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Biomedical subjects

R S Desowitz

Publications and source records attributed to R S Desowitz.

At least 37 records · Page 2Linked to original sources
PubMed1986

Entamoeba polecki and other intestinal protozoa in Papua New Guinea Highland children.

Relatively few cases of humans infected with Entamoeba polecki have been reported world-wide. Where man and pig live in close association and where sanitation is poor, pig to man transmission is considered to be the most likely source of human infection. In our survey of 184 children only fresh faeces were used, thus allowing the identification of trophozoites as well as cysts. Thirty-five children (19%) were found positive for E. polecki, although in one community ten of 23 (43.4%) over five-year olds were infected. Sera from 20 positive children were tested against E. histolytica antigen, but no positive reactions were observed. We propose the possibility of man to man transmission of E. polecki where the prevalence rate and intensity of infection are high.

Antibodies↗
PubMed1986

Human and experimental anisakiasis in the United States.

In the past 13 years, 24 cases of anisakiasis have been reported in the United States. Of these, 14 were infections by Phocanema sp. and found in California and Alaska, and most were of the tissue non-invasive type. The remaining 10 cases were infections by larvae of anisakis type I (L3 and L4). Of these 10 cases, 4 were found on the west coast, 5 were on the east coast and one was in Hawaii. In 3 of the 10 cases, the parasite invaded the digestive tract. A characteristic symptom of the throat named "tingling throat" was manifested in 16 of the 24 cases, and this symptom was found to be due to larvae of Phocanema in most cases. As a method for immunological diagnosis of anisakiasis, the radioallergosorbent test (RAST) is being investigated as a cooperative study with Ishikura. As a result, IgE obtained from the sera of 4 patients who had been parasitologically diagnosed as having the disease and one patient in whom the parasite had not been confirmed but was clinically diagnosed as having the disease reacted strongly with anisakis larva antigens, and this reaction was able to be distinguished from the immune response to antigens of other Ascaris. On the other hand, when RAST was applied to child bronchial asthma patients in Hawaii, they showed a strong response to the anisakis larva antigens. Because the causative factors of child bronchial asthma in Hawaii are few and the environmental conditions are also good (i.e., do not cause asthma), their asthma is surmised to be helminth-associated asthma. In view of this background, as well, the results of RAST are interesting. When anisakis larva antigens were analyzed, a strong immunosuppressive effect was confirmed in the high molecular weight fraction (MW: greater than 10,000), while the presence of a substance having mutagenicity was confirmed in the low molecular weight fraction (MW: less than 10,000). In addition, in the sea near Hawaii, we discovered a novel species of Phocanema, which were named Terranova HA.

Animals↗
PubMed1985

The radioallergosorbent test (RAST) for the serological diagnosis of human anisakiasis.

The serum of patients with parasitologically confirmed and one patient with a clinically presumptive case of anisakiasis were tested by the radioallergosorbent test (RAST) and counter-electrophoresis (CEP) for IgE and IgG antibodies, respectively, using antigens prepared from larval (L3) stage Anisakis simplex and larval (L2) stage Toxocara canis. All sera were RAST-positive to the A. simplex antigen and RAST-negative to the T. canis antigen. All sera were CEP-negative to both antigens. The presence of a specific IgE antibody suggests that the RAST could serve as a useful technique for the serodiagnosis of anisakiasis in man.

Adult↗
PubMed1985

A comparison of counterimmunoelectrophoresis and indirect haemagglutination tests for the immunoepidemiological investigation of kala-azar.

Counterimmunoelectrophoresis (CIE) using cell-free extracts of Leishmania donovani promastigotes and Trypanosoma brucei as antigens and indirect haemagglutination (IHA) using commercially prepared reagents were compared for their diagnostic efficacy and applicability to immunoepidemiological studies in an area of Bangladesh where kala-azar is present. The CIE was positive for all parasitologically confirmed cases whereas the IHA positivity was only 60%. The T. brucei antigen was equally as good, if not better, than the L. donovani antigen for CIE. The CIE test was negative for all of 34 apparently healthy villagers. For this same group of individuals, 10 (29%) were low titre-IHA positive. The findings suggest that CIE is the more reliable diagnostic test but both methods should be employed for immunoepidemiological investigations.

Counterimmunoelectrophoresis↗
PubMed1984

Antigen-specific and concanavalin A-induced lymphocyte blastogenesis responses during the course of Plasmodium berghei infection in rats.

Antigen specific and concanavalin A (Con A)-induced lymphocyte blastogenesis responses were monitored in the spleens of rats infected with Plasmodium berghei. Con A responses were depressed only at the time of peak parasitaemia. The antigen specific blastogenesis response was either not in evidence, or at a low level during the periods of patent or subpatent infection (up to 8 weeks after infection). Higher levels of blastogenesis were seen from 8 to 12 weeks after infection, which correlates with clearance of subpatent infection. Fractionation of immune spleen cell suspensions on nylon wool columns indicated that purified T cells did not respond to parasite antigen.

Animals↗
PubMed1984

Inhibition of the adverse reaction to diethylcarbamazine in Dirofilaria immitis-infected dogs by diazepam.

Eight dogs with a Dirofilaria immitis microfilaraemia predictive for a moderately severe post-diethylcarbamazine (DEC) reaction, and 6 dogs with a microfilarial density predictive for a severe, fatal or near-fatal, reaction were given 5 mg diazepam (Valium) by intramuscular injection followed, 30 minutes later, by an intramuscular injection of 5 mg/kg DEC. Diazepam completely, or almost completely, blocked the post-DEC adverse reaction in all dogs of both groups. However, 5 D. immitis-infected dogs given DEC immediately following the injection of diazepam all developed an adverse reaction of a degree of severity, as measured by clinical and haematological parameters, customary for their level of microfilaraemia.

