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Biomedical subjects

J R Joubert

Publications and source records attributed to J R Joubert.

At least 37 records · Page 2Linked to original sources
PubMed1989

Pigeon breeder's disease: the effect of antigen-specific antibodies on in vitro T cell responses of normal blood lymphocytes.

The effect(s) of affinity-purified antibodies to pigeon serum immunoglobulins on normal T cell responses in vitro was measured. Our results show that the antibodies partially inhibited the concanavalin-A-induced proliferation of normal lymphocytes (32% at 10 micrograms/ml concentration; p less than 0.001), whilst they had no significant effects at equivalent doses on the phytohemagglutinin-induced response. A study of the kinetics of this inhibition revealed that the antibodies exerted their effect(s) within the first 24 h of culture (p less than 0.001); this is probably due to their interference in early events intimately involved in the de novo synthesis and expression of activation antigens such as HLA-DR and Tac: antibody-treated cultures expressed 51.6 and 41.4% less HLA-DR and Tac, respectively. Two-colour immunofluorescence analysis showed that the specific antibodies bind to a subset of CD8+ cells only.

Alveolitis, Extrinsic Allergic↗
PubMed1988

Allergic asthma in different population groups in the western Cape. Causative and complicating factors.

Allergic asthma is a disease with a well-defined aetiology, the recognition and elimination of which could be achieved with relatively simple and inexpensive prophylactic treatment. Some of the well-known factors--respiratory tract infections, exposure to cigarette smoke, specific antigens and regular application of prophylactic treatment--which could cause or complicate asthma were studied in groups of white and coloured patients. More respiratory tract infections occurred in coloured patients and they were more exposed to their own and secondary cigarette smoke. Pets and grass pollen allergenicity was more common among whites while allergy to Aspergillus fumigatus and Ascaris lumbricoides was found more frequently among coloured patients. Both white and coloured patients had problems with regular prophylactic control of their symptoms with inhaled beta-stimulants, even after an average of two education sessions per patient, but this was of greater dimension for the coloured (60%) than the white group (27%) (P less than 0.001). It is not possible to separate causative from genetic factors when studying asthma in different population groups, but recognition of prevailing causative factors for each group could stimulate an educational approach aimed at control by prevention rather than treatment of acute attacks.

Adolescent↗
PubMed1988

Community-acquired pneumonia--factors influencing intensive care admission.

The mortality rate in critically ill patients with pneumonia who require invasive vital organ support, including mechanical ventilation, in an intensive care unit (ICU) remains above 50%. The contribution of these costly life support systems to the survival of patients with extensive pneumonia is a matter for debate. The high mortality rate in this group of patients can be attributed in part to the fact that they are frequently referred for ICU care when their condition has already deteriorated to the point of no return. A retrospective study over 18 months of 34 cases of community-acquired pneumonia (17 patients required ventilatory support in the respiratory ICU) was undertaken to identify criteria which would justify early admission to an ICU. These were first-line clinical and biochemical factors, three of which were present in all patients on admission to hospital: (i) bronchopneumonia or lobar pneumonia involving more than two lobes (P less than 0.001); (ii) respiratory rate greater than 30/min (P less than 0.001); and (iii) partial arterial oxygen pressure less than 8 kPa (P less than 0.001). Other systemic factors associated with a poor prognosis and admission to the ICU were clinical signs of septicaemia, abnormal liver function and low serum albumin value. A scoring system for severity of pneumonia based on these factors is proposed. The possibility of an improved prognosis in a potentially reversible disease can become a reality if this approach is employed prospectively.

Adult↗
PubMed1987

Intensive care management of acute organophosphate poisoning. A 7-year experience in the western Cape.

