Computed tomography of mediastinal lymph nodes in nonsmall cell lung cancer. A new approach based on the lymphatic pathway of tumor spread

Computed tomography was used to evaluate mediastinal lymph nodes in 97 patients with nonsmall cell lung cancer. All patients had thorough surgical-pathological determination of mediastinal node status. Twenty-three patients were found to have metastatic lymph nodes. The usual lymphatic pathways of tumor spread into the mediastinum were defined using the node mapping scheme suggested by the American Thoracic Society. We considered mediastinal nodes abnormal when the short axis of the largest mediastinal node in the lymphatic drainage territory of the cancer was greater than or equal to 10 mm and the difference between this node and the largest node in the other territories is greater than 5 mm. The sensitivity was 78%, the specificity 99%, the positive predictive value 95%, the negative predictive value 94%, and the accuracy 94%. Comparing our method to those that used the size criterion alone, the number of false positives was reduced.     

Hepatocellular carcinoma invading the right atrium: clinical, echographic and angiographic study

The authors report the case of a 54 year old woman suffering from hepatocellular carcinoma with tumor growth into right hepatic vein, inferior vena cava and right atrium. On cardiac examination, a pansystolic bruit and a diastolic rumble were audible at the tricuspid focus. Diagnosis was confirmed by inferior vena cavography and two-dimensional echocardiography, which demonstrated a large mobile mass in the right atrium moving to and fro through the tricuspid valve. This case report emphasizes the value of routine cardiac examination during the course of hepatocellular carcinoma.     

Delaying rejection in discordant heart xenografts in the rat: efficacy of cyclosporin, prostaglandin I2 and exchange transfusion

If effective modes of prevention of hyperacute rejection were available, the problem of the absence of enough suitable donors could be solved by the use of organ xenografts. Organ xenograft rejection is principally mediated by preformed antibodies which are responsible for the hyperacute pattern of rejection. We decided therefore to study various methods of prevention of rejection in the guinea pig to Lewis rat combination (donor-recipient discordant species) in which hyperacute rejection is particularly intense. Three series of experiments were performed. In the first series immunosuppression of the recipient was induced using an oral solution of cyclosporin A. In the second series antiplatelet-aggregation therapy was administered to the recipient, using intravenous prostacyclin (PGI2). In the third series antibody depletion of the recipient was attempted using exchange transfusion with or without prostacyclin perfusion. The most significant (p less than 0.01) prolongation of graft survival time was observed when combining exchange transfusion (8 ml) and PGI2 infusion (620 ng/kg/min). This observation suggests that, if antibody depletion in the recipient is the primary goal, measures aiming at reducing the consequences of the antigen-antibody reaction are also necessary to improve the results of organ xenografting.     

MEASUREMENTS OF INTERFACE PRESSURE BETWEEN BODY SITES AND THE SURFACES OF FOUR SPECIALISED AIR MATTRESSES

SUMMARY Four specialised air mattresses had interface pressure measured under six body sites prone to pressure sores in 10 subjects, supine and sitting. The mattresses were the Clinirest (SSI) and FirstStep (KCI) continuous airflow mattress overlays, and Airwave (Pegasus) and Nimbus (Huntleigh) alternating pressure air mattresses. On the mattress overlays, average supine interface pressures were 2.33 kPa (scapula), 4.15 kPa (elbow), 1.94 kPa (sacrum) and 2.79 kPa (buttock), although they were higher at the occiput (7.97 kPa) and heel (11.7 kPa). The alternating pressure air mattresses had an average minimum interface pressure close to zero for three sites, rising to 4.28 kPa under the heel. Average maximum interface pressures were 8.61 kPa (occiput), 5.21 kPa (scapula), 4.90 (elbow), 4.85 kPa (sacrum), 4.61 kPa (buttock) and 13.2 kPa (heel). No accepted scientific method exists for comparing the two types of mattress. Our data suggest a clinical benefit at the occiput and heel (supine) in using an alternating pressure air mattress and a benefit in using a continuous airflow mattress overlay at other sites.     

Identification of T cell epitopes within a 23-kD antigen (P24) of Toxoplasma gondii.

Among the potentially vaccinating antigens, the products excreted/secreted by the parasite T. gondii have been demonstrated to be excellent candidates. The molecular cloning of one of these antigens (P24) present in excreted/secreted antigens (ESA) has recently been carried out in our laboratory. The recombinant antigen P24 corresponds to a native molecule of 23 kD. We were interested in determining the main epitopes of the P24 antigen eliciting a T lymphocyte response using synthetic peptides derived from the primary structure of P24. Five peptides: 64-79, 88-109, 170-193, 194-208 and 231-250 were synthesized according to their hydrophobicity, mobility and accessibility profiles. The presence of T lymphocyte epitopes in these peptides has been examined in the rat model. The determination of T cell epitopes was carried out using T lymphocytes from infected rats, and from ESA and P24 expression vaccine virus immunized rats. The results showed that the stimulation of T cells with these peptides varied according to the period after Toxoplasma infection. The main T cell stimulation was obtained with the 88-109, 170-193 and 194-208 peptides. When Fisher rats were immunized with ESA, a most significant stimulation was achieved with the 170-193 and 194-208 peptides. In addition, T lymphocytes primed with P24 expressed vaccine virus immunization were more stimulated with the 88-109 and the 194-208 peptides. This study showed that P24-derived peptide-specific T cells were elicited in the three experimental situations, although no antibody response against the 23-kD native antigen was evidenced in the Fisher rat model. However, the native antigen (presented by irradiated parasites) can induce a proliferative response of the 170-193 peptide-specific T lymphocytes, confirming that this peptide contains an important T cell epitope. The adoptive transfer into athymic rats of T helper cells recovered from 170-193 peptide-immunized Fisher rat conferred a significant protection to infected nude rats despite the fact that no antibody production was observed.