Cervical cancer screening: are the 1989 recommendations still valid? National Workshop on Screening for Cancer of the Cervix.

Although screening for cervical cancer has been shown to be effective in reducing the morbidity and mortality associated with this disease, and despite many attempts to encourage the development of provincial programs, as of 1995 no province had a comprehensive screening program for cervical cancer. Participants at the Interchange '95 workshop, held in Ottawa in November 1995, reviewed the recommendations of the 1989 National Workshop on Screening for Cancer of the Cervix and identified factors that have impeded their implementation. Participants discussed the need for comprehensive information systems, quality control and strategies to increase recruitment of unscreened and underscreened women. They concluded that the formation of a Cervical Cancer Prevention Network involving key stakeholders will facilitate the development and implementation of provincial programs to ensure optimal screening. They agreed that, in the interim, recommendations for practising physicians should remain as they were following the 1989 workshop.     

Effect of radiation dose on the development of mixed haemopoietic chimerism following T cell-depleted allogeneic bone marrow transplantation.

The presence of mixed haemopoietic chimerism (MXC) was evaluated by cytogenetic and molecular analysis in 48 patients undergoing T cell-depleted BMT. The dose of total body irradiation (TBI) prescribed to all patients (14.4 Gy) was calculated to compensate for the absence of T cells in the graft. The actual midline dose of TBI received, however, differed significantly depending on the method of TBI administration. Thus, 35 adult patients received an average midline dose of 14.3 Gy, while 13 children received a lower dose of 13 Gy. The incidence of MXC in the adult group, who had received very close to 14.4 Gy to the midline, was 34% (12/35), which is lower than in most reported T cell-depleted series. During follow-up, chimerism remained relatively stable with time but varied between haemopoietic lineages. There was no relationship with relapse. MXC in the 13 children who had received a lower midline TBI dose was significantly higher at 69% (9/13) (p < 0.05) and increased to 90% (9/10) if patients who received additional chemotherapy in their conditioning were excluded (p = 0.001). This suggests that, in terms of marrow ablation, relatively small changes in the dose of TBI may be biologically significant, at least at this dose range. Again, in the lower TBI group MXC was not predictive of relapse.     

Systemic haemodynamics in infants with vein of Galen malformation: assessment and basis for therapy.

Systemic haemodynamics in three infants with severe cardiac failure secondary to vein of Galen malformation (VGAM) were studied using two-dimensional and Doppler echocardiography. In all cases, ventricular outputs were over two times normal and superior vena caval flows up to 10 times normal reflecting high flow through the low-resistance fistula. Severe pulmonary hypertension, right heart dilatation and retrograde flow in the descending aorta were uniformly present. Systemic blood flow below the head and neck was reduced resulting in metabolic acidosis at presentation. Two infants had patent arterial ducts, in which flow was entirely right to left and on entering the aorta passed predominantly retrogradely towards the VGAM. These findings provide a basis for understanding the pathophysiology of cardiac failure in VGAM and support treatment with pulmonary and systemic vasodilating agents.     

Reassessment of malignant "angioendotheliomatosis". Evidence in favor of its reclassification as "intravascular lymphomatosis"

Malignant angioendotheliomatosis (MAE) is a lethal intravascular proliferation which has been thought to be of endothelial origin. In order to characterize its cellular nature, we studied 15 cases of MAE immunocytochemically, using antisera for factor VIII-related antigen, cytokeratin, epithelial membrane antigen, vimentin, blood group isoantigens, thoracic duct lining cell antigens (TDLCA), common leukocyte antigen, and Ulex europaeus I lectin. In 14 of 15 cases, common leukocyte antigen was observed in malignant intravascular cells. Similar reactivity for factor VIII-related antigen was present in 14 cases, but was largely restricted to cells enmeshed in fibrin-platelet thrombi, and probably represents adsorption of platelet-derived factor VIII by tumor cells. All cases failed to bind Ulex europaeus lectin and lacked immunoreactivity for TDLCA, cytokeratin, epithelial membrane antigen, and blood group isoantigens; two manifested positivity for vimentin. Immunofluorescent microscopy of frozen tissue in one case showed monoclonal IgM-kappa immunoglobulin on the surfaces of tumor cells. Electron-microscopic study of three cases disclosed a predominant cell type lacking features of epithelial or endothelial differentiation; a minor cell population displayed endothelial characteristics and was thought to be reactive. Four patients with typical MAE also had extravascular large-cell lymphoma in lymph nodes, spleen, adrenal glands, stomach, or soft tissues. Six patients showed clinical evidence of autoimmune disease. These results suggest that MAE displays lymphoid rather than endothelial differentiation.