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Biomedical subjects

H Roberts

Publications and source records attributed to H Roberts.

At least 91 records · Page 5Linked to original sources
PubMed1989

Serodiagnosis of acute toxoplasmosis in macropods.

The sera of 34 Australian macropods, the brains of which had been bioassayed for Toxoplasma gondii, were used to establish that a titre greater than 1/32 was significant for a direct agglutination test against toxoplasmosis. In addition, the concentration of 2-mercaptoethanol required to destroy the IgM fraction of macropod serum was confirmed in a modified direct agglutination test. To further validate the tests, the serological responses of three eastern grey kangaroos (Macropus giganteus) dosed orally with T. gondii oocysts and one M. giganteus injected with T. gondii cysts were studied. The tests were then used to investigate a diagnosis of acute toxoplasmosis in four Tasmanian pademelons (Thylogale billardierii) clinically suspected of acquiring toxoplasmosis naturally. One hundred and fifty-one Bennett's wallabies (Macropus rufogriseus rufogriseus) and 85 T. billardierii were also tested to determine the prevalence of acute toxoplasmosis of macropods in the wild. Four percent of M. r. rufogriseus and 1.2% of T. billardierii possessed T. gondii-specific IgM in their sera.

Acute Disease↗
PubMed1989

The use of porcine factor VIII concentrate (Hyate:C) in the treatment of patients with inhibitor antibodies to factor VIII. A multicenter US experience.

The response to a highly purified concentrate of porcine factor VIII was evaluated in 45 bleeding episodes in 38 patients with high responding inhibitor antibodies to factor VIII. A total of 437 infusions were given. The patients came from 25 hemophilia centers in the United States. The majority had a life- or limb-threatening hemorrhage for which other modalities had not been successful. In 32 of 45 episodes, a good to excellent response was obtained. Adverse reactions were minimal, occurring in 17 treatment episodes, and were mostly treated with antihistamines and/or hydrocortisone. No clear predictor of clinical response to porcine factor VIII concentrate was identified, including pretreatment human and porcine inhibitor levels, percentage of cross-reactivity between the human and porcine antibodies, and the presence of measurable levels of factor VIII after the porcine factor concentrate was given. Anamnesis to porcine factor VIII did occur in some instances. Porcine factor VIII is a valuable modality in the treatment of serious hemorrhages in patients with inhibitors to factor VIII. Its use should be considered early in the course of severe hemorrhage in these patients.

Adolescent↗
PubMed1989

Familial protein S deficiency with a variant protein S molecule in plasma and platelets.

A protein S deficient family presenting a variant protein S molecule in plasma and platelets is described. The propositus, age 20, and two brothers suffered from venous thrombotic disease. The propositus, the only family member studied while taking oral anticoagulants, had a protein S antigen (ag) level of 17% and undetectable activity. As demonstrated by immunoblotting both the propositus and one clinically affected brother (42% ag, 7% activity) presented variant protein S molecules of 65,000 molecular weight (mol wt) while the other clinically affected brother (64% ag, 11% activity) had only protein S with normal electrophoretic mobility of 70,000 mol wt. The mother had normal protein S levels (93% ag, 100% activity) but had both normal and variant protein S molecules and based on her functional protein S data a normal anticoagulant activity of the variant molecule is suggested. One asymptomatic but protein S deficient sister (68% ag, 9% activity) as well as the asymptomatic protein S deficient father (59% ag, 10% activity) had only protein S molecules of 70,000 mol wt. The variant protein S bound to C4b-binding protein in plasma, and differed from normal protein S in carbohydrate content. Platelets of each family member contained the same immunoblotting pattern of normal and variant protein S forms as found in plasma, consistent with the hypothesis that protein S gene expression involves codominant expression of two alleles that is similar in cells that control the synthesis of both platelet and plasma forms of protein S.

Blood Coagulation Factors↗
PubMed1988

Prevalence of Toxoplasma gondii antibody in wild macropods.

An enzyme-linked immunosorbent assay (ELISA) was developed to measure total antibody to Toxoplasma gondii in serum samples from macropods. The validity of the assay was established by comparing parasite isolation in mice for 17 Tasmanian pademelons (Thylogale billardierii) and 17 Bennett's wallabies (Macropus rufogriseus rufogriseus). The ELISA was then used to detect antibody against T. gondii in serum from 236 macropods, collected from 21 locations in Tasmania, including Flinders Island. Antibody against T. gondii was detected in 20 animals (15 T. billardierii and 5 M. rufogriseus). There was a significant (p less than 0.01) difference in possession of T. gondii antibodies between adult (greater than or equal to 1 year of age) Tasmanian pademelons and Bennett's wallabies.

Animals↗
PubMed1988

The use of high-dose intravenous gamma-globulin in acquired von Willebrand syndrome.

Acquired von Willebrand syndrome has been reported in patients with a variety of primary diseases, many immunologic in nature. Usually, an autoantibody to von Willebrand factor can be identified. These patients often experience severe hemorrhages requiring large doses of cryoprecipitate or factor VIII concentrates, thus exposing them to viral and allergic complications. The success of intravenous gamma-globulin in the treatment of other autoimmune diseases prompted us to treat two patients with acquired von Willebrand syndrome with high-dose intravenous gamma-globulin. Two days after initiation of therapy, von Willebrand factor and factor VIII rose to normal levels in both patients. Patient 1 underwent dental surgery, and patient 2 underwent a splenectomy without increased bleeding and without additional factor coverage or desmopressin acetate therapy. Thus, intravenous gamma-globulin is efficacious for acquired von Willebrand syndrome and obviates the need for replacement therapy with its attendant complications.

Aged↗
PubMed1987

Antibody patterns in the serological diagnosis of acute lymphadenopathic toxoplasmosis.

Sera from six patients at various stages of acute lymphadenopathic toxoplasmosis were tested using nine different types of test currently available for the serological diagnosis of the disease. A diagnosis was made on positive serology in three of the patients. The antibody patterns of two of these patients were studied over a period of six months and the third was studied over two months. A diagnosis was made on lymph node morphology in the other three cases. Two serum samples were tested from each of these patients. The results obtained suggest that a rationalisation of the types of test used should be encouraged and that an enzyme-linked immunosorbent assay (ELISA) for parasite-specific IgG and an antibody class capture ELISA for parasite-specific IgM are sufficient to confirm the diagnosis of acute lymphadenopathic toxoplasmosis.

Adolescent↗
PubMed1985

Neurotic patients who terminate their own treatment.

40 new neurotic patients who lapsed from out-patient treatment were compared with 40 new neurotic patients who remained in treatment. The lapsed patients more often reported marital disharmony and 40% of them no longer felt ill at follow-up.

Adult↗