Twenty years of breast cancer in Iran: downstaging without a formal screening program.

BACKGROUND: breast cancer (BC) is the most common malignancy among Iranian women. Although the relative incidence of BC is low, the cause-specific mortality is much higher than developed countries. The present study surveyed the overall trend of BC in Tehran. PATIENTS AND METHODS: all breast pathologic records were studied in five major hospitals in Tehran during three phases (1: 1985-1995; 2: 1996-2000; and 3: 2001-2005). Malignant cases were classified according to the tumor-node-metastasis classification. Data were compared across the study. RESULTS: Of 9050 medical records from male and female patients with 'breast disease', 2946 females with BC were included. A significant increase in the diagnosis of palpable early BCs (stage II increased, stage III decreased) was observed between phases 1 and 2. A relative increases in stages 0 and I were noted between phases 3 and 2. Nevertheless, 76.8% of cases were T2 or higher and 65.3% had positive lymph nodes in the last phase. The proportion of patients with stage IIIb was increased in phase 3, despite the reduction in phase 2. CONCLUSIONS: despite the relative improvement in the status of BC patients, the vast majority are diagnosed in advanced stages. Specific screening measures should be implemented in Iran.

Effect of hirudin versus heparin on hemocompatibility of blood contacting biomaterials: an in vitro study.

Hirudin serves as an alternative anticoagulant for extracorporeal blood circulation. Comparing anticoagulation with hirudin (2.5 or 5.0 microg/mL) and heparin (2.0 or 4.0 IU/mL) human blood was circulated in a modified 'Chandler System' using PVC-tubes for 2 hours at 37 degrees C. Activation of coagulation (thrombin-antithrombin III-complex, prothrombin fragment 1+2 and D-Dimer), platelet (platelet factor 4 - PF4) and complement systems was analyzed. Both heparin concentrations and 5.0 microg/dL hirudin led to as significantly less activated plasmatic coagulation as 2.5 microg/dL hirudin. Decreased levels of PF4 and anaphylatoxin C5a (p<0.05) as well as terminal complement complex demonstrated improved hemocompatibility after anticoagulation with heparin in contrast to hirudin. Because initial coagulation cascade, platelet activation and complement activation is less influenced by hirudin than by heparin, hemocompatibility is more dependent on the characteristics of the biomaterials used. This predestines hirudin as anticoagulant for in vitro studies analyzing hemocompatibility of biomaterials or surface modifications.

The influence of hypoalbuminemia on maximal flow rates and transmembrane pressure during plasmapheresis--an in vitro study.

BACKGROUND: Plasmapheresis has been used for the treatment of acute liver failure (ALF). In these patients, hypoalbuminemia is often observed. Since albumin improves the disaggregability of erythrocytes, hypoalbuminemia might deteriorate rheology and thus influence the overall performance of plasmapheresis. METHODS: Hypoalbuminemia was mimicked by using porcine blood because of its physiologically low albumin/globulin ratio (AGR). Filters (n = 16) were integrated in a closed extracorporeal in vitro system. In the control group (n = 8), native porcine blood (AGR 0.8) was used. In the study group (n = 8), we used porcine blood supplemented with human albumin to obtain the human AGR value of 1.2. Two different heparinization protocols were compared in each group (2.5 IU/ml: n = 4 with albumin and n = 4 without albumin versus 5 IU/ml: n = 4 with and n = 4 without albumin). RESULTS: In both heparinization protocols the higher AGR led to lower transmembrane pressure (TMP) levels compared to the lower AGR. The reduced TMPs enabled higher blood flow and filtration rates. CONCLUSION: Maintenance of a physiological AGR in ALF patients might improve the performance of plasmapheresis and--as opposed to raised heparinization--contribute to a safer application.

Enhancing filtration rates by the use of blood flow around the capillaries of plasmafilters: an in vitro study.

