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Biomedical subjects

A Franco

Publications and source records attributed to A Franco.

At least 271 records · Page 15Linked to original sources
PubMed1987

"Anti-Ia reactivity in sera from patients with chronic active hepatitis (CAH)".

Anti-Ia reactivity in sera from patients with chronic active hepatitis (CAH) were characterized by determining cross-reacting specificities with the antigen defined by anti-Ia monoclonal antibody (MoAb) and by studying the effect of CAH sera on the autologous mixed leukocyte reaction (MLR). Preincubation with autoimmune CAH sera lowered the percentage of Ia+ non-T cells stained by anti-Ia MoAb. HBsAg+ve/HBeAg+ve sera did not exert any blocking activity while 4 out of 11 HBsAg+ve/anti-HBe+ve sera exerted a significant blocking effect. Preincubation of cells with normal human serum (NHS) plus aggregated IgG did not block the binding of MoAb anti-Ia. Sera from patients with autoimmune or HBsAg+ve/anti-HBe+ve CAH, that blocked the binding of anti-Ia MoAb to Ia positive target cells by more than 20%, clearly inhibited the autologous mixed lymphocyte reaction (MLR). Both IgG and IgM fractions obtained by affinity chromatography from CAH sera inhibited the autologous MLR and blocked the binding of anti-Ia antibody to Ia positive target cells. A significant positive correlation (p less than 0.001) between serum anti-Ia reactivity and serum liver membrane antibodies (LMA) was observed. In 4 "autoimmune" CAH patients, steroid treatment induced a dramatic decrease in the anti-Ia reactivity.

Antigen-Antibody Reactions↗
PubMed1987

[Chronic venous insufficiency and microcirculation. Physiopathologic and therapeutic reflections].

In patients with chronic venous insufficiency, tissular damage occurs as a consequence of microcirculatory disturbances. Venular distension, venulo-arteriolar reflex and probably valves in collecting venules are the only microcirculatory protective mechanisms against venous pressure overload. Edema is primarily a consequence of increased capillary hydrostatic pressure. However, the increase of endothelial macromolecular transport and a true lymphatic microangiopathy are important contributive factors. Venous ulceration is hypoxic although the amount of total blood flow is normal in the surrounding tissue. Several hypothesis were proposed for explaining this nutritional steal: arterio-venous shunt vessels have never been shown consistently, peri-capillary fibrin deposition might block oxygen diffusion, and last but not least, the abnormal geometrical arrangement of the capillary bed is facilitating functional shunting. On a therapeutic point of view, behind the classical hemodynamic therapy, the microvascular approach to chronic venous insufficiency supports the use of lymphatic manual drainage for controlling edema and rheologic therapy for improving skin capillary perfusion.

Humans↗
PubMed1987

[Phosphorus-31 NMR spectrometry of the calf muscles in patients with arterial claudication. Preliminary results].

Phosphorus NMR spectrometry allows non-invasive exploration in vivo of certain aspects of muscle energy metabolism. A study was conducted in 10 healthy volunteers and 12 patients with lower limb affections (stage II claudication) to define a precise methodology and to discuss perspectives offered by this new method, in the light of preliminary findings. Changes with time of amplitude of peaks of phosphocreatine (Pcr), inorganic phosphorus (Pi) and ATP, and of intracellular pH, showed that recovery of 80% of resting value of the ratio Pcr/Pi + Pcr after quantified exercise is a very discriminatory parameter correlated with severity of arteriographic findings in patients with claudication.

Energy Metabolism↗
PubMed1986

Alanine and lactate as gluconeogenic substrates during late gestation.

Rates of alanine incorporation into glucose by isolated liver cells of fed rats are 5-fold higher than those observed when lactate was used as substrate. The rates of gluconeogenesis from alanine and lactate in isolated liver cells of fed pregnant rats increase 50 and 200-400%, respectively, over virgins during the last 3 days of gestation. The results support the existence of an increase in the alanine-glucose cycle in the late pregnancy as an important homeostatic pathway in the supply of glucose to the growing fetus.

Alanine↗
PubMed1986

Effect of 28 consecutive days lymphoblastoid interferon (alpha-IFN) administration on hepatitis B virus related chronic liver disease.

Eight HBsAg, HBeAg, DNA-p, HBV-DNA-positive patients with biopsy-proven chronic hepatitis were treated with human lymphoblastoid interferon (Wellferon) given for 28 consecutive days at a dosage ranging from 2.5 to 7.5 MU/m2 i.m.; 10 patients were used as controls. Our results suggest that certain chronic carriers may respond to the treatment with this agent. In fact, the treated patients showed a permanent inhibition of HBV replication sooner and in higher percentage with respect to untreated patients (37.5% vs 20%). IFN administration does not induce any important changes in the immunoregulatory wetwork, but is able to increase significantly the cytolytic activity of NK cells in the patients who respond to the therapy with a permanent inhibition of HBV replication.

