New polymers for drug delivery systems in orthopaedics: in vivo biocompatibility evaluation

The use of biodegradable polymers for drug delivery systems excluded the need for a second operation to remove the carrier. However, the development of an avascular fibrous capsule, reducing drug release, has raised concern about these polymers in terms of tissue-implant reaction. Five novel polymers were evaluated in vivo after implantation in the rat dorsal subcutis and compared to the reference polycaprolactone (PCL). Poly(cyclohexyl-sebacate) (PCS), poly(L-lactide-b-1,5-dioxepan-2-one-b-L-lactide) (PLLA-PDXO-PLLA), two 3-hydroxybutyrate-co-3-hydroxyvalerate copolymers (D400G and D600G), and a poly(organo)phosphazene (POS-PheOEt:Imidazole) specimens were histologically evaluated in terms of the inflammatory tissue thickness and vascular density at 4 and 12 weeks from surgery. The highest values of inflammatory tissue thickness were observed in D600G (P < 0.01), PCS (P < 0.001) and PLLA-PDXO-PLLA (P < 0.001) at 4 weeks, while POP-PheOEt:Imidazole showed the lowest value of inflammatory tissue thickness (P < 0.05) at 12 weeks. D400G, D600G, PLLA-PDXO-PPLA and POP-PheOEt:Imidazole showed higher (P < 0.001) values of vascular density near the implants in comparison to PCL at 4 weeks. Finally, D400G and D600G increased their vessel densities while POP-PheOEt:Imidazole and the synthetic polyester PLLA-PDXO-PLLA presented similar vessel density values during experimental times. These different behaviours to improve neoangiogenesis without severe inflammatory tissue-responses could be further investigated with drugs in order to obtain time-programmable drug delivery systems for musculoskeletal therapy.

Oral low-dose cyclophosphamide in metastatic hormone refractory prostate cancer (MHRPC)

The chemotherapeutic approach to hormone-refractory metastatic prostate cancer (MHRPC) for a long time included only estramustine. Then, attempts have been made with other various agents as cyclophosphamide, vinblastine, etoposide, taxanes and carboplatinum. Although the new drugs and combinations have increased the response rate of MHRPC, they have had no impact on the natural history of MHRPC, which is about 1 year as median time of survival. After an occasional observation of prolonged response in a patient with MHRPC treated with a very well tolerated oral low-dose of cyclophosphamide, from February 1996 to October 2002, seven more patients with MHRPC and progressive disease were consecutively recruited. Response to treatment was evaluated by conventional radiological procedures and/or serial serum PSA measurements. The decline of PSA value was considered to assess the response consistent with the response guidelines from the prostate specific antigen-working group. All eight studied patients continuously received oral low dose cyclophosphamide until progression or the occurrence of significant toxicity. So far three patients (37.5%) progressed (PD), two (25%) showed PR and the three remaining SD. Response rate was 25%, and clinical benefit occurred in 62.5% of the studied patients. In the five patients with clinical benefit on cyclophosphamide median duration of clinical benefit, PR and SD were 9, 24+ and 8 months, respectively. In these five patients median overall survival times from cyclophosphamide and from the first regimen of chemotherapy were 17 and 33+ months respectively, while in the three patients with PD they were 4 and 13 months. The same interval times in patients with > or =50% decline of serum PSA were 29 and 50.5 months, while in those with <50% decline of the same marker, they were 13 and 32 months, respectively. Grade 2 or 3 neutropenia were observed in all the studied patients. In four (50%) of them pulmonary and urinary infections that were easily cured by the common antibiotics occurred. These data suggest that the metronomic use of cyclophosphamide, given alone, has similar or higher activity with lower toxicity than when administered with other active drugs. So it can be an useful option before or after the use of other single or combined potentially active chemotherapeutic agents.

Advanced breast cancer: an update and controversies on diagnosis and therapy

This review on advanced breast cancer considered important differences in the actual definition of this condition. Advanced breast cancer includes locally advanced, locoregionally recurrent and metastatic disease, which have different diagnosis, prognosis and therapy; their actual definitions are relatively uncertain. Differently from the common opinion that metastatic breast cancer (MBC) is a very severe incurable disease, recently it has been reported that a small but not irrelevant fraction of MBC patients can be cured or remain in long-term survival with complete remission. The type of metastases of the population studied in these reports was analysed and the authors hypothesised that the particularly high DFS reported mainly was attributable to the high proportion of patients with locoregional metastases only. Furthermore, the options and associations of the drug therapy available for treatment of advanced breast cancer have been reviewed.

