successive activation waves in two coupled blocks. Another type of neural network is used to achieve the empirical decomposition of the overall epidemic into simultaneous (corresponding to a layer) and successive local epidemics (corresponding to the various epidemic waves, associated with different layers). A simpler approximative algorithm for the estimation of the number of the mentioned simultaneous local typical epidemics is also presented.

The double-way effects of naloxone and clonidine on experimental stress analgesia

We have emitted the hypothesis that the double-way effect is possible not only due to the wide range of receptor substrates and receptor subtypes but it can manifest at the heterosynaptic and synaptic cotransmission level as a consequence of the informational unbalance which very low or very high doses of biological signals (in pathological disorders) or of drug signal (agonist or antagonist) can do on physiological balance between both two coupled synaptic systems. To verify this hypothesis we choosed as place of manifesting and observing of the phenomen the informational gearing between the endogenous opioid system as "modulator" and the catecholaminergic systems as "alarm". As drug signals we used naloxone (NALX) and clonidine (CLON). The function studied to reveal the double-way effect was stress analgesia monitored in the classical test of te "hot plate". The experimental stress was induced to the mouse by submitting to forced swimming using the "despair test". In the work are presented the dose-effect curves and inflexion points which mark the changing of the sense of the effect.

Antineutrophil cytoplasmic autoantibodies (ANCA)--markers in diagnosis and monitoring systemic vasculitides

We present a new class of autoantibodies--ANCA (antineutrophil cytoplasmic autoantibodies) which recognize as target antigen different enzyme constituents of primary granules of neutrophil granulocytes. These autoantibodies are present in a large number of diseases, such as: systemic vasculitides, idiopathic crescentic glomerulonephritis, inflammatory bowel diseases and in some other conditions, including rheumatoid arthritis, SLE, Felty syndrome, acute and chronic infections. ANCA not only facilitate the diagnosis but also have a pathophysiological role for some of the idiopathic vasculitides. In our study, including 110 patients referred to the laboratory for ANCA testing by indirect immunofluorescence technique, only 25 patients were positive with a diffuse cytoplasmic (c ANCA) or perinuclear (p-ANCA) pattern on alcohol fixed slides. Some relevant cases are presented in order to emphasize that ANCA antibodies are a useful marker in the early diagnosis of systemic vasculitides, allowing effective therapeutic handling.

Correlation between fibronectin and cardiothoracic ratio in heart failure treated with angiotensin converting enzyme inhibitors

A group of 17 patients with ischemic heart disease, significant left ventricular dilatation and congestive heart failure, class III NYHA (9 patients) and class IV NYHA (8 patients) was studied. The patients received angiotensin converting enzyme inhibitor--captopril 75 mg/day or perindopril 4 mg/day--added to diuretics, digitalis and nitrates. The plasmatic level of fibronectin was investigated, by radial immunodiffusion, before and one month after the beginning of the treatment with angiotensin converting enzyme (ACE) inhibitor. The plasmatic level of fibronectin is increased significantly (p < 0.001) while the cardiothoracic ratio is decreased significantly (p < 0.02) after one month of ACE inhibitors treatment. A positive correlation between the increase of the plasmatic level of fibronectin and the decrease of cardiothoracic ratio is found (r = 0.62; p < 0.01). The increased fibronectin plasmatic level can be a marker of the favorable effect of ACE inhibitor on the myocardium interstitium.

Homozygous or compound heterozygous qualitative antithrombin III deficiency

A male patient of 24 years who had experienced thrombotic episodes since the age of 15 displayed an unusually low antithrombin III (AT III) activity measured as heparin cofactor (13% of the normal), while a similarly decreased value (16% of normal) was found in a 26 year old brother who had suffered from thrombotic events since the age of 12 years. AT III heparin cofactor activities were close to 50% of normal in the father, mother, another brother and a sister, none of whom had experienced thrombotic episodes. Since all available members of the family, including the patient, displayed near normal AT III antigen levels (73-85%) normal total progressive antithrombin activities (92-110%) as assessed by the thrombin agarose diffusion technique and normal total progressive anti-Xa activities, the propositus and his brother could be considered to be homozygotes or compound heterozygotes for a qualitative familial AT III deficiency probably caused by an abnormality of the heparin binding site. Molecular techniques would be required to elucidate the precise mutation giving rise to the deficiency.

Simulation of a viral epidemic by means of a neural network

The neurons of the network used for the simulation of a viral epidemic correspond to the individuals of the community. The activation state of the neurons reflects the contagious state of the diseased persons. Variable thresholds are introduced for the differentiation of the neuronal non-activation states (susceptible or immune subjects). The thresholds are calculated depending on the cumulated values over time of the neural activation states. The network functions synchronously. In order to follow up the state of the neural network, recurrence relations were introduced. They were applied in two epidemiological situations which differ from each other by the spreading intensity of the virus over time, reflected by the particular values ascribed to the elements of the neural connection matrix.

