An epidemic of meningococcal infection at Zaria, Northern Nigeria. 1. General epidemiological features

In 1977 Zaria, in Northern Nigeria, was affected by a severe epidemic of group A meningococcal infection, 1,257 patients being admitted to hospital with the disease during a three-month period. The epidemic started towards the end of the dry season when it was hot, dry and dusty and finished shortly after the onset of the rains. The over-all attack rate was 3.6 per 1,000 but this varied considerably from area to area within the town. Few cases occurred amongst those belonging to the upper social classes. The disease was seen most frequently amongst those from five to 14 years old and there was a strong male preponderance. The over-all mortality was 8.3% but mortality was much higher (40.6%) amongst 67 patients with acute meningococcaemia.     

Storylines of research in diffusion of innovation: a meta-narrative approach to systematic review

Producing literature reviews of complex evidence for policymaking questions is a challenging methodological area. There are several established and emerging approaches to such reviews, but unanswered questions remain, especially around how to begin to make sense of large data sets drawn from heterogeneous sources. Drawing on Kuhn's notion of scientific paradigms, we developed a new method-meta-narrative review-for sorting and interpreting the 1024 sources identified in our exploratory searches. We took as our initial unit of analysis the unfolding 'storyline' of a research tradition over time. We mapped these storylines by using both electronic and manual tracking to trace the influence of seminal theoretical and empirical work on subsequent research within a tradition. We then drew variously on the different storylines to build up a rich picture of our field of study. We identified 13 key meta-narratives from literatures as disparate as rural sociology, clinical epidemiology, marketing and organisational studies. Researchers in different traditions had conceptualised, explained and investigated diffusion of innovations differently and had used different criteria for judging the quality of empirical work. Moreover, they told very different over-arching stories of the progress of their research. Within each tradition, accounts of research depicted human characters emplotted in a story of (in the early stages) pioneering endeavour and (later) systematic puzzle-solving, variously embellished with scientific dramas, surprises and 'twists in the plot'. By first separating out, and then drawing together, these different meta-narratives, we produced a synthesis that embraced the many complexities and ambiguities of 'diffusion of innovations' in an organisational setting. We were able to make sense of seemingly contradictory data by systematically exposing and exploring tensions between research paradigms as set out in their over-arching storylines. In some traditions, scientific revolutions were identifiable in which breakaway researchers had abandoned the prevailing paradigm and introduced a new set of concepts, theories and empirical methods. We concluded that meta-narrative review adds value to the synthesis of heterogeneous bodies of literature, in which different groups of scientists have conceptualised and investigated the 'same' problem in different ways and produced seemingly contradictory findings. Its contribution to the mixed economy of methods for the systematic review of complex evidence should be explored further.     

Children with acute Perthes' disease have asymmetrical lower leg growth and abnormal collagen turnover

Background Abnormalities in distal growth and low levels of insulin-like growth factor (IGF)-I have been reported in children with Perthes' disease. Our aim was to establish whether the acute phase of Perthes' disease is associated with abnormalities of growth, of bone or of collagen turnover.

Methods We performed a cross-sectional study of 15 children (3-11 years of age, 13 boys) at acute presentation and a longitudinal cohort study of 9 children. We measured (1) the lengths of both lower legs (by knemometry) at weeks 1, 2, 6 and 12, (2) height and weight at presentation and at the second-year follow-up, and (3) levels of IGF-I, IGFBP-3, collagen markers and bone alkaline phosphatase at weeks 1 and 12, and in year 2.

Results Height SD scores were normal at presentation but declined thereafter. Lower leg growth was not impaired at presentation but was asymmetrical, ceased during weeks 2-6, and then resumed symmetrically. Patients had persistently low IGF-I, low soft tissue collagen synthesis and enhanced collagen breakdown compared with age- and sex-related reference data. Markers of bone formation increased during follow-up.

Interpretation Acute changes in lower leg growth reflected differential weight bearing, then immobilization and remobilization. Persistently low IGF-I may have contributed to low soft tissue collagen synthesis and growth. Changes in bone formation markers most likely reflected bone healing.

  ▪     

Should people be physically active outdoors on smog alert days?

BACKGROUND: Given the importance of physical activity to well-being, there is a need to encourage people to be physically active year-round. At the same time, many people are vulnerable to adverse health effects from air pollution, especially on smog alert days. This study was undertaken to determine when air pollution levels tend to be lowest so that the public can modify strenuous outdoor activity accordingly. METHODS: Existing hourly air pollution data for Toronto were analyzed to determine how pollutant levels varied from hour to hour throughout each 24-hour day, to identify the times when pollution levels are at their lowest on average. RESULTS: Pollutant levels vary throughout the day, with concentrations of some pollutants (such as ozone, particles and sulphur dioxide) being highest during mid-day, and others (such as carbon monoxide and nitrogen dioxide) being highest with morning rush hour. Overall, pollutant concentrations tend to be lowest before seven a.m. and after eight p.m. INTERPRETATION: The public should be encouraged to maintain regular physical activity outdoors while monitoring any air pollution-related symptoms. The intensity of outdoor activity should be reduced, or activities replaced with indoor exercise, at those Air Quality Index (AQI) levels that trigger individual symptoms and when AQI values exceed 50. Where possible, strenuous activity should be taken when and where air pollution levels tend to be lowest, namely early in the morning and in low-traffic areas. More research is required to guide development of health protective advice on exercising when air quality is poor.     

