Relative contributions of the supraspinatus cord and strap tendons to shoulder abduction and translation

BACKGROUND

The supraspinatus (SS) is formed by a larger anterior bipennate muscle with a cord-like tendon and a posterior unipennate muscle with a strap-like tendon. There is a tendinous connection between the 2 SS subunits. Yet, the relative mechanical contribution of the SS cord and SS strap musculotendinous units to load transmission and subsequent shoulder abduction force is unknown. We hypothesized that a simulated SS cord vs. an SS strap tear would generate less shoulder abduction force and, further, an intact SS cord would offset the expected abduction loss from an SS strap tear, but the inverse would not be true.

MATERIALS AND METHODS

Twenty fresh-frozen cadaveric specimens were tested in a shoulder simulator with physiological load vectors applied to the upper and lower subscapularis, SS cord, SS strap, infraspinatus, and teres minor. The roles of the SS cord and SS strap muscles were delineated by varying their loads, while keeping constant loads on other muscles. The randomized testing trials included a native condition and 4 test cases that simulated tears by dropping the load and force transfer via the SS cord-to-SS strap connection by adding the load. Testing was completed at both 0° and 30° of abduction. During each test, shoulder abduction force, rotator cuff strains, and humeral translation were measured.

RESULTS

Simulated isolated SS cord and SS strap tears led to a significantly lower shoulder abduction force (P < .001). A simulated cord tear at 0° and 30° reduced the abduction force by 53% and 38%, respectively. A simulated strap tear at 0° and 30° dropped the abduction force by 27% and 23%, respectively. The decline in the abduction force was larger for the SS cord tear vs. SS strap tear (P ≤ .001). An SS cord tear with full-load transfer to the strap was able to recover to native values at both 0° and 30° (P ≥ .288). Likewise, an SS strap tear with full-load transfer to the SS cord showed a similar recovery to native values at both 0° and 30° (P ≥ .155). During full-load transfer, the tendon strain followed the loading pattern. An SS cord tear or SS strap tear did not cause a change in humeral translation (P ≥ .303).

DISCUSSION

The mechanical findings support the efficacy of nonoperative treatment of small (<10 mm) SS tears,11 because an intact SS strap tendon can effectively offset the abduction loss of a torn SS cord tear and vice versa.

Quédate Quieto Niño: Bilingualism and ADHD Presentation

Objective

This poster will focus on findings pertaining to the relationship between bilingualism and Attention Deficit/Hyperactivity Disorder (ADHD), a gap that currently exists in cultural neuropsychology. This poster will introduce the literature regarding bilingualism and the development of individuals’ executive functioning throughout their lifespan. Bilingual individuals often have enhanced executive functioning. This review will provide a foundation for the present study. Then, we will compare racial and ethnic differences in ADHD diagnosis and treatment. ADHD diagnoses tend to be higher for White children than for Hispanics raised in a non-English household. These findings suggest that bilingualism may affect the diagnosis and the expression of ADHD.

Participants and Method

This poster will consider the acquisition of executive control skills and language. Since ADHD and language develop before adolescence, this poster will focus on individuals between the ages of 3 and 12. This will allow us to better understand how language acquisition and the factors that surround language affect the expression of ADHD.

Results

The poster will present results from the literature review to better understand the results of bilingualism on ADHD. Bilinguals tend to outperform monolinguals in tasks related to reasoning and problem solving. However, bilinguals tend to struggle in tasks related to vocabulary retrieval. This is key because individuals with ADHD tend to perform worse on tasks related to executive functioning. The poster will display different methods used in past research in order to expand future implications.

Conclusions

ADHD appears to interrupt some skills that bilingual individuals possess. This interference may affect ADHD symptom expression and performance on neuropsychological testing. This may lead to misdiagnoses and a resulting lag in the provision of effective treatments for bilingual children. Thus, this poster will propose alternatives and implications for practice.

The spatial clustering of obesity: does the built environment matter?

BACKGROUND

Obesity rates in the USA show distinct geographical patterns. The present study used spatial cluster detection methods and individual-level data to locate obesity clusters and to analyse them in relation to the neighbourhood built environment.

METHODS

The 2008-2009 Seattle Obesity Study provided data on the self-reported height, weight, and sociodemographic characteristics of 1602 King County adults. Home addresses were geocoded. Clusters of high or low body mass index were identified using Anselin's Local Moran's I and a spatial scan statistic with regression models that searched for unmeasured neighbourhood-level factors from residuals, adjusting for measured individual-level covariates. Spatially continuous values of objectively measured features of the local neighbourhood built environment (SmartMaps) were constructed for seven variables obtained from tax rolls and commercial databases.

RESULTS

Both the Local Moran's I and a spatial scan statistic identified similar spatial concentrations of obesity. High and low obesity clusters were attenuated after adjusting for age, gender, race, education and income, and they disappeared once neighbourhood residential property values and residential density were included in the model.

CONCLUSIONS

Using individual-level data to detect obesity clusters with two cluster detection methods, the present study showed that the spatial concentration of obesity was wholly explained by neighbourhood composition and socioeconomic characteristics. These characteristics may serve to more precisely locate obesity prevention and intervention programmes.

