Femoral head avascular necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings

To better correlate the appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images with the stage of disease, MR images of 56 proved AVN lesions were compared with staging from corresponding radiographs (n = 56), Tc-99m scans (n = 41), and grade of symptoms (n = 28). Fractures complicating AVN were seen in 28 (50%) of 56 radiographs (radiographic stages III-V). With long repetition (TR) and echo delay (TE) times, a characteristic "double line sign" consisting of high signal intensity inside a low-intensity peripheral rim was seen in 45 lesions (80%). The central region within the rim was isointense with marrow fat on both short and long TR and TE images in 20 (71%) of 28 lesions uncomplicated by fracture (stages I-II) but in only four (14%) of 28 stage III-V lesions (P less than .001). Symptoms were least severe in lesions isointense with fat and most severe in lesions with low-signal central regions at short and long TRs and TEs. The peripheral double line sign on long TR/TE images may add specificity to the diagnosis of AVN by MR imaging. A chronologic pattern of central MR signal features is presented which may allow staging of AVN by MR imaging.     

Pulse pressure responses to psychological tasks improve the prediction of left ventricular mass: 10 years of follow-up

OBJECTIVES: To examine the role of casual blood pressure measurements and blood pressure responses to psychological tasks in the prediction of future left ventricular mass index (LVMI), and to determine the importance of different components of blood pressure, and the predictive value of an individual's personal characteristics and antihypertensive medication on future LVMI. METHODS: At baseline, blood pressure was recorded by casual measurements; during tests it was recorded by intra-arterial monitoring. The participants were healthy, untreated 35-45-year old men. Echocardiography data both at baseline and after 10 years of follow-up were available from 65 individuals, of whom 49 (75%) were not taking antihypertensive medication at follow-up. Those not taking antihypertensive medication were included in the prediction of LVMI (g/m2). RESULTS: Baseline LVMI correlated significantly with future LVMI only among the 49 unmedicated individuals (r = 0.52, P < 0.0001). The predictive value of baseline LVMI on future LVMI among them (adjusted coefficient of determination = 0.26) was not improved by the inclusion of casual blood pressure. In contrast, blood pressure responses to the psychological tasks improved the prediction of future LVMI by 4-13%. Pulse pressure was the blood pressure variable that entered the final prediction models; the correlations with future LVMI were best for pulse pressure response to habituation task (r = 0.43, P < 0.05) and to relaxation (r = 0.37, P < 0.05). CONCLUSIONS: To our knowledge, this is the longest prospective follow-up to show that blood pressure responses to psychological tasks improve the prediction of LVMI compared with casual blood pressure measurements. The pulse pressure, which reflects the properties of the arterial wall, is the most significant blood pressure variable in predicting future LVMI.     

Prevalence of antibodies to human immunodeficiency virus type 1 among blood donors prior to screening. The Transfusion Safety Study/NHLBI Donor Repository

The Transfusion Safety Study (TSS) and the National Heart, Lung, and Blood Institute (NHLBI) established a repository of approximately 200,000 sera from blood donors in late 1984 and early 1985. Collections were made in the four metropolitan areas with the highest prevalence of AIDS. Retrospective testing showed an overall anti-HIV-1 prevalence of 16 cases per 10,000 donations. In this study, the predictive value of a negative initial enzyme-linked immunoassay was estimated from both quality control specimens and the rescreening of 13,461 sera to be greater than 99.99 percent with respect to technical error. Among anti-HIV-1-positive persons, there was a 1.3- to 1.5-fold excess of first-time donors. The anti-HIV-1 prevalence among donors showed that infection was more common among young men than suggested by national reporting of AIDS cases. Anti-HIV-1 prevalence varied among the four metropolitan areas less than did reported AIDS cases, but, by 1987, the differences in the latter had decreased. Anti-HIV-1 prevalence in collection areas outside of the four major cities differed much more widely than that among the cities themselves. The TSS/NHLBI Donor Repository will remain available for the indefinite future for further evaluation of screening procedures for HIV-1 and other viruses for which transfusion is found to be an important route of transmission.     

