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Biomedical subjects

P C Frei

Publications and source records attributed to P C Frei.

At least 91 records · Page 5Linked to original sources
PubMed1981

Influence of (+)-cyanidanol-3 on the leukocyte migration inhibition test carried out in the presence of purified protein derivative and hepatitis B surface antigen.

It has been shown that (+)-cyanidanol-3, therapeutically administered during the course of acute hepatitis B, is able to favor the elimination of hepatitis B surface antigen (HBsAg) from the blood. This observation suggests that (+)-cyanidanol-3 might stimulate the cell-mediated immune response, since it is known that this type of response is responsible for elimination of the virus. In the present study, the possible action of (+)-cyanidanol-3 on this type of immunity was investigated by adding the substance in vitro to leukocyte migration inhibition tests, performed with the antigens purified protein derivative (PPD) and HBsAg and with leukocytes from individuals sensitized to these antigens. In normal individuals sensitized to PPD, the addition of (+)-cyanidanol-3 amplified the inhibition of migration by 7.0% (P less than 0.05). In patients previously infected by hepatitis B virus and sensitized to HBsAg, the addition of (+)-cyanidanol-3 amplified the migration inhibition by 10.5% (P less than 0.05). A trend to a dose-response relation was observed with the antigen PPD. (+)-Cyanidanol-3 did not modify leukocyte migration in the absence of an antigen. (+)-Cyanidanol-3 therefore seems capable of amplifying the cell-mediated immune response as measured by the leukocyte migration inhibition test. It is thus possible that it favors the elimination of HBsAg in patients by this mechanism.

Adult↗
PubMed1980

Effect of one gold salt, of betamethasone, and of aspirin on the chemotaxis of human neutrophils measured in vitro.

The effects of 1 gold salt, of betamethasone, and of acetylsalicylate on the chemotaxis of human neutrophils were compared in normal volunteers by means of a modified Boyden chamber. The gold salt inhibited chemotaxis by reducing both cell migration capacity and the capacity of plasma to attract the cell. Betamethasone reduced cell migration capacity, but not the chemoattractant capacity of plasma. Acetylsalicylate had no effect on these functions.

Aspirin↗
PubMed1980

Quantitation of immunoglobulin-associated HBs antigen in patients with acute and chronic hepatitis, in healthy carriers and in polyarteritis nodosa.

The incidence and amount of immunoglobulin (Ig)-bound hepatitis B associated surface antigen (HBs) has been determined in various forms of hepatitis B, using radioimmunological techniques. Both the total concentration of HBs and that of Ig-bound HBs were measured in serum samples from 54 patients with acute hepatitis B, 28 with chronic hepatitis and 28 healthy chronic carriers. The following observations were made: (1) Ig-bound HBs was detected in 79% of patients with acute hepatitis B in one or several samples; the highest level of Ig-bound HBs was observed 60-120 days after the onset of jaundice, while the total amount of HBs was progressively decreasing. (2) Ig-bound HBs was detected in 46% of 28 patients with chronic hepatitis. This frequency was higher in patients with chronic aggressive hepatitis (75%) than in patients with chronic persistent hepatitis (33%). The mean levels of total HBs and Ig-bound HBs are more significantly increased in patients with chronic aggressive hepatitis than in patients with chronic persistent hepatitis or healthy carriers. (3) Ig-bound HBs was detected in 46% of healthy chronic carriers. (4) The persistence of Ig-bound HBs in serum was not related to the antigen sub-type. (5) Extra-hepatic manifestations suggestive of an immune complex disease were observed in only 2 of 31 patients with chronic persistence of Ig-bound HBs. These data suggest that small amounts of HBs-antibody complexes may persist in circulating blood without always being harmful for the host.

Acute Disease↗
PubMed1979

[Retrospective study of 149 cases of hepatitis B virus infections. Study of markers and of evolution].

A retrospective study has been performed in 149 subjects with present or past HBs antigenemia. The group consisted of 8 asymptomatic carriers, 90 with acute hepatitis, 7 with fulminating hepatitis, 27 with chronic hepatitis, 16 with cirrhosis and 1 with hepatoma. The changes from one clinical condition to another, the sources of infection, the percentage of acute hepatitis in the history of chronic hepatitis cases and the working capacity an average of two years after the infection were studied. HBe antigen and the corresponding antibody were detected by immunodiffusion and the results compared with the clinical course.

Acute Disease↗
PubMed1978

[Effect of anti-inflammatory agents on chemotaxis of human neutrophils studied in vitro].

