Anatomy of the acromial arch: correlation of anatomy and magnetic resonance imaging

Summary Based on a retrospective study of 179 MRI records covering four populations (patients presenting with impingement without known injury (n=90), post-traumatic shoulder pain (n=28), instability or dislocation (n=36) and controls (n=25)), morphologic criteria are suggested to define presumedly normal arches and arches compatible with subacromial impingement. The subacromial arch is presumed normal or without impingement if the sagittal and frontal views show it to be parallel to the humeral head, and/or if there is a fatty layer interposed between the arch and the supraspinatus m. The arch is presumed aggressive or actually capable of giving rise to impingement if, in either the sagittal or frontal view, there is a zone of narrowing of the subacromial passage with an impression of the arch on the supraspinatus tendon or tendinous thinning at this level or just lateral to this narrowed zone. Based on these criteria, study of the 179 MRI records demonstrated a significant difference of distribution of the arches in the four populations. Aggressive arches were found in 45.5% of patients with impingement, 25% of patients with posttraumatic pain, 8.9% of patients with an acute or recurrent dislocation and 12% of controls. Conversely, a presumedly normal arch was found in 56% of the controls, 55% of patients with dislocation, 25% of posttraumatic painful shoulders and only 5.5% of patients with clinical impingement. Subacromial impingement may be due to the type 3 acromial dysplasia described by Bigliani or to a thickening of the coracoacromial ligament at its acromial attachment. This study was supplemented by 15 anatomic dissections which confirmed the regularity of attachment of the coracoacromial ligament at the inferior aspect of the acromion along its lateral border.

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Anatomie de la voûte acromiale : corrélation entre anatomie et imagerie par résonance magnétique

Résumé A partir de la lecture rétrospective de 179 dossiers d'IRM représentant quatre populations (patients présentant un conflit sans traumatisme reconnu (n=90), une douleur d'épaule post-traumatique (n=28), une instabilité ou une luxation (n=36) et sujets témoins (n=25)), les auteurs proposent des critères morphologiques pour définir des voûtes présumées normales et des voûtes susceptibles de rendre compte d'un conflit sous acromial. La voûte sous acromiale est présumée normale ou non conflictuelle si, sur les vues sagittales et frontales, elle apparait parallèle à la tête humérale et/ou il existe un liseré graisseux qui s'interpose entre la voûte et le m. supra-épineux. La voûte sous acromiale est présumée agressive ou susceptible de rendre compte d'un conflit si, sur l'une des vues sagittale ou frontale, il est observé une zone de rétrécissement du défilé sous acromial avec une empreinte de la voûte sur le tendon du m. supra-épineux ou un amincissement tendineux au niveau ou juste en dehors de cette zone de rétrécissement. A partir de ces critères, la lecture des 179 dossiers d'IRM permet de mettre en évidence une différence significative de répartition des voûtes dans les quatre populations. Les voûtes agressives s'observent chez 45.5 % des patients présentant un conflit, 25 % des patients pr%esentant une douleur au décours d'un traumatisme, 8.9 % des sujets examinés au décours d'une luxation aigue ou récidivante et 12 % des sujets témoins. A l'inverse, la voûte présumée normale est retrouvée chez 56 % des sujets témoins, 55 % des patients examinés pour une luxation, 25 % des douleurs d'épaule post traumatique et seulement 5.5 % des patients présentant un conflit clinique. Le conflit sous acromial peut être le fait d'une dysplasie acromiale de type 3 décrit par Bigliani ou d'un épaississement du ligament au niveau de son insertion acromiale. Ce travail est complété par 15 dissections anatomiques qui confirment la constance de l'insertion du ligament coraco-acromial sur la face inférieure de l'acromion le long de son bord latéral.

     

No association between nickel allergy and reporting cosmetic dermatitis from mascara or eye shadow: a cross‐sectional general population study

Background In theory, all pigmented make‐up products may contain metal allergens including nickel. Eyelid dermatitis has previously been observed among nickel allergic dermatitis patients following exposure to nickel containing mascara and eye shadow. However, an association between nickel eyelid dermatitis and nickel in make‐up products remains controversial. Objective This cross‐sectional patch test study investigated whether the frequency of self‐reported cosmetic dermatitis from mascara or eye shadow use was higher among nickel allergic Danish women than women without nickel allergy. Methods In 2006, a total of 1843 18–69 year old women completed a postal questionnaire including questions on cosmetic dermatitis and were patch tested with nickel sulphate. Data were analysed by logistic regression analyses and associations were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Results The prevalence of nickel allergy was similar among women who reported cosmetic dermatitis from eye shadow or mascara and among women who did not report such symptoms. Cosmetic dermatitis was positively associated with self‐reported atopic dermatitis and age. Conclusion Overall, no association between having nickel allergy and reporting cosmetic dermatitis from mascara or eye shadow use was found in the general population. This does not exclude a causal relationship in selected cases.     

