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Biomedical subjects

A Sala

Publications and source records attributed to A Sala.

At least 163 records · Page 9Linked to original sources
PubMed1993

Antimicrobial resistance among clinical isolates of Haemophilus influenzae in northern Italy. Collaborative Study on Pediatric Infectious Diseases.

Only scanty data are available on the susceptibility of Haemophilus influenzae in Italy. The in vitro activity of ampicillin, ampicillin-sulbactam, cefaclor, cefuroxime, cefotaxime, chloramphenicol, erythromycin and trimethoprim-sulfamethoxazole against 327 strains of Haemophilus influenzae (55 encapsulated, 272 non-typeable) isolated from adults and children in northern Italy, between January 1984 and December 1989, was compared. Patients were affected by meningitis or other invasive infections, conjunctivitis, otitis, sinusitis, pneumonia or bronchitis. Minimal inhibiting concentrations were determined by a microdilution technique in Mueller Hinton broth supplemented with 10 microliters/ml NAD and 2-5% lysed horse blood. A concentration of 1 x 10(5) to 5 x 10(5) CFU/ml was used as the inoculum. The antibiotics were tested at concentrations ranging from 0.03 to 64 microliters/ml with the exception of trimethoprim-sulfamethoxazole, for which the range of concentrations examined were 0.01/0.25 to 32/512 microliters/ml. All the strains tested were susceptible to ampicillin-sulbactam, cefuroxime and cefotaxime, and more than 95% were susceptible to ampicillin, cefaclor and chloramphenicol. Only 4% were susceptible to erythromycin but most minimal inhibiting concentrations fell into the intermediate category. Strains isolated from adults were more susceptible to trimethoprim-sulfamethoxazole than strains isolated from children (85% vs 66%; p = 0.011).

Adult↗
PubMed1993

Intracardiac ectopic thyroid: conservative surgical treatment.

The case of a patient with an intracardiac ectopic thyroid is reported. A cardiac tumor was found in a 66-year-old woman and was diagnosed by two-dimensional echocardiography. An intraoperative biopsy was performed, and the mass was recognized as an ectopic thyroid and treated with a conservative surgical approach because of the size, location, and relationship to adjacent structures. The 60-month follow-up shows normal echocardiographic images and the good clinical status of the patient.

Aged↗
PubMed1993

Formation of sulphidopeptide-leukotrienes by cell-cell interaction causes coronary vasoconstriction in isolated, cell-perfused heart of rabbit.

1. We have studied the transcellular biosynthesis of bioactive leukotrienes (LTs), generated upon blood cell-vascular wall interactions and their functional consequences, in the spontaneously beating, cell-perfused, heart of the rabbit. Rabbit isolated hearts were perfused under recirculating conditions (50 ml) with 5 x 10(6) cells of unpurified (buffy coat) or purified human neutrophils (PMNL), and challenged with 0.5 microM A23187 for 30 min. Coronary perfusion pressure (CPP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP) and left ventricular pressure (LVP) were monitored continuously. Leukotriene formation was measured by specific enzyme-immunoassay and confirmed by reversed phase h.p.l.c. and u.v. spectral analysis. 2. Basal CPP values averaged 44 +/- 1.4 mmHg; A23187 triggered a marked increase in CPP both in the presence of buffy coat cells (+100% above basal) and PMNL (+270% above basal); the latter change in CPP was accompanied by a rise in LVEDP (+138% above basal). 3. The increase in CPP was preceded by a statistically significant rise in iLTC4-D4 concentration in the circulating buffer. Pretreatment with two structurally unrelated LTD4 receptor antagonists, LY171883 and SKF104353 (10 microM), fully prevented the increase in CPP and LVEDP. A similar protection was also observed when the rabbit heart was perfused with PMNL that had been pretreated with MK886 (1 microM), a potent inhibitor of leukotriene biosynthesis. 4. The increased coronary tone was accompanied by a marked release of lactate dehydrogenase (LDH), a marker of ischaemic damage; pretreatment of the heart with the LTD4 receptor antagonists as well as of the PMNL with MK886 resulted in a complete suppression of LDH activity release. 5. Positive identification of LTC4-D4 in the perfusates was obtained and a significant correlation observed between the CPP values and iLTC4-D4 concentrations.6. This study suggests that challenge of PMNL present within the coronary vasculature, causes a LTD4-dependent coronary vasoconstriction, favoured by an efficient uptake of PMNL-derived LTA4 by endothelial cells. The activation of the 5-lipoxygenase pathway in the context of tight interactions between blood cells and coronary vasculature, is suggested to have an important outcome in the alterations of coronary flow and cardiac contractility.

