Inhibition of IgE-mediated mast cell activation by the paired Ig-like receptor PIR-B.

The potential of the paired Ig-like receptors of activating (PIR-A) and inhibitory (PIR-B) types for modifying an IgE antibody-mediated allergic response was evaluated in mouse bone marrow-derived mast cells. Although mast cells produced both PIR-A and PIR-B, PIR-B was found to be preferentially expressed on the cell surface, where it was constitutively tyrosine phosphorylated and associated with intracellular SHP-1 protein tyrosine phosphatase. PIR-B coligation with the IgE receptor (FcepsilonRI) inhibited IgE-mediated mast cell activation and release of serotonin. Surprisingly, the inhibitory activity of PIR-B was unimpaired in SHP-1-deficient mast cells. A third functional tyrosine-based inhibitory motif, one that fails to bind the SHP-1, SHP-2, and SHIP phosphatases, was identified in parallel studies of FcepsilonRI-bearing rat basophilic leukemia (RBL) cells transfected with constructs having mutations in the PIR-B cytoplasmic region. These results define the preferential expression of the PIR-B molecules on mast cells and an inhibitory potential that can be mediated via a SHP-1-independent pathway.

Function of killer cell inhibitory receptors for MHC class I molecules.

NK- and T-cells express at their surface, members of a multigenic family of killer-cell inhibitory receptors (KIR) for MHC Class I molecules. KIR engagement leads to the inhibition of NK- and T-cell activation programs. These receptors recruit the protein tyrosine phosphatases (PTPase), SHP-1 and SHP-2, upon tyrosine phosphorylation of immunoreceptor tyrosine-based inhibition motif (ITIM) expressed in both human and mouse KIR. We further define the ITIM amino acids sequence required in that recognition and demonstrate the critical role of the phosphoY-2 amino acid residue in this V/IxYxxL/V motif. In addition, using RBL-2H3 cells expressing endogenous Fc epsilonRI receptors as well as transfected CD25/CD3zeta chimera and p58.183 human KIR, we show that KIR inhibitory function requires co-engagement of KIR and ITAM-containing receptors. These results document the pathway used by KIR to down-regulate NK- and T-cell activation programs.

Early signaling via inhibitory and activating NK receptors.

This review focuses on recent findings on the structural features of inhibitory NK cell receptors containing immunoreceptor tyrosine-based inhibition motif (ITIM) and of NK cell activating receptors, both in human and mouse. First, the study of the inhibitory killer cell immunoglobulin-like receptors (KIR) unveiled the presence of intracytoplasmic ITIM and their capacity to recruit protein tyrosine phosphatases such as SHP-1 in vivo. A brief summary of the known SHP-1 targets may help us to understand the inhibition mediated by the KIR. The characterization of ITIM thus allowed the definition of a large group of inhibitory cell surface receptors. The second part of the review describes the known NK cell activating receptors. Most of them require association with ITAM-containing polypeptides in order to mediate cell activation.

Correlation between contrast enhancement in dynamic magnetic resonance imaging of the breast and tumor angiogenesis.

RATIONALE AND OBJECTIVE: The authors determined the relation between tumor angiogenesis in small invasive breast carcinoma and contrast enhancement on magnetic resonance imaging (MRI) after gadolinium injection. MATERIALS AND METHODS: Magnetic resonance imaging was performed before surgery in a prospective study of 20 patients who had a small palpable lump. Spin-echo sequences after injection of gadolinium were studied by factor analysis of medical image sequences and were compared with a histologic quantification of tumor angiogenesis after immunocytochemical staining. RESULTS: In nine cases, there was good correlation between the MRI and the histologic plane. In four patients, an early factor was found on MRI. This factor was related to a high concentration of arterioles located in the stroma or, in one patient, to the intratumor repair process. CONCLUSION: Early enhancement correlated well with the number of vessels determined histologically.

Retroperitoneal lymph node aspiration biopsy in staging of pelvic cancer: a cytological study of 228 consecutive cases.

