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A novel colorimetric assay was developed and validated for accurate quantitation of human immunodeficiency virus (HIV) DNA in peripheral blood mononuclear cells (PBMCs). We tested 318 sequential samples from 56 subjects, 53 of whom were undergoing dual or triple therapy. Patients were considered responders when viremia levels were below 5, 000 HIV RNA copies/ml. The mean DNA copy numbers for untreated and responder subjects were similar (72 and 75, respectively), while it was 4.54-fold higher for nonresponders (339). This report provides strong evidence that HIV DNA levels in PBMCs correlate with therapeutic efficacy and suggests that DNA quantitation is a useful tool to monitor the decay of the HIV reservoir toward disease remission, especially when viremia is undetectable.

A communication system for the automation of the follow up of AIDS patients set up by DIST at the Molecular Virology Unit in the Advanced Biotechnology Centre of Genova and at the Department of Internal Medicine of the Medical School of Genova is presented. This system includes a distributed database to store both clinical and virological data and a set of procedures to transfer patient data with a complete respect of requirements about completeness and privacy.

An identification system for aquatic bacteria which would be useful for aspects ranging from pollution monitoring to health care, is described. It contains relevant information concerning the nature, taxonomy and activity of aquatic bacteria and allows to identify fresh isolates by means of their chemotaxonomic profiles. The system is simple and user friendly, so that it can be used by people not familiar with computers and has a modular interface that allows an easy interaction with laboratory instruments. The system is also connected with artificial neural network based programs to identify strains starting from the considered chemotaxonomic features.

The diagnosis of dyspepsia is very difficult because the symptoms are clinically aspecific and the gastric emptying time tests are of complex interpretation. An integrated and automated analysis of clinical and instrumental data may improve the diagnostic process. We present a system to collect data on dyspeptic patient from different sources which has been set up to assist the clinician in the diagnosis of dyspepsia. The data base integrates a wide set of symptoms with data coming from laboratory tests. Moreover, we assess the feasibility of classifying gastric emptying profiles using both octanoid acid excretion data and electrogastrography.

Study Objective: The pulmonary parenchyma in patients with acute respiratory failure (ARF) is commonly not involved in a homogenous disease process. Conventional mechanical ventilation (MV) at elevated positive end-expiratory pressure (PEEP) and peak inspiratory pressure (PIP) aims at recruiting collapsed or nonventilated lung units. Invariably, those pressures are also transmitted to the healthiest regions, with possible extension of the disease process (barotrauma). During intratracheal pulmonary ventilation (ITPV), a continuous flow of fresh gas is delivered directly at the carina, bypassing the dead space proximal to the catheter tip. In healthy sheep, it allows lowering tidal volume (VT) to as low as 1.0 mL/kg, at respiratory rates (RR) up to 120 breaths/min, while maintaining normocapnia. In a model of ventilator-induced lung injury, we wished to explore whether ITPV, applied at low VT and low PEEP and tailored to ventilate the healthiest regions of the lungs, could provide adequate oxygenation and alveolar ventilation, without any attempt to recruit lungs., Design: Randomized study in sheep., Setting: Animal research laboratory., Participants: We induced ARF in 12 sheep following 1 to 2 days of MV at a PIP of 50 cm H2O, except that 5 to 8% of lungs were kept on apneic oxygenation of 5 cm H2O, sparing those regions from the injury process., Interventions: Sheep were randomized to volume-controlled MV (control group) (n = 6) with VT of 8 to 12 mL/kg, PEEP of 5 to 10 cm H2O, or to ITPV (n = 6) at PEEP of 3 to 5 cm H2O, VT of 2.5 to 4 mL/kg, PIP of <20 cm H2O, at RRs sufficient to sustain normocapnia., Measurements and Results: Hemodynamic status in the ITPV group progressively improved, and all six sheep were weaned to room air within 83+/-54 h. Sheep in the control group had progressively deteriorating conditions and all animals died after a mean of 50+/-39 h. Barotrauma and postmortem histopathologic changes were more pronounced in the control group., Conclusion: In this model of ventilator-induced lung injury, low PEEP-low VT ventilation with ITPV sustained normocapnia and prevented further lung injury, allowing weaning to room air ventilation.

