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Biomedical subjects

F Meloni

Publications and source records attributed to F Meloni.

At least 109 records · Page 6Linked to original sources
PubMed1983

[Polymyalgia rheumatica and giant cell arteritis, clinical and histopathological study of three cases].

We report three patients with giant cell arteritis but no clear clinical signs of temporal artery involvement, during an episode of polymyalgia rheumatica. In the first case a biopsy performed upon an apparently normal temporal artery showed a typical hortonian arteritis. The same finding was obtained from a pulseless right temporal artery in the second patient, who suffered a sudden blindness of right eye after a trigeminal neuralgia. In the third case the polymyalgic symptoms developed together with a syndrome of the aortic arc. The histologic findings of the temporal artery were normal, whereas the biopsy performed on both the subclavian arteries during surgical revascularization demonstrated a typical giant-cell arteritis in the acute stage. The cases mentioned above confirm that there is a close relation between polymyalgia rheumatica and Horton arteritis. In the latter the temporal localization could be inconstant.

Aged↗
PubMed1982

Studies on trypsin activation of inactive renin in rat plasma.

The experimental conditions of trypsin activation of inactive renin in rat plasma have been studied. Our results showed that the pH optimum of trypsin-activated renin is 6.2, the same as that of rat plasma active renin. Trypsin concentration and incubation time might also interfere with the activation process. Trypsin concentration below 2 mg/ml cannot activate inactive renin. Trypsin at a concentration of 6 mg/ml for 1 min. can cleave dialyzable fragments from renin substrate which can generate Angiotensin I at 37 degrees C with a pH optimum of 5.3 but which do not affect Angiotensin generation at pH 6.2. Longer incubations (more than 2 min.), on the contrary, can produce a cleavage at 4 degrees C of Angiotensin I containing fragments directly from renin substrate strongly interfering with measurements of renin activity at pH 6.2. Trypsin concentrations lower than endogenous rat plasma anti-trypsin activity do not activate inactive renin. Much higher concentrations of trypsin, however, are needed to obtain optimum activation of inactive renin. In average, 40% of the total circulating renin in rat plasma can be activated by trypsin.

Animals↗
PubMed1981

Optimum tryptic activation of inactive renin in human plasma is independent of endogenous anti-tryptic activity.

1. Plasma samples from 31 normal subjects were treated (at 4 degrees C, pH 7.0, for 2 min) with different concentrations of trypsin (500, 1000, 2000, 3000 and 4000 microgram/ml) in order to assess which concentration yielded the maximum activation of inactive renin. 2. Endogenous antitryptic activity was also measured in all samples; the mean value +/- SD (in microgram of trypsin inhibited by 1 ml of plasma) was 953 +/- 550 microgram/ml (range 34-1800 microgram/ml). 3. In the entire group of subjects the values of trypsin-activated renin measured with trypsin at 2000 microgram/ml were significantly higher than those obtained with lower or higher trypsin concentrations. 4. With subjects divided into subgroups according to their endogenous anti-tryptic activity, the maximum yield of activation was reached with trypsin at 2000 microgram/ml. 5. No significant correlations were found between single values of active, inactive or trypsin-activated renin and the corresponding levels of endogenous anti-tryptic activity. However, a weak but significant correlation (r = 0.39, P less than 0.05) was found between single values of anti-tryptic activity and the corresponding percentage of activation of inactive renin. 6. Thus the maximum activation of inactive renin at 4 degrees C for 2 min is obtained with trypsin at 2000 microgram/ml independently of the corresponding endogenous anti-tryptic activity. It is not excluded that the content of protease inhibitors in human plasma might affect the proportion in vivo of circulating active and inactive renin.

Adult↗
PubMed1981

Trypsin activation of inactive renin in human plasma. An assessment of some methodological aspects.

The following methodological aspects of the use of trypsin as activator of inactive renin in human plasma have been studied: a) the effect of SBTI on renin activity and angiotensin; b) the reaction velocity of trypsin on inactive renin; c) the optimum trypsin concentration; d) the ability of human plasma to neutralize exogenous trypsin. Our results show that: 1) Some commercially available SBTI may exert an angiotensinase-like effect which can be abolished by PMSF. 2) At 4 degrees C activation of inactive renin reached a maximum within the first two minutes then no further activation could be demonstrated. 3) Trypsin 2 mg/ml yielded more inactive renin than trypsin 1 or 0.5 mg/ml. A higher concentration (3 mg/ml) gave substantially equivalent activation as (with) trypsin 2 mg/ml whereas when using a still higher concentration (4 mg/ml) a degradation of the renin system components could be noted. 4) Endogenous trypsin inhibitors can eventually inactivate exogenous trypsin up to 3 mg/ml. About 20% of renin is destroyed by trypsin 4 mg/ml within 2 min at 4 degrees C while an additional 40% is lost during the incubation at 37 degrees C if no SBTI is added.