Animals↗
PubMed1993

[Process assessment in the care for patients with chronic degenerative disease in a basic health unit].

The efficacy of health actions, related to arterial hypertension and used as a strategy to decrease morbimortality due to cardiovascular diseases, in accordance with the "risk approach" and carried out in a Primary Health Care Clinic is assessed. These actions are based on the detection of arterial hypertension in the adult population attended at the Clinic and on the control of blood pressure levels in hypertensive individuals in which other known risk factors continue to be controlled, as well as on further treatment of eventual complications. Data relating to the 3,793 patients who were attended at least once by doctors of the adult sector of a training health-center located in S. Paulo county (Brazil) during the period from June 1990 to May 1991, inclusive, were evaluated. This evaluation was made according to each diagnosis undertaken as well as to the concentration of each type of consultation whether occasional, or follow-up. Of these 3,793 patients analysed, 839 presented arterial hypertension and/or diabetes, and were grouped into four categories: the exclusively hypertensive, the hypertensive with other associated chronic diseases (except diabetes), the diabetic and the diabetic with arterial hypertension. The results of this study brought the following aspects to light: 1) The low coverage of hypertensive individuals and diabetics being attended by the health service when only the population attended by the health service is taken into consideration. 2) The incidence of patients diagnosed as hypertensive in occasional consultations who did not return to the health service for medical follow-up indicates the difficulties involved in attracting such individuals permanently.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Regulation of BALB/c 3T3 fibroblast proliferation by B-myb is accompanied by selective activation of cdc2 and cyclin D1 expression.

The B-myb gene is expressed in many cell types at the G1/S transition of the cell cycle. Inhibition of B-myb expression in BALB/c 3T3 fibroblasts by introduction of a B-myb antisense construct greatly diminished cell proliferation, whereas constitutive expression of a human B-myb cDNA in these cells reduced their growth factor requirements and induced a transformed phenotype. Constitutive expression of B-myb cDNA was accompanied by activation of cyclin D1 and cdc2 expression but not of cyclin A and cyclin B. Transfection of BALB/B-myb cells (a cell line expressing high levels of exogenous human B-myb) with a cyclin D1 antisense construct drastically reduced cloning efficiency of these cells. These results suggest that the B-myb-encoded product regulates fibroblast proliferation by activating cdc2 and cyclin D1 gene expression and that abnormal expression of cyclin D1 might be a step in the process of transformation.

3T3 Cells↗
PubMed1992

Inhibition of Friend leukemia cell visceral metastases by a new monoclonal antibody and role of the immune system of the host in its action.

We developed a syngeneic mouse IgG2a monoclonal antibody (MAb) A9D41 directed against the Friend leukemia virus envelope gp70 antigen present on the cell surface membranes of virus producer 3C18 Friend leukemia cells (FLC). A9D41 showed a marked antitumor activity in DBA/2 mice given injections of gp70 positive 3C18 FLC, but it was ineffective in mice given injections of gp70 negative 745 FLC or unrelated tumor cells. A9D41 was particularly effective in inhibiting the development of 3C18 FLC liver and spleen metastases. MAb was also effective as adjuvant therapy in inhibiting visceral metastases after excision of an established s.c. FLC tumor, and combined therapy of A9D41 with mouse interferon alpha/beta was more effective than MAb or interferon alpha/beta alone. The immune system of the host played a decisive role in the antimetastatic action of A9D41. Thus, although MAb was cytotoxic for 3C18 FLC in vitro in the presence of rabbit complement, the F(ab')2 fragment was ineffective in vivo, and the antitumor effect of MAb was abolished in mice treated with an antibody to CD4 and diminished in natural killer cell-deficient beige and athymic nude mice. MAb-treated mice surviving injection of FLC developed an immune response to 3C18 FLC.

Animals↗
PubMed1992

Intraduodenal absorption in the rabbit of a novel heparin salt.

The intraduodenal absorption of a new low-molecular-weight heparin (LMWH) diamine salt (ITF 1331) was compared with the parent compound ITF 1060 and with sodium LMWH, in anaesthetized rabbits. The administration of either salt, but not of sodium LMWH, resulted in a dose-related increase in plasma anti-Xa activity. In this respect ITF 1331 was slightly superior to ITF 1060, and in acute-toxicity studies the counterion itself (ITF 258) was less toxic than that in ITF 1060 (counterion No. 4). These data confirm that a tertiary diamine within the counterion is an important structural requirement for the bioavailability of heparin by the intraduodenal route, and suggest that ITF 1331 may represent an important advance in the search for an oral heparin.