Adult↗
PubMed1986

Characterization of effector cells in lymphocytotoxicity to autologous hepatocytes in HBsAg-positive and autoimmune chronic active hepatitis (CAH).

Peripheral blood lymphocyte subsets involved in cytotoxicity to autologous hepatocytes have been characterized by isolation on antibody-coated Petri dishes in autoimmune and HBsAg-positive chronic active hepatitis (CAH). In autoimmune CAH and in HBsAg-positive CAH without HBcAg in liver tissue, cytotoxicity is sustained by non-T lymphocytes and is confined to M1-positive cells bearing Fc receptors: M1 cytotoxicity inhibition by adding aggregated IgG suggests that these cells are responsible for an antibody-dependent cell-mediated mechanism (ADCC). Moreover, when T-enriched fractions were separated in T4, T8 and 5/9 positive subsets, only the first one showed a significant cytotoxicity: T4 positive cells might act as cytotoxic T cells or might be involved in delayed type hypersensitivity (DTH) reactions. Cytotoxic T lymphocytes in HBsAg-positive CAH with HBcAg in liver tissue are confined in T8 positive subset, while helper/inducer T cells (T4 positive or 5/9 positive) seem to play an important role only in the induction of cell-mediated injury against hepatocytes. The inhibition of T cell-cytotoxicity by preincubating liver cells with monoclonal antibody (Mab) anti-HLA AB and not with Mab anti-HLA DR or aggregated IgG supports the involvement of the class I major histocompatibility complex (MHC) expressed on the hepatocyte surface.

Antibodies, Monoclonal↗
PubMed1986

Rate-responsive pacing in patients with left ventricular failure.

Aerobic and hemodynamic performance, at rest and during exercise, has been explored in patients with either atrial synchronous ventricular or respiratory-dependent ventricular pacing. In patients with chronic AV block and normal left ventricle, the cardiac output, VO2 at maximal exercise, and work tolerance increased significantly with rate-responsive pacing in comparison with fixed ventricular pacing. Chronic AV block and left ventricle dysfunction in patients with respiratory-dependent ventricular pacing improved maximal cardiac output, VO2 anaerobic threshold, and physical work capacity. The benefit of rate-responsive pacing was found to be significantly greater in patients with left ventricle dysfunction than in patients with normal left ventricle function.

Aged↗
PubMed1986

Cholinergic modulation of an acetylcholine receptor-like antigen on the surface of chick ciliary ganglion neurons in cell culture.

Chick ciliary ganglion neurons have a membrane component that shares an antigenic determinant with the "main immunogenic region" of the alpha subunits in nicotinic ACh receptors from skeletal muscle and electric organ. Ultrastructural studies on antibody binding in the ganglion have shown that the cross-reacting antigen on the neuron surface is located predominantly in synaptic membrane. Biochemical studies have shown that the cross-reacting component has a number of other properties expected for the ganglionic nicotonic ACh receptor and that it is distinct from the alpha-bungarotoxin binding component in the tissue. Here we show that ciliary ganglion neurons grown in dissociated cell culture express a similar component that cross-reacts with monoclonal antibodies to ACh receptors, and that the number of antibody-binding sites on the neurons can be modulated by exposure to cholinergic agonists and a protein neurotoxin that reversibly inhibits ACh receptors on the neurons. In most, though not all, cases, levels of ACh sensitivity associated with the neurons are specifically comodulated in parallel with the changes in number of antibody binding sites. The results suggest that at least a portion of the cross-reacting sites on the surface of ciliary ganglion neurons is likely to represent nicotinic ACh receptors. The fact that in some instances levels of ACh sensitivity can be altered without changing the number of cross-reacting sites, however, leaves open the possibility that not all of the sites are associated with receptors or that the neurons can alter the proportion of receptors that is functional.

Animals↗
PubMed1986

[Periungual capillaroscopy in rheumatoid arthritis. Prospective study of 80 cases].

This study involved the screening for dermal microcirculatory abnormalities using periungueal capillaroscopy in a group of 80 cases of rheumatoid arthritis, so-defined in terms of ARA criteria. Excessive erythrocyte aggregation and/or pericapillary edema were detected in 74% of cases and were statistically correlated with ESR, reflecting an inflammatory syndrome. Capillary neogenesis, probably in reaction to subclinical cutaneous vascularity, was detected in 59% of cases (86% of subjects presenting extra-articular rheumatism). In 28% of cases this was accompanied by spontaneous hemorrhage, suggesting a progressive condition. Stigmata of cutaneous atrophy were present in 54% of subjects. These findings demonstrate the frequency of subclinical cutaneous damage in rheumatoid disease and suggest the possibility of the clinical usefulness of capillaroscopy, a non-invasive technic, in the follow-up of this disease.