Enzyme Activation↗
PubMed1980

[Syphilitic aneurysms of the abdominal aorta. Considerations on 2 cases].

Abdominal aortic aneurysm have been considered in the modern literature only arteriosclerotic, apart from any possibility of superimposed bacterial infections. In 2 cases, after the hystological study on the aneurysmatic wall the Authors have found typical syphilitic lesions. both didn't have positive historical data and in one only serological tests were positive. This observation calls the attention on the importance of such an insidious pathology which is still present in spite of the decrease of the luetic epidemiology. It happens mainly in patients ignoring to be carriers of a remote infection or in those inadequately treated for it. Even it anamnestical and serological data are negative not only in presence of a thoracic aortic aneurysm but also in presence of an abdominal one, physicians must take syphilis into account in their diagnosis. The mistake comes often from an associated arteriosclerotic process present in elderly patients developing the aortitis a long time after infection. Therefore it is necessary to perform a careful hystological test of the aneurysmatic wall even if macroscopical examination suggests only arteriosclerotic lesions. An hystological evidence of syphilitic aortitis advises a long-term treatment aimed to avoid other localizations.

Aged↗
PubMedDate not supplied

Intralesional ethanol in the treatment of unresectable liver cancer.

Percutaneous ethanol injection (PEI) under ultrasonography guidance has been widely tried in not advanced hepatocellular carcinoma (HCC). Ten years after the introduction of PEI, some conclusions of its indications can be drawn. In our series, 210 cirrhotic patients were treated; 141 with multisession PEI in an outpatient clinic, 57 with "single session" PEI under general anesthesia, and 12 with both. The 1-, 3-, and 5-year survival rates (by Kaplan-Meier method) were 953%, 65%, and 41% for Child class A patients with single HCC < or = 5 cm, and 88%, 47%, and 33% for patients with multiple HCC up to five lesions < or = 5 cm. In these patients the local recurrence rate was 15% and the new lesion rate at the 5-year follow-up was 74%. One death due to hemorrhage from esophageal varices in a Child class C patient treated by single session PEI occurred. The large number of cirrhotic patients demand for effective, safe, repeatable, low-cost treatment that can be offered at many centers. PEI meets all these requirements. PEI is proposed as the treatment of choice for the mentioned patients, excluding candidates for liver transplantation and surgical resection according to the predictive adverse factors currently in use. "Single session" technique widened the indications of traditional PEI to larger lesions.

Aged↗
PubMedDate not supplied

Cefodizime modulates in vitro tumor necrosis factor-alpha, interleukin-6 and interleukin-8 release from human peripheral monocytes.

Among third-generation cephalosporins, cefodizime (CFDZ) has shown to modulate many functions of the host defense system against infections. The aim of the present study was to assess the in vitro CFDZ-dependent modulation of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha) and IL-8 release from lipopolysaccharide (LPS)-stimulated human peripheral mononuclear cells (MNCs). Two other third-generation cephalosporins: ceftriaxone (CFX) and ceftazidime (CFT), were also tested under the same experimental conditions. At concentrations ranging from 200 to 50 micrograms/ml, CFDZ significantly decreased TNF-alpha and IL-6 release from maximally (LPS 1 microgram/ml) stimulated MNCs (42% inhibition of TNF-alpha release with 100 micrograms/ml of CFDZ). On the other hand, CFDZ revealed a marked stimulatory effect on IL-8 release (200 micrograms/ml of CFDZ induced 51.5% enhancement of IL-8 release). On the contrary, both CFX and CFT failed to exert any significant effect on TNF-alpha, IL-6 or IL-8 release.

Cefotaxime↗
PubMedDate not supplied

Computed tomography of the ethmoid labyrinth and adjacent structures.