This study addresses the limited range of quantification with colorimetric assays (ELISA) starting from the analysis of color production in a reference external curve. An automatic ELISA management software, designated Quanti-Kin Detection System (QKDS) is described, which retains the sensitivity of the end-point reading and extends the dynamic range up to five logarithms with mathematical interpretation of color production. The QKDS software is a generic system suitable for different types of ELISA with substrate incubation at room temperature, does not require dedicated instruments, performs accurate quantification (including assay quality control) and has a user friendly interface. Specific applications were developed for three types of analytes: antibodies, viral antigens and nucleic acids. Data are presented on three representative QKDS applications to HIV antibodies, p24 antigen and proviral DNA kits. The precision of quantification is strictly correlated with the precision of the kit; however, for almost all samples with known analyte amount, the error percentage was below 10%, only for two cases in quantification of HIV proviral DNA the error percentage was around 25%. The necessity for a wide quantification range has been demonstrated by measuring clinical samples, which showed a distribution in all possible quantification ranges for all kits.

The traditional approach to biochemical identification of marine fresh isolates requires considerably long culture preparation times and large quantities of expensive materials and reagents, and the results are not reliable. On the other hand, taxonomy tests based on DNA composition, although sensitive and reliable, require long execution time and high costs. A method is presented for the classification of fatty-acid profiles, extracted from marine bacteria strains, at genus level based on supervised artificial neural networks. The proposed method allows the correct identification of all patterns belonging to the test set. Moreover, a quantitative measure of the importance of each fatty acid for bacterial classification is also achieved. This measure allows the determination of a cluster of fatty acids to be controlled with greater care. The results show that the proposed method is reproducible and rapid, so that it can be routinely used in the marine microbiology laboratory to identify fresh isolates.

Study Objectives: Previously we have shown that optimal pulmonary gas exchange can be sustained at normal airway pressures in a model of severe acute respiratory failure (ARF), using intratracheal pulmonary ventilation (ITPV), with weaning to room air. In an identical model of ARF, we have now explored whether ITPV, combined with continuous positive airway pressure (CPAP), can sustain adequate ventilation, with weaning to room air., Design: Randomized study in sheep., Setting: Animal research laboratory at the National Institutes of Health., Interventions: ARF was induced in 12 sheep, using mechanical ventilation at peak inspiratory pressure of 50 cm H2O, but excluding 5 to 8% of lungs. Sheep were then randomized into two groups: the CPAP-ITPV group (n=6), in which ITPV was combined with a novel CPAP system; and a control group (n=6) in which the same CPAP circuit was used, but without ITPV., Measurements and Results: All sheep in the CPAP-ITPV group were weaned to room air in 38.7+/-14 h. PaO2/fraction of inspired oxygen (FIO2) progressively increased from 108.8+/-43 to 355.7+/-93.1; PaCO2 remained within normal range; respiratory rate (RR) ranged from 18 to 120 breaths/min, and tidal volume (VT) was as low as 1.1 mL/kg. All sheep in the control group (CPAP alone) developed severe respiratory acidosis and hypoxemia after 4.8+/-4 h. PaO2/FIO2 decreased from 126.6+/-58.2 to 107.2+/-52.5 mm Hg, with a final PaCO2 of 166.8+/-73.3 mm Hg., Conclusions: All sheep treated with CPAP-ITPV maintained good gas exchange without hypercapnia at high RR and at low VT, with weaning to room air. All control animals treated with CPAP alone developed severe hypercapnia, respiratory acidosis, and severe hypoxemia, and were killed.

