Susceptibility to Yersinia pseudotuberculosis infection is linked to the pattern of macrophage activation.

T helper 1 cells play a crucial role in the clearance of Yersinia pseudotuberculosis infection. By producing cytokines and presenting antigens to T cells, activated macrophages can orientate the adaptive immune response. The pathway used by macrophages to metabolize arginine has been employed as an important parameter to discriminate their activation state. In this study, the pattern of macrophage activation in Y. pseudotuberculosis-infected BALB/c (Yersinia-susceptible) and C57BL/6 (Yersinia-resistant) mice and their immunostimulatory capacity were analysed. In the early phase of infection, macrophages obtained from C57BL/6 mice produced higher levels of NO, lower arginase activity, and larger amounts of IL-12 and TNF-alpha than macrophages from BALB/c mice. On the other hand, macrophages derived from BALB/c mice produced higher levels of IL-10 and TGF-beta than C57BL/6 mice. The Y. pseudotuberculosis infection leads to a fall in the macrophage immunostimulatory capacity of both strains of mice, with T-cell proliferation significantly reduced 12 h after infection. Moreover, we observed in the supernatant of co-culture of macrophages from infected mice with T lymphocytes from heat-killed Yersinia-immunized mice lower IFN-gamma production by cells from BALB/c mice than by C57BL/6 mice, and IL-4 was produced only by BALB/c mice on the first- and third-day post-infection. These results suggest that the pattern of macrophage activation is associated with susceptibility and resistance to Y. pseudotuberculosis infection in BALB/c and C57BL/6 mice.

Ischaemic pontomedullary transection with incomplete locked-in syndrome. A case report with MRI.

We describe a case of incomplete locked-in syndrome (LIS) due to basilar artery thrombosis, in which MRI showed a complete, sharply demarcated infarct at the pontomedullary junction. This supports experimental data showing that the lower reticular formation is not critical for the maintenance of consciousness. To our knowledge, this is the first reported case of ischaemic pontomedullary transection with LIS.

Successful nonoperative treatment of tuberculous spinal epidural abscess with cord compression: the role of magnetic resonance imaging.

A patient is described with a tuberculous spinal epidural abscess and signs of cord compression, who was successful treated without surgery. Magnetic resonance imaging, in addition to its role as a diagnostic tool, was helpful in monitoring the resolution of inflammation.

[Neuro-AIDS: a multicenter neuroradiological study]. / Neuro-AIDS: studio neuroradiologico multicentrico.

The results are described of a retrospective multicentric CT/MR study of 141 neuro-AIDS patients (IV group CDC classification); 114 patients were drug addicted, 13 homosexual, 8 polytransfused, and 6 had other risk factors. The mean age was 29.6 years. The pathologic agent was identified in 47 cases by c.s. fluid examination, biopsy, autopsy or specific treatment response: it was HIV in 20 cases, toxoplasmosis in 11, cryptococcosis in 9, leishmaniasis, salmonella and papovavirus in single cases. In the follow up of 2 cases, a Kaposi's sarcoma and a primitive CNS lymphoma occurred. The main clinical features were AIDS-dementia complex (45% of cases) and focal neurologic manifestations (36%). The neuroradiological protocol consisted of 238 CT exams (97 controls), most of them with DDD (delayed double dose) technique, 7 MR exams (0.15 T) and 2 angiographies. CT findings were divided into 3 groups: negative (16%), atrophic (47%) and focal lesions (37%). In the first and second group, HIV and cryptococcal infections were the main pathologic agents. In the third group toxoplasma infections were discovered, and TB granulomas and other pathologic conditions, with ring-like or nodular enhancement, in cortical/cortico-medullary location. In follow-up patients a high tendency of evolution towards focal lesions was observed, even in negative cases. The DDD enhancement technique allowed in most cases both the demonstration of very small lesions and their grading. According to the literature CT, though a highly sensitive method, is inferior to MR imaging; however our experience in this field is currently insufficient. The specific diagnosis of pathologic agents of neuro-AIDS is difficult, due to the high number of opportunistic AIDS-related infections and neoplasms, with overlapping features: differential diagnostic criteria can be assessed only by comparing the clinical, microbiological, topographic, CT and MR findings. CT and MR exams are necessary to guide and monitor therapy and to plan stereotaxis biopsy.

