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Biomedical subjects

G Conti

Publications and source records attributed to G Conti.

At least 145 records · Page 8Linked to original sources
PubMed1994

The expression of CD59 in normal human nervous tissue.

The expression of CD59, a complement regulator of the formation and function of the terminal cytolytic membrane attack complex, was studied in human normal nervous tissue by immunohistochemical markers using two monoclonal antibodies 1F5 and MEM43. CD59 was present on Schwann cells, neurons and endothelial cells in the peripheral nervous system (PNS), and on Schwann cells in culture. In the central nervous system (CNS) CD59 was found predominantly on endothelial cells. There was also a diffuse staining of white and grey matter of the spinal cord and brain, presumably of microglia, oligodendrocytes, astrocytes and neurons, as these cells were CD59 positive in culture. Furthermore, CD59 was detected in the cerebrospinal fluid (CSF) of healthy individuals. CD59 in the PNS and CNS was glycosyl-phosphatidylinositol linked and had a molecular weight of 19,000-25,000. The presence of CD59 on various cells of the nervous system and in the CSF suggests that regulation of complement activation by this protein is important in neural host defence mechanisms.

Adult↗
PubMed1994

Leukotrienes and alpha tumor necrosis factor levels in the bronchoalveolar lavage fluid of patient at risk for the adult respiratory distress syndrome.

OBJECTIVE: To examine bronchoalveolar lavage (BAL) fluid of patients at risk for Adult Respiratory Distress Syndrome in the attempt to provide evidence of an increased local production of Leukotrienes (LTS) and Tumor Necrosis Factor (TNF). DESIGN: Prospective, comparative, clinical study. SETTING: ICU in a university hospital. PATIENTS: 14 patients at risk for ARDS and 10 control patients undergoing mechanical ventilation, were studied. INTERVENTION: BAL was performed in each patient at the time admission to the ICU (T0), and after 48 hours (T1). RESULTS: Our controls never showed levels of TNF > 10 pg/ml and their LTS amounts were always below the detection limit. All patients at risk had levels of TNF ranging between 22 and 130 pg/ml, but no difference was noticed between patients who developed ARDS and those who did not, between survivors and non survivors, and between septic and non septic patients. LTD4 and LTB4 (ranging between 30 to 1365 pg/ml) were detected only in six of the 14 patients. Among these 6 patients, 4 developed ARDS. In these patients we could correlate LTB4 with TNF levels and the number of neutrophils recovered from the BAL fluid. CONCLUSION: In our patients leukotrienes and TNF in the BAL fluid correlate well with the acute inflammatory phase of ARDS, as reflected by the increase number of leukocytes in the fluid retrieved, but they do not appear to be clearly predictive index for the syndrome.

Adult↗
PubMed1994

Perianal streptococcal dermatitis: two familial cases.

Two familial cases of perianal streptococcal dermatitis in a 3-year-old girl and her 5-1/2-year-old brother are reported. The clinical features of well-demarcated perianal erythema variably associated with itching, painful defecation with subsequent constipation, rectal bleeding, and proctitis are reviewed, together with suggestions for the best therapy.

Anus Diseases↗
PubMed1994

Effects of hyperbarism on central respiratory drive and respiratory pattern in humans.

The aim of our study was to evaluate the effects of increasing pressure (from 1 to 3 and 6 atm abs) on respiratory drive, respiratory pattern, and inspiratory impedance of the respiratory system. Seven healthy volunteers were studied during a dry compression to 6 atm abs in a hyperbaric multiplace chamber. We observed a significant increase in tidal volume, P0.1 (the pressure generated in the airway after 100 ms of inspiration against a closed inspiratory line), Ttot, and Ti, and a significant respiratory rate reduction with increasing pressure from 1 to 3 atm.abs; P0.1 also increased significantly when comparing 3 and 6 atm abs measurement with 1 atm abs. The P > 0.01 and P0.1/(VT/Ti) showed a significant progressive increase compared with 1 atm abs. In conclusion, the passage from 1 to 3 and 6 atm abs causes, in healthy subjects at rest, an increase in the central respiratory drive activity, evaluated with P0.1 measurement. The response to the respiration system is an increase in tidal volume and Ti with a decrease in respiratory rate.

