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Biomedical subjects

S Britton

Publications and source records attributed to S Britton.

At least 91 records · Page 5Linked to original sources

Psychological factors influence the success of coronary artery surgery.

Thirty-six patients with angina were investigated by treadmill exercise testing and coronary angiography prior to coronary artery surgery. Severity of angina was judged by interview and self-assessment visual analogue scale and all patients were psychiatrically assessed. Further physical and psychiatric assessments were made at 3 and 6 months postoperatively. Eleven patients (31%) had significant psychiatric morbidity preoperatively and these had worse symptom scores and exercise tolerance compared with non-psychiatric cases, despite equivalent coronary angiographic findings and left ventricular function. Post-operatively, exercise tolerance improved equally in both groups but psychiatric cases remained significantly more symptomatic. Psychiatric morbidity remained unchanged throughout the study. We conclude that almost one third of patients with severe angina have psychiatric morbidity which is associated with a poor symptomatic response to coronary artery surgery, despite objective improvement in exercise tolerance. Ways of improving the symptomatic response to surgery in patients with coexisting psychiatric morbidity should be studied.

Adult↗

Acyclovir treatment in infectious mononucleosis: a clinical and virological study.

Fifty-six patients with a clinical and laboratory diagnosis of infectious mononucleosis who had not been ill for more than seven days, were randomised for peroral treatment with acyclovir (800 mg five times daily) or placebo for seven days in a double blind trial. Clinical, virological and immunological parameters were monitored in each patient for six months. During treatment, shedding of Epstein-Barr virus' as assessed in 36 patients, was significantly reduced (p less than 0.001). However, virus production in the oropharynx returned to pre-treatment levels one week after the cessation of therapy. Virus was detected in 35 patients at enrollment and in 28 of 36 patients at the six-month control. No effect on the clinical course of the disease was noticed. The virus-specific antibody response was also unaffected. A significant reduction in spontaneous outgrowth of in vivo Epstein-Barr virus-infected B-lymphocytes was found at 180 days after treatment in four acyclovir-treated patients compared to six controls (p less than 0.001). In another three patients with over-whelming clinical symptoms causing airway obstruction and/or disseminated intravascular coagulopathy, treatment with intravenous acyclovir (10 mg/kg three times daily) was combined with prednisolone (0.7 mg/kg daily) for ten days. Virus shedding ceased transiently during treatment, but returned to initial levels within one week. A dramatic clinical effect on the pharyngeal oedema and general health of the two patients with airway obstruction was noticed, but was much less evident in a patient with intravascular coagulopathy.

Acyclovir↗

Rapid detection of cytomegalovirus using immune scanning electron microscopy.

Monoclonal antibodies, specific for human cytomegalovirus, were conjugated to latex microspheres that were already labelled with rabbit anti-mouse immunoglobulin. The beads were then incubated with serum or urine from patients, and then collected on a filter surface, which was analyzed in a scanning electron microscope. Size, immunological specificity, and relative quantity of virus particles were determined within 2 h after serum or urine collection by the visualization of virus particles specifically bound to the latex-bead surface. No such binding of virus particles was detected in the various controls. This method was compared with conventional virus isolation by tissue culture. It enables identification of viruses within a few hours in different body fluids. Even without specific antibodies, the filtration method may permit the rapid detection of particles and the determination of their size in various body fluids.

Antibodies, Monoclonal↗

Rapid detection of cytomegalovirus using immune scanning electron microscopy.

Monoclonal antibodies specific for human cytomegalovirus were conjugated to latex microspheres that were already labelled with rabbit anti-mouse immunoglobulin. The beads were incubated with serum or urine from patients, and then collected on a filter surface, which was analyzed in a scanning electron microscope. Size, immunological specificity, and relative quantity of virus particles were determined within 2 h after serum or urine collection by the visualization of virus particles specifically bound to the latex bead surface. No such binding of virus particles were detected in the various controls. This method was compared with conventional virus isolation by tissue culture. It enables identification of viruses within a few hours in different body fluids. Even without specific antibodies, the filtration method may permit the rapid detection of particles and the determination of their size in various body fluids.

Antibodies, Monoclonal↗

Methods for the detection of a specific Mycobacterium leprae antigen in the urine of leprosy patients.

Two methods for detecting the phenolic glycolipid, PGL-1, a Mycobacterium leprae-specific molecule, in the urine of leprosy patients are described. Both methods rely on the 100-fold preconcentration of the urine, which can be accomplished by a single-step ultrafiltration procedure. The equivalent of approximately 2.5 micrograms of PGL-1/ml was detected in the urine of LL patients with an inhibition ELISA. The second method, a direct dot-blot assay on nitrocellulose paper, was much simpler and more sensitive. As little as 3 ng of antigen was detected by the dot-blot technique. PGL-1 was detected in the urine of LL patients.