Home blood pressure monitoring, secure electronic messaging and medication intensification for improving hypertension control: a mediation analysis

OBJECTIVE

We evaluated the role of home monitoring, communication with pharmacists, medication intensification, medication adherence and lifestyle factors in contributing to the effectiveness of an intervention to improve blood pressure control in patients with uncontrolled essential hypertension.

METHODS

We performed a mediation analysis of a published randomized trial based on the Chronic Care Model delivered over a secure patient website from June 2005 to December 2007. Study arms analyzed included usual care with a home blood pressure monitor and usual care with home blood pressure monitor and web-based pharmacist care. Mediator measures included secure messaging and telephone encounters; home blood pressure monitoring; medications intensification and adherence and lifestyle factors. Overall fidelity to the Chronic Care Model was assessed with the Patient Assessment of Chronic Care (PACIC) instrument. The primary outcome was percent of participants with blood pressure (BP) <140/90 mm Hg.

RESULTS

At 12 months follow-up, patients in the web-based pharmacist care group were more likely to have BP <140/90 mm Hg (55%) compared to patients in the group with home blood pressure monitors only (37%) (p = 0.001). Home blood pressure monitoring accounted for 30.3% of the intervention effect, secure electronic messaging accounted for 96%, and medication intensification for 29.3%. Medication adherence and self-report of fruit and vegetable intake and weight change were not different between the two study groups. The PACIC score accounted for 22.0 % of the main intervention effect.

CONCLUSIONS

The effect of web-based pharmacist care on improved blood pressure control was explained in part through a combination of home blood pressure monitoring, secure messaging, and antihypertensive medication intensification.

Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century

The continued retreat of ice shelves on the Antarctic Peninsula has been widely attributed to recent atmospheric warming, but there is little published work describing changes in glacier margin positions. We present trends in 244 marine glacier fronts on the peninsula and associated islands over the past 61 years. Of these glaciers, 87% have retreated and a clear boundary between mean advance and retreat has migrated progressively southward. The pattern is broadly compatible with retreat driven by atmospheric warming, but the rapidity of the migration suggests that this may not be the sole driver of glacier retreat in this region.

The classification of patients with chronic pain: age and sex differences

OBJECTIVE

To further develop an empirically based classification system for chronic pain patients through the examination of age and sex differences, and incorporation of pain duration in the grouping algorithm.

SUBJECTS

Three hundred seventy-four chronic pain patients (300 aged 13 to 59 years; 74 aged 60 to 89 years) assessed at an outpatient, multidisciplinary pain management centre.

METHODS

Patients completed measures of demographic and descriptive information, pain intensity (box rating scale), perceived disability (modified Pain Disability Index) and affective distress (Symptom Checklist-90 Revised) before multidisciplinary treatment. Standardized scores from the assessment measures were entered into a series of hierarchical, multivariate cluster analyses to identify underlying patient subgroups.

RESULTS

Age-based patient groupings from prior research were partially replicated. Significant differences in clinical presentations were observed across age and sex groups. Pain duration was found to make an important contribution to the patient groupings. 'Good control' (low pain, disability, distress) and variants of 'chronic pain syndrome' (elevated pain, disability, distress) groupings were identified across all analyses. Two variants of a 'stoic' profile were identified among older patients, with low levels of distress relative to pain and perceived disability. One of these profiles was associated with long pain duration and was found only among males. Several unique clinical profiles were identified for female patients.

CONCLUSIONS

There are important age and sex differences in the clinical presentations of chronic pain patients. Some older patients present with unique clinical profiles that may reflect cohort differences, and/or physiological or psychological adjustment processes. There appears to be a greater number of distinct chronic pain presentations among females. Research on the classification of chronic pain patients within homogeneous diagnostic subgroups is needed.

Computed tomography in the measurement of femoral anteversion

A new technique using computed tomography for measuring femoral anteversion is presented, with advantages over prior techniques. Computed tomography allows the visual portrayal of the cervical axis to be superimposed upon the diacondylar axis for direct goniometric measurement of the anteversion angle. Beyond its accuracy, the procedure requires no complicated positioning framework and can be done in a brief span of time.

Relationship between femoral anteversion and osteoarthritis of the hip

The purpose of this study was to establish a relationship between the magnitude of femoral anteversion and osteoarthritis of the hip. Sixteen osteoarthritic subjects were compared with 18 control subjects by an improved computed tomography (CT) scanning technique. Femoral anteversion was accurately determined with little radiation exposure. There was no significant difference in femoral anteversion between arthritic subjects and a "normal" control population. There was no significant difference in femoral anteversion between the involved and the uninvolved hips of these subjects with osteoarthritis. These results suggest that performing a derotational femoral osteotomy to prevent osteoarthritis is not indicated. The cause of primary osteoarthritis is multifactorial and does not depend solely on preexistence of higher femoral anteversion.