Prolonged exposure of microglia to lipopolysaccharide modifies the intracellular signaling pathways and selectively promotes prostaglandin E2 synthesis

During inflammatory or degenerative processes microglial cells are likely to be exposed to activating agents that persist in brain parenchyma for prolonged periods. As our knowledge on microglial activation is largely based on in vitro studies in which microglial cultures are activated by a single administration of pro-inflammatory stimuli, we investigated the effects of repeated endotoxin (LPS) challenges on microglial functional state. Primary rat microglial cultures were subjected to one, two or three consecutive LPS-stimulation and the production of tumor necrosis factor-alpha (TNF-alpha), nitric oxide (NO), prostaglandin E2 (PGE2) and 15-deoxy-Delta12,14-PGJ2 (15d-PGJ2) measured. The ability of microglial cells to produce NO, TNF-alpha and 15d-PGJ2 upon the first LPS challenge rapidly declined after the second and the third stimulations, whereas PGE2 synthesis remained constantly elevated. Accordingly, the expression of inducible NO synthase decreased whereas cyclooxygenase-2 and microsomal PGE synthase remained up-regulated. The signaling pathways evoked by single or multiple LPS-stimulation were also profoundly different, when considering the activation of the transcription factors nuclear factor-kappa B and CREB, and of the p38 MAPK. Our observations suggest that prolonged exposure to LPS, and likely other activating agents, induces in microglia a functional state clearly distinct from that triggered by acute stimulation. The progressive down-regulation of pro-inflammatory molecules and the sustained release of PGE2 could have important implications for the resolution of brain inflammation.

Comparative interspecies investigation on osteoblast cultures: data on cell viability and synthetic activity

The aim of the present study was to evaluate and compare the most common parameters that characterize the expression of primary osteoblast cultures from different origin (human, rat, sheep), and of the human osteosarcoma cell line MG-63 before and after stimulation with vitamin 1,25(OH)(2)D(3). Cell viability was quite similar for primary osteoblast cultures (MTT: 1.64-2.11 OD); a significant (P < 0.005) difference was found between sheep osteoblasts and MG-63 (DeltaMTT: 0.52 +/- 0.20 OD). Osteocalcin synthesis ranged from 15.18 to 27.00 pg/ml in primary osteoblast cultures, while it was significantly (P < 0.01) lower in MG-63 (OC: 6.67 +/- 0.52 pg/ml) when compared with primary human osteoblasts. Alkaline phosphatase, C-terminal procollagen type I, and interleukin-6 were significantly (P < 0.005) lower in rat osteoblasts when compared with primary human osteoblasts, and similarly transforming growth factor-beta1 was significantly (P < 0.05) lower in rat and sheep osteoblasts when compared with primary human osteoblasts and MG-63. Nitric oxide synthesis did not show any significant difference either before or after vitamin 1,25(OH)(2)D(3) stimulation. In conclusion, the current findings confirm the presence of interspecies differences between the selected osteoblast lineages before and after stimulation with vitamin 1,25(OH)(2)D(3). Above all, the culture of sheep osteoblasts was seen to behave more similarly to that of primary human cells, mainly in terms of cell viability, osteocalcin, interleukin-6 and transforming growth factor-beta1 production.

Effects of phosphatidylserine on p38 mitogen activated protein kinase, cyclic AMP responding element binding protein and nuclear factor-kappaB activation in resting and activated microglial cells

In the last few years, the interaction between phosphatidylserine (PS), a phospholipid that becomes permanently exposed on the external cell surface in the early phases of apoptosis, and its specific receptor (PtdSerR) has emerged as a crucial event for the engulfing of apoptotic cells and for preventing the acquisition of pro-inflammatory functions by peripheral macrophages. Recently, we demonstrated that PtdSerR is expressed in microglial cultures purified from neonatal rat brain, and that PS-liposomes, used to mimic apoptotic cells, strongly reduce the lipopolysaccharide (LPS)-induced release of inflammatory mediators. Here, we show that in resting microglia, PS-liposomes induce cyclic AMP responding element binding protein (CREB) phosphorylation but do not activate nuclear factor-kappaB (NF-kappaB) and p38 mitogen-activated protein kinase (p38), in line with the non-inflammatory consequences of the recognition and removal of apoptotic cells by macrophages. In LPS-activated microglia, PS-liposomes did not affect NF-kappaB activation but inhibited the phosphorylation of p38 and delayed that of CREB. To our knowledge, this is the first biochemical evidence of the molecular signaling evoked by PS/PtdSerR interaction possibly related to repression of pro-inflammatory activities in microglial cells.

