Low back pain in schoolchildren: occurrence and characteristics

Low back pain in adolescents is perceived to be uncommon in the clinic setting. However, previous studies have suggested that it may be an important and increasing problem in this age-group. The aim of this study was to determine the prevalence and important symptom characteristics of low back pain such as duration, periodicity, intensity, disability and health seeking behaviour at young ages. A population-based cross-sectional study was conducted including 1446 children aged 11-14 years in the North-West of England. A self-complete questionnaire was used to assess low back pain prevalence, symptom characteristics, associated disability and health seeking behaviour. An additional self-complete questionnaire amongst parents sought to validate pain reporting. The 1-month period prevalence of low back pain was 24%. It was higher in girls than boys (29 vs. 19%; 2=14.7, P<0.001) and increased with age in both sexes (P<0.001). Of those reporting low back pain, 94% experienced some disability, with the most common reports being of difficulty carrying school bags. Despite this high rate of disability, few sought medical attention. Adolescent low back pain is common although medical attention is rarely sought. Such symptoms in childhood, particularly as they are so common, may have important consequences for chronic low back pain in adulthood.     

National study of cause-specific mortality in rheumatoid arthritis,juvenile chronic arthritis,and other rheumatic conditions: a 20 year followup study

OBJECTIVE: To quantify risks for cause-specific mortality among hospitalized patients with rheumatoid arthritis (RA), juvenile chronic arthritis (JCA), and 4 other rheumatic conditions in a nationwide, population based cohort over a 20 year period. METHODS: All subjects were identified from Scottish hospital inpatient records from 1981 to 2000 and were followed up by computer linkage to the national registry of deaths. Expected mortality was calculated from national mortality rates and was related to the observed incidence by the standardized mortality ratio (SMR) and the corresponding 95% confidence interval (95% CI). RESULTS: Overall mortality was elevated in each of the 6 rheumatic conditions examined, most notably in JCA (males: SMR 3.4, 95% CI 2.0,5.5; females: SMR 5.1, 95% CI 3.2,7.8). Among patients with RA, there was an increased risk for death in all International Classification of Disease chapters other than those relating to mental disorders. Specific causes of death with an increased risk for subjects with RA included lung cancer [males: 1.4 (1.2,1.5); females: 1.6 (1.5,1.8)], hematopoietic malignancies [M: 1.8 (1.4,2.3); F: 2.0 (1.7,2.3)], coronary artery disease (CAD) [M: 1.6 (1.5,1.7); F: 1.95 (1.9,2.0)], respiratory infections [M: 1.9 (1.7,2.2); F: 2.4 (2.3,2.6)], chronic obstructive pulmonary disease [M: 1.8 (1.6,2.0); F: 2.1 (1.9,2.3)], and renal failure [M: 3.1 (2.5,3.9); F: 3.5 (3.0,4.0)]. Conversely, RA subjects were less likely to die from gastrointestinal tract malignancies [M: 0.82 (0.7,1.0); F: 0.8 (0.7,0.9)]. CONCLUSION: Population studies for primary data collection are required to extend our knowledge about the underlying mechanisms of early mortality in patients with rheumatic conditions.     

Regulation of short-chain fatty acid production

Short-chain fatty acid (SCFA) formation by intestinal bacteria is regulated by many different host, environmental, dietary and microbiological factors. In broad terms, however, substrate availability, bacterial species composition of the microbiota and intestinal transit time largely determine the amounts and types of SCFA that are produced in healthy individuals. The majority of SCFA in the gut are derived from bacterial breakdown of complex carbohydrates, especially in the proximal bowel, but digestion of proteins and peptides makes an increasing contribution to SCFA production as food residues pass through the bowel. Bacterial hydrogen metabolism also affects the way in which SCFA are made. This outcome can be seen through the effects of inorganic electron acceptors (nitrate, sulfate) on fermentation processes, where they facilitate the formation of more oxidised SCFA such as acetate, at the expense of more reduced fatty acids, such as butyrate. Chemostat studies using pure cultures of saccharolytic gut micro-organisms demonstrate that C availability and growth rate strongly affect the outcome of fermentation. For example, acetate and formate are the major bifidobacterial fermentation products formed during growth under C limitation, whereas acetate and lactate are produced when carbohydrate is in excess. Lactate is also used as an electron sink in Clostridium perfringens and, to a lesser extent, in Bacteroides fragilis. In the latter organism acetate and succinate are the major fermentation products when substrate is abundant, whereas succinate is decarboxylated to produce propionate when C and energy sources are limiting.     

