Triple-injection wrist arthrography: unidirectional communications are due to technical factors

One justification for triple-injection wrist arthrography is detection of unidirectional interjoint communication that might escape notice if only a single joint were injected. To determine whether the direction of 1-way communications is related to the choice of the first joint injected, the authors prospectively randomized 100 wrists undergoing consecutive single-contrast, fluoroscopically controlled arthrograms into 2 well-matched groups. One group received the initial injections into the midcarpal and distal radioulnar joints and the other group received the initial injection into the radiocarpal joint. Two unidirectional radial capsular communications with the radiocarpal joint were detected on delayed midcarpal joint injection. No other unidirectional communications were found. No statistically significant difference was found between the midcarpal and radiocarpal study groups. Thus, the first joint injected appears to be a major determinant in demonstrating unidirectional communications between wrist compartments.

Insulin VNTR allele-specific effect in type 1 diabetes depends on identity of untransmitted paternal allele. The IMDIAB Group

The IDDM2 type 1 diabetes susceptibility locus was mapped to and identified as allelic variation at the insulin gene (INS) VNTR regulatory polymorphism. In Caucasians, INS VNTR alleles divide into two discrete size classes. Class I alleles (26 to 63 repeats) predispose in a recessive way to type 1 diabetes, while class III alleles (140 to more than 200 repeats) are dominantly protective. The protective effect may be explained by higher levels of class III VNTR-associated INS mRNA in thymus such that elevated levels of preproinsulin protein enhance immune tolerance to preproinsulin, a key autoantigen in type 1 diabetes pathogenesis. The mode of action of IDDM2 is complicated, however, by parent-of-origin effects and possible allelic heterogeneity within the two defined allele classes. We have now analysed transmission of specific VNTR alleles in 1,316 families and demonstrate that a particular class I allele does not predispose to disease when paternally inherited, suggestive of polymorphic imprinting. But this paternal effect is observed only when the father's untransmitted allele is a class III. This allelic interaction is reminiscent of epigenetic phenomena observed in plants (for example, paramutation; ref. 17) and in yeast (for example, trans-inactivation; ref. 18). If untransmitted chromosomes can have functional effects on the biological properties of transmitted chromosomes, the implications for human genetics and disease are potentially considerable.

Acute cervical spine trauma: diagnostic performance of single-view versus three-view radiographic screening

PURPOSE

To compare the diagnostic accuracy of single-view and three-view cervical spine radiographs in acute trauma.

MATERIALS AND METHODS

Radiographs of 97 patients with acute cervical spine fractures were matched with those of 92 proved normal cases. Fourteen radiologists, including three senior attending radiologists each with more than 20 years of post-residency experience, four junior attending radiologists each with less than 5 years of practice experience, three senior radiology residents in their 3rd or 4th year of radiology residency, and four junior radiology residents at the end of their 1st year of radiology training, interpreted each case twice: once as a lateral-only study and again as a three-view study. Multireader-multicase receiver operating characteristic analysis was performed. Difficult cases were reviewed for trends in the errors.

RESULTS

Eight of 14 readers detected fractures better with the three-view series. Among junior attending radiologists, the differences were statistically significant. Most improvements were in fractures of the dens and fractures and unilateral dislocations of the articular mass. Overall, sensitivity increased from 81.8% to 83.3%. The reliability of fracture classification improved. Less experienced readers performed better with the three-view series.

CONCLUSION

A three-view screening radiographic series will allow most readers to detect a few more fractures than a single-view series. The improvements occur primarily in a subset of difficult-to-diagnose injuries.

Short-chain fatty acids promote the migration of colonic epithelial cells in vitro

BACKGROUND & AIMS

Repair of colonic epithelial erosions requires cell migration. This study aimed to examine the effects of physiologically relevant short-chain fatty acids on migration in colonic epithelial cell lines.

METHODS

Butyrate, propionate, and acetate were added to confluent monolayers of LIM1215 colon cancer cells after wounding. Migration in circular wounds was assessed after 24 hours.

