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Biomedical subjects

C Ruggiero

Publications and source records attributed to C Ruggiero.

At least 55 records · Page 3Linked to original sources
PubMed1994

Qualitative reasoning for AIDS treatment.

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.

Acquired Immunodeficiency Syndrome↗
PubMed1993

A qualitative model of the dynamics of blood glucose and its hormonal control.

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.

Blood Glucose↗
PubMed1993

Isolation of T-cell clones with specificity for arterial antigen from spontaneously hypertensive rats.

OBJECTIVE: It has been postulated that hypertension in the spontaneously hypertensive rat (SHR) results from autoimmune damage to the SHR vasculature. The objective of this study was to isolate autoreactive T-cells specific for arterial antigens, and to characterize these cells. DESIGN: The presence of autoreactive T-cells in the SHR has not been studied previously. Lymphocytes were isolated from spleens obtained from SHR and Wistar-Kyoto (WKY) rats aged 4, 8, 12, 16, 20, 24 and 28 weeks. METHODS: Limiting dilution analysis was used to clone and to establish arterial antigen-reactive T-cell clones. The specificity of these clones was assessed by measuring lymphokine production and T-cell proliferation induced by arterial antigen and by irrelevant control antigens. RESULTS: All of the SHR, regardless of age, possessed arterial antigen-specific CD4+, major histocompatability complex class II-restricted T-cells. The responses of freshly isolated spleen cells to arterial antigen were weaker than the proliferative responses of interleukin-2-expanded T-cells to arterial antigen. The T-cell clones also produced interleukin-2, interleukin-4 and interferon-gamma in response to arterial antigen. However, the presence of T-cells specific for arterial antigen is not unique to SHR, since a similar response was seen in normotensive WKY rats. CONCLUSIONS: The results indicate the existence of T-cells specific for arterial antigen in the spleens of both SHR and WKY rats. Thus, arterial antigen-reactive T-cells cannot be the initial cause of hypertension, but the activation of such autoreactive T-cells might be important in the development of hypertension.

Aging↗
PubMed1993

Peptides secondary structure prediction with neural networks: a criterion for building appropriate learning sets.

Artificial neural networks have been recently applied with success for protein secondary structure prediction. So far, one of the two main aspects on which neural net performance depends, the topology of the net, has been considered. The present work addresses the other main aspect, the building up of the learning set. We present a criterion to build up suitable learning sets based on the alpha-helix percentage. Starting from a set of several well known proteins, we formed 7 groups of proteins with similar helix percentages and we used them for the learning of the same neural net. We found that the best secondary structure prediction for each of the tested proteins (not belonging to the initial set) was the one obtained using the learning set whose helix percentage was closest to that of the tested protein. The accuracy of correct prediction of our method on three types of secondary structure (alpha-helix, beta-sheet and coil), has been compared with the accuracy of other secondary structure prediction methods.

Algorithms↗
PubMed1993

The effects of PEG-interleukin-2 and interleukin-2 on essential hypertension and cellular immune function in the spontaneously hypertensive rat.

The effects of recombinant human interleukin-2 covalently linked to polyethylene glycol (PEG-IL-2) or interleukin-2 (IL-2) on hypertension and in vitro suppressor T cell function in the spontaneously hypertensive rats (SHR) were investigated. Male young prehypertensive (4 weeks old) SHRs and adult (10 weeks old) SHRs with established hypertension were injected with low (5,000 units (u)/kg) or high (50,000-100,000 u/kg) dose of PEG-IL-2 or IL-2 as a single bolus or repeated injections. Systolic blood pressure was measured twice weekly using the tail-cuff technique. Systolic blood pressure in the PEG-IL-2 or IL-2 treated animals, irrespective of age, dose, or route of injection, did not differ significantly from that measured in vehicle-treated controls over a 10 week period. Mean arterial pressure measured by intra-arterial catheter was 159 +/- 7 mm Hg 10 weeks after treatment with repeated injections of 5,000 u/kg of PEG-IL-2 and 158 +/- 9 mm Hg in vehicle-treated controls. All rats injected with IL-2 had IL-2-specific IgG antibody in their sera. None of the PEG-IL-2 treated rats had any detectable anti-IL-2 antibodies in their sera. Thus, PEG-IL-2 showed far less immunogenicity than IL-2. Suppressor T (Ts) cells generated from adult SHR spleen cells failed to suppress pokeweed mitogen (PWM)-driven immunoglobulin G (IgG) synthesis. PEG-IL-2 or IL-2 supplementation both in vitro and in vivo restored the ability of adult SHR to generate Ts cells able to inhibit IgG synthesis. Our data suggest that PEG-IL-2 or IL-2 administration does correct a prominent defective Ts cell activity found in adult SHR, but that correction of this immune abnormality is not attended by an attenuation of hypertension.

