Biomedical subjects
Publications and source records attributed to M Russo.
Sera from typhoid fever patients in the early stage of the disease were tested for the presence of IgM antibodies to LPS of S. typhi by an ELISA method. IgM anti-LPS were present in all 10 typhoid patients, while they were undetectable in sera from both normal and febrile controls. Determination of IgM anti-LPS can be a diagnostic aid in the early phase of typhoid fever.
Ultrastructural studies of Nicotiana clevelandii plants systemically infected with Cymbidium ringspot virus, a member of the tombusvirus group, have shown that a clear-cut relationship exists between perioxisomes and multivesicular bodies (MVB). In infected cells, peroxisomes undergo a progressive vesiculation of the bounding membrane through the possible addition of membranous material by the endoplasmic reticulum and become very plastic. Portions of the ground cytoplasm are engulfed either through the invagination of the limiting membrane or the production of membranous appendages that fold back on the main body. Cytochemical tests have shown MVB to possess catalase and glycolate oxidase activity in the matrix. The vesicles contain RNA, a substantial amount of which is double stranded, as indicated by differential RNase digestion tests in high- and low-salt media. The double-stranded RNA may consist of replicative forms or replicative intermediates of the viral nucleic acid. If so, MVB (i.e., modified peroxisomes) may be directly involved in the replication of Cymbidium ringspot virus.
A monoclonal antibody to ovine corticotropin releasing factor (CRF) has been produced by fusion of a non-producing plasmacytoma cell line P3U1 with spleen cells of Balb/c mice immunized with the synthetic 41 amino acid peptide coupled covalently with rabbit myosin by a heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio) propionate. A total immunizing dose of 500 micrograms resulted in a highly specific, high-affinity antibody with a Ka of 0.15 x 10(12) M-1, which was used to establish a specific RIA with a sensitivity of 10 pg/tube. Levels of corticotropin releasing factor-like immunoreactivity (CRF-LI) in a pg/mg of hypothalamic tissue ranged from 4-10 in ovine, 2.5-8 in bovine, 47.5-67.5 in mouse and 2.3-20 in human tissue. Moreover, CRF-LI was widely distributed in extrahypothalamic mouse brain at concentrations approximately one half those seen in hypothalamus.
Adenosine deaminase (ADA) activity was measured in peripheral blood mononuclear cells (PBMC) from patients with chronic liver disease (CLD). Mean ADA levels were decreased in patients with untreated chronic active hepatitis (CAH). ADA levels in patients with CAH in remission under immunosuppressive treatment and in patients with inactive cirrhosis (IC) were similar to control values. ADA levels were not related to any of the biochemical parameters examined, or to the percentage of T cells evaluated on the same PBMC preparations. Our data suggest that biochemical and/or histological remission in CLD may be associated with normalization of ADA levels in PBMC.
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Cytochemical staining for acid alpha-naphthyl acetate esterase (ANAE) activity is widely used for identifying monocytes in mixed cell populations; esterase staining is usually performed on slide prepartions of whole blood, buffy coat or Ficoll-Paque separated mononuclear cells (MC). In this paper we propose a method for staining MC while they are in suspension, which utilizes, with slight modifications, the same reagents used in the procedure for esterase staining on smears. Suspension method is rapid and costless; furthermore, it overcomes the loss of esterase stainability observed in slide preparations of Ficoll-Paque separated MC.U
A rapid suspension method for alpha-naphthyl acetate esterase staining has been utilized to evaluate monocytes percentages in Ficoll-Paque separated mononuclear cells (MC) from normal individuals. In MC preparations from 24 normal subjects a mean percentage of 8% monocytes has been found, with a range from 2% to 20%. Cell fractions depleted of T-lymphocytes by rosette sedimentation showed 43% of esterase positive cells (range 31-53%), while very few monocytes (2%) appeared to contaminate the preparations of E-rosetting cells. The method for esterase staining of monocytes while they are in suspension is very simple and permits a rapid and accurate evaluation of monocyte percentages in mixed cell preparations.
