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Biomedical subjects

L Moro

Publications and source records attributed to L Moro.

At least 91 records · Page 5Linked to original sources

[Effects of radiotherapy on lymphocyte populations in lung cancer].

The authors report on the results of the immune monitoring of a study population of 31 patients with lung cancer who were treated with radiotherapy. A synthetic thymic pentapeptide, thymopentin, was employed whose effect was evaluated on the immunological parameters analyzed. After radiotherapy, a considerable and homogeneous decrement was observed in several lymphocytic subsets (less sensible in activated T-cells), together with a progressive decrement in the helper/suppressor ratio, in the long run. Monocytes and null cells showed more radioresistance. Thymopentin had no influence on the tested immunological parameters up to 6 months after radiotherapy; later on, a slightly more balanced helper/suppressor ratio could be noticed in the surviving patients who had been treated with thymopentin.

Adenocarcinoma↗

Determination of galactosyl hydroxylysine in urine as a means for the identification of osteoporotic women.

A sensitive and specific method is proposed to follow bone collagen degradation. The procedure consists of the measurement of galactosyl hydroxylysine (GH) in urine by HPLC. The aim of the work is to assess the predictive values of the method for the identification of post-menopausal osteoporotic women. By assuming the value of 12 mumol/g creatinine as the threshold value, the sensitivity of the test is 87% and the specificity 60%. Individuals with a GH/creatinine ratio of 12 or below are not likely to be at risk of bone fractures: an equivalent predictive value is provided by the measurement of bone density by quantitative computed tomography. This biochemical method is however simple and not invasive and may be frequently repeated.

Adult↗

Islet cell and insulin autoantibodies in organ-specific autoimmune patients. Their behaviour and predictive value for the development of type 1 (insulin-dependent) diabetes mellitus. A 10-year follow-up study.

To evaluate the behaviour and predictive value of islet cell and insulin autoantibodies in patients with organ-specific autoimmune diseases, we followed 21 non-diabetic subjects for a mean period of 84 +/- 27 months. Ten patients were persistently seropositive for complement-fixing islet cell antibodies and high titres of immunoglobulin G islet cell antibodies (greater than or equal to 1:8). The prevalence of persistent insulin autoantibodies in this group was 67%. Seven patients (70%) developed Type 1 (insulin-dependent) diabetes mellitus after a latency period of 2-60 months. The predictive value of complement-fixing islet cell antibodies was 65%, and in the presence of both complement-fixing islet cell and insulin autoantibodies the predictive value rose to 76%. Eleven patients were seronegative for complement-fixing islet cell antibodies and had low immunoglobulin G islet cell antibodies titres (less than 1:8) that were either persistent or transient, or that fluctuated during follow-up. The prevalence of persistent insulin autoantibodies in this group was 45%; only one subject developed Type 1 diabetes. The predictive value of persistent islet cell antibodies (complement-fixing positive/negative) was 54%, and it rose to 70% when both islet cell and insulin autoantibodies were present. Individuals with only insulin autoantibodies or immunoglobulin G islet cell antibodies did not develop diabetes mellitus. A high frequency of HLA-DR3 and/or DR4 was found in patients who developed diabetes mellitus. Thus, the presence of both islet cell and insulin autoantibodies in patients with organ-specific autoimmune disease appears to confer the highest risk of progression toward Type 1 diabetes.

Adolescent↗

[Epidemiologic study on the distribution of HLA antigens in rheumatoid arthritis].

Serologic HLA typing was carried out on 71 seropositive and 40 seronegative patients with rheumatoid arthritis and compared with values in 134 normal controls. A significant increase of HLA DR4 antigen, compared with control values, was found only in seropositive rheumatoid arthritis; HLA A1 and B35 antigens were significantly increased in seronegative rheumatoid arthritis patients (p less than 0.05), when compared with control values, but only HLA A1 antigen remained significantly higher when the p-correct test was performed.

Arthritis, Rheumatoid↗

A possible role for polyamines in cartilage in the mechanism of calcification.

The role of polyamines in cartilage is not known: they may be somehow related to the mechanism of calcification. In epiphyseal cartilage from calf scapulas, they are more concentrated in the ossifying area, where calcification takes place, than in the resting region. Spermidine is present in greater amounts than spermine and putrescine. Since ornithine decarboxylase (EC 4.1.1.17) is measurable only in the resting region of the tissue, it is in this area that polyamine biosynthesis occurs, while they accumulate in the ossifying area. Immunohistochemical evidence is obtained that only in the ossifying zone is spermidine extracellular. It is at this level that the matrix is rearranged to become calcified, and proteoglycans are dissociated and partially removed. The effect of polyamines on solutions of proteoglycan subunits has been studied in vitro by following variations of turbidity and viscosity. While in the presence of putrescine the specific viscosity decreases to asymptotic values, in the presence of either 30 mM spermidine or 2.5-10 mM spermine, the decrement is more marked. At the same concentrations, increase of the turbidity of proteoglycan subunit solutions was observed. Only spermidine showed the capacity of displacing proteoglycan subunits from a column of Sepharose 4B-type II collagen: at 15 mM concentration, about 90% of proteoglycans were removed from the column. Alkaline phosphatase activity, which plays an important role in calcification, is enhanced by spermidine and spermine. These results obtained in vitro support the hypothesis that polyamines may be related to calcification of preosseous cartilage.