RESULTS

The migration of LIM1215 cells was stimulated in a concentration-dependent manner by all short-chain fatty acids. In four experiments, 2 mmol/L butyrate, 8 mmol/L propionate, and 16 mmol/L acetate induced 112.6% +/- 6.7%, 98.5% +/- 5.4%, and 63.4% +/- 7.2% (mean +/- SEM) stimulation above control migration, respectively. Their effects were additive at submaximal concentrations and reversible. Butyrate also stimulated migration in two other colon cancer cell lines, Caco-2 and LIM2405. However, butyrate failed to stimulate the migration of nongastrointestinal and nonepithelial cell lines. The stimulatory effect of butyrate required protein and RNA synthesis but was independent of cell proliferation, presence of serum, beta-oxidation, transforming growth factor beta, intracellular acidification, and substratum composition.

CONCLUSIONS

In wounded in vitro models of colonic epithelium, short-chain fatty acids promote cell migration. If such an effect occurs in vivo, it would have ramifications for the biology and pathobiology of the colonic mucosa.

Epithelial migration in the colon: filling in the gaps

1. The efficient repair of gastrointestinal mucosal injuries is essential in the preservation of the epithelial barrier to luminal antigens. Accumulated evidence suggests that epithelial migration plays a major part in this repair by rapidly resealing defects induced by both physiological and pathological insults, a process termed restitution. 2. This migration has been modelled in various ways, most commonly in mechanically wounded monolayers of cell lines or cells in primary culture, and in wounded human or animal tissue. Evidence from these models indicates that migration is a highly complex process, which is likely to involve the tightly controlled spatial and temporal interaction of multiple factors: (i) extracellular molecules such as soluble factors (e.g. growth factors, trefoil peptides, cytokines) and matrix components (e.g. collagen, laminin, fibronectin); (ii) signalling molecules activated by the interaction of these factors with cell surface receptors (e.g. protein kinases, phospholipases, low-molecular-weight GTPases); (iii) factors which regulate adhesion to other cells (e.g. E-cadherin) and to matrix components (e.g. integrins, hyaluronic acid receptors); (iv) factors which regulate detachment from the extracellular matrix (e.g. urokinase-type plasminogen activator, matrix metalloproteinases); and (v) molecules which regulate cytoskeletal function (e.g. Rac), which allows the formation of specialized cellular processes termed lamellipodia. 3. The identification of physiologically relevant factors that stimulate epithelial cell migration, and a better understanding of their mechanism of action, may be beneficial in the development of novel therapeutic approaches in diseases such as inflammatory bowel disease through the pharmacological or dietary enhancement of this migration.

Trypanosoma cruzi: use of herpes simplex virus-thymidine kinase as a negative selectable marker

Trypanosoma cruzi, the protozoan that causes Chagas' disease, was transfected with a fusion gene of hygromycin phosphotransferase and herpes simplex virus-thymidine kinase, HyTK. Transfectants selected in hygromycin had thymidine kinase activity, whereas controls did not. In vitro growth of the mammalian life-stage forms, amastigotes and trypomastigotes, was inhibited 98% by the nucleoside analogue ganciclovir (5 micrograms/ml). Growth of the insect-stage form, epimastigotes, was not inhibited by ganciclovir (up to 250 micrograms/ml) or other nucleoside analogues. Intracellular uptake of ganciclovir by epimastigotes was found to be 10-fold less than that by amastigotes. Mice infected with the HyTK-expressing parasites and treated with ganciclovir had a statistically significant reduction of parasitemia by 57%; however, complete eradication of parasites was not achieved. The parasites recovered from the treated mice continued to be susceptible to ganciclovir in vitro. Parasite clones with higher expression of thymidine kinase were more sensitive to ganciclovir, suggesting that greater expression of the thymidine kinase gene may lead to parasites that can be fully eradicated from infected experimental animals.

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 (HHV8)--a new human tumour virus

Recently, a novel DNA virus has been molecularly cloned from Kaposi's sarcoma (KS) tissue, a tumour common in acquired immune deficiency syndrome (AIDS). Analysis of the viral genome confirms that it is a relative of human herpesviruses and the virus has been designated HHV-8. Epidemiological evidence suggests a strong aetiological link between the presence of HHV-8 DNA and/or antibodies against the virus, and KS. Additional sequence analysis suggests that the HHV-8 genome contains sequences which encode a D type cyclin and a number of other genes potentially implicated in growth deregulation which may be relevant to its proposed role as a transforming virus.