Animals↗
PubMed1992

[The use of the inferior epigastric artery as alternative conduit for myocardial revascularization: our experience].

When complete revascularization can not be obtained with the internal mammary artery and saphenous veins, the inferior epigastric artery may be an excellent alternative conduit. We describe our experience with this conduit, review the anatomy of this artery, and present the evolution of our harvesting technique through a pararettal approach. Proximal anastomoses were made first with the aid of an oval cuff of the common femoral artery (5 cases, Group A). Two patients (40%) of this group studied postoperatively revealed a graft occlusion. In the last 13 cases (Group B) we tailored the proximal anastomoses directly to the aorta. All patients studied postoperatively showed patent inferior epigastric artery grafts. There were no hernias and no deaths. Inferior epigastric artery can be considered a good alternative conduit in myocardial revascularization.

Abdominal Muscles↗
PubMed1991

Structural identification of cytochrome P450-dependent arachidonate metabolites formed by rabbit medullary thick ascending limb cells.

The medullary thick ascending limb of Henle's loop (mTALH) contributes importantly to the regulation of extracellular fluid volume and composition and metabolizes arachidonic acid (AA) chiefly by a cytochrome P450 monooxygenase pathway. Rabbit mTALH cells, when incubated with radiolabeled [14C]AA, form products that segregate into two peaks designated P1 and P2 based on their reverse-phase high pressure liquid chromatography retention times. We have now definitively identified their chemical structures. mTALH cells, isolated from the rabbit outer medulla, were homogenized and incubated with [14C]AA in the presence of NADPH. The AA metabolites in P1 and P2 were identified by gas chromatographic-mass spectrometric methods, including fast atom bombardment, negative ion electron capture, and electron ionization. All mass spectrometric data, the lack of UV chromophores, and comparisons with authentic standards were consistent with P1 containing two principal components: 19-hydroxy-5,8,11,14 eicosatetraenoic acid (19-HETE) and 20 - hydroxy - 5,8,11,14 - eicosatetraenoic acid (20-HETE), P2 contained primarily 1,20-eicosa-5,8,11,14-tetraenedioic acid (20-COOH-AA). The biological properties of P1 and P2 were compared with those of the authentic standards of 19- and 20-HETE and 20-COOH-AA. P1 dose dependently relaxed precontracted mesenteric arterial rings, as did authentic (19S)- and (19R)-HETE, whereas 20-HETE relaxed at lower and contracted at higher concentrations. As P1 contained a mixture of 19- and 20-HETE, each of these AA metabolites presumably contributed to the vascular relaxation produced by P1. Neither P2 nor 20-COOH-AA exhibited vasoactivity, but each demonstrated a similar potency in inhibiting rabbit medullary Na(+)-K(+)-ATPase activity. As previously reported, P2 was a more potent inhibitor of Na(+)-K(+)-ATPase than P1. The lesser inhibitory activity of P1 presumably reflects the presence of similar amounts of 19-HETE, the least active metabolite, and 20-HETE, which resembles 20-COOH-AA in its capacity to inhibit Na(+)-K(+)-ATPase. Thus, the biological activity of the less polar peak, P1, can be accounted for by 19- and 20-HETE, and that of P2, by 20-COOH-AA.

Animals↗
PubMed1991

Host humoral and cellular immune mechanisms in the continued suppression of Friend erythroleukemia metastases after interferon alpha/beta treatment in mice.

DBA/2 mice were injected intravenously with 2 x 10(6) 3C18 Friend erythroleukemia cells (FLC), a cell line resistant to interferon alpha/beta (IFN-alpha/beta). Although daily administration of mouse IFN-alpha/beta markedly increased the mean survival time, most IFN-treated mice continued to harbor FLC in different organs. To investigate the mechanisms responsible for this persistent suppression of FLC growth in IFN-treated mice, we undertook a series of adoptive transfer experiments with sera and spleen cells. Sera from FLC-injected, IFN-treated mice were very effective in conferring protection on DBA/2 mice even when injected systemically (intravenously) 18-24 h before intravenous challenge with FLC. These sera also exhibited antitumor activity when injected subcutaneously or intraperitoneally together with FLC. The protective factor in serum was shown to be an immunoglobulin. FLC-injected, IFN-treated mice developed antibodies to FLC demonstrable by radioimmunoassay and complement-dependent cytotoxicity. Sera from these mice recognized a specific 65-kD FLC membrane antigen(s) not detectable on membrane extracts from RBL-5 or ESb tumor cells, or on normal spleen cells. FLC-injected, IFN-treated mice also developed a specific cellular response demonstrable by transfer of protection with spleen cells injected intravenously or subcutaneously. Analysis of the responsible spleen cell populations indicated that the effector cells were neither T nor B cells. These results demonstrating the importance of host humoral and cellular immune mechanisms in the persistent suppression of FLC in IFN-treated mice may be relevant to the use of IFN-alpha/beta in patients in whom tumors may regress and tumor cells may then remain latent for extended periods of time.