Arthritis, Rheumatoid↗
PubMed1986

[Aneurysm of the popliteal vein. A rare cause of recurrent pulmonary embolism].

Popliteal vein aneurysm, a rarely observed, apparently benign lesion may nevertheless be the cause of disabling pulmonary emboli. Two personal cases and 13 reported in the literature are reviewed. Detected during phlebography of lower limbs during investigation of a pulmonary embolus, the aneurysm, of a sacciform shape, was located above the interline of the knee and often contained a thrombus: this site of onset facing the calf "venous pump" makes it an "experimental" emboligenic focus. The pulmonary embolus is a serious affection since it is repetitive: a pulmonary scan showed dissemination in the two fields of the hypovascularized zones. Identification of an acute or chronic cor pulmonale was a routine finding and a paradoxical embolus in the arterial territory was observed twice. Local surgery (venous repair or exclusion of the aneurysm) can be performed in association with anticoagulant therapy, but partial interruption of inferior vena cava appears to be the safer method of avoiding a recurrent embolus, which may be fatal.

Adult↗
PubMed1986

[Erythrocyte aggregation and its repercussions on conjunctival microcirculation in man. Morphometric study and biological correlates].

This study, involving the application of morphometric techniques to the conjunctival capillary bed in man, revealed a rarefaction of functional capillary density in patients with arteriolar sludge. Overall, in the population sample studied, capillary density and the degree of erythrocyte aggregation were correlated to erythrocyte sedimentation rate, despite the existence of discordant cases. These discordances were partially reduced by taking the hematocrit into account. Furthermore, multifactorial analysis of these parameters showed that hematocrit had an inhibitory action on erythrocyte aggregation which was more marked in vitro than in the microcirculation in vivo. By contrast, in vivo aggregation was more influenced by serum albumin levels. In both cases fibrinogen appeared to be the most significant pro-aggregant factor.

Blood Sedimentation↗
PubMed1985

Antigen specific suppressor T cells from chronic hepatitis B virus (HBV) carriers inhibit the responsiveness to HBsAg of allogeneic high-responder lymphocytes.

Immunoregulatory mechanisms in chronic HBsAg carriers have been investigated through the study of in vitro proliferative responses to HBsAg by allogeneic coculture experiments between T lymphocytes from HBsAg + chronic active hepatitis (CAH) patients (HBsAg no responder) and PBMC from subjects boosted with anti-hepatitis B vaccine (high responder). When high-responder PBMC have been challenged with the hepatitis B surface antigen (HBsAg) in the presence of HBsAg no-responder T lymphocytes, HBsAg no-responder T lymphocytes caused an antigen specific, dose-dependent, suppression of the responsiveness of high-responder PBMC. On the other hand, T cells from patients with autoimmune CAH did not exert any suppressor effect in our system. The suppressor T lymphocytes were mitomycin C resistant and were positive for OKT8, but were negative for OKT4. When T8 + cells were depleted from HBsAg no-responder PBMC, the in vitro immunoproliferative response to HBsAg in chronically HBV infected patients was markedly improved. Out data clearly demonstrate the existence of T8 + suppressor T lymphocytes that can control low responsiveness to HBsAg in chronic HBV patients.

Autoimmune Diseases↗
PubMed1985

[Statistical analysis of a file of angiologic data on a micro- computer. Discriminant analysis of occlusive impedance rheoplethysmography data].

The statistical analysis by multidimensional analysis of the data of a computerized file should lead to the improvement of the quality of the examinations. A discriminant analysis of the data of occlusive impedance rheoplethysmography allows a global analysis of all of the indices, by taking into account both their absolute values and their relative values. This results in a better compromise between the sensitivity and the specificity. The graphic representation gives an immediate conclusion and allows the functional outcome to be monitored.

Arterial Occlusive Diseases↗
PubMed1985

[Esophageal motility in Raynaud's disease, systemic scleroderma and presclerodermal Raynaud's syndrome].

Fifty-five consecutive subjects with Raynaud's phenomenon were submitted to esophageal manometry. According to the results of clinical examination and periungual capillaroscopy, they were divided into three groups: sixteen patients presented presclerodermal Raynaud's phenomenon, and nineteen, systemic sclerosis; twenty others had Raynaud's disease. Twenty volunteers formed the control group. Esophageal motor disorders were observed in the group with presclerodermal Raynaud's phenomenon, affecting the esophageal lower sphincter and the peristalsis of the body of the esophagus. In the group with systemic sclerosis, these motor disorders were associated with alterations in the amplitude and the duration of contractions. Esophageal motility was normal in subjects with Raynaud's disease. We can conclude that: 1) esophageal motor disorders can be seen in presclerodermal Raynaud's phenomenon. The kind of abnormalities observed at this stage of the disease are in favor of an early alteration of the neurogenic component of esophageal motility; 2) there is no relationship between esophageal motor disorders and Raynaud's phenomenon in scleroderma.

Adult↗