Organophosphate poisoning (OPP) was an important reason for admission of patients to the respiratory intensive care unit (ICU) at Tygerberg Hospital, Parowvallei, CP, during the period 1979-1985; a marked increase in the number of cases was evident over the last 2 years. We retrospectively reviewed the medical records of 61 patients with OPP admitted to the ICU over this 7-year period. Diagnosis was based on the history, clinical manifestations of OPP, and low pseudocholinesterase levels. Suicidal ingestion was the predominant cause of OPP. Of the 61 patients, 46 (75%) were under 40 years of age. In more than 50% of cases the clinical presentation was characterised by classic signs of OPP such as increased secretions, fasciculations and small pupils. In 61% the level of consciousness was disturbed. We retrospectively classified and graded patients on a scale of 0-3 on the basis of the initial clinical findings, blood gas values and chest radiographs, in an attempt to facilitate identification of high-risk cases. Patients with grade 3 intoxication (attempted suicide, stupor, partial arterial oxygen pressure (PaO2) less than 10 kPa and an abnormal chest radiograph--two or more factors present) were more likely to require ventilatory support and stayed in the ICU longer than patients with grades 0-2 intoxication (P less than 0.05). Patients who presented with pulmonary abnormalities (admission chest radiograph abnormal or PaO2 less than 10 kPa) also required ventilatory support more frequently than did patients whose chest radiographs and blood gas values were normal on admission. The mortality rate was 16% and most deaths were due to respiratory complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part II. Management of patients.

During the outbreak of Crimean-Congo haemorrhagic fever (CCHF) at Tygerberg Hospital 8 patients were diagnosed positive. CCHF was diagnosed in another patient several months later. The treatment of these 9 cases is outlined. When it became evident that CCHF could present with a spectrum of severity, treatment was adjusted according to each patient's requirements. The essential components consisted of correction of haematological abnormalities combined with hyperimmune serum; the latter is particularly important for the severely ill patient with no antibodies to CCHF. The antiviral agents ribavirin and interferon were used but evidence to substantiate their application in future cases was inconclusive. Interferon was discontinued because of severe side-effects, many of which simulated the clinical features of CCHF. Objective improvement after corticosteroid treatment was noted in only 1 patient, but some of her symptoms could have been due to a transfusion reaction. Antibiotics were not routinely used. The 2 patients who died were diagnosed late, did not receive hyperimmune serum, and eventually developed multi-organ failure. The course of CCHF can probably be modified if the diagnosis is made early, if antiserum is given, and if the haematological abnormalities are promptly corrected.

Adult↗
PubMed1985

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part IV. Preventive and prophylactic measures.

During the Crimean-Congo haemorrhagic fever (CCHF) outbreak at Tygerberg Hospital a particular problem existed: a simultaneous influenza epidemic complicated the screening of contacts because of its very similar clinical picture to that of early CCHF. The methods of identifying and screening contacts are described. Of 459 listed CCHF contacts, 7 (1,5%) developed the disease; 6 were contacts of the index case and only 1 a contact of a secondary case. Two of the 7 CCHF patients had no direct contact with the index case; this caused great concern about the dissemination, despite the otherwise full protective measures. Four of 46 blood contacts (8,7%) and 3 of 9 needle contacts (33%) developed the disease. Prophylactic interferon therapy had to be discontinued because of side-effects mimicking the symptoms of CCHF. Ribavirin was used prophylactically in 6 of the 9 inoculation contacts. One of the patients on ribavirin had a mild clinical course while 5 others who received the drug developed neither clinical CCHF nor antibodies to the virus. Two of the 3 needle contacts not treated with ribavirin had a severe clinical course. One contact with needle inoculation and 42 proven blood contacts who had not received ribavirin did not become infected. No firm conclusion can therefore be made about the protective value of prophylactic ribavirin.

Adult↗
PubMed1985

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part III. Clinical pathology and pathogenesis.

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in 8 patients; 7 were staff members at Tygerberg Hospital who had been infected by a patient in whom the disease had not initially been diagnosed. Two patients, the initial case and a staff member, died and 4 became seriously ill. The immunopathogenesis of CCHF appears to be multifactorial. Certain features were common to all patients--leucopenia, thrombocytopenia, elevated liver enzyme values and low serum total protein levels. Ultrastructural changes in and around skin capillaries, including intracytoplasmic endothelial tuboreticulated bodies, were found. Virus-like particles were found on electron microscopy. Important individual factors related to prognosis were identified. The patients who survived all mounted a good antibody response, and manifested no coagulation defect extensive enough to explain the haemorrhagic tendency. In the patients who died no evidence of antibody production was detected; both developed diffuse intravascular coagulation and in 1 evidence of immune complex formation and complement consumption was found. Hepatorenal failure and cardiovascular collapse characterized the terminal period. Early clinical recognition of CCHF with specific attention to factors amenable to treatment may vastly improve the prognosis.