Binding of G-CSF, GM-CSF, tumor necrosis factor-alpha, and gamma- interferon to cell surface receptors on human myeloid leukemia cells triggers rapid tyrosine and serine phosphorylation of a 75-Kd protein

Granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma-interferon (gamma-IFN), or tumor necrosis factor-alpha (TNF-alpha) triggered the rapid, stable phosphorylation of a 75-Kd protein (p75) when incubated with permeabilized HL60 human myeloid leukemia cells in the presence of [gamma-32P] ATP. Among several chemical inducers of HL60 cell differentiation, dimethyl sulfoxide also triggered p75 labeling, but retinoic acid or 12-O-tetradecanoylphorbol-13-acetate did not elicit this response. Pretreatment of cells with G-CSF or GM-CSF for more than 30 seconds before permeabilization rendered the p75 labeling undetectable, suggesting that ligand-stimulated labeling was rapidly completed within this time in intact cells. Phosphorylation of p75 occurred on serine and tyrosine residues. This conclusion was confirmed by direct phosphoamino acid analysis. Immunoblot analysis of lysates of intact HL60 cells that had been incubated with G-CSF, GM-CSF, IFN, or TNF confirmed that tyrosine phosphorylation of a p75 also occurred in response to these cytokines in intact cells. Pretreatment of intact HL60 cells with one biologic agent or dimethyl sulfoxide abolished p75 labeling in response to incubation of permeabilized cells with a second agent, strongly suggesting that the same protein was phosphorylated in response to these treatments. p75 labeling was strictly dependent on expression of the appropriate ligand receptor. Data suggest that activation of a tyrosine kinase system is an early response to the binding of G-CSF, GM-CSF, TNF, or IFN to their respective cell surface receptors, or to the addition of dimethyl sulfoxide, and that the resulting phosphorylation event(s) may play a role in securing common elements in the biologic responses to these agents.     

Heterogeneity of autoantibodies to factor VIII: differences in specificity for apparently distinct antigenic determinants of factor VIII coagulant protein

The interference of antibodies to factor VIII coagulant protein (VIII:C) of 9 nonhemophilic patients with the binding to factor VIII coagulant antigen (VIII:CAg) of a reference hemophilic 125I-Fab' reagent, used in a liquid phase VIII:CAg assay, was studied. The binding competition was estimated from immunoradiometric assay (IRMA) dose-response slope of VIII:CAg present in patient plasma, interference of antibodies with the 125I-Fab' binding to VIII:CAg in normal plasma, and the displacement of antibody from the complexes with VIII:CAg by the 125I Fab'. Antibody populations from three patients were studied in detail; in the VIII:CAg assay, two of them interfered with the 125I- Fab' binding, and one did not (patient 1). The formation of stable complexes between antibodies of each patient and VIII:CAg was demonstrated by protein-A-Sepharose adsorption. The 125I-Fab' binding to VIII:CAg-anti-VIII:CAg IgG complexes indicated that patient 1 antibodies and the 125I-Fab' recognized different antigenic determinants, whereas the other two patient antibodies and 125I-Fab' recognized closely related or identical VIII:CAg determinants. These results demonstrate an apparently selective recognition of at least two distinct VIII:CAg determinants by naturally occurring antibodies, suggesting a possibility of a wider use of these antibodies in studies of the structure and function of factor VIII.     