[Computed arthrotomographic evaluation of chronic lesions of the cruciate ligaments]. / Valutazione artro-TC delle lesioni croniche dei legamenti crociati.

The high incidence of cruciate ligament injuries as a result of acute knee trauma with hemarthrosis and abuse of diagnostic arthroscopies call for a suitable radiological imaging of the central pivot. Computed Arthrotomography (CAT) was used to examine the knee joint in 20 cases of clinically suspected chronic cruciate ligament injury. The images were correlated with arthroscopic and/or arthrotomic findings. Thirteen lesions of the anterior cruciate ligament (ACL) (65%) were found, plus 1 lesion of the posterior cruciate ligament (PCL) (5%), 2 associated lesions of ACL + PCL (10%), and 4 normal cases. Confirmation of pathology was available in all cases but one by arthroscopy and/or surgery. The central pivot diseases were classified as follows: absence, detachment, partial or complete tear. CAT findings of cruciate ligament injuries are emphasized and the role of the technique as compared to arthroscopy is discussed. CAT is useful in 3-D evaluation of central pivot and detection of different cruciate ligament injuries, with high sensitivity-specificity for ACL and high specificity-moderate sensitivity for PCL. In the evaluation of the chronic unstable knee, CAT is highly accurate and gives the surgeon useful information towards the planning of therapeutic procedures. CAT is almost non-invasive, well tolerated and easy to perform in out-patients, which make it a first-choice procedure in the screening of chronic ligament injuries.

[Traumatic lesions of the brachial plexus. Evaluation of 144 cases studied using direct cervical myelography and non-ionic contrast media]. / Le lesioni traumatiche del plesso brachiale. Valutazione di 144 casi studiati con mielografia cervicale diretta e mezzo di contrasto non ionico.

The authors report their experience in 144 patients with traumatic brachial plexus injury who underwent Direct Cervical Myelography (DCM). Sometimes the diagnostic investigation was completed by CT. Various myelographic patterns are described: pseudomeningocele, missing sheet of the root, scarring lesions. In 9 cases only, myelography was not sufficient to provide a complete diagnosis. The examination showed all plexus roots lacerated in 14 patients, a monoradicular lesion in 75 cases, and no lesion in 26 cases. Twenty-one out of the 26 negative cases were confirmed during surgery, while in 2 patients an intraspinal injury was found, which had not been detected due to the presence of scars. Scars often compress healthy roots, and may mask intraspinal injuries. In such cases, and when the spinal cord stretches towards the side of the lesion, Myelo-CT can be useful. DCM proved to be an extremely sensitive and specific method, which can be used as a first-choice radiological procedure in the study of traumatic injuries of the brachial plexus.

[Early angio-computer tomography of ruptured cerebral aneurysms in subarachnoid hemorrhage]. / Diagnosi precoce Angio-TC di aneurisma cerebrale fissurato in corso di emorragia subaracnoidea.

In acute subarachnoid hemorrhage a ruptured cerebral aneurysm can be detected by Computed Angiotomography (Angio-CT). In a hyperdense cistern by extravasal blood, a round low-density defect on plain CT which turns into high-density nodular mass with afferent and efferent arteries, is an important finding of ruptured aneurysm. The inverting-density cisternal defect in connection with cerebral arteries is essential for the direct and early Angio-CT diagnosis of ruptured aneurysm.

[Subarachnoid hemorrhage caused by rupture of cerebral aneurysm. Value of neuroradiological studies]. / Emorragia subaracnoidea da rottura di aneurisma cerebrale. Apporto delle indagini neuroradiologiche.

The role of neuroradiological examinations in the diagnosis and in the therapeutical indication of intracranial aneurysm are analyzed and discussed on the basis of a large review of the literature. Skull X-rays, Ct scan with and without intravenous contrast enhancement, magnetic resonance imaging and angiographic have different role and different timing. They are critically evaluated in order to point out an up-to-date diagnostic phase.