Antithrombin III deficiency

Data on clinical features and laboratory diagnosis of familial antithrombin deficiency, a rather heterogeneous group of disorders, are illustrated by observations on two Romanian kindreds afflicted by recurrent thrombotic episodes. In a first family, both plasma antithrombin III antigen and activity were reduced to 50% of normal, a condition characteristic for a heterozygous type I (quantitative) familial antithrombin III deficiency. In a second kindred, the two brothers who had experienced thrombotic events since they were teenagers, displayed exceedingly low AT III heparin cofactor activity (13% and 16% of the normal, respectively) while values around 50% of the normal were recorded in their parents who had not experienced thrombotic episodes. Since plasma antithrombin III antigen and total progressive antithrombin III activity were within normal limits in all the investigated members of this family it was considered that the two brothers were homozygotes or compound heterozygotes and the parents were heterozygotes for a qualitative-antithrombin III deficiency caused by an abnormality of the heparin binding site.

The evolution of the painful sensitivity in acute and chronic stress

The clinical research was made on two groups of young volunteer students. We considered stress consisting in chronic informational overexposure during the examination session and the acute stress from their emotions before a hard examination. The painful sensitivity was analysed by measuring the retraction time of the finger from water at 55 degrees C. The experimental research was made on a group of 100 male mice. The acute stress was performed by subjecting each mouse to swim (behavioral despair test). Painful sensitivity was determined by the test of the hot plate heated at 50 degrees C. Individuals with hyper (H) and hypo (h) painful sensitivity were selected for the tests. In chronic stress, the results proved increased painful sensitivity (hyperalgia) more important at "h" compared to "H" (p < 0.05). In acute stress decreased painful sensitivity (stress analgesia) was noticed more significant at "H" compared to h" (p < 0.05). All these results suggested that the extreme "H" and "h" are two different stress behaviors with opposite mechanisms involved in stress analgesia. This hypothesis is related with studies which demonstrate the involvement in stress analgesia of non-opioid monoaminergic mechanisms together with the opioid mechanisms (Lewis, 1980).

Microalbuminuria in hypertensive patients

The present study was designed to evaluate the urinary albumin excretion in 62 patients with essential hypertension. None of them had prior proteinuria or history of nephropathy or uropathy. Patient data, blood pressure, proteinuria using Bradford's method, albuminuria by radial immunodiffusion, urinary SDS-PAA electrophoresis, plasma glucose, serum creatinine, serum cholesterol were determined. The urinary albumin excretion was significantly higher (p < 0.001) in the group of hypertensive patients (19.22 +/- 2.36 micrograms/min) compared to a group of 20 control subjects (4.17 +/- 0.67 microgram/min). Compared to a subgroup of hypertensive patients without ischemic heart disease (12.07 +/- 1.30 micrograms/min) microalbuminuria was higher (43.74 +/- +/- 5.74 micrograms/min; p < 0.001) in a subgroup of 14 patients with essential hypertension and ischemic heart disease with severe coronary events: unstable angina pectoris (9 patients), myocardial reinfarction (2 patients), ventricular arrhythmias (3 patients). A positive correlation between the microalbuminuria and the duration of hypertension was found (r = 0.64; p < 0.001). Therefore, microalbuminuria may represent a marker of the severity of vascular involvement in hypertensive patients.

Experimental model of psychic stress

An experimental model for the induction of an informational psychic stress in the rat, comparable with the psychic stress in man, is described. The method consists in the production of the emission of significant acoustic signals by an "emitting" group of animals, subjected in an aleatory manner to electroshocks. The acoustic nociceptive signals are heard by a "receiving" group of animals. In this "receiving" group are studied the behaviour and the neuroendocrine changes. This experimental model may be useful for studies of psychopharmacology, for the research of psychotropic drugs and for the determination of their action upon the harmful effect of informational aggressions and psychic stress.

Endogenous opioid abstinence syndrome

Starting from the observation that an increase of stress analgesia is followed by a hyperalgesia period, with a series of symptoms characteristic of the exogenous opioid abstinence syndrome (EXOAS), the authors supposed also the possibility of the existence of an endogenous abstinence syndrome (ENOAS). In order to demonstrate the existence of this syndrome, they investigated at first the possibility of the appearance of an acute tolerance to opioids. Then they followed-up the course of behaviour during and after informational stress in untreated animals, in animals treated with naloxone, which--being an antagonist of opioids--can induce EXOAS in toxicomaniacs, and in animals treated with clonidine and propranolol, that are used in the treatment of EXOAS. Experimental researches have demonstrated the possibility of ENOAS occurrence, its aggravation by naloxone and its improvement with clonidine and propranolol.