Health and exposures of United Kingdom Gulf war veterans. Part II: The relation of health to exposure

OBJECTIVES—To investigate whether, in personnel who served with the United Kingdom forces in the Gulf war, self reported exposures were related to symptoms in a way that was consistent, specific, and credible.
METHODS—Responses to symptom and exposure questionnaires, completed 7 or more years after the war, were collected from 7971 subjects deployed in the Gulf, from two exposed cohorts, in a study with an overall response rate of 85.5%. Exposures were considered in three groups, those outside the control of the subjects, the use of prophylaxis, and indicators of susceptibility. Health indices derived from symptom questionnaires were related to reports of 14 exposures in these three groups in a series of multiple regression analyses to allow for confounding. The relation of exposure to complaints of widespread pain and to symptoms suggesting peripheral neuropathy were examined by logistic regression.
RESULTS—Consistent but weak correlations between exposures and with health effects were found in independent analyses of the two (main and validation) cohorts. Three exposures outside the control of the subject, the number of inoculations, the number of days handling pesticides, and the days exposed to smoke from oil fires, were consistently and independently related to severity. The number of inoculations was also associated with higher scores on a factor weighted on symptoms associated with skin and musculoskeletal complaints. The number of days handling pesticides related particularly to scores on a neurological factor and to symptoms consistent with toxic neuropathy.
CONCLUSION—The relations between exposures and ill health were generally weak. Consistent, specific, and credible relations, warranting further investigation, were found between health indices and two exposures, the reported number of inoculations and days handling pesticides.


Keywords: Gulf war; inoculations; pesticides     

Proteinase-activated receptors

Proteinase-activated receptors are a recently described, novel family of seven-transmembrane G-protein-coupled receptors. Rather then being stimulated through ligand receptor occupancy, activation is initiated by cleavage of the N terminus of the receptor by a serine protease resulting in the generation of a new tethered ligand that interacts with the receptor within extracellular loop-2. To date, four proteinase-activated receptors (PARs) have been identified, with distinct N-terminal cleavage sites and tethered ligand pharmacology. In addition to the progress in the generation of PAR-1 antagonists, we describe the role of thrombin in such processes as wound healing and the evidence implicating PAR-1 in vascular disorders and cancer. We also identify advances in the understanding of PAR-1-mediated intracellular signaling and receptor desensitization. The cellular functions, signaling events, and desensitization processes involved in PAR-2 activation are also assessed. However, other major aspects of PAR-2 are highlighted, in particular the ability of several serine protease enzymes, in addition to trypsin, to function as activators of PAR-2. The likely physiological and pathophysiological roles for PAR-2 in skin, intestine, blood vessels, and the peripheral nervous system are considered in the context of PAR-2 activation by multiple serine proteases. The recent discovery of PAR-3 and PAR-4 as additional thrombin-sensitive PARs further highlights the complexity in assessing the effects of thrombin in several different systems, an issue that remains to be fully addressed. These discoveries have also highlighted possible PAR-PAR interactions at both functional and molecular levels. The future identification of other PARs and their modes of activation are an important future direction for this expanding field of study.     

Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital: implications for management guidelines

BACKGROUND: Since the last British study of the microbial aetiology of community acquired pneumonia (CAP) about 20 years ago, new organisms have been identified (for example, Chlamydia pneumoniae), new antibiotics introduced, and fresh advances made in microbiological techniques. Pathogens implicated in CAP in adults admitted to hospital in the UK using modern and traditional microbiological investigations are described. METHODS: Adults aged 16 years and over admitted to a teaching hospital with CAP over a 12 month period from 4 October 1998 were prospectively studied. Samples of blood, sputum, and urine were collected for microbiological testing by standard culture techniques and new serological and urine antigen detection methods. RESULTS: Of 309 patients admitted with CAP, 267 fulfilled the study criteria; 135 (50.6%) were men and the mean (SD) age was 65.4 (19.6) years. Aetiological agents were identified from 199 (75%) patients (one pathogen in 124 (46%), two in 53 (20%), and three or more in 22 (8%)): Streptococcus pneumoniae 129 (48%), influenza A virus 50 (19%), Chlamydia pneumoniae 35 (13%), Haemophilus influenzae 20 (7%), Mycoplasma pneumoniae 9 (3%), Legionella pneumophilia 9 (3%), other Chlamydia spp 7 (2%), Moraxella catarrhalis 5 (2%), Coxiella burnetii 2 (0.7%), others 8 (3%). Atypical pathogens were less common in patients aged 75 years and over than in younger patients (16% v 27%; OR 0.5, 95% CI 0.3 to 0.9). The 30 day mortality was 14.9%. Mortality risk could be stratified by the presence of four "core" adverse features. Three of 60 patients (5%) infected with an atypical pathogen died. CONCLUSION: S pneumoniae remains the most important pathogen to cover by initial antibiotic therapy in adults of all ages admitted to hospital with CAP. Atypical pathogens are more common in younger patients. They should also be covered in all patients with severe pneumonia and younger patients with non-severe infection.     

Hospitalization among workers compensated for occupational asthma

Occupational asthma (OA) can cause persistent symptoms, but populations with OA have not been followed for the development of serious outcomes such as hospitalization. Subjects receiving compensation for OA during 1980-1993, and a comparison sample of workers with musculoskeletal injuries (INJ) were identified from the Ontario Workers' Compensation Board. We also identified for comparison a group of asthmatic patients (AP) seen at a tertiary care hospital clinic during the same period. The file was matched with the Ontario Ministry of Health data base of hospitalizations through 1996. We compared the frequency of hospitalization of the subgroups with that expected in the general population using standardized morbidity ratios (SMRs), and directly by proportional hazards regression. The study group included 844 OA claimants, 1,556 INJ claimants, and 402 AP. Although admissions for all causes combined and respiratory disease among INJ were less than expected in the general population, admissions for all causes combined exceeded that expected among OA and AP. Admissions for respiratory disease were markedly greater than expected among OA (SMR 9.2) and AP (SMR 17) because of even greater excess admissions for asthma (SMRs 45 and 81, respectively). Compared with those with INJ, those with OA were more likely to be hospitalized for all causes combined (adjusted relative risk [RR] 1.4, 95% confidence interval [CI] 1.2 to 16); cardiovascular disease (RR 1.4, 95% CI 0.9 to 2.0); respiratory disease (RR 5.4, 95% CI 3.8 to 7.7); and asthma (RR 28.1, 95% CI 10.2 to 77.2) but not for malignancies (RR 1.0) or injuries (RR 0.9). Those with OA were admitted to hospital about half as frequently as AP for respiratory disease and asthma (although this was modified by smoking status and sex), but were 30% more likely to be admitted for ischemic heart disease (IHD). Among the OA claimants, factors that were significantly associated with hospitalization for asthma included older age and exposure to agents other than isocyanates. Those with OA became less likely to be hospitalized for asthma with increasing time after onset, particularly after 5 or more years. We conclude that subjects with OA suffer higher rates of hospitalizations for all causes combined, respiratory disease, and asthma than other workers, although less than among AP seen at a tertiary care center.     

The effect of oxytocin in induced labour on neonatal jaundice.

A prospective study in 180 mothers and babies examined the effects of oxytocin in induced labour on plasma bilirubin levels in cord blood, as well as on the incidence of neonatal jaundice. Raised plasma bilirubin levels in cord blood, probably enhanced by breakdown of fetal red cells, appeared to be a dose dependent effect of oxytocin. Commensurate with this was the finding that a larger proportion of babies in the induced group manifested a greater severity of jaundice.