L-arginine and L-lysine stimulation on cultured human osteoblasts

Essential amino acids, such as L-Arginine (Arg) and L-Lysine (Lys), are involved in bone metabolism and growth. Our previous studies analyzed the effect of these amino acids on rat osteoblast cultures and in experimental animals. In this study, we evaluated the effect of L-Arg and L-Lys on cultured human osteoblasts. Primary human osteoblast cultures were divided into four groups: the Arg Group received 0.625 mg/ml per day of Arg, the Lys Group 0.587 mg/ml per day of Lys, the Arg-Lys Group received both amino acids, whereas the Control Group was sham-treated. After 7 days, the following parameters were tested in all groups: alkaline phosphatase (ALP), nitric oxide (NO), calcium (Ca), phosphorus (P), osteocalcin (OC), type I collagen (PICP), interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) on culture supernatant, platelet derived growth factor (PDGF), insulin-like growth factor-I (IGF-I), and MTT proliferation test on cells. Arg administration significantly increased ALP, NO, PICP and IGF-I production and reduced the level of IL-6. Lys administration over the same time interval mainly affected cell proliferation, as evidenced by the MTT test and immunostaining for PDGF. The same positive effects evidenced by the single administrations of the two amino acids resulted from their simultaneous administration. However, synergism could be demonstrated only for the decrease in the level of IL-6. Arg and Lys show a positive effect on human osteoblasts, which is related partly to the production of those factors required for matrix synthesis, and partly to the direct or mediated activation of cell proliferation.

Atherosclerosis and cancer: common pathways on the vascular endothelium

This article reviews experimental and clinical data on atherosclerosis and cancer showing common pathogenic mechanisms. It is suggested that common pathways follow dysfunction of the vascular endothelium. The activation of the haemostatic system and the overexpression of cytokines and adhesion molecules by the endothelial cells represent important features of this dysfunction. These mechanisms can be responsible for progression of both diseases and explain the higher incidence of thromboembolic events in cancer patients, the occurrence of similar laboratory findings and the effect of many drugs on the course of the two diseases. Our article confirms that atherosclerosis and cancer share common mechanisms, and we hope it will stimulate further clinical trials on the use of drugs active on the haemostatic system in cancer patients.

Phalangeal ultrasonography in forearm fracture discrimination

Over the last decade, the use of ultrasounds has been developed into an effective tool for investigating bone tissue and predicting the risk of fracture in osteoporosis. Studies have focused on hip and vertebral fractures while no information is available on the use of phalangeal ultrasonography to identify patients with forearm fractures. Thus, the current authors decided to compare 50 postmenopausal women with low energy forearm fractures (Fractured Group) with a control age-matched group of 94 women (Control Group). Measurements were taken at the distal metaphysis of the proximal phalanxes of the hand of the non-fractured arm using the DBM Sonic Bone Profiler. The reproducibility of the method was assessed by amplitude-dependent speed of sound (AD-SoS) CV% = 0.64 and by Ultrasound Bone Profiler Index (UBPI) CV% = 2.38. In the Control Group, the AD-SoS and UBPI mean values and standard deviations were significantly higher compared to the group with fractures (P < 0.0005). The receiver operating characteristic (ROC) curves were calculated and the areas under the curve (AUC) were 0.78 +/- 0.04 for AD-SoS and 0.77 +/- 0.05 for UBPI, respectively. Logistic regression analysis adjusted to age revealed that both AD-SoS (78.2%, ORAD-SoS = 12.03, P < 0.0005) and UBPI (76.0%, ORAD-SoS = 7.39, P < 0.0005) parameters discriminated correctly between fractured and non-fractured control women whereas the association of both parameters could not allow better discrimination. The present results showed that ultrasound investigation at the phalanxes is reproducible and efficiently discriminates between subjects with forearm fractures and those in the control subjects.