Animals↗
PubMed1991

Direct airway injury results in elevated levels of sulfidopeptide leukotrienes, detectable in airway secretions.

Sulfidopeptide leukotrienes (LTC4/D4/E4) are suspected to be important lipid mediators in inflammatory responses in the lung. Previous investigations have provided evidence to support enhanced synthesis and secretion of these eicosanoids into bronchoalveolar lavage fluid in patients with Adult Respiratory Distress Syndrome (ARDS). We have prospectively examined the relationship between sulfidopeptide leukotriene levels in tracheal aspirates of 14 intubated and mechanically ventilated patients. When compared with the aspirate from one patient who required ventilation because of respiratory muscle weakness, the tracheal aspirates from eight ARDS patients had elevated leukotriene levels (range 2020-2052 pg/aspirate). However, the aspirates from four of the five patients with direct airway injury [inhalational burn (n = 3) and massive aspiration of gastric contents (n = 2)] contained significantly higher amounts of sulfidopeptide leukotrienes (range 10309-52244 pg/aspirate). Three of the five patients with direct airway injury did not develop ARDS. We conclude that simple aspiration of tracheal secretions can be used to monitor airway leukotriene biosynthesis in patients with lung injury and that elevated airway leukotriene levels may reflect airway epithelial damage, but may not predict the development of ARDS.

Adult↗
PubMed1991

Systemic to pulmonary bronchial blood flow in mitral stenosis.

We measured systemic to pulmonary bronchial blood flow [Qbr(s-p)] during total cardiopulmonary bypass in 15 patients with mitral stenosis and elevated pulmonary venous pressure (group A, mean pulmonary wedge pressure = 22.2 +/- 5.4 mm Hg, mean +/- SD) and in 15 patients with coronary artery diseases and normal pulmonary venous pressure (group B). Qbr(s-p) is the volume of blood accumulating in the left side of the heart in the absence of pulmonary and coronary flows. This blood was vented through a cannula introduced into the left atrium and measured. Qbr(s-p) was 76.3 +/- 13.9 ml/min (2.18 +/- 0.37 percent of extracorporeal circulation pump flow) and 22.3 +/- 2.1 (0.63 +/- 0.15) in group A and B, respectively (p less than 0.01). During total cardiopulmonary bypass, pulmonary venous pressure is approximately atmospheric pressure, and no differences in systemic blood pressure, extracorporeal circulation pump flow, and airways pressure were observed between group A and B. Therefore, vascular resistance through the bronchial vessels draining into the pulmonary circulation is reduced in patients with mitral stenosis and elevated pulmonary venous pressure.

Adult↗
PubMed1991

In-vitro susceptibility of Haemophilus influenzae to loracarbef (LY 163892) and other oral antibiotics. Collaborative Study Group on Pediatric Infectious Disease in Lombardy.

Data on susceptibility of Haemophilus influenzae are scanty in Italy. We compared the activity of loracarbef (Ly 163892), a new carbacephem, with that of 4 other agents against 265 strains of H. influenzae (46 type b, 219 nontypable) isolated from adults and children at Istituti Clinici di Perfezionamento of Milano, between 1/1/84 and 1/1/89, and also from 7 children at pediatric departments in Lombardy during 1988. In adults 72 strains were all isolated from sputum of patients with pneumonia or chronic bronchitis; in children 199 strains were isolated from conjunctiva (53% of the patients had also a concomitant respiratory infection), 24 from middle ear, 18 from sputum and 32 from blood or cerebrospinal fluid. Minimal inhibiting concentrations (MIC) were determined by the broth microdilution technique. The incidence of resistance of H. influenzae to ampicillin was 3.8%; the lowest percentage of resistance was found for loracarbef (0%) and the highest for erythromycin (94% for strains isolated from children and 97% for strains isolated from adults).

Adult↗