Age Factors↗
PubMed1993

Interpretation of gascromatographic data via artificial neural networks for the classification of marine bacteria.

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.

Algorithms↗
PubMed1992

Abnormal activation and loss of suppressor T cells in the spontaneously hypertensive rat.

Suppressor T cell function in the spontaneously hypertensive rat (SHR) and normotensive Wistar Kyoto (WKY) rats was analyzed using syngeneic mixed lymphocyte reaction (SMLR) and concanavalin A (Con A) activation. A depressed SMLR was found in adult SHR but not in adult WKY. IL-2 synthesized by SHR was 40-fold lower than that of WKY, and the suppressor T cells generated in the SMLR were incapable of suppressing IgG synthesis. Precursors of cells that can be activated by Con A to become functional suppressor cells are reduced in adult SHR. Supernatant fluids derived from Con A-activated spleen cells from adult SHR failed to significantly inhibit IgG synthesis by cultures of syngeneic spleen cells compared to supernatant fluids from young SHR or WKY Con A-activated spleen cells. However, spleen cells from both adult SHR and WKY proliferated strongly and released equivalent amounts of IL-2 in response to Con A. Addition of exogenous IL-2 to the SMLR cultures in vitro restored the ability of SHR T cells to respond in the SMLR, with generation of cells capable of suppressing IgG synthesis. Administration of SHR with IL-2 in vivo also restored the suppressor T cell function in the SMLR. These results suggest a defective suppressor T cell activation and loss of suppressor T cell activity as the SHR age.

Animals↗
PubMed1992

[The shape of the nasopharynx in youth: statistical study].

The particular shape of the nasopharynx in the child can influence morphology and physiopathologic behaviour of the mucosa. In such a perspective, it appeared interesting to evaluate the kind and the entity of its variations by means of nuclear magnetic resonance (NMR) in 50 patients (age range: 2 months-16 years). The results show that the nasopharyngeal shape (represented either by bending radius and shape factor) varies in a statistically significant way during the considered age range, while the dimension of the pharyngeal tonsil remains constant in the studied cases. The statistically significant shape variation of the tonsil appears, so, related to its involvement in the shape variation of the whole nasopharynx.

Adolescent↗
PubMed1992

[Dimensions of the human aortic arch and thoracic aorta studied by nuclear magnetic resonance].

The size of the aortic arch and thoracic aorta was measured in 50 healthy volunteers studied by NMR. In each case the following parameters were measured and statistically elaborated: diameter (in mm) of ascending aorta (between onset and arch beginning), of aortic arch (intermediate zone), of isthmus, of descending aorta (between isthmus and diaphragm), of diaphragmatic isthmus; a mean diameter was also calculated, and for every diameter mean and standard deviation were obtained. Moreover, the length (in mm) of superior and inferior contours of the aortic arch, as the ratio of these two values were obtained. At last, total length of considered aortic tract, area of visualized surface and theoretic volume were obtained. For each parameter a diagram was then plotted, with age in ordinates and values of above mentioned parameters in abscissae. Statistical evaluation allows to affirm that the size of the aorta grows with ageing. On the contrary, the ratio between superior and inferior contour of the aortic arch tends to remain unvaried; this fact seems to disagree with the current opinion that the superior wall of the arch grows with age more than the inferior one.

Adolescent↗
PubMed1992

[Psychic disorders. An unknown complication of surgery of the posterior cranial fossa].