Alkaline Phosphatase↗

Biochemical and immunohistochemical evidence that in cartilage an alkaline phosphatase is a Ca2+-binding glycoprotein.

A glycoprotein that exhibits alkaline phosphatase activity and binds Ca2+ with high affinity has been extracted and purified from cartilage matrix vesicles by fast protein liquid chromatography. Antibodies against this glycoprotein were used to analyze its distribution in chondrocytes and in the matrix of calcifying cartilage. Under the light microscope, using immunoperoxidase or immunofluorescence techniques, the glycoprotein is localized in chondrocytes of the resting zone. At this level, the extracellular matrix does not show any reaction. In the cartilage plate, between the proliferating and the hypertrophic region, a weak immune reactivity is seen in the cytoplasm, whereas in the intercolumnar matrix the collagen fibers appear clearly stained. Stained granular structures, distributed with a pattern similar to that of matrix vesicles, are also visible. Calcified matrix is the most stained area. These results were confirmed under the electron microscope using both immunoperoxidase and protein A-gold techniques. In parallel studies, enzyme activity was also analyzed by histochemical methods. Whereas resting cartilage, the intercellular matrix of the resting zone, and calcified matrix do not exhibit any enzyme activity, the zones of maturing and hypertrophic chondrocytes are highly reactive. Some weak reactivity is also shown by chondrocytes of the resting zone. The observation that this glycoprotein (which binds Ca2+ and has alkaline phosphatase activity) is synthesized in chondrocytes and is exported to the extracellular matrix at the time when calcification begins, suggests that it plays a specific role in the process of calcification.

Alkaline Phosphatase↗

Alkaline phosphatase binds to collagen; a hypothesis on the mechanism of extravesicular mineralization in epiphyseal cartilage.

Affinity chromatography on Sepharose 4B-collagen gels was used to test the affinity of alkaline phosphatase for collagen. Results indicate that alkaline phosphatase of preosseous cartilage binds to collagen probably by electrostatic interactions, this interaction is inhibited by proteoglycan subunits. These results suggest that, in vivo, the formation of a collagen-alkaline phosphatase complex may be a step of the process leading to cartilage calcification.

Alkaline Phosphatase↗

Mobilization of heparan sulfate induced by immunostimulation in a patient with mucopolysaccharidosis IIIA.

Unspecific immunostimulation by bacterial vaccines of a patient with mucopolysaccharidosis IIIA (Sanfilippo A) syndrome induces a marked increase in the urinary excretion of heparan sulfate and of uronate-containing oligosaccharides. This event is presumably linked to an increased vascular permeability and exocytosis of storage material, elicited by mediators of inflammation, as well as to enhanced degradation of stored polymers in activated macrophages and surrounding tissue.

Bacterial Vaccines↗

Bioavailability study on a new slow-release formulation of ketoprofen.

Four healthy subjects volunteered for a crossover bioavailability study to compare the rate and extent of absorption of plain capsules and new slow-release capsules of ketoprofen. The formulations were administered in two consecutive 4-day periods at the following dose schedules: 2 x 50 mg plain capsules t.i.d. and 150 mg slow-release capsules b.i.d. The plasma levels profile of unchanged ketoprofen was assessed by GLC during the 4th day of treatment with each formulation. The absorption from slow-release capsules was slower and more sustained than from plain capsules but almost complete. The bioavailability properties of new slow-release capsules of ketoprofen appear suitable for clinical use with reduced frequency of daily dosing.

Adult↗

Physiological disposition of a series of rifamycins in rat: a comparative study.

The disposition of four C3-substituted piperazinyl rifamycins was studied in the rat following the intravenous administration of 5 mg/kg of the 14C-labelled antibiotics. Considerable quantitative differences in the pharmacokinetics of these antibiotics were shown in blood levels, tissue distributions and body clearances. Feces were largely the major route of elimination for the parent drug and metabolites. The results suggest that the liver compartimentalization, regulating the biliary excretion, is to be the kinetic parameter affecting the pharmacokinetic behaviour of this class of antibiotics.

Animals↗

Protein binding of a series of rifamycins to bovine serum albumin as measured by the "two-phase partition" technique.

A "two-phase partition technique" was developed and improved so as to be useful for the study of the interaction of proteins with low-molecular-weight ligands. The technique permits the macromolecule to be present almost entirely in one of the two aqueous phases without the aid of any physical solid interface, which is particularly useful in studies of lipophilic ligands. Compared with the other two-phase systems set up for binding studies, that used in this work takes advantage of the use of a more suitable medium, which permits a better protein partition even at very low ionic strengths. As an example of its usefulness the measurement of the binding parameters of a series of rifamycins to bovine serum albumin is reported.

Buffers↗

Properties of beta-glucuronidase activity in human synovial fluid.

The purpose of the present study was to evaluate the properties of beta-glucuronidase (EC 3.2.1.31) in human synovial fluid. It was shown to have a pH requirement of 5.0 and a KM value of about 8.0 - 10(-3) M using phenolphthalein beta-glucuronide as the substrate. At low substrate concentration an endogenous inhibitor is demonstrable. The inhibition is of the competitive type and is removed by proteolytic digestion of synovial fluid, whereas hyaluronidase digestion and addition either of Triton X-100 or of various salts to the assay mixture, are ineffective. The possibility that the inhibitor is a protein from serum is discussed.

Animals↗