Using a modified Boyden chamber the effect of three antiinflammatory drugs on the chemotaxis of human neutrophils has been tested in vitro. Gold salt produced a reduction of both neutrophil migration and the ability of plasma to attract this cell. Betamethasone decreased chemotaxis by an action on the cell itself but not on the plasma. Aspirin had no effect on this function. These data suggest that antiinflammatory drugs act through different mechanisms and that the reduction of neutrophil chemotaxis may contribute to the antiinflammatory action of gold salts.

1-Propanol↗
PubMed1978

Chemotaxis of human polymorphonuclears in vitro. V. Role of the nonsegmented neutrophils and of the experimental conditions in the impairment of chemotaxis observed during bacterial infections.

Chemotaxis of human leukocytes was studied in vitro with a microfilter having pores of 3 micrometer used as a substrate for the gradient. Under these conditions, nonsegmented neutrophils did not reach the compartment filled with the attractant, but a significant proportion of them did so when filters with larger pores were substituted. When leukocytes from infected patients were tested with the usual 3 micrometer pore filters, chemotaxis was reduced (as previously shown), but less markedly and less frequently in simultaneous experiments with larger pores. In experiments performed under agarose layers instead of filters, nonsegmented neutrophils responded normally to chemoattraction, again suggesting that their impaired migration in filter experiments was a matter of pore size. When leukocytes from infected patients were assayed under agarose, no impairment occurred; on the contrary, a slight increase in both chemotaxis and random motility was observed. It was therefore concluded that some published cases of impaired neutrophil chemotaxis in infection might be due to technical bias related to pore size.

Bacterial Infections↗
PubMed1977

[Comparison between the presence of specific circulating immune complexes and the leukocyte migration inhibition test in different clinical forms of hepatitis B].

Circulating immune complexes were measured by a radioimmunoassay specific for HB complexes in different clinical situations related to hepatitis B virus infection. The leukocyte migration inhibition test (LMIT) was performed simultaneously. Comparison with the clinical situation suggests that immune complexes are not responsible for the lesions, but that these lesions might be produced by the immunity demonstrated by the LMIT. A deficiency of this immunity is responsible for the persistence of infection. However, in chronic active hepatitis, LMIT is as deficient as in carriers and in this form of hepatitis the frequency and quantity of complexes are the highest: it is thus possible that in this case the lesions are nevertheless produced by the complexes.

Antigen-Antibody Complex↗
PubMed1977

[Immune mechanisms in hepatitis B. New aspects and consequent practices].

The different types of immune responses occurring during hepatitis B virus infection are reviewed. The responses specific for HBsAg (hepatitis B surface antigen) are important in the pathogenesis of chronic liver disease. The cell-mediated immunity specific for this antigen seems to be responsible for cytolysis occurring when the antigen is located within the hepatocyte (acute and persistent hepatitis). It is also responsible for the subsequent elimination of the virus. Immune complexes in antibody excess probably provoke the lesion of fulminant hepatitis. Complexes in the zone of antigen excess, which are responsible for the extrahepatic lesions of the prodromic phase, may perhaps also play a pathogenetic role in some forms of chronic active hepatitis.

Antigen-Antibody Complex↗
PubMed1976

Lack of leukocyte migration inhibition by hepatitis B antigen and normal nonspecific immunoreactivity in asymptomatic carriers.

The immune response to hepatitis B surface antigen (HBS Ag) was studied in 25 asymptomatic carriers by the leukocyte migration-inhibition (LMI) test in agarose. In the presence of purified HBS Ag, inhibition was demonstrated in only four of 25 carriers, in contrast to 24 of 28 patients who cleared the antigen after acute infection with hepatitis B. Tuberculin purified protein derivative (PPD) was also used as an antigen for the LMI test in these carriers. Inhibition was demonstrated in only 12 of 25 individuals who had positive PPD skin tests, in contrast to all of 14 normal noncarrier individuals with positive PPD skin tests and none of 12 normal noncarrier of the asymptomatic carriers gave normal results. The lack of an immune response to HBS Ag was thought to be responsible for the persistence of the antigen and also for the absence of symptoms.

Adult↗
PubMed1975

[Chemotaxis of human polymorphonuclear cells in vitro. Study of inflammatory rheumatic diseases].

Sixty-eight determinations of leukocyte chemotaxis were performed in 42 patients suffering from systemic lupus erythematodes (17 cases), rheumatoid arthritis (15 cases) and scleroderma (10 cases). In contrast to the results of others, this study showed a deficiency in only 15 of 42 cases (35.7%). Impairment of chemotaxis was always transitory and demonstrable only during acute phases of disease. Intrinsic deficiency of PMN leukocytes as well as deficiency of plasma factors were related to the clinical and biological course of the disease and to the treatment.

Antibodies, Antinuclear↗