Psychic trouble is not generally recognised as a possible complication of posterior fossa surgery. Reviewing a series of 63 pediatric patients operated on for posterior fossa intraxial tumors, the Authors found 21 cases of psychic troubles in the post-operative period. The incidence was higher in: a) medulloblastoma; b) rostral vermis location; c) supracerebellar infratentorial and transvermian approach. The neuropathophysiological basis of the phenomenon is discussed.

Brain Neoplasms↗
PubMed1992

[Severe head trauma in the pediatric patient. Our experience].

A retrospective study in a pediatric population of 324 severe head trauma patients hospitalized at Santobone Children's Hospital has been carried out; diagnostic investigations and therapeutic aspects are stressed on the baw of pathophysiological features of such patients.

Brain Injuries↗
PubMed1991

A qualitative approach to cell growth modeling and simulation for cancer chemotherapy.

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.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Anesthesia in the diagnostic stages of cerebral arteriovenous malformations in children under 3 years of age].

From 1974 through 1989, 36 patients with arteriovenous malformations were treated in the neuroradiological unit of the Santobono Children's Hospital, in Naples, 7 of these patients were younger than 3 years of age. During such a time-span, dramatic improvements in diagnostic work-up were jelded by introduction of CT-scan and MRI; better angiographic techniques, progress in anaesthesia drugs, equipment and procedures and more rational surgical modalities. Anaesthesia must be tailored in each patient with special consideration of the clinical and neurological conditions of the patients as well of the neuroradiological procedure, specifically, with minimal side effects on cardiovascular and respiratory functions as well on intracranial pressure. The present paper discuss of equipment for cardiovascular assistance and drugs to be employed in the various steps of the diagnostic work-up of such patients.

Anesthesia, General↗
PubMed1990

[Peroperative recovery in surgery of arteriovenous malformations in children under the age of 3 years].

From 1974 through 1989, 36 patients with arteriovenous malformations were studied in the neurosurgical department of the Santobono Children's Hospital in Naples; 7 of these patients were younger than three years of age: 5 underwent surgery. The remaining 2 patients presented, respectively, an aneurysm of the vein of Galen and an arteriovenous malformation of the brain stem. Improvements in surgical and anesthesiological techniques allow to treat lesions considered as not amenable to surgery until recent years, with minimal occurrence of preoperative and postoperative complication and a significant amelioration of prognosis.

Anesthesia, General↗
PubMed1989

Hematopoietic bone marrow recovery after radiation therapy: MRI evaluation.

Magnetic resonance imaging (MRI) is able to detect the increase of adipocytes in the hematopoietic bone marrow that occurs as a consequence of radiotherapy and is indicative of the loss of myeloid tissue. By monitoring this process, it is also possible to determine the recovery of the bone marrow. The amount of viable hematopoietic tissue plays a fundamental role in determining whether the patient is able to undergo further antineoplastic therapy, particularly chemotherapy. We examined 35 patients who had been treated with radiotherapy for Hodgkin's lymphoma (12), uterine cervix carcinoma (nine), ovarian dysgerminoma (six), testicular seminoma (four), and non-Hodgkin's lymphoma (four). We observed that radiation-induced modifications of the MRI pattern in the bone marrow are tightly linked to two parameters; the administered radiation dose and the length of time passed after the treatment. Bone marrow recovery was observed only when patients were treated with doses lower than 50 Gy. The earlier radiation-induced modifications of the bone marrow MRI pattern occurred 6 to 12 months after irradiation, and they were most evident 5 to 6 years after the treatment. From 2 to 9 years after radiotherapy, we observed partial recovery. Complete recovery, when it occurred, was observed only 10 to 23 years after the treatment. Our results indicate that MRI studies are likely to be useful in the assessment of radiation-induced injuries.

Bone Marrow↗
PubMed1989

Artificial intelligence techniques for the control of cancer cells.

NEWCHEM, an artificial intelligence system for the control of cancer cell growth, is described. This system takes into account the most recent advances in molecular and cellular biology and in cell-drug interaction, and aims to develop optimal strategies for the selective control of cancer cell through qualitative reasoning from first principles at cellular level.

Computer Simulation↗