Background: Intratracheal pulmonary ventilation (ITPV) is a form of tracheal gas insufflation in which all gas emerges in a cephalad direction from the tip of a reverse-thrust catheter positioned within an endotracheal tube. In vitro experiments have shown that this rapid gas flow, with 5 ml/h of normal saline added to the gas flow, continuously removes tracheal secretions from within the endotracheal tube. The authors evaluated its effectiveness to remove mucus in long-term studies in sheep., Methods: Fourteen healthy sheep were tracheally intubated and ventilated for 3 days with ITPV or with volume-controlled ventilation. Measurements were made of the total amount of secretions within the endotracheal tubes (weight gain), the protein content within the endotracheal tubes, and the increase in resistance to constant air flow. The structure of the airways was examined grossly and histologically. Three additional sheep were ventilated for 24 h with ITPV, and Evans Blue dye was added to the saline to assess the distribution of the infused saline., Results: There was significantly less mucus in endotracheal tubes of sheep ventilated with ITPV than with conventional ventilation, as shown by minimal weight gain (0.70 +/- 0.14 g vs. 2.44 +/- 0.81 g; P < 0.001), lower protein content (14.09 +/- 10.79 mg vs. 294.99 +/- 153.06 mg; P < 0.001), and lower resistance to constant air flow (6.15 +/- 0.54 cm H2O x 1(-1) x s(-1) vs. 15.34 +/- 5.28 cm H2O x 1(-1) x s(-1); P < 0.001). Results of gross and histological examinations of the tracheas of animals in both groups were similar, and the tracheas were well preserved. More than 95% of the instilled saline was recovered during ITPV. Only traces of Evans Blue dye were found near the tip of the endotracheal tubes., Conclusion: Intratracheal pulmonary ventilation makes it possible to keep the endotracheal tubes of sheep ventilated for 3 days free of mucus without suctioning.

In 1968, an ad hoc committee of Harvard faculty publicly redefined death as "brain death". What interests and issues compelled the redefinition of death, and formed the "spirit" of this precedent-setting policy? This paper reports on an historical study of the files of the Harvard ad hoc committee, the proceedings of an international conference on ethical issues in organ transplantation, and a review of the medical literature and media in the decades preceding the redefinition of death. This analysis of the technological and professional forces involved in the redefinition of death in 1968 questions two common theses: that technological "progress", primarily in the areas of life support and electroencephalography, literally created brain-dead bodies and dictated their defining features (respectively), and that Harvard's definition of brain death by committee constituted a net loss of autonomy for medicine. In fact, medical researchers through the 1960s disputed and negotiated many features of the brain death syndrome, and transplantation interests-perhaps more kidney than heart-played a particularly influential role in tailoring the final criteria put forth by Harvard in 1968. It is also doubtful whether Harvard's definition of brain death by multidisciplinary committee undermined medical privilege and autonomy. The Harvard Ad Hoc Committee may not have succeeded in establishing definitive, indisputable brain death criteria and ensuring their consistent application to all clinical cases of brain death. However, it did gain significant ground for transplant and other medical interests by (1) establishing brain death as a technical "fact" and the definition of brain death as an exercise for medical theorists, (2) involving non-medical ethics and humanities experts in supporting the technical redefinition of death, and, (3) successfully involving transplant surgeons in the redefinition of death and attempting (albeit unsuccessfully) not to exclude them from the actual diagnosis of death in individual cases.

We present a local Dissemination of EPIC, a project which has been devised to support health and social primary care by an information system. One key point of the EPIC project was a standardization effort at European level, providing a standardized basis for the management system based on client needs for planning and manpower control. Whilst EPIC has been designed as a general community information system, the main EPIC applications focus is on the care of the elderly. Savona is a middle size Italian town with a high percentage of elderly people and has already had an experience of integration of health and social care within an Italian project. It has therefore been regarded as a suitable site for the dissemination of EPIC. The EPIC application solved some of the information problems which emerged during the validation of the previous Italian project, such as the definition of the requirements; the collection, processing and retrieval of the clinical/social data; the definition of responsibilities and relations of the operators.