Knowledge of the status of the pelvic lymph nodes is important for accurate staging and adequate treatment of patients with genitourinary tract cancer (bladder and prostatic carcinoma, testicular tumors, and uterine carcinoma). A total of 228 consecutive patients underwent preoperative evaluation of the lymph node status by lymphangiography combined with fine-needle aspiration biopsy. A lymphadenectomy was performed in 94 patients. The overall diagnostic accuracy was 93%. There were 5% false-negative results and no false-positive diagnoses. Fine-needle aspiration biopsy is an inexpensive method with which to detect the presence of metastatic lymph nodes visualized by bipedal lymphangiography. It is also a safe and well-tolerated method, with a low morbidity and no mortality. The various cytological features are described as are some possible pitfalls.

Comparison of cytologic examination of smears and histologic examination of tissue cores obtained by fine needle aspiration biopsy of the liver.

Biopsies of 30 consecutive suspected liver cancers were performed with 19-gauge fine needles having circumferentially bevelled tips that produced tiny tissue cores suitable for histologic study. The histologic results were compared with the cytologic results on aspirates obtained at the same time with 22-gauge Chiba needles. While cytologic examination of the aspiration smears produced better results than did histologic study of the tiny tissue cores, an improved overall accuracy of 86% was achieved with the combined cytologic and histologic results. The FNA core biopsy technique did not increase the complication rate.

The cocaine body-packer syndrome: evaluation of a method of contrast study of the bowel.

The questionable reliability of the conventional procedures for detection of ingested drug packages triggered us to evaluate the accuracy of a method of contrast study of the bowel in 23 nonsurgically managed cocaine body-packers. A single dose (60 mL) of a water-soluble contrast compound (amidotrizoate + meglumine) was given orally after initial clinical examination and drug detection in urine. Thereafter, roentgenograms were performed daily after spontaneous passage until obtaining two packet-free stools and negative views. Roentgenograms showed packages when performed at least 3 h after the ingestion of the contrast compound. Sensitivity and specificity of the method with respect to the detection of residual packets in the body, assessed by subsequent examination of stools, was good and did not diminish as the number of packages decreased during the time spent in ward. No side-effects were observed. We conclude that oral administration of a water-soluble contrast compound is an easily performed, efficient, and safe method for the nonsurgical management of cocaine body-packers.

[How to obtain a negative from a video recording]. / Comment obtenir un cliché à partir d'un enregistrement vidéo.

A. system of reproduction of an ultrasound image is proposed for obtaining easily filed permanent images (on film or paper) from any type of video recording.

[Sprains and luxations of the cervical spine in children. Report on 17 cases]. / Entorses et luxations du rachis cervical chez l'enfant. A propos de 17 cas.

Seventeen cases of sprains and luxations of the cervical spine in children are discussed. Radiological criteria of rotatory sprains and anteroposterior C1-C2 instability are presented in the 6 cases with these lesions, as well as those observed, only after several weeks, in 11 children with inferior cervical spine disorders (3 luxations of which 2 were chronic, and 8 severe sprains). The indications for therapy in each type of lesion are briefly discussed.

[Posttraumatic esophagopericardial fistula]. / Fistule oesopéricardique post-traumatique.

The outcome in a case of esophagopericardiac fistula due to a closed chest injury was spontaneously favorable, the absence of infective complications probably resulting from adequate antibiotic therapy.

Phlebography with non-elaborate equipment. / La phlébographie du pauvre.

A simplified phlebocavographic technique is proposed, using a standard radiology table and two 30 x 90 cassettes with a screen. These are placed under the floating tray of the table, and are maintained in place with two corner pieces.

[Spondylo-enchondrodysplasia]. / Spondylo-enchondrodysplasie.

A case is reported of spondyloenchondrodysplasia associating platyspondylia and generalized enchondromatosis, affecting the spine also but absent in the extremities. A literature review enabled this entity to be grouped within the framework of other enchondroplasias with vertebral lesions. Radiologic signs and genetic data suggest heterogeneity of this group of affections.