The architecture of ethmoid labyrinths as well as their relationships with adjacent structures are reviewed, giving special emphasis to the anatomic variants common in this area. The study was performed on six young normal subjects who were submitted to high resolution computed tomography. Approximately 25 axial scans, parallel to the floor of the anterior cranial fossa, were performed on each subject; four to five coronal CT scans were also added. Further data were supplemented by examinations of 62 patients affected by nonneoplastic disease of the paranasal sinuses. Microsurgery is replacing classic macrosurgery in the treatment of nonneoplastic disease of the paranasal sinuses. This new trend requires a perfect preoperative delineation of the anatomy. For this purpose, the present paper contains a list of 10 questions which can be answered exhaustively by computed tomography on the basis of the data illustrated. The answers cover most requirements of sinus microsurgery.

Adult↗
PubMedDate not supplied

Motor responses of the esophagus and lower esophageal sphincter (LES) to vestibular stimulation in man.

Pressure recordings in the esophageal body, LES and stomach were performed in 10 healthy subjects before and after caloric stimulation of the labyrinth. While esophageal and stomach responses varied or were absent, all subjects showed variations at the LES level. Duration of LES relaxation was increased and both time and amplitude of LES augmentation were significantly reduced. The physiological mechanism of labyrinthine-digestive connections and the possibility of clinical applications are discussed.

Acoustic Stimulation↗
PubMedDate not supplied

Ginkgo biloba (EGb 761) in the treatment of equilibrium disorders.

In an open, controlled study, 44 patients complaining of vertigo, dizziness, or both, caused by vascular vestibular disorders were randomly treated with extract of Ginkgo biloba (EGb 761) 80 mg twice daily or with betahistine dihydrochloride (BI) 16 mg twice daily for 3 months. A complete neuro-otologic and equilibrimetric examination was performed at baseline and after 3 months of treatment, with evaluation of clinical findings. In the first month of therapy, vertigo and dizziness improved in 64.7% of patients treated with BI and in 65% of those who received EGb 761. Compared to baseline, no statistically significant changes were observed in cranial scans for patients with a "central" cranial pattern. Likewise, no changes versus baseline were observed in both groups for the equilibrium score. The comprehensive test battery showed the following findings: EGb 761 induced a slight decrease of saccadic delay and considerably increased saccadic velocities; BI improved saccadic accuracy but did not modify delay; EGb 761 improved smooth pursuit gain at 0.4 Hz 40 degrees/s three times more than BI; both drugs asymmetrically reduced nystagmus maximum velocity at 40 degrees/s; both drugs asymmetrically improved the sinusoidal vestibulo-ocular reflex; BI considerably reduced--whereas EGb 761 considerably improved--visuovestibular ocular reflex. No side effects were recorded during the trial except for transient mild headache and gastric upset in 2 patients receiving EGb 761 and transient cyanosis of nails and lips in 1 patient given BI. These results suggest that EGb 761 and BI operate at different equilibrium receptor sites and show that EGb 761 can considerably improve oculomotor and visuovestibular function.

Aged↗
PubMedDate not supplied

Cutaneous vasculitis and reactive arthritis following respiratory infection due to Chlamydia pneumoniae: report of a case.

Unlike Chlamydia trachomatis and C. psittaci, the association of C. pneumoniae infection with immunological complications, such as reactive arthritis (ReA) or erythema nodosum (EN) has been rarely reported. Here we present the case history of a patient with C. pneumoniae community acquired pneumonia (CAP) who subsequently developed a ReA and a cutaneous vasculitis. A 45-year-old HLA B27 negative male developed an asymmetric and additive arthritis and a cutaneous leukocytoclastic vasculitis with IgM and complement papillary deposition along hypodermic vessel walls about three weeks after the onset of respiratory symptoms. The diagnosis of chronic Chlamydia pneumoniae infection was based on serology and PCR. Cultural and serological investigations for other infectious agents commonly involved in ReA were negative. This is the first report on the occurrence of two immune-based complications, associated to Chlamydia pneumoniae infection. Therefore, since this infection is very common in our population, although often asymptomatic, should be systematically considered as a common causative agent of ReA and of vasculitis.

Arthritis, Reactive↗
PubMedDate not supplied

Immunocytological and mineralogical study of bronchoalveolar lavage in a group of subjects exposed to asbestos.