Design of a summary screen for an ICU patient data management system

The paper describes a used-centred design for the summary screen of a computerised ICU patient data management system (PDMS). The screen also forms the resting state display, or default screen, and provides the principal navigation tool to other functionality within the system. The design process identified the most frequent potential users of this screen to be the nurses. Their tasks and the information resources required to perform them were analysed. The analysis identified that the nurses' main task of planning and implementing patient care required an awareness of a set of physiological parameters which provided an overview of the patient's general condition. Novel formats are proposed for displaying the trends in physiological parameters and these have been incorporated into a proposed screen design. These display formats have been evaluated by ICU nurses; they were adjudged to be clear, relevant, easy to learn and simple to use. Nurses considered the content of the screen, and the display formats used, to be suitable for maintaining an awareness of a patient's state during routine patient management.

A new method of accurately identifying costs of individual patients in intensive care: the initial results

OBJECTIVES

To analyse the patient-related and non-patient-related costs of intensive care using an activity-based costing methodology.

DESIGN

A retrospective cost analysis of 68 patients admitted sequentially over a 10-week period.

SETTING

The Adult General Intensive Care Unit of the Royal Hallamshire Hospital, Sheffield.

RESULTS

The results showed large variations in the costs obtained for individual patients. The calculation of the costs for the initial period of stay showed a wide variation depending on whether the costs were determined per calendar day or per first 24-h period. Significant correlations of costs between the first 24 h of stay and the admitting Acute Physiology and Chronic Health II score (p < 0.004) and daily costs with the Therapeutic Intervention Scoring System scores (p < 0.0001) were found. The average daily patient-related cost of care was Pounds 592. Overhead costs were calculated at Pounds 560 per patient day, which made the total cost of a day's treatment in intensive care Pounds 1152.

CONCLUSIONS

The use of average costs or scoring systems to cost intensive care is limited, as these methods cannot determine actual resource usage in individual patients. The methodology described here allows all the resources used by an individual patient or group of patients to be identified and thus provides a valuable tool for economic evaluations of different treatment modalities.

MR imaging of clinically suspected scaphoid fractures

OBJECTIVE

The purpose of this study was to evaluate the usefulness of MR imaging in revealing occult fractures in patients with clinically suspected acute scaphoid fractures who have normal or equivocal findings on radiographs.

SUBJECTS AND METHODS

Thirty-six patients underwent MR imaging within 7 days of wrist injury. All had physical findings suggestive of scaphoid fracture. Coronal T1-weighted, short inversion time inversion recovery, and either T2-weighted or proton density-weighted fast spin-echo sequences with fat suppression were used. Follow-up radiographs were obtained at least 2 weeks after MR imaging whenever possible. All imaging studies were reviewed by two musculoskeletal radiologists.

RESULTS

MR imaging revealed 22 occult fractures in 20 patients. Thirteen of these 22 fractures were in the scaphoid bone, and nine were in the distal radius. On MR images, 16 patients had no evidence of fracture. Follow-up radiographs were available in 14 of the 20 patients who had occult fracture revealed by MR imaging. Eleven of the 13 occult fractures of the scaphoid bone were followed up (two were lost to follow-up), and 10 of the 11 showed signs of healing. Five of the nine lesions of the distal radius were followed up, and three of these showed evidence of healing fracture. Three patients without MR evidence of a fracture had follow-up radiographs that showed no fracture. Three patients had findings consistent with bone contusion on MR images; in two patients, the contusion was associated with other fractures, and in one patient, the contusion was isolated.

CONCLUSION

MR imaging can reveal occult wrist fractures when findings on radiographs are normal or equivocal.

Diagnosis of injuries after stab wounds to the back and flank

BACKGROUND

Historically, patients with deep posterior wounds underwent a formal celiotomy to rule out injury. Currently, we use a policy of selective management. The purpose of this review is to evaluate our experience with selective management to identify potential areas of further improvement.

METHODS AND RESULTS

This study includes 203 patients over a 10-year period. By changing from a policy of mandatory exploration to selective management the total celiotomy rate decreased from 100 to 24% and the therapeutic celiotomy rate increased from 15 to 80%.