Investigation of risk factors for porcine Taenia solium cysticercosis: a multiple regression analysis of a cross-sectional study in the Yucatan Peninsula, Mexico

A cross-sectional survey for seropositivity to cysticercosis of pigs in the Yucatan Peninsula, Mexico, was carried out in 1996 together with a standardized questionnaire on predetermined individual pig and household risk factors for porcine infection. Serum samples from 697 pigs were analysed by immunoblot for antibodies to Taenia solium cysticercosis and questionnaires from 227 households in 18 villages were collected. All the data were analysed using multivariate analytical techniques taking household clustering into account. The overall porcine seroprevalence in the area was found to be 29%. The most important risk factors for seropositivity in pigs were presence versus absence of a toilet (adjusted odds ratio [adj. OR] 2.37, P = 0.005), crowded households (adj. OR 1.75, P = 0.034) and both corralling (adj. OR 2.14, P = 0.017) and letting pigs loose (adj. OR 2.32, P = 0.035) versus tying them up. There was evidence of clustering at household level and that possible risk factors at municipal or village level may also interact with higher risk management practices such as allowing pigs to run loose.

A meta-analysis of studies of the effect of GnRH 11-14 days after insemination on pregnancy rates in cattle

A number of studies have used GnRH between 11 and 14 days after insemination to improve pregnancy rates in cows, however published results have not been consistent. We wished to investigate whether a consolidated estimate of the response could be quantified. Therefore we conducted a meta-analysis of the available data, 19 studies from 14 published papers, on the effect of GnRH analogs on pregnancy rate when given between Days 11 and 14 after first insemination. Odds ratios (the relative probability of pregnancy between treated and control cows) were compared for each study and found to vary significantly among studies, ranging from 0 to 22%. We showed by logistic regression analysis that response to GnRH treatment varied with cow type (beef or dairy), age (cow or heifer), estrus synchronization (synchronized or natural), pregnancy diagnosis (method and time) and effect of individual study. When all these variables were included only 6 of 14 publications could be analyzed, representing 2,541 instead of 10,945 cows. In this limited subgroup of data, a significant improvement in pregnancy rate was detected among treated cattle (odds ratio = 1.33; P<0.01).

Sources of toxoplasma infection in pregnant women: European multicentre case-control study. European Research Network on Congenital Toxoplasmosis

OBJECTIVE

To determine the odds ratio and population attributable fraction associated with food and environmental risk factors for acute toxoplasmosis in pregnancy.

DESIGN

Case-control study.

SETTING

Six large European cities.

PARTICIPANTS

Pregnant women with acute infection (cases) detected by seroconversion or positive for anti-Toxoplasma gondii IgM were compared with pregnant women seronegative for toxoplasma (controls).

MAIN OUTCOME MEASURES

Odds ratios for acute infection adjusted for confounding variables; the population attributable fraction for risk factors.

RESULTS

Risk factors most strongly predictive of acute infection in pregnant women were eating undercooked lamb, beef, or game, contact with soil, and travel outside Europe and the United States and Canada. Contact with cats was not a risk factor. Between 30% and 63% of infections in different centres were attributed to consumption of undercooked or cured meat products and 6% to 17% to soil contact.

CONCLUSIONS

Inadequately cooked or cured meat is the main risk factor for infection with toxoplasma in all centres. Preventive strategies should aim to reduce prevalence of infection in meat, improve labelling of meat according to farming and processing methods, and improve the quality and consistency of health information given to pregnant women.

Retrospective study of the relationships between age, inflammation and the isolation of bacteria from the lower respiratory tract of thoroughbred horses

A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (P = 0.031), and the groups at highest risk were the two- and four-year-olds. Lower airway inflammation was more common in the four-year-olds at National Hunt yards than in the four-year-olds at flat racing yards (P = 0.040, odds ratio = 3.80).

Port-site metastasis after laparoscopic cholecystectomy for benign disease

We describe the case history of a patient presenting with a port-site metastasis from an occult pancreatic malignancy after laparoscopy for benign gallbladder disease. While port-site recurrence is well recognized after laparoscopy for malignant disease, its presentation after laparoscopy for benign disease is rare, this being only the third such case to be reported in the literature. It emphasizes that all pathology localizing to port sites after surgery should be investigated, as it may represent the earliest sign of a hitherto occult intra-abdominal malignancy.

Application of an immunoassay to determine risk factors associated with porcine cysticercosis in rural areas of Yucatan, Mexico

A Western blot assay for identification of 26 kDa and/or 8 kDa antigens in a crude saline extract (CSE) of Taenia solium metacestodes, previously developed for human cysticercosis, was evaluated for use with pigs. The test population used for assay standardisation consisted of 45 cysticercotic pigs (5 pigs positive by necropsy and 40 selected by tongue palpation and LL-Gp immunoblot but not confirmed by necropsy), 48 pigs with heterologous infections and 40 negative controls from endemic and non-endemic areas. The test detected 93% of the cysticercotic group and was 100% specific. In a field study this antigen preparation was compared by immunoblot with antibody recognition for Gp13-50 antigens in a lentil-lectin semi-purified glycoprotein extract of T. solium (LL-Gp). The seroprevalence to CSE antigen was slightly lower (26/75) when compared to LL-Gp (29/75) and this represented a non-significant difference. The CSE Western blot assay was used to assess seroprevalence of T. solium cysticercosis in pig populations in the state of Yucatan, Mexico. A total of 1099 pigs sampled at random from 25 villages revealed a seroprevalence of 23% (253/1099). Seroprevalence in intensively reared, farmed pigs was 2% (7/228). In comparison with farmed pigs, the seroprevalence was 33% (172/513) in free-roaming backyard pigs (OR=13.86, CI=4.0747.22, p<10(-6)) and 25% (74/98) in semi-confined backyard pigs (OR=14.03, CI=5.60-35.16, p<10(-6)). There was no significant difference in seroprevalence by sex (p=0.23). Seroprevalence decreased with age (chi(2)-test for linear trend=7.803, p<0.006). Results of this study demonstrate that the CSE Western blot can be applied for reliable immunodiagnosis of T. solium cysticercosis in pigs. Furthermore, variation in pig husbandry in Yucatan indicated significantly higher exposure to cysticercosis in free-roaming backyard pigs compared to intensively reared animals from the same area.