Twenty-five subjects (24 males and 1 female, mean age 57.4 years) who have been exposed to asbestos underwent chest radiography, high resolution computed tomography (HRCT) of the chest, lung function tests and bronchoalveolar lavage (BAL) for evaluation of cell components (total cell count, percentages of macrophages, lymphocytes, neutrophil and eosinophil granulocytes and the lymphocyte subpopulations CD3+, CD4+, CD8+, CD19+ and HLADR+), soluble factors (IL-8, IL-10, IL-12 and MCP-1 in the supernatant) and concentration of asbestos fibre. The subjects were subdivided according to the degree of their exposure, to the concentration of asbestos fibres in the BAL and to chest X-ray findings using the I.L.O. classification (0/0pl, 0/1 and 1/0 and above). According to the exposure index, we showed statistically significant (p < 0.05) higher lymphocytes percentage in the BAL of subjects with moderate exposure and significantly higher levels of IL-10 (p < 0.05) in the supernatant of subjects showing an absence of asbestos fibres in their BAL. In the group of subjects with a 0/0 and 0/1 radiological profile, the cellular component of the BAL was characterised by a higher percentage of lymphocytes (p < 0.02), whereas a trend toward an increase in the number of neutrophils was noted in subjects with obvious pulmonary fibrosis. The percentage of neutrophils was inversely correlated with some parameters of respiratory function such as vital capacity (p = 0.03) and the partial pressure of oxygen (p = 0.05) in the blood. Investigating the cytokines in the supernatant of the BAL, we found a trend toward lower concentration of IL-10 in the group showing the worst radiological picture (I.L.O. > or = 1/0), and a statistically significant negative correlation between this cytokine and pO2 (p = 0.048). Concerning the other cytokines and chemokines studied (MCP-1, IL-8 and IL-12), no significant differences were found to be associated with the radiological profiles. There were, however, positive correlations between the concentration of IL-8 and the percentage of neutrophils (p = 0.038) and between the concentration of MCP-1 and the percentage of lymphocytes (p = 0.006). A negative relationship between the concentrations of IL-12 and IL-10 has been also observed (p = 0.028). This research allows us to hypothesise that IL-10 may have a pathogenetic role in the evolution of asbestosis.

Adult↗
PubMedDate not supplied

[Changes is Th1/Th2 balance in hemodialysis patients: effect of different membranes].

BACKGROUND: Hemodialysis (HD) patients present an immunodeficiency that is mainly related to the defect of cell-mediated immunity. We have previously shown the polarisation of T-helper cells toward the phenotype in HD treatment with cuprophan membrane. In the present study, we have examined the effect of a Vitamin E-coated dialyser (Excebrane, VE) on the activity of the two Th subsets. METHODS: We studied 8 healthy controls and 10 patients on RDT for at least 6 months with cellulose membrane (AC), then switched to HD-VE. Blood was collected from HD patients while on treatment with AC, and after 1 year of treatment with VE. CD4+ cells were isolated from peripheral blood mononuclear cells (PBMC) by negative selection, treating PBMC with a cocktail of anti-CD8, -CD16, -CD19, -CD36 and -CD56 antibodies labelled with magnetic beads, and passing them through a magnetic field. The collected Th cells were cultured for 48 h with and without phytohemagglutinin (PHA). IFNgamma and IL-4 were measured in the supernatant using the ELISA assay. RESULTS: The constitutive release of IL-4 by CD4+ cells was abated significantly by treatment with VE. IFNgamma released by mitogen-stimulated CD4+ recovered with VE. CONCLUSIONS: This study demonstrates that treatment with vitamin E-coated dialyser improves the defect of PBMC function associated with cellulose membrane dialyser consisting of altered spontaneous and mitogen-stimulated cytokine release. The effects of vitamin E-coated filter, in particular the recovery of reactive IFNgamma production by Th1 cells and the restriction of spontaneous IL-4 release by Th2 cells may have clinical importance.

Adult↗
PubMedDate not supplied

[Clinical results of the various replacement therapies for chronic renal failure: haemodialysis and renal transplantation].

Results from recent studies have demonstrated that kidney-transplanted patients have better expectation and quality of life than dialysis patients on a waiting list for kidney transplant. Moreover, the scientific literature has conclusively shown that the survival of the patient and of the kidney graft are better in patients who received a kidney from a living donor, than in patients who received a cadaveric kidney. The main factors that may have a negative influence on the kidney transplant are: the recipient's age, diabetes mellitus, smoking and the time spent on dialysis before the transplant. The shortage of cadaveric kidneys and the small number of living kidney transplant are the main obstacles to a more widespread use of kidney transplantation. Kidney transplant from living donors needs to be implemented because it represents the best treatment for patients with kidney failure and it can decrease or even avoid the need for dialysis before kidney transplantation.

Actuarial Analysis↗