Urine collection pads: are samples reliable for urine biochemistry and microscopy?

The aim of the study was to validate the reliability of samples obtained with urine collection pads (UCP) for selected laboratory biochemical analyses, urine cell microscopy, and bedside semi-quantitative stick urinalysis. A series of laboratory experiments was performed to test agreement between urine concentrations, or results, before and after passage through a UCP (incubated for 37°C for 15 min). The following urinalyses were performed: electrolytes, calcium, phosphate, urate, osmolality, pH, protein, catecholamines, toxicology for drugs of abuse, stick urinalysis for glucose, ketones, protein, blood, leucocytes and nitrites, and microscopy for red and white cells. Close agreement was shown for all laboratory analyses except proteinuria, which was underestimated by, on average, 10% after UCP passage. However, stick urinalysis for proteinuria remains sufficiently reliable for clinical use. UCP substantially retain or destroy red and white cells, but stick urinalysis for blood and leucocyte esterase remains reliable. In conclusion, urine samples derived from UCP show good agreement across a clinically relevant range for the biochemical analyses undertaken in this study. Microscopy of UCP samples is unreliable for cellular material but semi-quantitative stick urinalysis for red and white cells is a satisfactory alternative.     

Artificial attenuation of ECG voltage produces shortening of the corresponding QRS duration: clinical implications for patients with edema

BACKGROUND: Prolonged QRS duration (QRSd) is a useful index for the management of patients with congestive heart failure (CHF). QRSd is affected by changes in the ECG voltage (ECGV) in the context of development and amelioration of peripheral edema (PERE), independent of underlying pathology. Nowadays, physicians accept QRSd measured by computer techniques. The latter offers the possibility of testing the hypothesis that artificial alteration of the ECGV, simulating effects of PERE, could lead to changes in the QRSd. METHODS: To this end, voltage was attenuated by 25%, 50%, and 75% in 100 digital ECGs recorded from normal subjects and in 20 patients with complete left bundle branch block (LBBB), by merely increasing the calibration strength by 4/3, 2, and 4, respectively, and by using the same data. RESULTS: All ECGs were analyzed by the same computer program and this led to a reduction of global QRSd by 2.3 +/- 2.9%, 5.7 +/- 4.0%, and 11.9 +/- 6.2%, respectively, in the normal subjects, and 1.6 +/- 1.4%, 3.4 +/- 1.7%, and 8.2 +/- 3.6%, respectively, in the patients with LBBB. Correlation of the percent change in the global QRSd and the percent change in ECGV was good with an r = 0.65, and P = 0.00005 in the normal subjects, and an r = 0.74 and P = 0.00005 in the patients with LBBB. CONCLUSIONS: Apparent shortening in QRSd as a function of ECGV attenuation due to PERE could have implications in the follow-up of patients with CHF, and their selection for implantable cardioverter/defibrillators, or cardiac resynchronization therapy.     

Drug distribution during massing and its effect on dose uniformity in granules

Drug distribution during the initial stages of wet massing in a wet granulation process has been studied as a function of the relative solubility of the drug and the composition of the binder. The results of this initial wet massing process have been correlated with the drug distribution/granule size profile of the granulations.     

Chronic widespread pain and fibromyalgia: Should reports of increased mortality influence management?

There have been few studies examining whether persons with chronic widespread pain or fibromyalgia are at increased risk for dying prematurely. Among the studies conducted there is little consistency in results. If there is an increased mortality risk, it is of the order of a 30% excess and it may be related to the lifestyle of patients with these symptoms, including lack of exercise. Skilled judgment is required in determining whether reports of new symptoms are likely to indicate underlying new pathology. Studies are currently underway which will determine whether initial observations of an increased mortality risk can be replicated.     

Predictors of outcome for orofacial pain in the general population: a four-year follow-up study

Orofacial pain is often persistent, but it is not clear why it lasts in some patients but not in others. We aimed to describe the natural course of orofacial pain in a general population sample over a four-year period and to identify factors that would predict the persistence of pain. A cross-sectional population-based survey was conducted in the United Kingdom, involving 2504 participants (participation rate 74%), of whom 646 (26%) reported orofacial pain. Overall, 424 (79% adjusted participation rate) of these individuals participated at the four-year follow-up, of whom 229 (54%) reported orofacial pain and 195 (46%) did not report such pain. Persistent orofacial pain was associated with females, older age, psychological distress, widespread body pain, and taking medication for orofacial pain at baseline. These findings may have implications for the identification and treatment of patients with orofacial pain.