Cognitive-behavioral pain management for elderly nursing home residents

A cognitive-behavioral pain management program for elderly nursing home residents with chronic pain was compared with an attention/support control treatment in a randomized pre-/post-comparison group design with follow-up. Thirteen women and nine men, ranging in age from 61 to 98 (M = 77.2), from two large nursing homes participated in the treatment programs through 10 weekly group sessions. Results revealed that the subjects who received the cognitive-behavioral training reported less pain and pain-related disability, although the two programs were perceived as equally credible both before and after treatment. No significant treatment effects were found for depression and physician medication ratings. Treatment effects were maintained at 4-month follow-up, despite an overall increase in reported pain. Findings indicate that elderly nursing home residents with chronic pain and without serious cognitive impairment can benefit substantially from training in cognitive and behavioral pain management strategies that are known to be effective with younger age groups and the community-resident elderly population.

Suspected scaphoid fractures in skeletally immature patients: application of MRI

PURPOSE

The purpose of our study was to evaluate the MR findings in the wrists of pediatric patients who have sustained acute wrist injuries and to determine if this imaging method yields more information than combined serial radiographs and physical examinations.

METHOD

Eighteen skeletally immature patients (11 boys and 7 girls, age range 8-15 years) who had presented to the emergency room within 2 days following acute wrist trauma underwent serial clinical, radiographic, and MR examinations if there was a suspicion of a scaphoid fracture.

RESULTS

Ten patients had a scaphoid abnormality on MR images. Six had fractures and four had regional bone marrow edema. Initially, all but two fractures were radiographically occult, although the other fractures eventually became evident on later studies. Those with marrow edema did not progress to fractures. Obliteration of the scaphoid fat stripe occurred in five patients with a scaphoid fracture and in six patients who did not have a fracture. Dorsal soft tissue swelling occurred in eight patients, five of whom had scaphoid fractures. Seven patients had evidence of extensor tenosynovitis on MRI.

CONCLUSION

A normal initial MR image had a negative predictive value of 100%. Persistent snuffbox pain may represent injury to the scaphoid, extensor tendons, or dorsal soft tissues. An outcome study evaluating the benefits of early application of MR in the pediatric population is warranted.

Cysteinyl leukotriene involvement in chronic lung disease in premature infants

The pathophysiology of chronic lung disease (CLD) in premature infants who require mechanical ventilation and prolonged oxygen supplementation has been well-described but the underlying mechanisms are not understood. Our aim was to test the hypothesis that excess cysteinyl leukotriene (LT) production was a contributing factor in CLD. We compared LT production and lung function, at 7 months of age, in nine premature infants with CLD and in eight control infants without CLD. None of the control infants developed any neonatal respiratory problems, but two subsequently required bronchodilator therapy. Respiratory function was assessed by the measurement of thoracic gas volume (TGV), airways resistance (Raw) and functional residual capacity (FRC). Total cysteinyl LT production was quantified by measurement of leukotriene E4 (LTE4) in a spot urine sample. Although all patients were asymptomatic at follow-up, there was evidence of significant lung function abnormalities in infants with CLD. The CLD infants had significantly elevated TGV, Raw and FRC values reflecting airway obstruction when compared to the controls. Urinary LTE4 levels were significantly higher in the CLD infants when compared to the controls (geometric mean: 741 and 337 pmol.mmol-1 creatinine, respectively). There was no direct correlation between urinary LTE4 levels in the CLD group and TGV, Raw or FRC values. Although this study is small and a direct correlation between lung function and urinary leukotriene E4 was not demonstrated, pathological lung function and an enhanced urinary leukotriene E4 production in infants with chronic lung disease would tend to suggest that the cysteinyl leukotrienes were involved in the sequelae of this disease.

Madelung deformity in skeletally immature patients: morphologic assessment using radiography, CT, and MRI

PURPOSE

The purpose of this study was to define the pathoanatomy of the distal radius and surrounding soft tissues, identify the factors that may contribute to diminished forearm rotation, and relate these findings to alterations in wrist motion in skeletally immature patients with the Madelung deformity.

METHOD

Four skeletally immature female patients with bilateral Madelung deformities (eight wrists) underwent evaluation of each wrist with radiography, CT, and MRI to assess the morphology of the deformity. Two patients (four wrists) had isolated idiopathic Madelung deformities, and two patients (four wrists) had Madelung deformities secondary to dyschondrosteosis.