Long-term monitoring of cell-mediated immunity in disease-free breast cancer patients: a preliminary retrospective study

In 102 N- and 44 N+ disease-free breast cancer patients, lymphocytic populations and skin reaction of delayed hypersensitivity (SRDH) were monitored up to 266 months after mastectomy to find out whether they were similar or different from control values. In two selected groups of 34 N- and 11 N+ breast cancer patients, the whole 10 year follow-up was divided into three subintervals, each of them lasting 40 months and the time course of lymphocytic populations was evaluated. In the 102 N- patients, mean CD4+, CD8+, CD3+ values were lower (P < 0.01, P < 0.001, P < 0.01, respectively) while CD4+/CD8+ ratio was higher (P < 0.05) than in controls. Fifteen N- breast cancer patients (16%) were anergic compared to 30(32%) of controls (P < 0.05). In the 34 selected N- breast cancer patients soon after mastectomy the mean value of CD4+, CD8+, CD3+ T subpopulations was lower (P < 0.01, P < 0.001, P < 0.01, respectively) than in controls. Successively their mean value increased so that in the last subinterval they were not or were only slightly lower (P n.s., P < 0.05, P < 0.05, respectively) than in controls. In the 44 N+ patients, mean CD4+, CD8+, CD3+ values were lower (P < 0.001, v < 0.05, P < 0.01, respectively) and CD19+ lymphocytes higher (P < 0.001) than in controls. Five N+ breast cancer patients (13%) were anergic compared to 32% of controls (P < 0.05). In the 11 selected N+ breast cancer patients soon after mastectomy, the mean value of CD4+, CD8+ T subpopulations and CD16+56+ cells was significantly lower (P < 0.001, P < 0.001, P < 0.01, respectively) than in controls. Successively their mean value constantly increased so that in the last subinterval, no or slight (P n.s., P < 0.05, P n.s., respectively) significant difference compared to controls occurred. The mean CD4+/CD8+ ratio value of N- patients was significantly higher than in controls. However in the last subinterval, the significance was lower than in the first one (P < 0.05 and P < 0.01, respectively). In the N+ patients, the mean value of CD4+/CD8+ ratio was constant, although not significantly, lower than in controls; however it progressively increased from the first to the last subinterval. Therefore the significance of the difference of the mean CD4+/CD8+ ratio between N- and N+ patients strongly decreased from the first to the last subinterval (P < 0.001 and P < 0.05, respectively). These data indicate that in breast cancer patients, following mastectomy, a significant activation of memory and CD4+ T cells and long-term decrease of the circulating immunocompetent CD4+, CD8+ and CD16+56+ cells occurs. The prolonged disease-free interval observed in the 34 N- and 11 N+ breast cancer patients can be correlated with the restoration of the normal state of cell-mediated immunity.

Differential effects of the nonsteroidal antiinflammatory drug flurbiprofen and its nitric oxide-releasing derivative, nitroflurbiprofen, on prostaglandin E(2), interleukin-1beta, and nitric oxide synthesis by activated microglia

Increasing experimental, clinical, and epidemiological studies point to the pivotal role of inflammation in the pathogenesis of acute and chronic neurodegenerative diseases and to the protective effects of nonsteroidal antiinflammatory drug (NSAID) therapies. Nonetheless, NSAID long-term therapies are limited by their significant adverse effects on gastrointestinal tract and kidneys. Nitroflurbiprofen (NO-flurbiprofen) belongs to a novel class of antiinflammatory agents obtained by derivatization of conventional NSAIDs with a nitric oxide (NO)-releasing moiety, which strongly reduces their untoward side effects without altering the antiinflammatory effectiveness. The recent evidence of neuroprotective effects of NO-NSAIDs in animal models of chronic brain inflammation prompted us to investigate the activities of NO-flurbiprofen and its parent molecule flurbiprofen on activated rat microglia, the brain resident macrophages. We found that NO-flurbiprofen was as potent as flurbiprofen in preventing prostaglandin E(2) synthesis in lipopolysaccharide-activated microglial cultures. At variance with previous observations on peripheral macrophages is that NO-flurbiprofen did not show any additional capacity to inhibit interleukin-1beta synthesis compared with flurbiprofen. Moreover, NO enhanced the expression of the inducible NO synthase; this effect was most likely attributable to the NO released from the drug, as suggested by experiments performed in the presence of the NO donor Deta-NONOate, which similarly to NO-flurbiprofen is characterised by a slow and long-lasting release. Our findings indicate that NO-NSAIDs may differently affect peripheral and brain macrophages. Given their potential therapeutic role in brain inflammation, further in vivo and in vitro studies are required to understand fully their mechanism of action in the CNS.

