Humoral immune response against hepatitis C virus.

Antibodies are in several instances a reliable marker indicating vigorous immune response against infectious agents and in several viral diseases presence in the blood of specific anti-viral antibodies indicates an effective protection. However, this is not always true. For example, in the case of hepatitis C virus (HCV) an important human pathogen considered the causative agent of the nonA- nonB hepatitis, in spite of an intense antibody response there is no protection against a new infection and in the majority of infected individuals the virus overcomes host defences establishing a persistent infection. Here we describe how the dissection of the humoral immune response against HCV glycoprotein E2 of infected patients was useful for a better comprehension of the virus-host interplay. Cross-reactive antibodies directed against E2 are produced by the HCV-infected patient, but not all of them are protective, and some could even result to be detrimental for the patient. The cross-reactive anti-HCV/E2 humoral antibody response is complex and not necessarily completely beneficial to the host.

[Double-contrast arthrography of the knee: a digital technique study]. / Artrografia a doppio contrasto del ginocchio: studio con tecnica digitale.

From October 1989, in our Radiology Department, digital radiographic techniques have been applied to double-contrast arthrography of the knee. In this preliminary work we examine the diagnostic contribution of computed radiography to arthrographic findings by comparing image quality of conventional and digital radiographs using a dedicated Philips unit. The digital unit is compatible with all the extant radiographic equipment in our department and automatically supplies two images, the first one resembling a conventional radiograph, the second one characterized by a broader exposure range that allows a clear visualization of soft tissues. To obtain high-quality radiographs the processing curves of the system were modified, in particular by shifting the curve leftward, thus reducing its slope, and by amending the parameters related to spatial frequencies. The changes in the reading curves made these images more useful: they were more homogeneous and allowed a better evaluation of fine details. Relative to the second type of images, characterized by both edge enhancement and a broader recording range, it was enough to shift the curve along the X-axis to compensate for a moderate image overexposure. Keeping in mind that the aim of this preliminary work was not compare the two techniques from a diagnostic point of view, in the authors' opinion the two yield similar information for the diagnostic evaluation of meniscal traumas. On the contrary, if the same principles are applied to the evaluation of capsulo-ligamentous components, digital arthrography appears to be more accurate than the conventional technique, the latter being deceptive especially in the evaluation of cruciate ligaments.

Diagnostic potential of double contrast arthrography of the knee with the digital technique.

Experience with digital radiography applied to double contrast arthrography of the knee performed with a photostimulable phosphor plate is reported. The image processing technique used to improve the digital image is described, and some theoretical considerations are discussed. A preliminary comparison is also made between arthrographic images obtained with conventional screen-film systems and the digital system, especially in respect of the image quality and visualization of the soft tissue structures least well demonstrated with conventional arthrography.

Computed radiography in neonatal intensive care.

The Authors report their experience in the employment of a computerized digital radiographic system in Neonatal Intensive Care. The analog screen-film system is replaced by photosensitive imaging plates, scanned after X-ray exposure by a laser that releases the digital image, which can then be manipulated on computer work-stations. In a period of twelve months about 200 chest-abdomen X-ray examinations in Neonatal Intensive Care have been performed using this method with good technical and diagnostic results. The use of digital radiography in the neonatal area is of high interest: this system produces good quality images, there is a reduction in radiation dose and 'retakes', the system allows selective enhancement of different structures and their magnification.

[Echo-guided biopsy in peripheral pulmonary lesions. Our experience]. / Biopsia ecoguidata delle lesioni polmonari periferiche. Nostra esperienza.

Twenty-nine patients with peripheral intrathoracic lesions underwent real-time US and US-guided biopsy. The lesions were mainly atypical fluid collections in 3 patients and mainly solid in the extant 26. Biopsies performed with fine aspirating or cutting needles (20-22 gauge) were successful in all patients; an unquestionable diagnosis was made in 27 cases with cytology and/or histology. Only one patient experienced mild asymptomatic pneumothorax after biopsy, which did not require chest-tube drainage. The authors stress the important diagnostic role of US-guided fine-needle biopsy as an useful and safe method for the evaluation of peripheral intrathoracic lesions.

[Digital radiography in neonatal intensive care]. / La radiografia digitale nella terapia intensiva neonatale.

The authors report their experience with the routinary use of a computerized digital radiography system in Intensive Neonatal Care department. The conventional screen-film system is replaced by photostimulable imaging plates, which are scanned during processing by a laser providing the digital image. The latter is subsequently processable on high-resolution monitors. Over a 6-month period 86 examinations were performed with this method in Intensive Neonatal Care; good technical results were obtained. The use of digital radiography in intensive neonatal care is extremely promising for it allows high-quality images to be obtained, and radiation dose and number of acquisitions to be reduced. Finally, work stations allow both selective visualization of different body structures and their magnification.

Arthrography of the plica syndrome and its significance.

The plica is a synovial fold inside the knee joint that may become symptomatic if for any reason the fold is converted into a bowstring. In 42 patients with chronic knee problems, arthrograms of the knee were obtained with evidence of the plica syndrome. Twenty-four were asymptomatic, 18 symptomatic, and of these 16 were excised. After a mean follow-up period of 3 years, 10 of the symptomatic patients were free of symptoms, while eight were unchanged or worse. The plica syndrome is not common, and careful assessment must be made by exclusion with clinical examination, double-contrast arthrography, and arthroscopy.

Diagnosis and treatment of popliteal cysts.

The authors reviewed 122 patients affected with popliteal cysts and treated between 1975 and 1985 with or without surgery; follow-up ranged from 1 to 7 years (average 3 years and 2 months). The patients were subdivided into 3 age groups, and observed for the clinical, anatomo-pathological and therapeutic differences among them. Cysts affecting children and adults were considered to be acute, or chronic bursitis, and those affecting elderly patients true cysts deriving from the joint cavity. The diagnostic effectiveness of arthrography and sonography is emphasized.

[Double-contrast arthrography of the knee in traumatic capsular-ligamentous lesions. A critical review]. / L'artrografia a doppio mezzo di contrasto del ginocchio nelle lesioni traumatiche capsulo-legamentose. Revisione critica.

The authors conducted a statistical study and a critical review on a series of 1,300 patients examined with double-contrast fluoroscopically guided knee arthrography using a simple examination technique. Arthrographic diagnoses were subsequently compared with arthrotomic (500 patients), arthroscopic (350 patients), and clinical (450 patients) diagnoses. The critical review pointed out the high diagnostic accuracy (90%) and the good sensitivity (87%) of arthrographic examination in patients affected with pathologic conditions of the cruciate ligaments. In collateral ligament diseases and in capsular ruptures arthrographic sensitivity was not as high but still acceptable (74%). Capsular tears and medial collateral ligament tears can be identified when contrast medium is seen leaking from the knee joint. Cruciate ligament tears may be partial or complete: if a tear is partial the synovial surface of the cruciate ligament cannot be identified the cruciate ligament is wavy, lumpy, or focally thin, while in complete tears the synovial surface of the cruciate ligament cannot be identified either entirely or partially.