Antigens, Bacterial↗

Responsiveness in diffuse versus local cutaneous leishmaniasis is due to parasite differences.

Leishmania aethiopica infection results in two main clinical entities, diffuse disease (DCL) and localized ulcers (LCL). The lack of reactivity to leishmanial antigens has been attributed, among other things, to some inherent immunological defect of the host or considered as a consequence of the initial site of infection. Properties unique to the infecting parasite have been said to contribute little if anything to the differences between DCL and LCL found in the same areas of Ethiopia. Data are given to show that infected individuals respond by higher production of IL-2 to antigens from LCL isolates (lcl antigen), than to antigens derived from DCL isolates (dcl antigen). Furthermore, dcl antigen induced less gamma interferon from lymphocytes of all individuals tested than did lcl antigen. Lymphocytic proliferation of cells from control individuals working in the endemic area was higher in response to lcl isolates than to dcl isolates. These findings suggest that some differences in the parasites may contribute to the clinical outcome of infection with L. aethiopica.

Adult↗

A single cell assay for the study of gamma-interferon formation in leprosy patients.

The number of gamma-interferon producing cells in the peripheral blood of leprosy (LL and BT) patients and controls was studied by the reversed protein A plaque assay before and after exposure in vitro to Mycobacterium leprae bacilli and Epstein-Barr virus (EBV). The level of spontaneous gamma-interferon production was significantly higher in BT patients compared to LL patients and controls. Mycobacterium leprae induced a specific gamma-interferon response in lymphocytes from BT patients and from healthy contacts whereas in LL patients and non-exposed controls the response was low or non-existing. There were no significant differences in the gamma-interferon response to EBV between the above groups.

Antigen-Presenting Cells↗

Effect of acyclovir on infectious mononucleosis: a double-blind, placebo-controlled study.

Thirty-one patients with clinical and laboratory diagnoses of infectious mononucleosis who had had symptoms for seven or fewer days were randomized for intravenous treatment with acyclovir (10 mg/kg) or placebo at 8-hr intervals for seven days in a double-blind trial. Clinical signs and symptoms were registered, and excretion of virus in the saliva as well as antibody responses in sera and saliva were assessed before, during, and at regular intervals in the six months after treatment. Acyclovir significantly (P less than .001), but reversibly, inhibited oropharyngeal shedding of Epstein-Barr virus. The humoral and cellular immune responses, however, did not differ between the two groups; nor did the development of viral latency. There were no significant (P greater than .05) differences in individual clinical symptoms or in laboratory parameters between the two groups; however, when data concerning duration of fever, weight loss, tonsillar swelling, pharyngitis, and self-assessment by the patient were combined, a significant (P less than or equal to .01) effect of treatment with acyclovir was evident.

Acyclovir↗

Chest physiotherapy in primary pneumonia.

One hundred and seventy one patients with primary pneumonia entered a single blind, placebo controlled trial of physiotherapy. Treatment was allocated at random, physiotherapy consisting of postural drainage, external help with breathing, percussion, and vibration and the controls receiving advice on expectoration, deep breathing, and how to exercise to avoid thrombosis. Principles of pharmaceutical management were the same in the two groups. There was no objective evidence that daily physiotherapy helped during the acute phase of the disease. On the contrary, in younger patients, smokers, and patients with interstitial pneumonia physiotherapy appeared to prolong the duration of fever as well as the hospital stay. It is concluded that chest physiotherapy is at best useless in patients with primary infectious pneumonia.

Adolescent↗

Immunoglobulin M and immunoglobulin G secretion by human B cells exposed to RU 41.740, a glycoprotein extract from Klebsiella pneumoniae.

RU 41.740, a glycoprotein extract from Klebsiella pneumoniae, was seen to activate human B cells to immunoglobulin secretion in vitro. The effects of RU 41.740 on human B cells were compared to those induced by pokeweed mitogen, a T-cell-dependent polyclonal B-cell activator, and Epstein-Barr virus, a T-cell-independent polyclonal B-cell activator. Exposure of human B cells to all of these agents resulted in increased immunoglobulin M (IgM) and immunoglobulin G (IgG) secretion. IgM and IgG secretion induced by RU 41.740 appeared to be T cell dependent when B cells were isolated from human peripheral blood. However, this activity may have been T cell independent when B cells were isolated from human spleen. RU 41.740-induced IgM secretion by peripheral blood B cells was seen to peak after 6 days in culture; IgG secretion peaked after 7 days in culture. The optimal concentration of RU 41.740 for the induction of IgM and IgG secretion by human B cells in vitro was seen to be 200 micrograms/ml.

Adult↗