Alanine Transaminase↗
PubMed1983

Anisakis simplex and Terranova sp.: inhibition by larval excretory-secretory products of mitogen-induced rodent lymphoblast proliferation.

Excretory-secretory products were collected from supernatants of in vitro cultures of larval nematodes, Anisakis simplex (type I) and Terranova sp. (Hawaii type A). These materials were found to be more potent inhibitors of rodent lymphocyte blast transformation induced by concanavalin A and bacterial lipopolysaccaride than whole worm extracts of the same parasites. Inhibition of blast transformation was a result of cytostatic rather than toxic effects on proliferating lymphoid cells. The material(s) responsible for suppression are greater than 10,000 MW and are heat labile.

Animals↗
PubMed1983

Histopathology induced by larval Terranova (Type HA) (Nematoda: anisakinae) in experimentally infected rats.

Terranova Type Hawaii A larvae, gavaged into the stomach of Wistar rats, demonstrated the ability to invade the stomach and intestinal tissues of the rat without penetrating the serosa. Lesions induced by these third-stage larvae were present in 25 of 37 (68%) inoculated rats. Larvae adhered to the mucosa of the stomach within 1 hr PI. Mucosal ulceration and acute, focal, hemorrhagic areas in the mucosa and submucosa were associated with most worm-penetrations. Reactions of inflammatory tissue occurred from 4 hr to 6 days PI and granulomas occurred by day 7 PI. Indurated craterlike lesions were noted 10 to 15 days PI. Resolving granulomas were present by day 30 PI. Chronic gastric ulcers were observed at day 30 PI.

Animals↗
PubMed1983

The occurrence of an adverse reaction to chloroquine in Dirofilaria immitis-infected dogs.

The occurrence of an adverse reaction in Dirofilaria immitis-infected dogs following an intramuscular injection of chloroquine is described. The manifestations of this adverse reaction were characteristic of a neurologic disorder rather than the hypovolemic, shock-like state of the post-DEC adverse reaction previously described in dogs. In 3 of the 12 dogs the adverse reaction was of sufficient severity as to be fatal. Alterations in serum fibrinogen, serum transaminase levels and platelet numbers occurred but the magnitude of changes were not as great as that in the post-DEC adverse reaction. Following the injection of chloroquine the microfilaremia increased to a degree that was greater than the increase following DEC administration in the dog.

Animals↗
PubMed1982

Inhibition of the adverse reaction to diethylcarbamazine in Dirofilaria immitis-infected dogs by lodoxamide ethyl.

Lodoxamide ethyl, a new oral anti-allergy drug, was tested for its ability to inhibit the post-treatment adverse reaction to diethylcarbamazine (DEC) in Dirofilaria immitis-infected dogs. Lodoxamide was highly effective, as judged by the absence of both overt signs and characteristic post-DEC changes in platelet numbers, serum fibrinogen level, and serum transaminase (SGOT, SGPT) levels, in blocking the reaction in dogs with a microfilaremia level that would make them moderately reactive. Lodoxamide was less effective in blocking the reaction in dogs with microfilaremias greater than approximately 10,000 mf/ml, a level which is regularly associated with a severe post-DEC adverse reaction. Some dogs with this level of microfilaremia were fully protected, others partially protected, and others were afforded no protection. Two other agents tested, indomethacin and homochlorocyclizine, were found to have comparatively little or no blocking activity.

Amino Acids↗
PubMed1981

Antibodies to canine helminth parasites in asthmatic and nonasthmatic children.

We studied the prevalence of IgE and IgG antibodies to Toxocara canis and Dirofilaria immitis, helminth parasites of dogs, in asthmatic and nonasthmatic children born and raised in Hawaii. The serologic pattern of the two groups was found to differ significantly. Of the 80 asthmatic subjects, 45.0% had IgE antibody and 17.5% IgG-precipitating antibody to one or both parasites. In contrast, of the 96 nonasthmatic children studied 7.5% were positive for IgE antibody and 31.3% positive for IgG antibody.

Adolescent↗
PubMed1981

Observations on the adverse reaction to diethylcarbamazine in Dirofilaria immitis-infected dogs.

The severity of the adverse reaction, as assessed by clinical, haematological, and biochemical abnormalities, following treatment of Dirofilaria immitis-infected dogs with diethylcarbamazine (DEC) was found to be related to the level of microfilaraemia. The magnitude of change in the blood constituents studied was proportional to the severity of the side reaction. The most notable alterations in dogs experiencing a moderate or severe adverse reaction were a decrease in platelet numbers and fibrinogen level, a rise in serum transaminases, and the appearance of fibrin monomers. The practical value of qualitatively and quantitatively characterizing the post DEC adverse reaction is discussed.

Animals↗
PubMed1980

Effect of selenium and dimethyl dioctadecyl ammonium bromide on the vaccine-induced immunity of Swiss-Webster mice against malaria (Plasmodium berghei).

The results of the study described in this paper demonstrate that selenium, administered in drinking water, potentiates the protective effect of a killed Plasmodium berghei vaccine for Swiss-Webster mice. We also report that a vaccine consisting of P. berghei antigen combined with the adjuvant dimethyl dioctadecyl ammonium bromide conferred a significantly high level of protective immunity. An additive effect was shown in that the greatest degree of protection was afforded to the group of mice maintained on selenium and vaccinated with antigen-dimethyl dioctadecyl ammonium bromide. Almost all of the animals treated in this manner survived the challenging infection, the course of which was typically of a transitory parasitemia not exceeding 10% at the peak.

Animals↗