Mathematical stochastic models of some typical viral epidemiological evolutions

The formalisms of the probability distribution and of the associated generator function are used to establish the equations for the first and second moments of the numbers of susceptible and contagious individuals. Applications are given for the linear cases for the epidemic evolutions, for the endemic situations and for virosis in course of eradication.

Mathematical model for the AIDS epidemics evolution in Romania

The individuals are distributed in 9 risk groups (adults and children), in which an HIV transmission way is predominant. Taking into account a simplified graph of the HIV infection evolution, kinetic equations for the number of individuals from each risk group--situated in various stages of HIV infection--are written. The approximative solutions of these equations give us: the characteristic exponents of the temporal evolutions of the main and secondary local epidemics; the ratios Ci/Bi and Di/Bi of asymptomatically contaminated and dead (as consequence of AIDS) versus symptomatically contaminated; the onset of local epidemics in various risk groups; the relative amplitude of the secondary local epidemics versus the main local ones.

Mathematical model for the AIDS epidemic's evolution in Romania

The individuals are distributed in 9 risk groups (adults and children), in which an HIV transmission way is predominant. Taking into account a simplified graph of the HIV infection evolution, kinetic equations for the number of individuals from each risk group--situated in various stages of HIV infection--are written. The approximative solutions of these equations give us: the characteristic exponents of the temporal evolutions of the main and secondary local epidemics; the ratios Ci/Bi and Di/Bi of asymptomatically contaminated and dead (as consequence of AIDS)--versus symptomatically contaminated; the onset of local epidemics in various risk groups; the relative amplitude of the secondary local epidemics versus the main local ones.

The control of some viral epidemics by antiepidemic programmes elaborated by an expert system

A base of data for viral epidemiological studies is presented containing correlation between outer symptoms (observable characteristics of the mass morbid phenomena), inner symptoms (characteristics of intensity of elementary processes implied in the virosis propagation) and influencing factors (risk or protective ones). A resolutive nucleus of processing these is divided in to three parts: an inductive one (specification of the mentioned correlations, of the mathematical model and its equation solutions); a deductive one (explaining or prognosing the epidemiological evolution); a decisional one (specifying the antiepidemic services, necessary for a possible or desired reduction of the morbidity).

Functional and antigenic antithrombin III in angina pectoris and acute myocardial infarction patients

Plasma antithrombin III was measured by an immunological approach (AT III:Ag) using an antiserum developed in our laboratory and by its ability to inhibit thrombin (functional assay) using a chromogenic synthetic substrate in 12 patients with myocardial infarction, 9 patients with angina pectoris and 10 healthy control subjects. In the early stage (3 to 24 hours after the onset of pain) of an acute myocardial infarction AT III:Ag (115.67% +/- 21.23) was found to be significantly (p less than 0.01) higher than functional (free) AT III (92% +/- 10.27). This difference was less obvious 10 days later (AT III:Ag 118% +/- 18.93; functional AT III 104.94 +/- 14.45). There was also no significant difference between AT III:Ag and functional AT III in patients with angina pectoris as well as in controls. Since AT III:Ag represents total plasma AT III while functional AT III represents only free AT III the difference between these two variables could provide informations about the amount of the anticoagulant forming complexes with activated clotting factors. It is therefore considered that the significant increase in the difference between AT III:Ag and functional AT III in the early stage of acute myocardial infarction is likely to suggest an intravascular activation of coagulation.

[The improvement of a serological screening method in blood transfusion]

The mathematical analysis was done of the opportunity of modifying the serological screening method in view of the reduction to a minimum of the costs. Two factors were considered: dimensions of the pool and specific incidence of the markers in the population.

Reduced passage of alpha 2-macroglobulin into malignant serous effusions and diminished antifibrinolytic potential of the fluid

The ratio of the relative concentrations of large and small proteins between effusions and serum was measured in patients with benign and malignant effusions. The ratio of values for a large protein, alpha 2 macroglobulin (alpha 2 M) was significantly (p less than 0.0005) lower in the 22 patients with tumoral effusion (0.436 +/- 0.016) and in the 16 patients with transudates (0.388 +/- 0.017) than in the 21 cases with inflammatory exudates (0.838 +/- 0.036) while the ratios between relative concentrations of the lower molecular weight alpha 1 antitrypsin (alpha 1AT) in serous fluids and sera were similar (close to 1.0) in all the above mentioned conditions. Most inflammatory exudates inhibited fibrinolysis in a urokinase activated system, while the activity of the inhibitors of fibrinolysis was very weak in tumoral effusions and in transudates. These findings suggest a rather selective passage of plasma proteins into a tumoral effusion, a fact that might be relevant for a pathogenic diagnosis.

