Standardization of the indirect fluorescent antibody test for malaria.

Methods are described whereby results of malarial immunofluorescence tests can be evaluated objectively. The IFA test was quantitated by standardizing the physical system against a fluorescent standard and preparation of biological standards of malarial antisera and fluorescein labelled conjugates. Using these known standards the reactivity of antigens was characterized. It was found that antigen preparations are best when they include mature schizonts, and keep best when they are stored in a dry condition at or below -20 degree C. However, even under carefully controlled conditions of storage, antigens showed considerable variation of reactivity between individual batches.     

Repeatability of non-invasive measurement of intracerebral pulse wave velocity using transcranial Doppler

In the present study, the repeatability of three techniques for measuring peripheral PWV (pulse wave velocity) has been studied. A transcranial Doppler provided a wave reading from the middle cerebral artery. Using the transit time between the R-wave of an ECG and the 'foot' of this wave we were able to calculate a PWV (PWV-brain). An ear clip transducer provided a pressure wave reading (PWV-ear). A third pressure reading came from a Finapres transducer on the left middle finger (PWV-finger). The PWV was calculated as distance between two points/transit time of the pulse wave. Eleven volunteers had three sets of readings averaged for each technique taken in two separate sessions. There was good agreement between observers for the mean PWV values, and good agreement for mean results in different sessions. The RC%s (repeatability coefficient percentages) for between-observer repeatability in each session were good and approximately equivalent for PWV-finger (5-7%) and PWV-brain (5-7%). The repeatability of the PWV-ear measurement was less satisfactory (8-18%). The RC% for the same observer between sessions was less good, being 11% for the PWV-finger, 16-17% for PWV-brain and 11-19% for PWV-ear. The RC%s for the inter-session inter-observer measurements were between 10.7-12.1% for the PWV-finger, 14.7-19.5% for PWV-brain and 8.3-15% for PWV-ear. The transit time RC%s were lower in most measurements. The between-observer repeatability of all measures was satisfactory. Owing to the less good repeatability on different occasions, the use of PWV-brain and PWV-ear will depend on the magnitude of differences to be expected.     

Therapeutic management of acute intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a stroke resulting from spontaneous rupture of an intracranial vessel and is associated with high early mortality and long-term morbidity rates. With the exception of dedicated stroke units or neurocritical care, no surgical or medical intervention has been proven to effectively improve outcome following ICH. Pharmacotherapeutic considerations include optimal blood pressure control and the choice of antihypertensive agents. Acute haematoma expansion represents the most obvious acute treatment target. The use of haemostatic agents may have a role in ICH management; although it appears improved patient selection may be required before the use of these agents can be demonstrated clinically. In patients with anticoagulant-associated ICH, a number of therapeutic agents may be used to urgently reverse the coagulopathy, although further clinical trials are required. Recurrent bleeding and future thrombo-embolic event rates in patients who require anticoagulation following ICH risks are difficult to determine accurately, although risk stratification data are emerging. This article reviews the pathophysiology, natural history and the evidence supporting present therapeutic management practices for ICH. The authors' practice based on best available evidence is provided.     

Blood pressure management in acute intracerebral haemorrhage guidelines are poorly implemented in clinical practice

Background

Optimal management of blood pressure (BP) in spontaneous intracerebral haemorrhage (ICH) is controversial. We assessed adherence to BP guidelines and its management in ICH in a tertiary Canadian Stroke Centre.

Methods

We conducted a retrospective analysis of 142 CT confirmed primary ICH patients admitted within 24 h of symptoms between 2005 and 2006. Initial practice with respect to BP control was reviewed and compared with current guidelines. This retrospective sample was compared with a prospective cohort participating in a BP lowering trial for the attainment of pre-defined BP targets. We also assessed the effect of BP treatment on hematoma expansion and mortality.

Results

Blood pressure treatment orders were established in 73% of the 142 patients (median age 71 years, 61% male). Only 26% of patients had target orders as advised in the current AHA guidelines. Only 54% achieved BP targets as compared with 83% of the prospective cohort within 1 h. Patients with established BP orders were more likely to have repeat brain imaging (70.2%) than those without (39.5%; p = 0.001 Mortality rates were 29.8% and 47.4% in those with and without BP targets respectively (p = 0.051).

Conclusions

Management of BP varies considerably and there appears to be little adherence to recommended guidelines. Targets are achieved more rapidly if a BP treatment protocol is utilized.     

Pulmonary antibacterial defense mechanisms are depressed by halothane

Pulmonary antibacterial activity was determined by challenging halothane-exposed and control mice to radiolabeled (32P) Staphylococcus aureus produced by an aerosol generator and by determining the relative changes in viable bacterial and radioisotope counts in ground lung immediately after exposure and 4 hours later. Mice that were anesthetized for 4 hours with 1 or 2 MAC halothane and allowed to recover for 1 hour showed higher 4-hour bacterial counts when compared to controls, while radioisotope counts were the same in both groups. These data indicate that 1 and 2 MAC halothane anesthesia is associated with depressed lung bactericidal activity but that physical clearance mechanisms are not depressed.     

Detection and measurement of species-specific malarial antibodies by immunofluorescence tests.

Species-specific serodiagnosis of malaria could be made by means of the standardized indirect fluorescent antibody test, either by determination of the usual end-point titres or by fluorescent intensity measurements on antigens. The malarial antibody levels could also be measured by the fluorescent intensity measurements at a single serum dilution. Thus the fluorescent intensity measurements could effectively replace the end point titre determination, with the advantages of standardization and saving in technician time.