Adult↗
PubMed1985

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part I. Clinical features.

Crimean-Congo haemorrhagic fever (CCHF) is a rare disease in South Africa. From 1981 to September 1984, 8 sporadic primary cases were reported. An outbreak of CCHF in a large university hospital is described; of 8 patients diagnosed 2 died (the index and a secondary case). Four patients were seriously ill and 2 had a mild illness. Problems were encountered in diagnosing the disease, which presents initially with influenza-like symptoms, differing only in severity from influenza. However, petechiae and other manifestations of a bleeding tendency distinguished it from influenza in the later phase of the disease. Special investigations, especially those revealing leucopenia and thrombocytopenia, were critically important in early diagnosis. The dilemma of handling this highly contagious disease is that definite virological diagnosis is time-consuming and is conducted in only one high-security laboratory 1600 km distant. A further case was admitted 3 months later from a different locality and confirmed virologically but no secondary cases could be confirmed or traced.

Adult↗
PubMed1985

Inhalation therapy during acute asthma. The role of a combined steroid and beta-stimulant preparation.

A compound consisting of a beta-stimulant, salbutamol (Ventolin; Allen & Hanburys) (100 micrograms/puff), and a steroid, beclomethasone dipropionate (Becotide; Allen & Hanburys) (50 micrograms/puff), was studied to test the hypothesis that the corticosteroid could enhance the bronchodilator properties of the beta-stimulant during chronic asthma and simulated acute attacks (antigen challenge). Conventional doses (200 micrograms and 100 micrograms of salbutamol and beclomethasone respectively) were compared using a schedule which included a second administration 1 hour later. The results obtained on the baseline bronchial responsiveness of chronic asthmatics and during the delayed asthmatic response (simulated acute asthma) were similar. The compound was as effective as salbutamol alone but not more so. A significantly greater bronchodilator response was recorded in all patients after the second administration of both the compound and salbutamol alone. The practical advantages of having one rather than two inhalers are evident, but the appropriate application of this compound agent, probably in a prophylactic role, must be defined.

Acute Disease↗
PubMed1985

Lung function and plasma levels of thromboxane B2, 6-ketoprostaglandin F1 alpha and beta-thromboglobulin in antigen-induced asthma before and after indomethacin pretreatment.

The effect of specific antigen challenge on the lung function of eight allergic asthmatic patients after placebo and indomethacin pretreatment has been investigated. Plasma levels of thromboxane B2(TxB2), metabolite of thromboxane A2, 6-keto-PGF1 alpha, metabolite of epoprostenol, (prostacyclin, PGI2) and beta-thromboglobulin (beta TBG) following antigen challenge in these eight patients have also been measured after placebo and indomethacin pretreatment. Each patient underwent two antigen inhalations 1 week apart. One challenge took place after 4 days pretreatment with indomethacin capsules 25 mg four times daily, and the other took place following 4 days placebo pretreatment, one matched capsule four times daily. The order of administration was random but balanced and blind with respect to the patient. Following placebo pretreatment two patients presented with an early antigen response only, four presented with a biphasic antigen response and two presented with a delayed antigen response only. The asthmatic response for each patient was consistent on re-exposure. Indomethacin pretreatment suppressed the delayed antigen induced asthmatic response. This suppression was reproducible. There was a rise in plasma TxB2 levels on antigen challenge following placebo pretreatment but not following indomethacin pretreatment, whereas there was a rise in 6-keto-PGF1 alpha after antigen challenge following indomethacin but not placebo pretreatment. No significant change in plasma beta TBG or platelet counts from control values was observed following antigen challenge with either placebo or indomethacin pretreatment. It is suggested that the production of PGI2 and suppression of TxA2 by indomethacin pretreatment contribute to the suppression of the delayed antigen induced asthmatic response and that platelets play a minimal role in this process.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Non-steroid anti-inflammatory drugs in asthma: dangerous or useful therapy?