Plasma von Willebrand factor antigen and activity and platelet aggregability in patients with proteinuria

Using a complex stimulating mixture containing ADP, epinephrine and collagen, a significantly (p less than 0.002) enhanced platelet aggregability, expressed as platelet sensitivity factor (PSF) was noted in platelet rich plasma of patients with proteinuria (PSF = 472 +/- 125), as against normal weight normolipidemic control subjects (PSF = 32.76 +/- 2.67). A significantly negative correlation (r. -0.579; p less than 0.001) was found between serum albumin concentration and the logarithmic values of platelet sensitivity factor. Plasma von Willebrand factor activity expressed as a percentage of normal was also significantly (p less than 0.001) higher in proteinuric patients (287% +/- 25.8) than in control subjects (99% +/- 5.02), but this hemostatic variable did not correlate with the logarithm of platelet sensitivity factor. Platelet aggregability was higher in hyperlipidemic nephrotic patients than in proteinuric patients with normal serum lipids, while renal failure led to a decrease of platelet function. The raised plasma levels of von Willebrand factor noted in proteinuric patients were not influenced by either hyperlipidemia or by chronic renal failure. It is concluded that changes affecting platelet function in the nephrotic syndrome are produced by other mechanisms than these leading to an increase of endothelia-derived von Willebrand factor. Both changes may, however, contribute to the thrombotic tendency of nephrotic patients.

von Willebrand factor in the plasma of patients with rheumatic diseases

von Willebrand factor (vWf), an endothelial cell product, was evaluated in 39 patients with rheumatoid arthritis, 19 patients with connective tissue diseases and vasculitis, 21 patients with nonrheumatoid inflammatory arthritides, 14 patients with osteoarthritis and 19 controls. High plasma vWf levels were found in rheumatoid arthritis patients: 196.35 +/- 85.8 (p less than 0.001 versus control) connective tissue diseases and vasculitides: 306.50 +/- 43.4 (p less than 0.001 versus control) and inflammatory nonrheumatoid arthritides: 193.35 +/- 90.6 (p less than 0.01 versus control). Highly increased vWf concentrations of more than 300%, were found in one patient presenting Wegener granulomatosis, 6 patients with vasculitis associated to connective tissue diseases, 7 patients with rheumatoid arthritis and 2 patients with active forms of inflammatory arthritides. vWf was correlated with fibrinogen in the subgroup of systemic lupus erythematosus patients. Elevated vWf levels may reflect vascular damage as well as the acute phase reaction. Highly elevated levels of vWf appear to indicate a poor prognosis.

[The logic of diagnoses used in expert systems. II. Applications in virology]

Inference capacity of different clinical or paraclinical examinations are analyzed, whose results allow to establish the definitive diagnosis through gradual integrations. The knowledge of the inference capacity is very useful for the expert systems applied in virology.

Clinical studies on plasma antithrombin III using an antiserum prepared in our laboratories

Using an antiserum obtained in rabbits injected with antithrombin III purified in our laboratories, the plasma level of this inhibitor of coagulation was found to be significantly (p less than 0.001) decreased in 8 patients with decompensated cirrhosis of the liver (15.66 mg/dl +/- 2.22) and in 18 nephrotic patients (21.74 mg/dl +/- 1.75). When compared to values noted in 22 normal-weight normolipidemic control subjects (31.54 mg/dl +/- 0.81), the plasma level of antithrombin III was slightly (p less than 0.05) higher in the 18 hyperlipidemic subjects (36.11 mg/dl +/- 1.9). Owing to an extremely wide dispersion of individual values, the mean level of antithrombin III noted in 16 critically ill postoperative patients (28.16 mg/dl +/- 2.98) did not significantly differ from control values, although this protease inhibitor was obviously decreased in those postoperative patients who developed multiple organ failure or disseminated intravascular-coagulation. Among the 11 patients with recurrent venous thrombosis, two subjects with familial deficiency in antithrombin III were detected. The results provide evidence that the antiserum prepared in our laboratories is a useful tool for detecting acquired and inherited antithrombin III deficiencies.

Lupus anticoagulant and transient severe bleeding tendency in a girl aged nine years

A 9-year old girl admitted in our clinic for severe hemorrhagic syndrome was found to display a high level of lupus anticoagulant (LA) leading to an important prolongation of phospholipid-dependent coagulation. Positive antinuclear and anti DNA antibodies, as well as very low levels of complement C3 and C4 proteins confirmed the diagnosis of systemic lupus erythematosus. Therapy with cortisone and cyclophosphamide led to normalization of the clotting tests but could not arrest the development of renal and hepatic lesions. The patient is one of the few cases with presence of lupus anticoagulant associated with severe hemorrhagic diathesis, in opposition to the more frequently reported thrombotic tendency connected with antiphospholipid antibodies.