CONCLUSIONS

In stable patients, a diagnostic peritoneal lavage should be performed as the initial diagnostic study. When diagnostic peritoneal lavage is negative, triple contrast computed tomography should be performed to evaluate the remaining retroperitoneal structures. Any suggestion of pericolonic extravasation of contrast or air, edema, or hemorrhage must be interpreted as a positive study and prompt consideration for operative exploration.

Quantitative analysis of the plain radiographic appearance of Brodie's abscess

RATIONALE AND OBJECTIVES

The authors quantitate the radiographic features that distinguish the plain radiographic appearance of Brodie's abscess (BA) from other solitary lesions of bone.

METHODS

Plain radiographs of 709 solitary bone lesions were reviewed, including 21 BAs. These were analyzed according to demographic, gross anatomic, and structural features. Vector analysis of groups of features was performed to determine those that are most sensitive and specific for the radiographic appearance of BA relative to other lesions of bone.

RESULTS

Brodie's abscesses, in our series, are most commonly medullary-based (86%) lytic lesions (100%), with a geographic pattern of destruction (100%), well-defined edges (90%), marginal sclerosis (86%), and no bone enlargement (95%). In general, they have no periosteal reaction (71%), cortical break (95%), or visible matrix (90%). They typically are localized to the diaphysis or metaphysis (86%) of tubular bones, particularly in the lower extremity (63%). By vector analysis, the radiographic and demographic description of BA that provided the greatest sensitivity (67%-76%) while maintaining high prevalence (20%-21%) included a well-defined lytic lesion with a geographic pattern of destruction, and no bone enlargement or matrix or cortical break arising in patients younger than 40 years old. Although BAs commonly are small lesions with maximum diameters < 50 mm, size criteria did not greatly affect the sensitivity or specificity for detection of BA in our database. The differential diagnosis generated by vector analysis includes osteoid osteoma, nonossifying fibroma, giant cell tumor, eosinophilic granuloma chondroblastoma, and fibrous dysplasia, as the major lesions.

CONCLUSIONS

Although BA can present with a variety of radiographic features, a relatively specific set of radiographic characteristics can be defined to assist in plain-film diagnosis and to help refine the differential diagnosis of similar-appearing lesions.

Quantitative analysis of the plain radiographic appearance of Ewing's sarcoma of bone

RATIONALE AND OBJECTIVES

The authors quantitate the radiographic features that distinguish the plain radiographic appearance of Ewing's sarcoma (ES) from other solitary lesions of bone.

METHODS

A total of 709 cases of focal bone lesions, including 44 ES, were analyzed according to demographic, anatomic, and plain radiographic features. Vector analysis of groups of features was performed to determine those that are most sensitive and specific for the appearance of ES in contrast with other lesions in the database.

RESULTS

In our sample, Ewing's sarcoma is most consistently a medullary-based (91%) lytic (89%) lesion with at least a partially permeative appearance (82%), poorly defined edges (82%), no margination (91%), and a soft-tissue mass (61%). When these lesions occur in long bones, they most commonly are found in the diaphysis (75%) and are proximal more often than distal. Vector analysis suggests that any primary bone lesion without radiographically visible matrix and with either a soft-tissue mass, an appearance of permeative destruction alone or in combination with other patterns of bone destruction is suspect for the diagnosis. This small subset of common features appears to have a high sensitivity (89%) and prevalence (47%) of ES among the lesions meeting these criteria. Limiting the age of the patients to progressively younger age groups increases the specificity but lowers sensitivity. The vector analysis-generated differential diagnoses includes osteosarcoma, giant-cell tumor, lymphoma, and chondrosarcoma.

CONCLUSIONS

A relatively specific set of radiographic features can be defined, which will assist in the radiographic diagnosis of ES and improve upon current textbook descriptions.

Usefulness of turbo spin-echo MR imaging in the evaluation of meniscal tears: comparison with a conventional spin-echo sequence

OBJECTIVE

Fast (turbo) spin-echo imaging techniques have replaced conventional spin-echo protocols in a large proportion of MR applications, with the principle advantage of decreased imaging time. The choice of echo train length is a key determinant of time savings realized, but the echo train length can also adversely affect image quality if too many echoes are incorporated into an image. Several recent studies have shown conflicting results regarding the usefulness of turbo spin-echo imaging in the evaluation of meniscal tears. We compare a turbo spin-echo sequence that has an echo train length of five with a conventional spin-echo sequence for evaluating meniscal tears.