Human immunodeficiency virus type-1 Tat protein induces nuclear factor (NF)-kappaB activation and oxidative stress in microglial cultures by independent mechanisms

We have extended our previous findings and shown that human immunodeficiency virus Tat protein, in addition to nitric oxide (NO), stimulated rat microglial cultures to release pro-inflammatory cytokine interleukin-1beta and tumour necrosis factor-alpha in a nuclear factor (NF)-kappaB-dependent manner. At the same time, Tat stimulated the accumulation of free radicals, as indicated by the increased levels of isoprostane 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha)), a reliable marker of lipid peroxidation and oxidative stress, by a mechanism unrelated to NF-kappaB activation. The presence of free radical scavengers abrogated Tat-induced 8-epi-PGF(2alpha) accumulation without affecting NO and cytokine production. Consistently, Tat-induced IkappaBalpha degradation - an index of NF-kappaB activation - was not affected by free radical scavengers, but was prevented by an NF-kappaB-specific inhibitor. Our observations indicate that NF-kappaB plays a key role in Tat-dependent microglial activation, and that oxidative stress and NF-kappaB activation induced by Tat occur by independent mechanisms.

Usefulness and limits of distal echo-Doppler velocimetric indices for assessing renal hemodynamics in stenotic and non-stenotic kidneys

BACKGROUND

Distal echo-Doppler velocimetric indices are widely used for revealing the presence of a renal artery stenosis but there is scarce information as to whether they reflect the renal hemodynamics in stenotic and nonstenotic kidneys.

OBJECTIVES AND METHODS

We evaluated the pulsatility and resistive indices (PI and RI), acceleration (A) and acceleration time (At) and correlated their values with those of effective renal plasma flow (ERPF), glomerular filtration rate (GFR), renal vascular resistance (RVR) and filtration fraction (FF) estimated by single kidney scintigraphy in 24 kidneys with 70-95% renal artery stenosis (atherosclerotic n = 17, fibromuscular n = 7) and in 27 non-stenotic kidneys (11 contralateral to renal artery stenosis and 16 of patients with essential hypertension). In patients with stenotic kidneys, these measurements were repeated within 7 days after a successful percutaneous transluminal renal angioplasty (PTRA) (in 11 arteries performed in combination with stent implantation).

RESULTS

Prior to dilation we found that the stenotic kidneys had significantly lower values of ERPF, GFR and higher RVR than the non-stenotic kidneys and that these hemodynamic alterations were associated with those, also statistically significant, of the four velocimetric indices. In non-stenotic kidneys, there were highly significant relationships between PI and ERPF, and RVR (r = -0.68 and 0.81 respectively P < 0.01); similar relationships were found for RI (r = -0.67 and 0.78 P < 0.01) whereas no such correlations were found between these two velocimetric indices and GFR and FF; also no correlations were found between A and Atand ERPF, GFR, RVR and FF. In stenotic kidneys no significant correlations were found between any of the velocimetric and the hemodynamic indices. Renal artery dilation induced clear cut increments in ERPF, GFR and reduction in RVR in post-stenotic kidneys, which were associated with normalization of all four velocimetric indices. No relationships were observed between the renal hemodynamic and the velocimetric changes induced by dilation; however in post-stenotic kidneys the relationships between PI and RI, ERPF and RVR were restored as in nonstenotic kidneys.

CONCLUSIONS

These data indicate that PI and RI can be used to assess ERPF and RVR both in non-stenotic and post-stenotic kidneys; however, none of the velocimetric indices examined in this study can provide valid informations on the renal hemodynamics of stenotic kidneys and on their changes induced by PTRA.