RESULTS

Radiographically, all wrists demonstrated dorsal bowing of the radius, marked ulnar tilting of the radius and radial tilting of the ulna, volar tilting of the distal articular surface of the radius, and triangulation of the epiphysis. On CT, patients with the idiopathic deformity demonstrated dorsal ulnar subluxation and relative supination of the carpus with respect to the distal radius. Patients with dyschondrosteosis demonstrated no ulnar subluxation and relative pronation of the carpus. All wrists demonstrated a fixed pronated deformity of the distal radius. On MRI, a physeal bar that bridged the distal metaphysis of the radius to the epiphysis was identified in all eight wrists, located on the volar aspect of the radius at the lunate facet. An anomalous volar ligament, a volar radiotriquetral ligament, and the short radiolunate ligament were hypertrophied in seven wrists.

CONCLUSION

Based on its location, it is likely that a physeal bar impedes the normal development of the distal radius ulnarly. Hypertrophy of the short radiolunate ligament may be an important contributing factor to carpal pyramidalization owing to tethering on the volar pole of the lunate. Diminished forearm rotation is likely related to carpal malalignment, a fixed pronated deformity of the distal radius, and dorsal bowing of the radius.

Human and bovine tuberculosis in the Monze District of Zambia--a cross-sectional study

One hundred and seventy-six randomly selected rural households in the Monze District of Zambia were interviewed; 103 of these presented cattle for tuberculin testing. Of the 2226 cattle tested, 165 (7.4%) were positive reactors; 33% of herds contained positive animals. Risk of a positive reaction varied with an animal's age and body condition. Cattle in larger herds were more likely to give positive reactions. Ten households reported a human case of tuberculosis (TB) during the preceding 12 months; the herds or these households were six times more likely to have a tuberculin-positive animal than herds in households without a reported human TB case.

Characterization of the gap junction protein connexin56 in the chicken lens by immunofluorescence and immunoblotting

PURPOSE

To characterize the chicken lens gap junction protein, connexin56 (Cx56).

METHODS

The methods used were immunoblotting, immunofluorescence, alkaline phosphatase treatment, in vitro translation, and primary tissue culture.

RESULTS

Connexin56 translated in vitro showed a single band with an electrophoretic mobility of approximately 66 kd. Multiple bands of 67 to 90 kd were detected in immunoblots of chicken lens homogenates using antibodies raised against a peptide from Cx56. Most, if not all, of these bands represented different phosphorylated forms of Cx56, because immunoreactive Cx56 was detected as a doublet of 65 to 67 kd after treatment of lens homogenates with alkaline phosphatase. Indirect immunofluorescence demonstrated that Cx56 was localized at membrane appositions between lens fibers and bow region cells. Levels of Cx56 increased from embryonic days 4 to 15; thereafter, levels remained fairly constant until hatching, after which they declined. Before embryonic day 9, the slowest migrating bands were not as abundant as they were at later ages. After embryonic day 20, less Cx56 was observed by immunofluorescence in the nucleus than in the cortex; however, both regions had similar levels of Cx56 as measured by immunoblotting. The pattern of bands differed between the two lens regions, suggesting differential protein modification. Immunoreactive Cx56 bands of 35 to 38 kd were detected unless homogenates were prepared in the presence of ethylenediaminetetraacetic acid (EDTA). Cx56 was also detected in lentoid-containing primary cultures derived from chicken lens.

CONCLUSIONS

Cx56 is a phosphoprotein. Its appearance and modification by phosphorylation, as detected by immunoblotting, correlate with lens fiber differentiation.

Pain and the use of health services among the elderly

This study examined pain management strategies and the relationship of pain to the use of health services in a sample of community-resident Canadian elderly. Analyses with the Andersen-Newman framework of need, enabling and predisposing variables revealed that pain did not make an incremental contribution to explaining service use. Traditional measures of need for services accounted for the majority of explained variance in health service use. The substantial number of participants who were found to be coping with chronic, frequent pain relied on themselves as much as formal health services for dealing with their pain. The most common coping style for these pain sufferers was a combination of analgesics and accepting mild pain as part of daily life. This combination of medical intervention and attitudinal factors appears to make the coping process very manageable.

Atopic children with cystic fibrosis have increased urinary leukotriene E4 concentrations and more severe pulmonary disease

BACKGROUND

We investigated the hypothesis that cysteinyl leukotriene (LT) production is altered in atopic patients with cystic fibrosis (CF).

METHODS

Urinary LTE4 was measured in two groups of children with CF: atopic (ACF group, n = 22) and nonatopic (NACF group, n = 13); and in two groups of unaffected children, those with atopic asthma (AA group, n = 11) and nonatopic normal control subjects (NN group, n = 12).

RESULTS

Atopic groups excreted significantly more urinary LTE4 (geometric means [95% confidence intervals] in picomoles per millimole creatinine), ACF group: 104 (73-147) and AA group: 195 (136-282) compared with NACF group: 19 (9-39) and NN group: 27 (15-48). The ACF group had significantly more airflow obstruction than the NACF group, with forced expiratory volume in 1 second (percent predicted, mean +/- SD) in ACF: 58 +/- 21 versus NACF: 81 +/- 23, and forced vital capacity (percent predicted, mean +/- SD) 72 +/- 17 versus 87 +/- 23, respectively. There were significant correlations between the degree of airflow obstruction, bronchodilator responsiveness, and urinary LTE4 concentration within the entire CF group. We used multiple regression analysis to assess the respective influence of age, atopy, sensitization to Aspergillus fumigatus, and colonization with Pseudomonas aeruginosa on urinary LTE4 concentration. The atopic state was the only significant variable associated with urinary LTE4 production in subjects with CF.