Hemoglobin stimulates mononuclear leukocytes to release interleukin-8 and tumor necrosis factor alpha

Incubation of human mononuclear leukocytes (MNL) with human stroma-free hemolysate (SFH), purified adult hemoglobin Ao (HbAo), and oxidized HbAo (METHb) caused MNL to release compounds into the supernate that mediated neutrophil (polymorphonuclear leukocytes, PMN) chemotaxis and PMN adherence to human umbilical vein endothelial cells (HUVEC). Chemotaxis and PMN adherence to HUVEC were reduced significantly when supernates were preincubated with neutralizing antibodies to interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha), respectively, suggesting that IL-8 and TNF-alpha played significant roles in mediating these activities. Greatest chemotactic activity was observed in supernates of MNL treated with HbAo; while greatest PMN/endothelial cell (EC) adherence activity was observed in supernates of MNL treated with METHb. Furthermore, PMN/EC adherence activity was a function of METHb content in each hemoglobin solution. PMN chemotaxis, PMN adherence to HUVEC, and cytokine release increased as a function of increasing incubation time. Chemotactic activity was detected in HbAo- treated and METHb-treated MNL supernates after incubation for 6 hours and was maximal by 10 hours. IL-8 was detected in both HbAo and METHb- MNL supernates by 4 hours. PMN/EC adherence activity was detected in HbAo-MNL supernates at 10 hours and in METHb-MNL supernates at 4 hours. TNF-alpha was detected in METHb and HbAo-MNL supernates at 4 and 12 hours, respectively. These results suggest that hemoglobin solutions stimulate MNL to release IL-8 and TNF-alpha in quantities sufficient to induce PMN chemotaxis and PMN adherence to HUVEC. This is a US government work. There are no restrictions on its use.     

Intolerance to cereals is not specific for coeliac disease

BACKGROUND: Abdominal complaints after ingestion of cereals are not uncommon. We assessed how reliable such a history is as a marker for the presence of overt coeliac disease, and whether we should also take into account latent coeliac disease and cereal allergy. METHODS: The study group comprised 93 consecutive adults from health centres spontaneously reporting abdominal symptoms after consumption of cereals. Small bowel mucosal morphology, CD3+, alphabeta+ and gammadelta+ intraepithelial lymphocytes (IELs), HLA DQ alleles and serum IgA-class endomysial (EmA), tissue transglutaminase (tTg) and gliadin (AGA) antibodies were determined. Skin prick and patch tests and serum radioallergosorbent tests for cereals were carried out. Thirty non-coeliac adults served as biopsy controls. RESULTS: Eight (9%) patients had coeliac disease and one mild partial villous atrophy. Altogether 17 had an increased density of gamma delta+ IELs without atrophy. However, only seven (8%) showed evidence of latent coeliac disease, i.e. both an increase in gammadelta+ IELs and the presence of coeliac disease-type HLA. One or more of the allergy tests for cereals was positive in 19; 9 adopted a gluten-free diet and abdominal symptoms were alleviated in all. In non-coeliac patients, serum EmA and tTg tests were negative in all, whereas AGA was seen in 40%. CONCLUSIONS: Intolerance to cereals is not a specific sign of overt or latent coeliac disease. All experimental dietary interventions before proper diagnosis of coeliac disease are therefore to be discouraged. Allergy to cereals, on the other hand, should be considered even in adults.     

Increased alveolar nitric oxide concentration in asthmatic patients with nocturnal symptoms.

Nocturnal asthma symptoms and impaired lung function at night are related to inflammatory activity in the peripheral lung compartment. Exhaled nitric oxide (NO) measurement at multiple exhalation flow rates can be used to separately assess alveolar and bronchial NO production and inflammation. The authors hypothesised that asthmatic patients with nocturnal symptoms have a higher alveolar NO concentration than those with only daytime symptoms. The authors asked 40 patients with newly-diagnosed steroid-na?ve asthma about their nocturnal asthma symptoms through the use of a written questionnaire. Alveolar NO concentration and bronchial NO flux were assessed in the 40 asthmatics and 40 healthy controls. Nineteen of the 40 patients reported nocturnal symptoms. Patients with nocturnal symptoms had a higher alveolar NO concentration (1.7+/-0.3 (mean+/-SEM) parts per billion (ppb)) than patients without nocturnal symptoms (0.8+/-0.3 ppb, p=0.012) or healthy controls (1.0+/-0.1 ppb, p=0.032). Bronchial NO flux was higher both in patients with (2.4+/-0.4 nL x s(-1), p<0.001) and without (2.6+/-0.4 nL x s(-1), p<0.001) nocturnal symptoms, compared to controls (0.7+/-0.1 nL x s(-1)). Nocturnal symptoms in asthmatic patients are related to a higher alveolar nitric oxide concentration. The results suggest that assessment of alveolar nitric oxide concentration can be used to detect the parenchymal inflammation in asthmatic patients with nocturnal symptoms.