Serum IgA and IgG functional antibodies and their subclasses to Streptococcus pneumoniae capsular antigen found in two aged‐matched cohorts of children with and without otitis media with effusion

Serum IgA and IgG functional antibodies and their subclasses to Streptococcus pneumoniae capsular antigen found in two aged‐matched cohorts of children with and without otitis media with effusion The relationship between acute otitis media and otitis media with effusion (OME) is uncertain and the aetiology of OME is multifactorial. Otitis media with effusion may be an inflammatory condition; both bacteria and viral infections could play a part in this inflammation. The four bacteria Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus and Branhamella catarrhalis cause 60% of the infections whereas S. pneumoniae accounts for up to 35%. IgA provides the dominant surface response to polysaccharide and lipopolysaccharide antigens, of which IgA₂ is the main subclass. Once the mucosa has been breached, most protection is provided by IgG. IgG₂ acts mainly against bacterial capsular antigens. This study looked at two groups of 50 children with and without OME who were aged between 3 and 10 years. The aims were to determine if, firstly, the levels of the serum immunoglobulins were different in the two groups, secondly whether these children made the appropriate antibody response to the capsular antigen to S. pneumoniae (PCP), and finally if there was a delay in the maturity of the IgA response. The total IgG, IgA and all subclass levels were measured using radial immunodiffusion. Levels of functional IgA and IgG were measured using ELISAs (25 patients in each group). The results were analysed with non‐parametric tests. The immunoglobulin levels were within the normal levels for both groups. There were very good correlations between the IgG total anti‐PCP and the IgG₂ anti‐PCP (R > 0.9, p = 0.001). There was a good correlation between the levels of both IgG total and IgG₂ anti‐PCP against IgA total anti‐PCP in both groups (R > 0.85, p > 0.01). This confirms a normal antibody response between both groups of patients. The ages of the controls and patients (50 samples) were correlated with increasing titres of circulating functional antibodies (P = 0.001). This is highly suggestive of a normal age‐related response. In conclusion, the findings were contradictory to our original hypothesis that there is a subtle difference in surface protection between children with and without OME. We believe that a previous history of recurrent acute otitis media is unrelated to the development of OME after 3 years of age.     

Effect of pregnancy on the pharmacokinetics of metformin.

AIMS: To determine the effects of pregnancy on metformin pharmacokinetics. METHODS: Seven women with Type 2 diabetes mellitus taking metformin throughout pregnancy were studied on two occasions, once at 28-36 weeks gestation and once at least 8 weeks postpartum. Serum metformin concentrations were determined across a dosing interval using high-performance liquid chromatography. The areas under the serum concentration-time curve from 0 to 4 h post-dose (AUC0-4) and 0 to 8 h post-dose (AUC0-8) where possible, were compared in the pregnant and non-pregnant state. RESULTS: Metformin concentrations were lower in pregnancy in six subjects, with a mean (95% CI) AUC0-4 that was 69% (53.6, 84.8) of the postpartum value. The AUC0-4 of one subject was higher in pregnancy at 142% of the postpartum value. Overall, the mean (95% CI) AUC0-4 during pregnancy for all seven subjects was 80% (51.3, 107.8) of the postpartum value (P = 0.053, two-tailed t-test; P = 0.027, one-tailed t-test). CONCLUSION: These results are consistent with our hypothesis that the clearance of metformin increases in pregnancy as a result of enhanced renal elimination. A larger study is required to establish whether metformin dose adjustments are required in late pregnancy to maintain therapeutic effect.     