We present a new model of sleep regulation which integrates the two process model and the limit cycle reciprocal interaction model. In the two process model the interaction of a homeostatic process (S signal) and of a circadian process determines the timing of sleep and waking. In the limit cycle model, the NREM-REM sleep cycle is generated by the reciprocal interaction of two coupled cell population. The present model integrates the two considered models introducing the trigger REM-NREM generated by the REM-ON signal and activated when REM-ON overcomes the S signal.

Four meanings of medical necessity have emerged, evolved, and dominated past and current health policy debates about the appropriate level of service coverage under Canada's health insurance program. To explore the shift in definition, provincial government and national health care association position papers responding to federal legislative and policy reviews of Canada's health insurance program from 1957 to 1984 were examined, as were more current reports on medical necessity. Four meanings of medical necessity predominated: "what doctors and hospitals do"; "the maximum we can afford"; "what is scientifically justified"; and "what is consistently funded across all provinces." These meanings changed with time as different stakeholder associations and governments redefined the concept of medical necessity to achieve different policy objectives for health service coverage under Canada's health insurance program.

The present work aims to obtain groups of patients with similar profiles of p24 antigen concentration and of CD4+ cell counts. These two markers were chosen because their evaluation represents a significant step in the clinical follow up of HIV-1 infected subjects. The classifications were obtained by a Kohonen neural net trained in three ways: with p24 antigen profiles only, with CD4+ cell count profiles only and with both sets of profiles. The results show that the clustering fashion of the two parameters closely resembles the clustering fashion of CD4+ only rather than the one of p24Ag, both with reference to cluster formation and with reference to distance among clusters.

The aim of the present work is to obtain groups of patients with similar profiles of p24 antigen concentration and of CD4+ cell counts. These two markers were chosen because their evaluation represents a significant step in the clinical follow up of HIV-1 infected subjects. The detection methods for p24 antigen concentration and for CD4+ cell counts are well assessed and guarantee easy reproducibility of data obtained in different laboratories. A set of observations with the same time intervals were derived from a continuous function obtained for each patient by a back-propagation neural net trained on the raw data from the patient. The classifications were obtained by a Kohonen neural net trained in three ways: with p24 antigen profiles only, with CD4+ cell count profiles only and with both sets of profiles. The results show that the clustering fashion of the two parameters closely resembles the clustering fashion of CD4+ only, rather than that of p24Ag, both with reference to cluster formation and with reference to distances between clusters.

Objective: To examine several hospital-based procedures for systematic utilization differences between the genders and among ethnic groups (Asian, black, Latino, and white)., Methods: California hospital discharges in 1989 and 1990 were sampled by principal diagnosis. Odds ratios for treatment by demographic class were estimated for heart transplantation, kidney transplantation, extracorporeal shockwave lithotripsy, hip replacement, carotid endarterectomy, coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, pacemaker implant, and automatic cardioverter-defibrillator implant. Logistic regression controlled for insurance status, age, diagnosis, and comorbidity count., Results: The following results were statistically significant (P < .05). Males' odds of receiving most procedures exceeded those of females by 115% (odds ratio, 2.15) for coronary artery bypass grafting, 86% for heart transplantation, 38% for defibrillator implants, 34% for angioplasty, 28% for pacemaker implants, and 24% for hip replacement. Whites' odds of receiving several procedures exceeded those of blacks by 204% for kidney transplantation, 186% for defibrillator implant, 144% for coronary artery bypass grafting, 127% for endarterectomy, and 100% for angioplasty. Whites' odds of receiving some procedures also exceeded those of Latinos by 72% for angioplasty, 58% for kidney transplantation, and 49% for coronary artery bypass grafting. Whites' odds of receiving endarterectomy or angioplasty exceeded those of Asians by 108% and 30%, respectively. Asians had 113% higher odds than whites of receiving hip replacement., Conclusions: The array of utilization differences across 4 demographic comparisons and 9 hospital procedures suggests systematic trends in high-technology allocation. Generally, women received procedures less often than men and minorities less than whites.