Adult↗
PubMed1994

Radioimmune western blotting in comparison with conventional western blotting, second and third generation ELISA assays for the serodiagnosis of HIV-1 infection.

We compared the performance of second and third generation ELISA assays to detect antibodies to HIV-1 virus with conventional Western blotting (WB) and radioimmune Western blotting (RIWB). Both sera from commercial seroconversion panels and serial dilutions of a serum for HIV-1 antibodies were tested with Murex HIV Recombinant, Vidas bioMérieux HIV 1/2 (2nd generation ELISA) Murex HIV 1-2 (3rd generation ELISA), as well as with WB and RIWB. In seroconversion panels all ELISA assays were positive for the same serum with the exception of the first serum of Panel D which was negative with both sample Murex assays and borderline with Vidas assay. This serum was negative with WB but evidenced antibodies to gp160 p66, p51, p24 HIV-1 proteins when assayed by RIWB. In only two cases did WB reveal antibodies to HIV-1 proteins before ELISA assays (Panel A and E); not only did RIWB show the same sensitivity as WB in the two last panels, but it also detected antibodies to HIV-1 proteins earlier than WB, ranging from a few days (Panel C) to approximately 12 weeks (Panel D). The results obtained by testing the dilutions of the serum positive for anti HIV-1 antibodies showed the following degrees of sensitivity: Murex HIV 1-2 (the most sensitive), Murex HIV Recombinant and Vidas bioMérieux HIV 1/2. Although WB was more sensitive than the ELISA assays and picked out antibodies to gp160, gp120 and p24 HIV proteins at 1/4000 serum dilution, the most sensitive test was RIWB which at 1/20,000 serum dilution enabled detection of antibodies to gp160, p66 and p24 HIV proteins.

AIDS Serodiagnosis↗
PubMed1994

[Perianal streptococcal dermatitis].

Perianal streptococcal dermatitis is a childhood disorder caused by group A beta-hemolytic streptococci which was first described by Amren in 1966. The incidence of this dermatosis, characterized by well defined erythema in the perianal area, has certainly been underestimated and to the authors' knowledge there have still been no reports of this pathology in Italy. Perianal streptococcal dermatitis merits attention given that affected subjects do not always receive appropriate treatment and on average there is a 6-month lapse between the appearance of symptoms and diagnosis. The authors present two cases which were recently referred to their attention and discuss the methods of contagion, the difficulties of clinical diagnosis, associations with other streptococcal disorders and the treatment of this morbid condition.

Anus Diseases↗
PubMed1993

Use of heat and moisture exchanging (HME) filters in mechanically ventilated ICU patients: influence on airway flow-resistance.

OBJECTIVE: To investigate the flow-resistance of a new generation of Heat Moisture Exchanging Filters (HME filters) during 24 h of clinical use. DESIGN: Before-after trial. SETTING: A general Intensive Care Unit of a university hospital. PATIENTS: A consecutive series of 96 patients undergoing mechanical ventilation for respiratory insufficiency of various etiology and severity. METHODS: The characteristics of the secretions collected by tracheal suctioning and the pressure/flow relationship of the HMEs before and after 24 h of clinical use were analyzed. RESULTS: The resistance of the HMEs when dry was 2 hPa/l.s, and it increased to a maximum of 1 hPa/l.s in 83% of the patients after 24 hours; in four patients with particularly heavy secretions HME resistance was 4-5 hPa/l.s. There were no significant modifications of the secretions within the investigation period, excluding, in particular, an increase in density with consequent tracheal tube obstruction. CONCLUSION: The gas conditioning efficiency and design performance of the tested HMEs did not create a significant obstacle to airflow medium term mechanical ventilation; however, these devices should be cautiously used in patients with heavy bronchial secretions.

Adolescent↗
PubMed1993

Propofol induces bronchodilation in mechanically ventilated chronic obstructive pulmonary disease (COPD) patients.