SUBJECTS AND METHODS

Forty knees in 39 consecutive patients referred for MR study of the knee were imaged using both conventional spin-echo and turbo spin-echo sequences. The turbo spin-echo sequence provided both proton density-weighted and T2-weighted images (dual echo technique) with an effective echo-train length of five. Nineteen knees (38 menisci) were studied arthroscopically. The arthroscopic findings were considered the reference standard. Spin-echo and turbo spin-echo images were reviewed retrospectively, and results were compared statistically.

RESULTS

Of the 80 menisci evaluated with MR imaging, spin-echo and turbo spin-echo images provided concordant results in 95% of cases, with no statistically significant difference found between the two techniques (p < .05). Seventeen tears were found at arthroscopy in 38 menisci studied. Spin-echo and turbo spin-echo imaging had identical specificities (90%) and similar sensitivities (88% and 82%, respectively).

CONCLUSION

This study shows that proton density-weighted sequences with an echo train length of five preserve sufficient high-spatial-frequency information to provide performance similar to that of conventional spin-echo sequences. Our data support the conclusion that fast spin-echo imaging with short echo train length is a reasonable substitute for conventional spin-echo imaging in the evaluation of the knee.

Dynamics of respiratory patterning in normal infants and infants who subsequently died of the sudden infant death syndrome

Despite evidence that respiratory control mechanisms may be altered in infants who succumb to the sudden infant death syndrome (SIDS), overall respiratory variability in SIDS victims is comparable to that of control infants. We assessed dynamic characteristics of breathing in 16 recordings of apparently healthy infants who subsequently died of SIDS, and 35 recordings of age-matched control infants. Each breath-to-breath interval in 10-min epochs of quiet sleep and rapid eye movement sleep was plotted against the previous interval. Dispersion of next-intervals was determined after short, intermediate, and long interbreath intervals. In SIDS victims, dispersion after long intervals (slow respiratory rates) was significantly restricted relative to control infants. Moreover, after long breath-to-breath intervals, SIDS victims showed smaller mean breath-to-breath changes in respiratory rate than did controls. The findings indicate that breath-to-breath respiratory patterns differ in infants who succumb to SIDS, and the differences occur preferentially at low respiratory rates.

Prevalence of red marrow around the knee joint in adults as demonstrated on magnetic resonance imaging

RATIONALE AND OBJECTIVES

We determined the prevalence of red marrow around the knee joint in adults and evaluated variations with age, gender, and other variables.

METHODS

One hundred ninety-nine adult patients presenting for routine knee magnetic resonance (MR) imaging completed a questionnaire that covered age, gender, menstrual history, past pregnancies, smoking history, and medications. The presence or absence of visible red marrow in the distal femur and proximal tibia on both coronal and sagittal MR images was recorded for each patient. Associations between the presence of red marrow and the other recorded variables then were evaluated.

RESULTS

Red marrow was present in more than half of the women and less than one sixth of the men, a statistically significant difference. The age distribution of red marrow in men and women also was different. Red marrow was the most common in women aged 30-60 years. In men, there was no clear-cut age trend. Red marrow also was more likely to be present in obese individuals and smokers. No association was found between the presence of red marrow and any of the other recorded variables.

CONCLUSION

There are clear gender, age, obesity, and smoking-related differences in the prevalence of red marrow around the knee joint in adults. Red marrow is relatively common in this site in all age groups, and its presence should not be a cause for clinical concern.

Eosinophil apoptosis and the resolution of airway inflammation in asthma

Asthma is accompanied by the accumulation of potentially damaging eosinophils within inflamed airways. How eosinophils may be removed from the airways is not clear. The phagocytic removal of eosinophils in vitro requires that they undergo apoptosis, a form of cell death. We postulated that eosinophil apoptosis may occur in vivo, promoting the removal of airway eosinophils and the resolution of inflammation in asthma. We examined eosinophil apoptosis in sputum samples obtained from 11 subjects during an asthma exacerbation and 2 wk after corticosteroid treatment of the exacerbation. Airway function improved following corticosteroid treatment, and eosinophilic inflammation subsided, with significant decreases occurring in the number of airway eosinophils and the percentage of activated eosinophils. The proportion of apoptotic airway eosinophils increased significantly following corticosteroid treatment, and eosinophil products were apparent within macrophages. Our findings indicate that eosinophil apoptosis is clinically relevant in asthma. Apoptosis may represent a mechanism that promotes the resolution of eosinophilic inflammation in asthma.