The fatty acid methyl ester composition of a total of 71 marine strains representing the genera Alteromonas, Deleya, Oceanospirillum, and Vibrio was determined by gas-liquid chromatographic analysis. Over 70 different fatty acids were found. The predominant fatty acids were 16:0, 16:1 cis 9, summed-in-feature (SIF) 4 (15:0 iso 2OH and/or 16:1 trans 9) and SIF 7 (18:1 cis 11, 18:1 trans 9, and/or 18:1 trans 6) for all the strains considered, but minor quantitative variations could be used to distinguish the different genera. In addition to a conventional statistical processing method to analyze the data and draw comparison between species and genera, an approach involving neutral network-based elaboration is applied. The statistical analysis and dendrogram representation gave a comparison of the species considered, while the neural network computation provided a more accurate assignment of species to their genera. Moreover, by using neural networks, it was possible to conclude that only 22 fatty acids were important for the identification of the marine genera considered. A database of Alteromonas, Deleya, Oceanospirillum, and Vibrio fatty acid methyl ester profiles was generated and is now routinely used to identify fresh marine isolates.

The aim of this study was to evaluate the rCBF (133Xe clearance method) in migrainous patients free from attack. Fifty patients suffering from migraine without aura (group M) and 20 suffering from migraine with aura (group MA) (age range 20-50 years) were submitted to 32 channel rCBF mapping during the interictal period. The rCBF data of patients were compared with those obtained from 60 healthy control subjects (group C) and 21 patients suffering from tension-type headache (group TH). The mean (average of all channels) rCBF values were: group M = 70.5 +/- 13.7 ml/100g/min; group MA = 56.6 +/- 11.4 ml/100g/min; group C = 62.3 +/- 8.3 ml/100g/min; group TH = 62.1 +/- 8.4 ml/100g/min (F = 11.93; p < 0.001). As expected, patients belonging to group TH had a normal rCBF. The mean rCBF of group M was significantly higher than that of groups C and TH, while in group MA it was significantly lower than in groups C and TH. Group M showed a diffuse hyperemia, while group MA showed rCBF values significantly lower than normal in posterior regions, according to aura. Our results suggest that: (a) the rCBF pattern in migrainous patients is different from that in both controls and TH patients, even during the interictal period; (b) patients suffering from migraine with and without aura are two distinct subpopulations with opposite rCBF deviations.

Background: A new endotracheal tube (ETT) was fabricated and tested in sheep. It had no tracheal cuff; airway seal was achieved at the level of the glottis through a no-pressure seal made of "gills"; the laryngeal portion was oval-shaped; and the wall thickness was reduced to 0.2 mm., Methods: Sheep were tracheally intubated either with a standard tube or with the new tube, and their lungs were mechanically ventilated for 1 or 3 days. Air leak was recorded at different peak inspiratory pressures (PIPs). Liquid seepage into the trachea was assessed using an indicator dye. Tracheolaryngeal lesions were scored grossly and histologically., Results: There was no air leak up to 40 cmH2O of PIP, in either group, in short- and long-term studies. Methylene blue leaked across the cuff in two sheep with standard ETTs. No dye leaked across the gills with the new ETTs. In the new ETT group, the trachea appeared better preserved, grossly and histologically, than in the standard ETT group at both 1 and 3 days (P < 0.05). At day 1, the larynx and vocal cords appeared grossly less injured in the new ETT group (P < 0.05), whereas there was no difference at day 3. Histology did not show significant difference on vocal cords, epiglottis, and larynx between the two groups at any time., Conclusions: The novel, no-pressure seal design of the new ETT is highly effective in preventing air leak and aspiration. It causes no significant tracheal injury.

The most frequently used methods for protein secondary structure prediction are empirical statistical methods and rule based methods. A consensus system based on object-oriented programming is presented, which integrates the two approaches with the aim of improving the prediction quality. This system uses an object-oriented knowledge representation based on the concepts of conformation, residue and protein, where the conformation class is the basis, the residue class derives from it and the protein class derives from the residue class. The system has been tested with satisfactory results on several proteins of the Brookhaven Protein Data Bank. Its results have been compared with the results of the most widely used prediction methods, and they show a higher prediction capability and greater stability. Moreover, the system itself provides an index of the reliability of its current prediction. This system can also be regarded as a basis structure for programs of this kind.