DLCO/Q and diffusion limitation at rest and on exercise in patients with interstitial fibrosis

Pulmonary diffusing capacity for carbon monoxide (DLCO) and pulmonary capillary blood flow (Qp) were measured on exercise in patients with a low DLCO with the aim of predicting, from the overall DL/Qp ratio, diffusion limitation for oxygen and relating it to the fall in arterial oxygen saturation actually observed. Five patients with cryptogenic fibrosing alveolitis (DLCO ranging from 20-54% predicted normal) exercised for 5 min at a work load equal to 60% of their maximum (45 to 90 watts). At 5 min (and previously at rest) they rebreathed rapidly for 15 sec from a 1.0 L bag containing helium (He), sulphur hexafluoride (SF6) and freon-22, 30% oxygen in argon and less than 1 ppm 11C-labelled carbon monoxide. Pulmonary capillary blood flow (Qp) and diffusing capacity (DLCO) were measured from flow-weighted breath-by-breath concentrations of freon-22 and 11CO, after correction for gas mixing delays (using He and SF6). Oxygen saturation (SaO2) (ear oximetry), MO2 and MCO2 and cardiac frequency were measured. PAO2 (ideal) was derived and mixed venous O2 saturation and content were calculated (Fick); PaO2 and PVO2 were derived from standard dissociation curves. For comparison, DLCO and Qp were measured in a similar fashion in five normal subjects exercising at 60 watts. Mean DLCO in patients with fibrosis was 9.62 (SD 2.88) ml.min-1, mm Hg-1 on exercise and mean Qp was 10.48 (SD 1.79) L.min-1 giving mean DLCO/Q ratios of 0.92 (SD 0.28). At 60 watts mean DLCO/Qp in normal subjects was 2.54 (SD 0.3), 2.76-times greater than in patients. SaO2% fell in patients by 3-15% on exercise. Predictions of alveolar-end capillary PO2 gradients from these overall DL/Q gradients showed that diffusion limitation accounted for 99% of the alveolar-arterial PO2 gradient on exercise in fibrosing alveolitis. Hughes (1991 Respir. Physiol. 83:167-178) [corrected] suggests that this simple approach overestimates the contribution of diffusion limitation by about 30%.     

Reemergence of Positive Symptoms after Initial Response to Risperidone

Risperidone was effective in successfully treating a patient's negative symptoms of schizophrenia as well as reducing adverse effects from typical antipsychotic drugs. Auditory hallucinations reemerged after 8 months, however, and again after 24 months of risperidone therapy. Reemergence of psychotic symptoms after initial response might be explained by inadequate dosage, by the natural course of the patient's schizophrenia independent of drug therapy, or by the possibility that, for this patient, risperidone was less effective than chlorpromazine for the positive symptom of auditory hallucinations.     

Nursing Assessment of Altered Sexuality: A Review of Salient Factors and Objective Measures

TOPIC. Nursing assessment of altered sexuality.
PURPOSE. To review salient factors affecting assessment and objective measures available for use in assessment.
SOURCE. Literature specific to nursing assessment of sexuality and to instruments measuring altered sexuality.
CONCLUSIONS. Many standards of care include the assessment of sexuality, and nurses believe it to be an important aspect of care. However, the assessment of altered sexuality does not often occur in actual practice. The use of an objective measure of sexuality is recommended for both initial and on-going assessments in acute-care and community-based settings.     

The action of amlodipine on voltage-operated calcium channels in vascular smooth muscle.

1. The activity of the Na+/K(+)-pump in rat peritoneal mast cells was measured at various time intervals after induction of cellular histamine release by compound 48/80 or by the antigen-antibody reaction. The Na+/K(+)-pump activity was assessed as the ouabain-sensitive potassium uptake of the cells using 86Rb+ as a tracer for potassium (K+(86Rb+)-uptake). 2. Stimulation of the cells with compound 48/80 induced a time and concentration dependent increase of the Na+/K(+)-pump activity. The pump activity was maximal 2 min after stimulation of the cells. Then, the activity gradually decreased and reached a level not significantly different from the controls after 2 h of incubation. 3. When the cells were stimulated by the antigen-antibody reaction, there was also a rapid (within 5 min) stimulation of the Na+/K(+)-pump. In contrast to the stimulation with compound 48/80, the pump activity returned to the control level after 60 min of incubation with antigen. 4. The ouabain-resistant potassium uptake of the cells was increased after stimulation of the cells, regardless of the secretagogue used. This probably reflects the increased surface area of the cells present after the histamine release. 5. On the basis of the present results, we suggest a role for the Na+/K(+)-pump in the recovery process of the mast cell following histamine release.