Effect of L-lysine and L-arginine on primary osteoblast cultures from normal and osteopenic rats

A therapeutic role of amino acids L-lysine (Lys) and L-arginine (Arg) in osteoporosis and fracture healing was demonstrated previously by in vivo studies. In the present study, primary cultures of osteoblasts were used to investigate the effect of amino acids on gene expression (alkaline phosphatase activity, ALP; osteocalcin, OC; type I collagen), nitric oxide production (NO) and proliferation (MTT) of cells. Cells were isolated from the distal femurs of normal and osteopenic rats. Normal and osteopenic bone-derived cells were divided into four groups: control, Lys (0.587 mg/mL/d), Arg (0.625 mg/mL/d), and Lys + Arg (0.587 + 0.625 mg/mL/d). No evidence of differences between normal and osteopenic bone-derived cultures in basal conditions was observed. A significant (P = 0.002) increase of 10.4% in NO production was observed in normal bone-derived osteoblasts treated with Lys + Arg when compared to the control group at 7 days. At the same time, normal bone-derived osteoblasts treated with Arg and Lys + Arg showed significant increases in type I collagen synthesis of 25.3% and 28.4%, respectively, when compared to the control group. Osteopenic bone-derived osteoblasts showed significant (P = 0.002) increases of 27.6% in MTT and 28.7% in cell count at 48 hours when treated with Lys + Arg in comparison with the control group. At 7 days, NO production and type I collagen synthesis increased significantly (P< 0.005) both in osteopenic bone-derived osteoblasts treated with Arg (NO: 18.5%; type I collagen: 34.4%) and Lys + Arg (NO: 23.7%; type I collagen: 20.9%) compared to the control group. Finally, a significant (P = 0.025) decrease of 5.8% in OC level was observed in osteopenic bone-derived osteoblasts treated with Arg. Results suggest that the potential therapeutic effect of Lys and Arg on bone could be related, at least in part, to an improvement of NO production and type I collagen synthesis by osteoblasts both in normal and in osteopenic bone. In osteopenic bone-derived osteoblasts this synthetic phase is preceded by an initial increase of cell proliferation.

The role of tumour markers in improving the accuracy of conventional chest X-ray and liver echography in the post-operative detection of thoracic and liver metastases from breast cancer

The aim of this retrospective study was to assess the value of a serum tumour marker panel in selecting from among the patients with equivocal chest X-ray (CXR) or liver echography (LE) those with thoracic or liver metastases respectively. Between January 1984 and December 1999, 467 (341 non-relapsed and 126 metastatic) breast cancer patients were followed-up postoperatively. Among the 126 metastatic patients 36 showed thoracic (19 patients) or liver (17 patients) metastases, alone or in conjunction with other organs as the first evidence of distant spread. We focused on this series of 377 patients including 341 non-relapsed plus 36 with liver or thoracic metastases. The patients were followed-up after mastectomy with serial determinations of a panel of CEA-TPA-CA15.3 tumour markers, bone scintigraphy, CXR and LE. Up to December 1999, equivocal CXR occurred in 23 (6.1%) patients of whom 11 (47.8%) developed thoracic metastases; 14 (3.7%) patients showed an equivocal LE of whom 5 developed liver metastases. In the 37 patients with equivocal CXR or equivocal LE prolonged clinical and imaging follow-up over 41 +/- 36 months (mean +/- SD, range 3-163) was used to ascertain the presence or absence of thoracic or liver metastases. In the 23 patients with equivocal CXR the negative and positive predictive values of the tumour marker panel to predict thoracic metastases were 92% and 100% respectively. In the 14 patients with equivocal LE the negative and positive predictive values of the tumour marker panel for prediction of liver metastases were 90% and 100% respectively. This study shows that in breast cancer patients the CEA-TPA-CA15.3 tumour marker panel has a high value for selecting those patients at high risk of developing clinically evident pulmonary or liver metastases from amongst those subjects with equivocal CXR or equivocal LE.

Angioplasty of atherosclerotic and fibromuscular renal artery stenosis: time course and predicting factors of the effects on renal function