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High concentrations of bovine factor VIII cause clumping of platelets into a few very large aggregates. This response is termed superaggregation. It is distinct from factor-VIII-induced agglutination but is also independent of both extracellular calcium ions and platelet energy metabolism. Neither agglutinating lectins nor aggregating agents, including thrombin, ADP, the ionophore A23187, and U46619, a prostaglandin analog, can induce superaggregation, even at very high concentrations. Washed platelets undergo superaggregation, and superaggregation does not increase the amounts of fibrinogen or albumin trapped by agglutinated platelets. It is not inhibited by membrane-stabilizing drugs or by colchicine or cytochalasin-B. Formaldehyde and glutaraldehyde prevent superaggregation without affecting the binding of radiolabeled factor VIII to the platelets. Superaggregated platelets are separated by approximately 50 nm and are not shape-changed or degranulated. In adenosine diphosphate (ADP) induced aggregation, the platelets are distorted and only 30 nm apart. Superaggregation is reversed by dextran sulfate, and the dispersed platelets are still able to respond to ADP. Our observations are consistent with the binding of high molecular weight multimers of bovine factor VIII to more than one receptor on each platelet, with superaggregation occurring through recruitment of additional receptors. This process may be interrupted by protein crosslinking reagents, such as formaldehyde and glutaraldehyde.
Purine nucleoside phosphorylase (PNP) activity was measured in peripheral blood mononuclear cells and in T-enriched populations from 6 normal subjects. PNP activity in T-enriched populations were in average 50% of that in unseparated mononuclear cells. In our cell preparations, T-cells appeared to contribute to 27-49% of total biochemical PNP levels in peripheral blood mononuclear cells. T-lymphocytes obtained by rosetting with sheep red blood cells could be a suitable cell population for determining PNP activity in patients with immune disfunction.
Adenosine deaminase activity has been determined in T-enriched and T-depleted preparations of peripheral mononuclear cells from 6 normal subjects. T-enriched populations showed ADA levels lower than unseparated mononuclear cells (1.84 +/- 0.30 vs. 2.36 +/- 0.59 nmol NH3/min/10(6) cells). The highest values were found in T-depleted populations (2.46 +/- 0.39). Considering T cells percentages in our mononuclear cell preparations, T cells account for 64% of the biochemical ADA activity of peripheral blood mononuclear cells and the remaining 36% is due to non-T cells. The method for cell separation and enzymatic activity determination we used could be highly suitable for monitoring ADA levels in pathological conditions.
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Adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) levels of peripheral blood mononuclear cells were measured in 34 patients with various types of solid tumours. The mean ADA activity was found to be significantly lower than in controls (P less than 0.005). Patients with nonresectable tumour or with recurrence after radical surgery showed low ADA levels, while patients operated upon and without recurrence had enzymatic activity not different from that of normal controls. The mean value of PNP activity was similar to that of normal controls; no differences were observed between operated patients without recurrence and cases with nonresectable tumour or with recurrence after surgical treatment. No effects on ADA and PNP levels appeared to be induced by chemotherapy.
Adenosine deaminase in the peripheral lymphocytes (L-ADA) was determined in 27 patients with typhoid fever and in 15 normal controls. Increased values of enzymatic activity were found in the typhoid fever patients compared with the controls. The increase was prolonged and not correlated to treatment. L-ADA levels could be related to the immune response.
Changes in circulating platelets were observed after placement of woven Dacron aortic prostheses in dogs. Platelets had increased sensitivity to aggregating agents for up to 6 months postoperatively, during which period platelet survival was maximally shortened. Platelet survival gradually lengthened but remained less than preoperative values, even at 18 months. Platelet 5HT, consistently reduced after placement of aortic prostheses, closely paralleled changes in platelet survival. Studies with platelets labeled simultaneously with 14C-5HT and 51Cr suggested in vivo platelet release and reutilization of 5HT. In vitro platelet uptake of 14C-5HT, however, was depressed. Urinary excretion of 5HIAA increased slightly, but not significantly, after placement of aortic prostheses. These findings suggested that platelet interaction with the prosthetic surface led to partial release of platelet storage granule contents. Reutilization of released 5HT occurred but was limited because of impaired platelet uptake or storage of 5HT. Platelet damage was suggested by 51Cr-platelet cross-transfusion experiments. Platelets from normal dogs had normal recovery and reduced survival when cross-transfused into animals with aortic prostheses. When platelets from dogs with aortic prostheses were cross-transfused into normal animals, recovery was strikingly reduced and survival very short. Taken together, these studies suggest that, in dogs, platelet interaction in thrombosis on prosthetic surfaces is, in part, a reversible process, with platelets re-entering the circulation in an altered state.
Peripheral E-rosette forming cells (E-RFC) have been enumerated in 15 patients with type B acute viral hepatitis (AVH-B) using sheep red blood cells pretreated with 2-aminoethylisothiouronium bromide (SRBCAET). Percentages of E-RFC in mononuclear cells (MC) preparations obtained during the acute stage of the disease were not different from those in normal controls. Patients re-assayed in the resolving period of AVH-B universally showed significantly reduced values of E-RFC compared to the acute phase values. Defective rosetting with SRBCAET may reflect immune-related modifications associated with the recovery from hepatitis B virus infection.