Neutral maltase: the first human B-cell enzymatic marker reflecting terminal differentiation of mature B cells into plasma cells

Neutral maltase activity (alpha-D-glucoside glucohydrolase; EC: 3.2.1.20) was measured in B and T lymphocytes from peripheral blood of normal subjects and patients suffering from chronic or acute lymphoid leukemias. Neutral maltase activity is undetectable in T cells from normal subjects as well as in patients with chronic or acute T-lymphoid leukemias. Conversely, whereas this enzyme activity is always undetectable in chronic or acute B-lymphoid leukemia, neutral maltase activity is expressed in mature B cells from normal subjects. The detection of higher neutral maltase activity in plasma cells from myelomas than in normal B cells supports the concept that the expression of neutral maltase activity is related to the stages of differentiation and maturation reached by lymphocytes of the B-cell lineage. Neutral maltase therefore appears as the first B-cell enzymatic marker described that is expressed in the course of terminal differentiation of mature B cells into plasma cells.     

Factors influencing 20-hour increments after platelet transfusion

The 20-hour posttransfusion platelet count determines transfusion policy for patients requiring platelet support, and yet factors influencing the 20-hour count have been poorly defined. The clinical factors influencing both the 1- and 20-hour corrected count increment (CCI), were studied in 623 human leukocyte antigen (HLA)-unmatched platelet transfusions in 108 patients. The 1- and 20-hour CCIs were highly correlated (r = 0.67, p less than 0.001). On average, the 20-hour CCI was 64 percent of the 1-hour CCI. Multiple linear regression analyses identified splenectomy, bone marrow transplantation, disseminated intravascular coagulation, administration of amphotericin B, palpable spleen, and HLA antibody grade as the major factors influencing the 20-hour posttransfusion CCI. Platelet-specific antibodies, number of concurrent antibiotics, clinical bleeding, and temperature did not significantly influence the 20-hour posttransfusion CCI. The 1-hour CCI was the only significant factor influencing the 20-hour CCI in a regression model containing the 1-hour CCI and the above factors. Thus, the same clinical factors exert a major influence on the CCI at both 1 and 20 hours after platelet transfusion, with no evidence that any factor has more influence at 20 hours after transfusion than at 1 hour.     

Adrenal gland: MR imaging

The authors investigated the utility of magnetic resonance (MR) imaging in identifying the normal adrenal gland in 100 patients as well as in distinguishing adrenal adenomas (n = 12) from malignant neoplasms (n = 14). The left adrenal gland was seen in 99 of 100 cases and the right in 91 of 100 cases. The adrenals were most easily seen with T1-weighted spin-echo pulse sequences. The ratio of the intensity of the adrenal mass to that of fat at 2,100/90 (repetition time msec/echo time msec) was most helpful in distinguishing adrenal adenomas from malignant neoplasms. In contrast to other studies, the adrenal mass/liver intensity ratios were not helpful. All ten lesions with adrenal mass/fat ratios at 2,100/90 of 0.8 or greater were malignant, whereas all eight adrenal masses with a ratio less than 0.6 were adrenal adenomas. However, eight (31%) of the masses (four adenomas and four malignant neoplasms) had ratios between 0.6 and 0.8. Although MR imaging has considerable potential in characterizing adrenal masses, larger studies are needed to determine its true sensitivity and specificity.     

Prevalence of heterozygotes for hemochromatosis in the white population of the United States

In previous studies, the prevalence of HLA-linked hemochromatosis, thought to be the most common genetic illness in whites, has been estimated by identifying homozygotes in the population. Because not all homozygotes express the disease phenotypically, the accuracy of these estimates is uncertain. We analyzed the distribution of transferrin saturation values in the second National Health and Nutrition Examination Survey to estimate the prevalence of hemochromatosis heterozygotes in the US population. After removing values for possible homozygotes, two populations were present (P < .01 for each gender). When weighted to reflect the US adult white male population as a whole, a proportion of 850 per 1,000 (95% confidence interval, 0.81 to 0.89) were included in a population with a lower mean saturation of 29.7% (29.1% to 30.3%), whereas 150 per 1,000 (0.11 to 0.19) comprised a population with a higher mean saturation of 47.0% (45.1% to 49.0%). Similar results were found for the female population. The gene frequencies were estimated to be 0.081 from the male population and 0.070 from the female population corresponding to prevalences of homozygotes of 6.6 and 4.8 per 1,000, respectively. Our results confirm that the gene for hemochromatosis is common.     

Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

Background  

Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results.     

Variations in clinical decision-making between cardiologists and cardiac surgeons; a case for management by multidisciplinary teams?

Objective  

To assess variations in decisions to revascularise patients with coronary heart disease between general cardiologists, interventional cardiologists and cardiac surgeons