IDDM2-VNTR-encoded susceptibility to type 1 diabetes: dominant protection and parental transmission of alleles of the insulin gene-linked minisatellite locus

IDDM2-encoded predisposition to type 1 diabetes has recently been mapped to the minisatellite or variable number of tandem repeat (VNTR) locus upstream of the insulin and insulin-like growth factor II genes on human chromosome 11p15.5. In a UK case-control study (n = 228 sporadic diabetics; n = 441 healthy controls), we show here that the genotype homozygous for VNTR class I alleles is predisposing to disease (RR = 2.68), and VNTR class III alleles are dominantly protective (RR = 0.37). In 722 diabetic families from the UK (n = 356), USA (n = 173), Denmark (n = 55) and Sardinia (n = 138), we have analysed the transmission of class I alleles to diabetic offspring from class I/III heterozygous parents. We confirm that in families from the USA, class I alleles are transmitted preferentially from fathers. However, in family data sets from the UK, Denmark and Sardinia, the reverse is true and maternal transmission is stronger. Furthermore, in the UK family data set, the difference between maternal and paternal transmissions is significant (P < 0.05). It is therefore unlikely that 'maternal imprinting' alone explains the parent-of-origin effects in IDDM2-encoded predisposition to type 1 diabetes, at least not in the UK. There is a relationship between VNTR class (allele length) and insulin gene expression, though some results from different studies are conflicting. In the human adult cadaveric pancreas, we confirm our preliminary results that class III alleles are associated with lower levels of insulin mRNA in vivo. Similar results have been obtained independently in human foetal pancreas samples. It is difficult to explain how these marginally lower levels of insulin expression could account for the observed VNTR class III-encoded protective effect. Perhaps the site of action of IDDM2, mediated by VNTR allelic variation, is not the pancreas but some other organ such as the thymus.

The use of continuous quality improvement methods to implement practice guidelines in asthma

National asthma management guidelines have improved awareness of the rising morbidity and mortality from asthma but have not been widely implemented at a local level. This paper describes the use of continuous quality improvement techniques to facilitate the implementation of asthma management guidelines within a tertiary hospital setting. A baseline audit demonstrated satisfactory emergency assessment and treatment, but identified poor compliance with the patient education aspects of the asthma management plan. An evaluation of the literature demonstrated that programs combining asthma education and management were effective when directed towards adults with a recent severe asthma exacerbation. An asthma education and management service was developed to address these deficits. A repeat audit was conducted which identified improvements in asthma control and management skills for patients attending the education program, together with reductions in asthma re-admission rates for patients referred to the service. Ongoing quality assessments will target non-attenders to the service and the maintenance of asthma skills. An area Asthma Health Outcomes Council was formed to address the issues of asthma management throughout the area health service.

Fatigue in selected primary care settings: sociodemographic and psychiatric correlates

OBJECTIVES

To determine the prevalence and sociodemographic and psychiatric correlates of prolonged fatigue syndromes among patients in primary care.

DESIGN

Prospective questionnaire survey.

PATIENTS AND SETTING

Adults over 18 years attending three general practices in metropolitan Sydney and one on the Central Coast, north of Sydney.

RESULTS

Of 1593 patients, 25% had prolonged fatigue, while 37% had psychological disorder. Of the patients with fatigue, 70% had both fatigue and psychological disorder, while 30% had fatigue only. The factors associated with prolonged fatigue were concurrent psychological disorder, female gender, lower socioeconomic status and fewer total years of education. Patients with fatigue were more likely to have a current depressive disorder.

CONCLUSIONS

Prolonged fatigue/neurasthenia syndromes are common in Australian primary care settings, and are commonly associated with current depressive disorders. Such syndromes, however, do not fit readily into current international psychiatric classification systems.