CONCLUSIONS

The similarities in urinary LTE4 between ACF and AA groups suggest that the atopic state is the prime determinant of urinary LTE4 excretion. Enhanced cysteinyl LT production associated with atopy in CF may increase the severity of pulmonary disease.

Sputum tumour necrosis factor-alpha and leukotriene concentrations in cystic fibrosis

It is postulated that a vigorous host inflammatory response in the cystic fibrosis lung contributes to lung injury. Tumour necrosis factor-alpha (TNF-alpha) may play a part in that process and in the generation of leukotrienes. Therefore, the relationships between sputum TNF-alpha, leukotriene concentration, and lung function abnormalities in 16 children with cystic fibrosis were investigated. Each subject provided sputum samples and performed spirometry. TNF-alpha was measured by enzyme linked immunosorbent assay; individual leukotrienes were separated using high performance liquid chromatography and quantified by radioimmunoassay. The geometric mean concentration of TNF-alpha was 129.7 pg/ml and 95% confidence interval 48.2 to 348.3. Mean (SEM) leukotriene B4 (LTB4) was 97.8 (22.9) pmol/g and total cysteinyl leukotrienes were 60.9 (14.8) pmol/g. Mean (SD) forced expiratory volume in one second (FEV1) of the group was 53 (15)% of predicted and forced vital capacity (FVC) was 65 (14)% of predicted. There was a significant positive correlation between TNF-alpha and both LTB4 and the total cysteinyl leukotriene sputum content. An inverse relationship existed between TNF-alpha and FEV1 and FVC. Moreover, a negative correlation was observed between sputum LTB4 and FEV1 and FVC. These results suggest that TNF-alpha and the leukotrienes may participate in the airways inflammation and airflow obstruction observed in cystic fibrosis subjects and support the hypothesis that TNF-alpha upregulates the 5-lipoxygenase pathway in vivo.

Communal farmers and tick control--a field study in Zimbabwe

Intensive dipping of cattle to control ticks and tick-borne diseases precludes development of endemic stability to the latter. Alternative control strategies have been recommended which reduce the frequency of dipping and permit the expression of tick resistance and endemic stability. However, such strategies imply acceptance by cattle owners of higher tick burdens. In this study the views of a group of communal farmers to tick control are described and the impact of these views upon adoption of other strategies is discussed.

Treatment of osteoid osteoma by computed tomography guided excision in the pediatric patient

An osteoid osteoma is a benign lesion that can occur in any bone. Controversy exists regarding treatment of this condition. This study demonstrates that the nidus of an osteoid osteoma can be disrupted and removed by use of the CORB biopsy system guided by computed tomography (CT) scan. Of nine patients followed for an average of 42.5 months (range 18-76 months), seven have had complete resolution of their pain after this procedure. The technique failed in two patients, who each required two separate en bloc excisions with bone grafting to resolve each lesion. CT-directed CORB appears to be useful in localization and removal of the nidus of an osteoid osteoma.

Death certification in fractured neck of femur

Fracture of the neck of the femur is a major public health problem within the elderly population of most industrialised countries whose health services are increasingly being taken up with its management. Moreover, within Britain, there is evidence of a real increase in its incidence even allowing for the ageing of the population. A condition whose aetiology is still far from clear (and where no strategy for prevention can therefore be formulated), and which is of such importance to the planning and provision of services demands detailed investigation and careful monitoring. Mortality data are an important part of epidemiological studies of disease problems and, in Britain, in resource allocation through the Resource Allocation Working Party (RAWP) formula. In this study, a cohort of 2,631 elderly patients, resident in the largest health district in the country, and admitted to hospitals over a seven year period with the diagnosis of fractured neck of femur, was assembled. Hospital records were linked to national mortality data to determine whether patients had died and, where this was so, to record underlying cause of death. A total of 930 deaths occurred within the study cohort but only 52 were certified as dying from fractured neck of femur; even amongst those who died in the hospital to which they were admitted with the fracture, less than a fifth of deaths were attributed to the fracture as underlying cause. Diseases of the circulatory system accounted for almost half of all underlying causes of death and bronchopneumonia a further 20%. These findings suggest a gross undercertification of fractured neck of femur as a cause of death in the elderly and are consistent with other studies. They may be explained by a failure of junior hospital doctors to understand the importance of accurate certification of cause of death and a misguided attempt to reduce the burden to coroners of having to consider each death from this cause.(ABSTRACT TRUNCATED AT 250 WORDS)

Mental and physical health of elderly people: five-year follow-up of a total population

The change in mental and physical functioning over 5 years for 594 survivors of a community survey of the elderly is described. An increase in cognitive impairment, physical disability and incontinence over the period was found with increasing age. Women in the two oldest age groups had a significantly greater increase in physical disability than men. An annual incidence of cognitive impairment of 1.4% was found and the implications of this are discussed.