The aim of this study was to evaluate the effects of propofol administration (2 mg.kg-1 i.v.) on the airways resistances and respiratory mechanics of patients affected by COPD exacerbation, requiring mechanical ventilation. Twenty patients required anaesthesia for diagnostic or therapeutic procedures. Fourteen consecutive patients were divided at random into two groups: Group P received propofol and Group C (control) received only Intralipid 10%; an additional group of six patients received i.v. flunitrazepam (0.03 mg.kg-1). Lung mechanics (dynamic and static compliance, peak inspiratory pressure, intrinsic positive and expiratory pressure, minimal and maximal resistances of the respiratory system) were evaluated in basal conditions and 3 and 6 min after propofol, Intralipid or flunitrazepam administration. We did not observe significant variations of the evaluated variables after Intralipid or flunitrazepam (Groups C and F), while in patients who received propofol (Group P), we observed the following modifications: dynamic compliance increased from 2.3 +/- 0.3 to 2.8 +/- 0.4 ml.kPa-1 (P < 0.05), peak inspiratory pressure decreased from 3.3 +/- 0.7 to 2.8 +/- 0.4 kPa (P < 0.05), minimal resistances of the respiratory system (that mainly reflect airways resistances) decreased from 1 +/- 0.2 to 0.7 +/- 0.2 kPa.l-1 x s-1 (P < 0.01). Our results suggest that propofol induces bronchodilation in mechanically ventilated COPD patients, and that this effect is not related specifically to the induction of general anesthesia.

Aged↗
PubMed1993

[Flaccidity and erection of the human penis: morphological data].

Erection of the human penis, a simple and at the same time complex phenomenon, requires the involvement of numerous sustaining mechanisms. This paper presents a summary of the morphological research work done by the author, mainly concerning the mechanisms regulating the blood flow distribution in the arteries and veins, the arteriovenous anastomoses, the two corpora cavernosa of the penis with their tunica albuginea, the urethral corpus spongiosum, the capsular membrane which envelopes the latter, and finally the paraurethral glands. Although it is true that the primary mechanism of penile erection is represented by the central and peripheral nervous system, it must not be forgotten that the basis for this phenomenon consists of the structures of the corpora cavernosa of the penis as well as all of the other penile morphological structures.

Humans↗
PubMed1993

Reaction of 1-aminophthalazines with alpha-halocarbonyl compounds: imidazo[2,1-a]phthalazines and their benzodiazepine receptor activities.

The one-pot synthesis and the benzodiazepine receptor binding activity of some imidazo[2,1-a]phthalazines bearing different substituents at position-2 and/or 3 and/or 6 is reported. The dissimilar binding results of the reported compounds are discussed in relation to the nature and/or position of the substituents on the tricyclic ring system.

Animals↗
PubMed1992

Detection of IgA and IgM antibodies to HIV-1 in neonates by radioimmune western blotting.

OBJECTIVE: To detect infection with HIV-1 by IgA and IgM response at birth in children born to HIV-1 seropositive mothers. DESIGN: Western blotting and radioimmune western blotting on stored sera from infected and uninfected babies born to HIV-1 seropositive mothers. Sera were pretreated to remove IgG. SETTING: Parma and Bologna, Italy. SUBJECTS: 12 infected and five uninfected babies born to HIV-1 seropositive mothers and three babies born to seronegative mothers. MAIN OUTCOME MEASURES: Effectiveness of western blotting and radioimmune western blotting in detecting antibodies to HIV-1 gene products. RESULTS: With conventional western blotting we found IgA class antibodies to HIV-1 proteins in serum from three out of 12 infected children; in two of these three the serum was collected at age 3 months (positive controls). Radioimmune western blotting detected both IgA and IgM antibodies in serum from all infected children tested, whereas all serum from uninfected children born to seropositive and seronegative mothers showed no such antibodies. CONCLUSION: Although the technique should be tested on more patients, radioimmune western blotting seems to be a valuable tool for serological diagnosis of congenital HIV-1 infection at birth in neonates born to seropositive mothers.

Blotting, Western↗
PubMed1992

Expression of genes encoding receptors for IgG (FcRIII) and for C3b/C4b (Crry) in rat sciatic nerve during development and Wallerian degeneration.