The therapeutic potential of non-steroid anti-inflammatory drugs in clinical asthma is offset by the real possibility of hypersensitivity and induction of severe airways obstruction. The influence of indomethacin on the antigen-induced asthmatic response was tested. Early and delayed asthmatic responses were recorded after antigen challenge in 13 subjects. Indomethacin pretreatment totally or partially inhibited the delayed asthmatic response in 10 of 11 subjects. Inhibition by indomethacin of products of the arachidonic cascade which participate in the pathogenesis of the delayed asthmatic response could explain this phenomenon. A similar therapeutic response was documented without adverse drug reactions when five subjects were restudied after several months. In the same group the early asthmatic response was suppressed in six, enhanced in two and unchanged in four of 12-subjects. This variable response indicates that spasmogenic prostaglandin breakdown products may be important for certain individuals, but are generally of less importance in the early asthmatic response. Clinical trials with indomethacin as a steroid saving agent in allergic asthma appear feasible and can be conducted safely.

Adolescent↗
PubMed1983

Flunisolide nasal spray in the treatment of perennial rhinitis.

Twenty patients with perennial rhinitis took part in a double-blind, randomized, cross-over comparison of flunisolide nasal spray (Syntaris; Syntex) and its vehicle. The sprays were used twice daily for 4 weeks and a total daily dose of 200 micrograms flunisolide was used. Flunisolide was superior to the placebo in relieving sneezing, runny nose and nose-blowing (P less than 0,05). Patient and doctor treatment preferences were significantly in favour of the active spray. Side-effects were mainly confined to nasal irritation and occurred equally in both treatment groups.

Administration, Intranasal↗
PubMed1983

Interaction of liposomes with human leukocytes in whole blood.

The uptake of multilamellar liposomes into human leukocytes in whole blood in vitro was evaluated on the basis of the cellular association of liposomal markers (3H-labelled cholesterol, lipid phase; [14C]inulin, aqueous phase). The entry of liposomes into human blood leukocytes was linear for 60 min and was mediated by a saturable mechanism displaying affinity constants of 0.28 +/- 0.17 and 0.16 +/- 0.05 mM liposomal lipid (means +/- S.E.) for liposomal lipid and aqueous phase markers, respectively. Amicon filtration analysis of incubation mixtures containing blood and liposomes (phosphatidylcholine:dicetyl phosphate:cholesterol, 70:20:10) showed that 34% of [14C]inulin was lost (neither liposome-associated nor cell-associated) after 60 min. By preincorporating sphingomyelin (35 mol%) into multilamellar liposomes, the leakage of the model aqueous phase marker inulin was reduced to 8% after 60 min, thus enhancing the drug carrier potential of liposomes in blood. As a consequence of their interaction with liposomes, the polymorphonuclear leukocytes in whole blood decreased in apparent buoyant density, while maintaining their viability. These results indicate that blood leukocytes in their natural milieu of whole blood are capable of interacting with, and taking up multilamellar liposomes.

Biological Transport, Active↗
PubMed1982

Systemic sporotrichosis: pulmonary complications of a well-known cutaneous fungal disease. A case report.

Pulmonary involvement during Sporotrichium schenkii infection can present as either primary pulmonary or systemic disease. The clinical and radiological features in the primary form closely resemble those of adult-type tuberculosis. On clinical, radiological and histopathological grounds pulmonary involvement during systemic spread can be difficult to distinguish from sarcoidosis. The diagnostic and therapeutic problems encountered in a woman with systemic sporotrichosis infection with pulmonary involvement are described.

Female↗
PubMed1982

A radioallergosorbent test (RAST) for Ascaris lumbricoides.

An antigen from Ascaris lumbricoides obtained from infected humans has been prepared which can be used for detecting immune response to Ascaris using the skin-prick test. A comparison of immune skin responses between this antigen and the commercial (Bencard) Ascaris suum antigen has been made and a RAST technique for the in vitro detection of specific IgE to Ascaris lumbricoides has been developed using the Lumbricoides antigen. A correlation between skin-prick test and RAST determinations and between RAST and total serum IgE antibodies has been demonstrated. The correlation of RAST results and serum IgE levels agreed with the division of the patients into two classes-allergic and non-allergic-on the basis of clinical criteria for allergy.

Antigens↗