The effects of percutaneous transluminal renal angioplasty (PTRA) on the renal function of stenotic kidneys are usually assessed by evaluating the changes in serum creatinine, which is quite a rough indicator of glomerular filtration rate (GFR). In 27 hypertensive patients with 19 atherosclerotic and 11 fibromuscular significant renal artery stenoses, we investigated with renal scintigraphy the short-term (5 days) and long-term (10 months) effects of a technically successful PTRA (in seven cases combined with a stent implantation) on GFR of the stenotic and contralateral kidneys; these measurements were combined with those of plasma renin activity (PRA) and of angiotensin II (AII). We found that in short-term studies after PTRA GFR rose from 29.7 +/- 3.5 to 34.6 +/- 3.1 mL/min and from 36.9 +/- 4.0 to 45.1 +/- 4.3 mL/min, respectively, in atherosclerotic and fibromuscular poststenotic kidneys. In long-term studies GFR further and significantly increased, to 37.8 +/- 3.2 mL/min in the former group, whereas it stabilized in the latter group (46.0 +/- 3.6 mL/min). In patients with fibromuscular stenosis these changes in GFR were associated with clear-cut reductions in blood pressure (BP), PRA, and AII; these decrements also occurred in patients with atherosclerotic stenosis but to a much lesser extent. We also found that in short- and long-term studies the percent of PTRA-induced increments of GFR in the poststenotic kidneys were inversely correlated with the baseline values of GFR. In addition, the absolute and percent increments of GFR were positively correlated with the basal levels of AII. Thus the time course of the improvement in GFR after angioplasty may differ in kidneys, depending on the etiology of the stenosis, in that in those with fibromuscular stenosis it was entirely apparent within a few days whereas in those with atherosclerotic stenosis it required several months to be fully expressed. Also, it appears that the more compromised kidneys are those that benefit most from the dilatation and that AII levels are useful indicators of the possibility that the stenotic kidney will have a favorable functional outcome in terms of restoration of renal blood flow.

Von Willebrand's factor mediates the adherence of human tumoral cells to human endothelial cells and ticlopidine interferes with this effect

The aim of this study was to explore whether von Willebrand's factor (vWF) plays a role in the adhesion of human colon tumor cells to human endothelial cells in our coculture system. Cell colony density was evaluated basally (endothelial plus colon tumor cells) and following the addition of: purified vWF, vWF plus vWF-blocking antibodies, antibodies against various integrins and adhesion molecules (alpha2 b integrin, beta1 integrin, beta3 integrin, intercellular adhesion molecule-I, intercellular adhesion molecule-II, vitronectin receptor CD61 CD51, laminin alpha6/beta4 receptor), and various drugs inhibiting the hemostatic system (ticlopidine, heparin, acetyl salicylic acid [ASA], defibrotide, indobuphen, dipyridamole, sulfinpyrazone). Furthermore, vWF concentration was measured in the supernatant fluid of the coculture system basally and following the addition of the above-listed drugs. Cell colony density (as measured by light absorption) increased by 33% following the addition of vWF and returned to a value similar to the basal level with antibodies against vWF, while it did not change significantly following the addition of antibodies against the other integrins or adhesion molecules tested. The same parameter was reduced by 35% following the addition of ticlopidine, while it showed a smaller or no change with the other drugs tested. Similarly, vWF concentration in the cell coculture supernatant showed the greatest reduction (from 0.22 to 0.11 mg/mL) following the addition of ticlopidine. These data suggest that vWF mediates the adherence of human tumor cells to human endothelial cells and that ticlopidine interferes with this effect.

Postoperative follow-up of breast cancer patients: overview and progress in the use of tumor markers

The role of serial measurement of serum tumor-associated antigens (TAA) in the postoperative follow-up of breast cancer patients is not considered by most authors. The authors of this article review the literature and original data showing benefits from the use of TAA in the postoperative follow-up of breast cancer patients. An increase in the lead time from the first pathological finding to the definite evidence of distant metastases has been observed in follow-up studies which have used TAA compared to those which did not use them. The sensitivity and specificity of TAA in the diagnosis of distant metastases have been markedly improved by selecting an appropriate combination of TAA and by identifying specific conditions associated with breast cancer responsible for false-positive results as well as by adopting a 'dynamic' evaluation of multiple successive determinations of TAA. TAA accurately predict patients with bone metastases and can be used to guide imaging techniques. The anticipation of distant metastasis by TAA can be used to initiate a relatively early treatment which has been shown to prolong overall survival in a previous study. It is hoped that these data will stimulate further trials including TAA in the follow-up of breast cancer patients.