In 16 mechanically ventilated patients with acute lung injury (ALI) (eight patients with moderate ALI [moderate group], eight patients with severe ALI [adult respiratory distress syndrome, ARDS group]) and in eight normal anesthetized-paralyzed subjects (control group), we partitioned the total respiratory system mechanics into the lung (L) and chest wall (w) mechanics using the esophageal balloon technique together with the airway occlusion technique during constant flow inflation. We measured lung elastance (Est,L), chest wall elastance (Est,w), and total lung (Rmax, L) and chest wall (Rmax,w) resistance. Rmax,L includes airway (Rmin,L) and "additional" lung resistance (DR,L). DR,L represents the "additional" component due to the viscoelastic phenomena of the lung tissues and time-constant inequalities (pendelluft). Measurements were repeated at 0, 5, and 10 cm H2O of positive end-expiratory pressure (PEEP) in the control group and at 0, 5, 10, and 15 cm H2O PEEP in patients with ALI. The end-expiratory lung volume (EELV) was measured at each level of PEEP. Specific total lung (sRmax,L), airway (sRmin,L), and "additional" lung (sDR,L) resistances were obtained as Rmax,L x EELV, Rmin,L x EELV, and DR,L x EELV, respectively. At PEEP 0 cm H2O, we found that both Est,L (23.7 +/- 5.5 and 13.8 +/- 3.3 versus 9.3 +/- 1.7 cm H2O/L; p < 0.01) and Est,w (13.2 +/- 5.4 and 9.9 +/- 2.1 versus 5.6 +/- 2.3 cm H2O/L; p < 0.01) were markedly increased in patients with ARDS and moderate ALI compared with control subjects, with a significant (p < 0.01) effect of the severity of the disease on Est,L (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

This paper surveys recent health care reform debates and empirical evidence regarding the potential role for risk adjusters in addressing the problem of competitive risk segmentation under capitated financing. We discuss features of health plan markets affecting risk selection, methodological considerations in measuring it, and alternative approaches to financial correction for risk differentials. The appropriate approach to assessing risk differences between health plans depends upon the nature of market risk selection allowed under a given reform scenario. Because per capita costs depend on a health plan's population risk, efficiency, and quality of service, risk adjustment will most strongly promote efficiency in environments with commensurately strong incentives for quality care.

We present a qualitative model of the interaction between the HIV-1 virus and the human cell, based on qualitative process theory. This model takes into account a previous qualitative model of the cell growth. The model presented here can be regarded as a first step for setting up a comprehensive model of the HIV-1 virus-cell interaction in which the possible points where a drug can attack the virus are evident. The first simulation trials indicate that the presented model reproduces (even though in a simplified way) the features of the real behaviour that have been considered in the modelling phase. Although our simulation is limited in the knowledge it expresses, it still gives a stimulating opportunity for the evaluation of the criteria chosen as discriminant in the interaction between virus and cell.

We present a qualitative model of the interaction between HIV-1 virus and human cell, based on qualitative process theory. This model can be regarded as a first step for setting up a comprehensive model of the HIV 1 infection treatment in which the possible points where a drug can attack the virus are evidentiated. The first simulation trials indicate that the model reproduces the major features of the real behavior of the virus inside and outside the human cell.

A qualitative model of the short term glucose regulation system is presented. The model is based on the qualitative process theory, based on the concept of physical process defined by the property of causing changes in objects over time. The model has been successfully validated on inputs of several tests. It is intended to employ this model within a comprehensive system encompassing qualitative and quantitative aspects of modelling, building an environment useful for new treatment planning and for education.