[Cerebral schistosomiasis. X-ray computed tomographic aspect. Apropos of a case]. / Bilharziose cérébrale. Aspect tomodensitométrique. A propos d'une observation.

A patient with cerebral schistosomiasis, a diagnosis suggested by residence in an endemic zone, presented non-specific appearances on computed tomography imaging seen as multiple hypodense zones filling with contrast medium at the periphery. Diagnosis was confirmed by biopsy during operation on a cerebral lesion and the regression of the lesions during specific therapy.

[Radiological appearances of post-traumatic fat emboli. A report on 27 cases (author's transl)]. / Aspects radiologiques des embolies graisseuses post-traumatiques. A propos de 27 cas.

Initial radiological appearances and changes occurring during the course of post-traumatic fat emboli in 27 patients are described. An alveolar filling syndrome usually appears after a free interval of 44 hours, and is followed by an interstitial syndrome on about the 12th day which usually regresses completely by the 20th day without sequelae. Five of the 27 patients died of either secondary infection or anoxia.

[Bilateral post-traumatic stenosis of the internal carotid arteries. A case report and follow-up (author's transl)]. / Sténose bilatérale post-traumatique des carotides. A propos d'un cas avec survie.

Bilateral stenosis of the internal carotid arteries in their extracranial pathway was observed in patient following a road accident. Arteriography was repeated on three occasions, and demonstrated regression of the lesions with complete recovery and lack of sequelae without the need for surgical intervention.

[Intrathoracic and retroperitoneal plasmacytomas in multiple IgA myeloma]. / Plasmocytomes intrathoraciques et rétropéritonéal au cours d'un myélome multiple à IgA.

A case of multiple myeloma of bone with retroperitoneal extension is reported and results of ultrasound and computed tomography imaging in this affection discussed. The tumoral mass can be evaluated with precision due to the reliability of CT scan imaging in the diagnosis of bony lesions and a positive diagnosis made and follow up reviews of changes in extra-osseous myelomatous masses conducted by combined ultrasound and CT scan imaging.

[Thymic seminoma]. / Séminome thymique.

A 27-year-old man presented with signs of a thymic seminoma. This rare tumor is difficult to diagnose on histologic examination, and pre-operative diagnosis is important because of its marked radiosensitivity (which justifies limited excision only).

[Post-traumatic resorption of a vertebral body in a patient with spondylarthritis (author's transl)]. / Résorption post-traumatique d'un corps vertébral chez un spondylarthritique.

Rheumatoid pelvispondylitis in the lumbar spine can be the cause of a fracture of a vertebral body following usually minimal trauma. If no treatment is applied, a pseudo-arthrosis with severe bone resorption can occur. The whole vertebral body was affected in this way in the case reported.

[Xanthogranulomatous pyelonephritis with fatty proliferation of the renal space. Aspects in x-ray computed tomography and MRI]. / Pyélonéphrite xanthogranulomateuse avec prolifération graisseuse de la loge rénale. Aspects en tomodensitométrie et en IRM.

The authors report one case of one case of xanthogranulomatous pyelonephritis associated with very extensive fatty proliferation in the renal space. This mass surrounded a small, pyelonephritic kidney with a considerable xanthomatous component containing a coral calculus. It was associated with a streaming abscess in the lumbar fossa. The computed tomography (CT) and magnetic resonance imaging (MRI) features are described in this article.

[90 fine-needle punctures for diagnosis of the upper abdomen under ultrasonic guidance. Contribution of cyto- and histologic analysis]. / Etude de 90 ponctions à l'aiguille fine à visée diagnostique de l'abdomen supérieur sous contrôle échographique. Apport de l'analyse cyto et histologique.

Fine needle puncture was performed of upper abdomen in 19 cases. The method is rapid, reliable, of low cost and only weakly traumatic. The recent possibility of coupling histologic and cytologic analysis with fine needles provides improved results by increasing diagnostic precision and identification of malignant tumors and benign tumors of difficult cytologic diagnosis.