Northern blots were used to examine the expression of genes encoding receptors for IgG (FcRIII) and for C3b/C4b (Crry) in rat sciatic nerve during development and Wallerian degeneration. Steady state levels of FcRIII (1.4 kb) and Crry (1.9 and 2.1 kb) mRNAs were higher in adult rat nerves than in 6 day and 21 day postnatal rat nerves, indicating that the expression of these receptors is developmentally regulated. The FcRIII and Crry cDNA probes also hybridized with total RNA from 3 day old rat Schwann cells and from adult rat peritoneal macrophages. The size of the FcRIII mRNA expressed by cultured Schwann cells (1.6 kb) differed from that expressed by peritoneal macrophages (1.4 kb); the two may be splice variants of one transcript or products of related genes. Peritoneal macrophages contained approximately 100 times higher FcRIII mRNA levels than Schwann cells. In contrast, steady state levels of both 1.9 and 2.1 kb Crry mRNAs were similar in cultured Schwann cells and macrophages. Nerve transection induced a generalized increase in the level of sciatic FcRIII mRNA (1.4 kb) 3 days post-surgery, whereas the level of Crry mRNA was increased only in the nerve segment immediately to the cut. The increase of FcRIII mRNA that occurred in Wallerian degeneration was most likely due to infiltration of macrophages, as FcRIII mRNA-positive macrophages were demonstrated in the degenerating nerves by in situ hybridization. FcRIII mRNA-positive macrophages were not found in normal nerve. The functions of FcRIII and Crry in peripheral nerves are uncertain, but they may be of significance in phagocytosis, antibody-dependent cellular cytotoxicity, and in local immune regulation.

Aging↗
PubMed1992

A fibre optics system for the evaluation of airway pressure in mechanically ventilated patients.

OBJECTIVE: The present study was intended to evaluate the "in vivo" endotracheal (ET) tube resistance and respiratory mechanics in mechanically ventilated patients with respiratory failure by using fiber optic catheters. DESIGN: Two fiber optic catheters, consisting of a thin probe with a pressure transducer on the tip, were used. The first was placed at the proximal side of the ET tube and the second was positioned distally beyond the end. A low compliant air-filled catheter connected to a traditional pressure transducer was placed close to the proximal fiber optic device to compare the pressure values obtained with both systems. SETTING: The study was performed in the General Intensive Care Unit of Rome "La Sapienza", University Hospital. PATIENTS AND PARTICIPANTS: Seven patients admitted for the management of acute respiratory failure of different etiologies were included in the protocol. All the patients were intubated and mechanically ventilated for at least 48 h prior to the investigation. MEASUREMENTS AND RESULTS: The endotracheal tube resistance was obtained both by the end-inspiratory occlusion method and measuring pressure proximally and distally to the ET tube. The measurement of respiratory mechanics was obtained proximally and distally to the ET tube. Different flows and tidal volume changes were performed. The results showed that the fiber optic device gives an adequate evaluation of airway pressure and the possibility for an easy detection of obstructions and/or deformations of the ET tube. The area described by inspiratory and expiratory pressure recorded at both sides of the ET tube showed a positive relationship between the surface and flows while no surface changes were shown when the tidal volumes were modified. Thoraco-pulmonary compliance measured proximally and distally to the ET tube gave rise to a small and statistically insignificant difference. CONCLUSION: This study confirms that 48 h after the positioning of ET tubes the airflow resistance is significantly higher than might be expected from the "in vitro" data. The presence of the endotracheal tube can interfere with the evaluation of thoraco-pulmonary mechanics, particularly in dynamic conditions. The fiber optic system represents an interesting and simple tool for the evaluation of ET tube resistance and pulmonary mechanics in patients undergoing mechanical ventilation.

Adult↗
PubMed1992

The induction of mitotic chromosome malsegregation in Aspergillus nidulans. Quantitative structure activity relationship (OSAR) analysis with chlorinated aliphatic hydrocarbons.

The biological activity of 24 chlorinated aliphatic hydrocarbons has been studied in the mold Aspergillus nidulans. The ability to induce chromosome malsegregation, lethality and mitotic growth arrest has been experimentally determined for each chemical. These data, together with those of 11 related compounds previously investigated, generated a data base which was used for quantitative structure-activity relationship (QSAR) analysis. To this aim, both physico-chemical descriptors and electronic parameters of each compound have been calculated and included in the analysis. The QSAR analysis indicated that toxic effects induced by chlorinated aliphatics in A. nidulans are mainly dependent on steric factors, as indicated by the correlation with molar refractivity (MR). Conversely, the ease with which they accept electrons, parametrized by LUMO (energy of the lowest unoccupied molecular orbital), plays a prevailing role in determining the aneuploidizing properties. An involvement of free radicals, generated by the reductive metabolism of haloalkanes, is hypothesized as an explanation of the data.

Aneuploidy↗