The role of large-needle aspiration biopsy in the preoperative selection of palpable thyroid nodules: a summary of principal data

This report summarizes clinical and pathologic data showing the role of preoperative large-needle aspiration biopsy (LNAB) histology for a better evaluation of the palpable thyroid nodules that were non-diagnostic or microfollicular at fine-needle aspiration (FNA) cytology. LNAB performed on 261 nodules with non-diagnostic cytology showed findings which were adequate for diagnosis in 130 (49.8%) and inadequate in 131 (50.2%) cases. Two hundred sixty nodules that were diagnosed as microfollicular at FNA were also examined by LNAB; inadequate specimens were obtained in 17% of cases; pure microfollicular structure was confirmed by aspiration needle biopsy in 35% of the nodules and LNAB showed the remaining 48% to contain a macrofollicular component suggesting a benign hyperplastic lesion. Seventeen nodules that were found to be microfollicular at FNA and micromacrofollicular at LNAB were excised and the postoperative result was benign in all cases. Twenty-five nodules diagnosed as microfollicular on both FNA and LNAB were excised and the postoperative diagnoses were benign (20 nodules) or malignant (five nodules). These data indicate that LNAB histology can be used for the preoperative selection of the palpable thyroid nodules that were non-diagnostic or microfollicular at FNA cytology.

Large-needle aspiration biopsy for the preoperative selection of palpable thyroid nodules diagnosed by fine-needle aspiration as a microfollicular nodule or suspected cancer

The palpable thyroid nodules with a fine-needle aspiration (FNA) diagnosis of microfollicular nodule or suspected cancer usually are excised; however, most of them are proved benign by postoperative histologic examination. We reviewed the clinical and pathologic data for patients with thyroid nodules with an FNA diagnosis of microfollicular nodule or suspected cancer; nodules also were examined by large-needle aspiration biopsy (LNAB) to assess whether the distinction achieved by LNAB into pure microfollicular or mixed microfollicular-macrofollicular nodules could be used preoperatively to better predict malignancy. One hundred fourteen nodules of this type were excised. The prevalence of cancer was 22% (14/63) among the microfollicular and 4% (2/51) among the microfollicular-macrofollicular nodules at LNAB. These data indicate that histologic examination of the LNAB specimen can be used for preoperative selection of thyroid nodules diagnosed by FNA as a microfollicular nodule or suspected cancer.

[Carbon dioxide angiography. A new injection system]

PURPOSE

To evaluate the usefulness of a new carbon dioxide (CO2) intravascular injection system in digital subtraction angiography.

MATERIAL AND METHODS

March 1998 to May 1999, thirty-nine patients were submitted to digital subtraction angiography with CO2 injection by a new delivery system, CO2-Angioset, OptiMed, Ettingen, Germany. The patients were 29 men and 10 women, whose age ranged 32 to 76 (mean: 47), eighteen of them with absolute or relative contraindications to iodinated contrast media and 6 with poor diagnostic findings at previous conventional angiography. CO2 was used for comparison with iodinated contrast agents in 4 patients. We studied the following vascular districts: renal arteries in 9 patients, portal vein in 18, lower limb arteries in 7, upper limb veins in 4. In 1 patient CO2 angiography was carried out for the diagnosis and interventional treatment, by transcatheter embolization, of a postbioptic arteriovenous renal fistula. During the procedure, arterial blood pressure, EKG status and oxygen stauration were monitored, and subjective sensations recorded in all patients.

RESULTS

CO2 angiography provided adequate visualization of vascular districts and of abnormal findings in 32 cases (82%), while its results were considered insufficient for correct and complete assessment in 7 cases (18%). In detail, renal arteries studies were adequate in 9/9 cases, providing good depiction of the arterial trunk and main branches but poor demonstration of interlobar and arcuate arteries. The portal trunk was well depicted in 12/18 cases, but CO2 angiography results were insufficient in 3 cases because of poor catheter wedging in the hepatic vein and in 2 cases because of CO2 drainage by an accessory hepatic vein. Peripheral circulation was clearly depicted in 5/7 cases, while there was incomplete filling of the abdominal aorta and of iliac and femoral arteries in 2 cases. We had only one transient complication (2.57%) due to mesenteric ischemia during an aortic injection, with mild abdominal pain and diarrhea which subsided spontaneously in few minutes.

CONCLUSIONS

In our experience the CO2-Angioset delivery system has proved to be a simple and safe tool, particularly suitable for use in patients at risk for allergic reactions to iodinated contrast agents and in those with renal function impairment. Also, the system can help carry out some interventional procedures such as arteriovenous fistula embolization and transjugular portosystemic shunting.