As the low clearance rate of plasmaseparation limits its use in the treatment of patients suffering from liver failure, sepsis or MOF, we intend to develop strategies for a plasmaseparation unit which increases plasmafiltration rates. Our first question focused on whether commercially available plasmaseparation filters, and in particular their membranes, are suitable for the inversion of blood and plasma compartments. This experimental study was performed using in vitro systems. Commercially available plasmafilters PF2000N (Gambro) and Plasmaflo (Asahi) were compared in both their normal operating mode with blood flow through the capillary lumen, and in the inverse mode. Inverse mode means that blood flows through the outer space of the capillaries while plasma was obtained from the lumen. Heparinised porcine blood (5 I.U./ml) was used in a heated, recirculating in vitro circuit. Our main results were that the normal use of both filter types Plasmaflo and PF2000N enabled maximal blood flows (Qb) of 200 ml/min and filtration rates (Qf) of 25-40 ml/min. Operating the filters in the inverse mode enabled Qb up to 500 ml/min and Qf up to 100 ml/min. Hemolysis, platelet counts and coagulation parameters did not differ significantly regardless of whether the normal or inverse mode was used. The tested plasmafiltration membranes appear to be suitable for use in inverse mode. Although in our experiments, hemocompatibility tests did not indicate severe problems induced by the module geometry, the development of a module specially constructed for blood flow outside of the hollow fibers appears to be necessary in order to minimise shunts and low perfusion areas.

Computed tomography and histologic results in the early stages of endotoxin-injured pig lungs as a model for adult respiratory distress syndrome.

RATIONALE AND OBJECTIVES: To determine early radiographic changes in diffuse alveolar injury, the authors correlated computed tomography (CT) and histopathology in pigs with recurrent endotoxinemia. METHODS: Five pigs received recurrent endotoxin over a 17-hour period. Three pigs received physiologic saline and served as controls. Hemodynamic and blood-gas data were analyzed. CT was performed immediately before killing the animals. The lungs were cut into 5-mm-thick slices in the same axis as the CT scans and were investigated by light and electron microscopy. RESULTS: Hemodynamic data, blood-gas analysis, and morphologic changes closely simulated the clinical situation of septic shock in the five pigs that had received endotoxin. Results of histologic examination depicted changes similar to those associated with adult respiratory distress syndrome (ARDS). CT clearly demonstrated both interstitial, and to a minor degree, intra-alveolar lesions in the endotoxin-injected group, which correlated well with dilated lymph vessels, thickened interstitium, and areas of dystelectasis on histologic examination. Although there was a rather uniform clinical picture, CT and histologic findings showed different degrees of involvement. CONCLUSIONS: CT clearly depicts changes in endotoxin-injured pig lungs in an early clinical state, which are similar to changes associated with ARDS on histologic examination.

Heparin-coated versus non-coated surfaces for extracorporeal circulation.

Studies were made to compare completely heparin-bonded (HBS) and conventional extracorporeal circulation surfaces using capillary membrane oxygenators (CMO) in sheep and dogs for up to five days. The aims were: to investigate the need for systemic heparinization in the case of heparin-coated surfaces, to assess blood compatibility and gas exchange performance of both systems and the extent of complement activation, and to find solutions for plasma leakage by the use of CMO. All studies were performed under standardized conditions, such as drugs, surgery, priming, blood flow rate etc. For heparin-coated surface studies all blood interfaces (CMO, catheters, tubes, etc) were coated. It was possible to eliminate systemic heparinization totally when HBS were used. During the five-day non-heparin application period blood coagulation parameters were almost unchanged and in the physiological range, platelets did not drop below 80%, hemolysis was negligible and gas exchange performance was unaffected. Less complement activation occurred with HBS than with non-coated surfaces.

Technical aspects of plasma leakage prevention in microporous capillary membrane oxygenators.

A limiting factor in using microporous capillary membrane oxygenators (CMO) for long-term extracorporeal lung support is leakage. Application of heparin-coated CMO requires additional examination because leakage is probably caused by the temperature conditions of the gas, the blood and the circuit environment, and the surface tension phenomenon at the micropores. The authors designed a thermostatized box in which the temperature of flowing gas (Tg) and blood (Tb), and the interior temperature of the box (Ti) could be regulated independently. Tb was adjusted to the animal's body temperature, and Tg was kept about 2 degrees C higher to prevent condensation of the evaporated fluid from the blood side, through the micropores, into the gas phase. Ti was maintained between Tg and Tb. The saturated outlet gas could therefore condense only outside the box. This system was used during 5 days of venovenous bypass using a covalently heparin-bonded (Carmeda) CMO (Maxima, Medtronic) in four adult sheep. No plasma leakage occurred, the surface tension of condensate water remained constant, and the gas exchange capacity of CMO was unchanged.