The potential role of endogenous sex hormones in regulating hypothalamo-pituitary-adrenal (HPA) axis function was investigated after a single injection of endotoxin in adult (8 week old) BALB/c mice of both sexes. The effect of LPS on plasma ACTH, corticosterone (B), testosterone and oestradiol (E) levels and on anterior pituitary (AP) ACTH and adrenal B contents at different times after treatment was studied. The results indicate that: (a) basal B but not ACTH plasma levels were significantly higher in female than in male mice; (b) LPS significantly increased both ACTH and B plasma levels over the baseline 2 h after injection, both hormone levels being higher in female than in male mice; (c) although plasma ACTH concentrations recovered the basal value at 72 h after LPS in animals of both sexes, plasma B levels returned to the baseline only at 120 h after treatment; (d) E plasma levels significantly increased 2 h after LPS and returned to the baseline at 72 h post-treatment, in both sexes; (e) at 2 h after LPS, testosterone plasma levels significantly decreased in male mice and increased in female mice, recovering the baseline level at 120 and 72 h after LPS, respectively; (f) AP ACTH content was similar in both sexes in basal condition and it was significantly diminished 72 h post-treatment without sex difference; whereas AP ACTH returned to basal content 120 h after LPS in males, it remained significantly decreased in females; (g) basal adrenal B content was higher in female than in male mice, and it significantly increased in both sexes 2 h post-LPS, maintaining this sex difference. Whereas adrenal B returned to basal content 72 h after treatment in male mice, it remained significantly enhanced up to 120 h post-LPS in female animals. The data demonstrate the existence of a clear sexual dimorphism in basal condition and during the acute phase response as well as in the recovery of the HPA axis function shortly after infection.

We propose a new method for classification of marine bacteria. This method uses gaschromatograms, which contain information of fatty acid percentage contents of the fresh isolate. For the interpretation of these gaschromatograms we use a surpervisioned artificial neural network. We present a preliminary study on this matter, whose first results show good convergence and classification features.

We propose a new method for classification of marine bacteria. This method uses gaschromatograms, which contain information of fatty acid percentage contents of the fresh isolate. For the interpretation of these gaschromatograms we use a surpervisioned artificial neural network. We present a preliminary study on this matter, whose first results show good convergence and classification features.

This paper presents Visual Heuristics, a consultation system for diagnosis based on thorax radiograph recording. Visual Heuristics uses both prototypical representations of physiological and pathological states and reasoning aimed to infer conclusions from pathological or physiological conditions, establishing correspondences between pathological or physiological states and semantic descriptions of images. Images are assembled with groups of descriptors that guide the recognition process, achieving the possibility of comparisons with real images on the basis of 'expected' images. The system may be employed to generate a dynamic atlas that does not contain proper images, but generates them.

A qualitative model of cell growth, based on qualitative process theory, is presented. The model can be used to analyze the effects of the interaction of antiproliferative drugs on cells when the effects of each specific drug are known, mainly when designing multi-drug protocols for optimal cancer treatment.

A diagnostic-therapeutic protocol for colorectal haemorrhage is suggested. The Authors underline the need to remove inflammatory foci when a perforation of the colon occurs; furthermore, in the acute obstruction due to colorectal carcinoma a resection followed, when possible, by an immediate anastomosis is recommended.