Dynamic receptive field plasticity in rat spinal cord dorsal horn following C-primary afferent input

The central terminals of cutaneous primary afferent neurons are spatially ordered in the dorsal horn in a highly organized fashion such that a point-to-point map represents the body surface. This afferent terminal somatotopic map correlates with the map of the receptive fields of the cells on which they terminate. The location, size and modality of the cutaneous receptive fields of dorsal horn neurons necessarily depend upon the anatomical presence of afferent nerve fibres which deliver information from the periphery, directly or indirectly, to the cells. However the receptive field size and modality of a cell do not depend only on anatomical connections. Excitatory and inhibitory interneurons, descending influences and facilitations or depressions of synaptic contacts can alter receptive field properties. Here we show that prolonged and substantial cutaneous receptive field changes can be produced by brief inputs from peripheral unmyelinated afferent fibres.

Prolonged C-fibre mediated facilitation of the flexion reflex in the rat is not due to changes in afferent terminal or motoneurone excitability

A standard suprathreshold mechanical stimulus applied to the hindpaw of decerebrate-spinal rats produces a discharge in hamstring flexor alpha-motoneurones which is stable for hours, provided no tissue injury is produced. Tissue injury results, however, in a decrease of threshold and an increase in the responsiveness of the reflex. This reflex hypersensitivity can be mimicked by brief (20 s) low frequency (1 Hz) conditioning stimuli to muscle or cutaneous nerves, if C-fibres are recruited. The prolonged post-conditioning facilitation of the flexion reflex by C-afferent volleys is now shown to be independent of changes in the excitability of the test afferent terminals in the dorsal horn and of the motoneurones. The hypersensitivity is therefore due to changes in the interneurones that link cutaneous nociceptive afferents with flexor motoneurones.

Evaluation of the nitrosamine hypothesis of gastric carcinogenesis in precancerous conditions

A 24 hour gastric aspiration study was carried out on nine Polya gastrectomy, eight pernicious anaemia, and nine matched control subjects. Intragastric pH, bacteria, nitrite, and N-nitroso compounds were assessed half hourly whilst ambulant and hourly when in bed. Both total and nitrate reducing bacterial counts were positively related to pH (chi 2 = 279.3; p less than 0.001), as was nitrite concentration (F = 19.1; p less than 0.0001). By contrast, total (F = 40.6; p less than 0.0001) and stable (F = 257.4; p less than 0.0001) N-nitroso compound concentrations were negatively related to pH. Clear differences in these gastric juice factors were not apparent between matched control and either pernicious anaemia, or Polya gastrectomy because the Polya gastrectomy and matched control groups were heterogeneous for gastric acidity. Thus, although eight of eight pernicious anaemia subjects were hypoacidic (defined as intragastric pH greater than 4 for greater than 50% of both daytime and night time periods), only five of nine Polya gastrectomy and two of nine matched control subjects were hypoacidic. When subjects were rearranged into hypoacidic (n = 15) and acidic (n = 11) groups, bacterial counts (p less than 0.01) and nitrite concentrations (p less than 0.01) were higher, whereas N-nitroso compounds tended to be lower (NS) in the hypoacidic group. These data suggest that, although hypoacidity predisposes to bacterial overgrowth and nitrite generation, it does not enhance nitrosation. Instead, this is maximal at low pH, suggesting chemical rather than bacterial nitrosation, contrary to the nitrosamine hypothesis of gastric carcinogenesis.

Use of the computerized tomographic scan in the diagnosis and treatment of abscesses

Over a 5 year period, 89 patients underwent one or more computerized tomographic scans to locate an abscess during 92 hospitalizations. The scans were a most sensitive (93 percent), specific (98 percent), and accurate (96 percent) means of abscess detection. Thirty-nine patients had positive scans. Sixteen patients were treated directly by open surgical methods, 1 of whom required percutaneous drainage in the postoperative period for incomplete drainage. An additional 23 patients underwent attempted percutaneous abscess drainage. In 17 patients, drainage was successful. Five patients underwent percutaneous drainage and later required laparotomy, two of whom underwent unavoidable surgical procedures and three surgery for incomplete drainage. Overall, percutaneous abscess drainage was successful in 83 percent. Of 11 deaths, 8 occurred in the group with computerized tomographic scans negative for abscess. Three of these were false-negative scans. Three deaths occurred in the group with scans positive for abscess. All were of patients with hepatic abscesses treated by open surgical drainage, one after failed percutaneous drainage. Twelve patients had multiple organ failure, and 8 of these patients died, for a mortality of 67 percent. The computerized tomographic scan is the diagnostic procedure of choice in the diagnosis of abscesses. In selected patients, percutaneous abscess drainage is also a successful means of abscess treatment and avoids the complications of a laparotomy. The onset of multiple organ failure in the surgical patient should alert the diagnostician to the possibility of a septic focus. The role of early laparotomy in these patients is uncertain. We recommend early use of the computerized tomographic scan in the septic surgical patient. Prompt diagnosis and treatment of abscesses, whether by open or percutaneous routes, may avert the development of multiple organ failure and reduce morbidity and mortality.