Bilateral adrenalectomy (ADX) leads to increased ACTH synthesis and secretion. It is thought that endogenous glucocorticoids exert a feedback mechanism at both pituitary and brain levels. The present study has been performed in order to determine the effect of ADX on the release of hypothalamic neuropeptides with corticotropin-releasing activity (CRA) and if there exists a median eminence site of glucocorticoid action to regulate hypothalamic-pituitary-adrenal (HPA) function. Adrenalectomized and sham-operated male rats were killed at different periods after surgery (2, 5, 7 and 14 days) and trunk blood was collected for ACTH and corticosterone (B) concentrations measurement. Brain (median eminence, ME; and medial basal hypothalamus, MBH) and pituitary (anterior lobe, AP; and neurointermediate lobe, NIL) tissues were dissected in order to evaluate either peptide content or in vitro hormone release. The results indicate that ADX blunted plasma B levels and increased AP ACTH content and secretion in a time-related fashion up to the 14th day. ADX significantly decreased both CRF and CRA contents in the ME at all periods studied; ME arginine-vasopressin (AVP) increased 7 and 14 days after ADX. MBH CRF decreased after ADX, but returned to sham value 2 weeks later; similarly, MBH AVP decreased at all periods after ADX. Removal of endogenous glucocorticoids did not vary neither oxytocin (OXY) content in the ME and MBH nor AVP and OXY contents in the NIL. In our superfusion experiments, we found that ADX increased basal AVP release and did not change spontaneous CRF secretion from ME terminals. Dexamethasone (Dxm, 10 nM) diminished AVP but not CRF output by ME tissues from adrenalectomized rats. A direct relationship was found between ME CRF and 28 mM KCl (hK+)-induced CRF release by MEs from adrenalectomized rats. ME fragments from adrenalectomized rats were hyperresponsive to kH+ stimulation of AVP release. Dxm (10 nM) decreased the hK(+)-evoked CRF and AVP release by MEs from adrenalectomized rats. ADX and dexamethasone treatment did not influence basal and hK(+)-elicited ME OXY release. Additionally, a rapid glucocorticoid inhibitory effect on ACTH secretion by isolated AP cells from both sham and adrenalectomized rats was found, and an in vitro corticotrope hyporesponse to 0.63 nM CRF and 9.25 nM AVP stimulation during several days after ADX.(ABSTRACT TRUNCATED AT 400 WORDS)

The nuclear matrix (NM) is a salt and nuclease-resistant nuclear substructure. It is associated with active DNA transcription and has been shown to contain acceptor sites for steroid receptors in a number of specific target tissues. We have investigated the presence of acceptor sites for the androgen receptor (AR) in the NM of human newborn foreskin. The NM was prepared from the 800 g pellet by successive treatments with detergent, DNase and high salt extraction. It contained 13 +/- 7% of total proteins and 10 +/- 6% of total DNA. After extensive washing, the NM spheres were incubated in the presence of cytosol and [3H]methyltrienolone +/- 200-fold excess of unlabeled steroid. Maximal binding of the AR to NM was reached in 30 min and decreased slightly thereafter to reach an equilibrium which was maintained for 18 h. Binding was saturable. In the absence of AR, the steroid did not bind to NM. When Scatchard analysis was performed on cytosol previously incubated with NM, cytosolic binding capacity significantly decreased relative to preincubation values (3.6 +/- 1.9 to 1.3 +/- 1.2 fmol/mg protein, P less than 0.05, n = 6). In contrast, apparent binding affinity was not changed. 0.8 mg of NM protein could bind AR from 2.4 mg of cytosol protein. In conclusion, NM from human foreskin binds the AR with high affinity. This binding is rapid and is maintained for at least 18 h. This is consistent with a potential role of NM in the mechanism of action of androgens in their target tissues.

The labeling index (LI), representing the percentage of S-phase cells, was measured in the healthy colorectal mucosa of subjects without a personal or familial history of neoplasm as well as in persons with a positive history, and was compared to the LI in benign or malignant lesions in a total of 128 subjects. In the healthy mucosa, LI was lowest in control subjects; it rose progressively in patients with a personal history of adenoma, patients with non colorectal cancer, and colorectal cancer patients respectively. There was a significant increase in LI from healthy mucosa to adenoma to carcinoma. The pattern of labeling in the crypts was studied in 56 subjects with different familial and personal histories. Limitation of labeling to the deepest part of the crypts was observed in control subjects and to a lesser extent in the healthy mucosa of patients with adenoma. An upward shift of the proliferative zone was observed in patients with a personal or familial history of cancer; adenomatous lesions had an inverse labeling distribution: labeling decreased from the luminal aspect towards the deep segments. High LI values and a shift of the proliferative zone towards the surface of the crypt may identify individuals at high risk for cancer of the colon and rectum.