Cutaneous receptive field and morphological properties of hamstring flexor alpha-motoneurones in the rat

Intracellular recordings have been made from twenty antidromically identified posterior biceps femoris/semitendinosus (p.b.s.t.) hamstring flexor alpha-motoneurones in the decerebrate-spinal rat. The hamstring motoneurones had either low or no spontaneous background activity. In nineteen of the twenty cells high-frequency phasic responses could be elicited by stimulation of the ipsilateral hind paw with firm pressure or pinch. There was no response to light touch or brush. Contralateral cutaneous mechanoreceptive fields with higher thresholds and weaker responses were present in 70% of the motoneurones. Noxious heating of the ipsilateral hind paw produced excitatory responses in six of eight cells tested and two of these cells also responded to heating of the contralateral hind paw. Stimulation of the ipsilateral sural nerve at graded strengths that successively activated A beta, A delta and C afferents produced excitatory post-synaptic potentials (e.p.s.p.s) at progressively longer latencies in the motoneurones. The C-fibre induced e.p.s.p. lasted up to 200 ms. Horseradish peroxidase was injected into ten motoneurones and in seven cases full reconstructions of dendritic field, cell body and axon could be made. In agreement with previous reports from studies in the cat, the dendritic fields of rat motoneurones are very extensive in the rostrocaudal, mediolateral and dorsoventral planes. The general pattern of dendritic branching for each motoneurone in this functionally homogeneous population was uniformly organized. Three major spatial orientations were always present: a rostrocaudally restricted series of dendrites emerging from the cell body and directed dorsolaterally towards the dorsolateral funiculus with branches in the lateral dorsal horn, a laterally, and a ventromedially directed series of branches arranged obliquely in the ventral horn, both of which were distributed rostrocaudally for equal distances from the cell body. Many of these dendritic branches terminated within the lateral and ventral white columns. Although the sizes of the rat flexor motoneurones' somas (51 +/- 4.9 micron, S.E., n = 10) were similar to those of cat lumbosacral alpha-motoneurones, the tip-to-tip rostrocaudal extent of their dendritic fields (1130 +/- 34 micron, S.E., n = 7) was half that reported in the cat. These results are discussed in terms of the organization of the cutaneous flexor withdrawal reflex in the rat.

Twenty-four-hour continuous electrocardiography during exercise and free activity in 80 apparently healthy runners

To determine the incidence of arrhythmias and conduction disturbances in trained athletes and the level of physical training at which they occur, 24-hour ambulatory electrocardiographic recordings were obtained in 80 healthy runners during both exercise and free activity. Subjects were grouped according to the number of miles per week (mpw) they had regularly run during the previous 3 months: Group I--0 to less than or equal to 5 mpw (less than or equal to 8 km); Group II--greater than 5 to less than or equal to 15 mpw (greater than 8 to less than or equal to 24 km); Group III--greater than 15 to less than or equal to 30 mpw (greater than 24 to less than or equal to 48 km); and Group IV--greater than 30 mpw (greater than 48 km). Ectopic ventricular complexes occurred in 41 of 80 subjects (50%) and ectopic supraventricular complexes occurred in 33 (41%). There were 2 episodes of paired ventricular ectopic activity and a 5-beat run of ventricular tachycardia with exercise. The study revealed no significant differences in the occurrence of arrhythmias or conduction disturbances in the different groups, although the 2 episodes of paired ventricular ectopic activity and 5-beat run of ventricular tachycardia are of concern.

When is arthrography indicated in Legg-Calvé-Perthes disease?

We evaluated plain radiographs and arthrograms of twenty-one children with active Legg-Calvé-Perthes disease in order to determine the value of the arthrography. We found that when epiphyseal protrusion was shown by the arthrograms it could be seen on the plain radiographs as well in all patients. Also, an acetabulum-head index of less than 90 or an acetabulum-head quotient of less than 92 as determined on plain radiographs correlated well with a diagnosis of protrusion. Thus, an arthrogram is not necessary to make the diagnosis of protrusion in most patients. The arthrogram is more useful in delineating changes in the articular surface for prognoses concerning arthritis and in tailoring the treatment to the individual patient.

Practical considerations in the use of computed tomography in the measurement of femoral anteversion

A new technique is presented for measuring femoral anteversion by computed tomography, which has advantages over earlier techniques. Computed tomography allows the visual portrayal of the cervical axis to be superimposed on the diacondylar axis for direct goniometric measurement of the anteversion angle. In addition to being accurate, the procedure requires no complicated positioning framework and can be done in a brief span of time. Clinical experience with 111 hips in 56 patients has produced accurate data, particularly with regard to congenital dislocation of the hip and Legg-Calvé-Perthes disease.

BCG treatment of transplanted rat tumours of spontaneous origin

Six transplanted rat tumours (three mammary carcinomas and three fibrosarcomas), all of spontaneous origin and of limited immunogenicity, have been examined for susceptibility to immunotherapy with BCG (Glaxo). Growth of limited numbers of cells from five tumours was suppressed when cells were injected subcutaneously in admixture with BCG organisms. There was no clear correlation between the immunogenicity of tumour lines and their susceptibility to regionally applied BCG. Active specific immunotherapy, using vaccines of viable or radiation-attenuated tumour cells in admixture with BCG, was reproducibly successful with only one tumour, the mammary carcinoma Sp4, this being the most immunogenic of the tumours examined. These studies indicate that naturally arising tumours are less susceptible to BCG-mediated suppression than carcinogen-induced tumours widely used for experimental immunotherapy, but indicate that local application of BCG may give the best therapeutic response.