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Biological RV for asbestos implies several problems, due to the difficult interpretation of values obtained from various biological samples (sputum, BALF, lung tissue). Therefore, it seems it advisable to refer to environmental concentrations (ERC), which are not avoidable, since asbestos is an ubiquitous contaminant. On the basis of the available studies the 1 f/L value is usually reported as the most representative, although more recent and reliable studies would indicate lower values, at least for outdoor concentrations, as determined by SEM. However, further studies are needed: standardized methods based on SEM (author's opinion) should be adopted; the accuracy of such technique is sufficient for air concentrations from 0.05-0.1 f L-1 upwards, with the advantage of lower costs and time as compared to TEM.

The authors review the results of clinical experiences regarding arterial and venous homografts. For the treatment of mycotic aneurysms and infected prostheses, in situ repair with vascular homografts represents a valuable alternative to conventional surgical treatments. In fact the large caliber arterial homografts allow safe in situ reconstruction, decrease early and midterm mortality and reinfection rates; the best results are achieved in case of infected grafts, whereas the prognosis of vasculo-enteric fistula remains very poor. The small caliber arterial homografts also have demonstrated satisfactory results in term of patency, although further experiences with longer follow-up are required. Vein homograft constitutes an alternative by-pass conduit for limb revascularisation in patients who lack adequate autogenous vein: although limb salvage rate is satisfactory, long term patency rate is poor when compared with autogenous veins. Improvement of preservation methodics, pharmacological control of rejection and tissue engineering represent the future perspectives in this field.

Hepatocellular carcinoma is one of the most frequent forms of cancer worldwide and its diagnosis and treatment have changed substantially during the last few years. Recent advances in ultrasonography, spiral computed tomography scan and nuclear magnetic resonance have further simplified the diagnostic approach to hepatocellular carcinoma. Ultrasonography is the reference examination, giving a wide variety of information on tumour size, location, relationship with portal and hepatic veins and splanchnic haemodynamics. Surgical resection and liver transplantation can both be defined as curative treatment while other techniques such as percutaneous ethanol injection and chemoembolization must be considered as palliative. Therapeutic strategies for hepatocellular carcinoma are based upon data concerning the characteristics of the tumour the functional status of non-tumoural liver parenchyma and patients' general conditions. Surgery of hepatocellular carcinoma in cirrhotic liver is mainly restricted by lack of functional hepatic reserve and by the limited capacity of hepatic regeneration. The best surgical results are obtained in early tumoural stages which generally need limited resection. Nevertheless, major liver resections have a specific role in selected cases. Recurrence rate after surgical resection is high and is related to a large number of factors. For this reason, liver transplantation, removing at the same time, the tumour and the underlying disease, is considered, theoretically, the best treatment for hepatocellular carcinoma, but its role is still debated and limited by difficult organ sharing. Integration of present therapeutic schemes are under evaluation with promising preliminary results.

Chrysotile and crocidolite fibers incubated in normal human plasma (NHP) generated from the C5 component of complement C5a-type fragments that stimulated polymorphonuclear leukocyte (PMN) chemotaxis. Absorption of NHP with antiserum against C5a totally abolished neutrophil chemotactic activity. Asbestos fibers also produced C5a small peptides in the presence of ethylene glycol bis(beta-aminoethyl ether) N,N,N'N'-tetraacetic acid (EGTA) but not ethylene diamine tetraacetic acid (EDTA). Activation of C5 was significantly inhibited when asbestos fibers were pretreated with iron chelators such as sodium dithionite (DTN), deferoxamine (DFX), or ascorbate (AA). Concentration-related inhibition of C5 activation was also observed when asbestos fibers were added concurrently to plasma in the presence of DFX, 1,3-dimethyl-2-thiourea (DMTU), a strong hydroxyl scavenger, or aprotinin (APR), a specific protease inhibitor. Further, chrysotile and crocidolite significantly increased plasma kallikrein activity. Data demonstrate that asbestos-induced C5 activation plays a role in inflammatory reactions characteristic of asbestosis through mechanisms involving iron ions, hydroxyl radicals, and oxidized C5-ike fragments. The ferrous ions present at the asbestos fiber surface trigger this activation and catalyze, via Fenton reaction, the production of hydroxyl radicals, which in turn convert native C5 to an oxidized C5-like form. This product is then cleaved by kallikrein, activated by the same asbestos fibers, yielding an oxidized C5a with the same functional properties as C5a.

Asbestos bodies (AB) were harvested from human lung tissue digests and isolated from uncoated asbestos fibers. Samples containing 1000 AB were added to a reactive solution to investigate the ability of AB to oxidize deoxy-D-ribose and generate reactive oxygen species (ROS) in the presence of ascorbate and hydrogen peroxide as determined by formation of thiobarbituric acid (TBA)-reactive products. Three types of asbestos fibers were tested for comparison, since they are known to be able to produce ROS. The absorbance values measured with 1000 AB were significantly higher than those observed with 1000 fibers of the three types of asbestos. Since in our reaction system the only source of transition metals was the iron-rich AB, data suggest iron derived from the ferritin coating of AB was involved in oxidant generation. Addition of iron to AB enhanced TBA-reactive product formation, while chelation of Fe with deferoxamine reduced this reaction. Hydroxyl radical scavengers 1,3-dimethyl-2-thiourea (DMTU) and mannitol (MN) also effectively blocked TBA-reactive product generation. Data indicate the importance of Fe in AB-induced oxidant damage. With the addition of polymorphonuclear leukocytes (PMN) to AB, incubation in the reactive solution gave very high amounts of TBA-reactive products, but using a reactive solution devoid of ascorbate, very low amounts of TBA-reactive products were generated. In the latter condition, the superoxide of cell membranes probably reduced and removed iron from AB-coating ferritin, but less effectively than ascorbate. Further after the possible reoxidation of Fe2+, Fe3+ could be coordinated by lactoferrin. Since such availability of reductant is never approached in living systems, the iron in the AB coating is unlikely to function as a catalyst of Fenton-type reactions in vivo.

A 39-year-old man was hospitalized with a history of fatigue, dyspnoea and low grade fever which seemed to be related to his working environment. The patient was employed in a salami factory, working near the area where the salami are seasoned with fungal inocula. Chest X-ray showed diffuse initial changes of reticulonodular pattern that disappeared after a brief course of steroids therapy. Precipitating antibodies to Penicillium notatum and Aspergillus fumigatus were found both in plasma and bronchoalveolar lavage fluid. This, together with the finding of a lymphocytic alveolitis with CD4+ depletion and CD8+ increase, suggested the possibility of extrinsic allergic alveolitis of fungal aetiology. Qualitative and quantitative monitoring with an impinger of both the working and outside environment for aerial fungal concentration demonstrated a very high level of contamination (up to 1.14x10(9) fungal propagules m-3 of air) and an inside/outside ratio from 21 to about 2000. Penicillium camembertii was the most common species found in all the indoor sites (60-100% of the fungal load). The patient's BALF and serum both displayed precipitating antibodies to P. camembertii from the powder used for the inoculum and the air samples. These results together with the patient's working history gave some evidence of relationship between the indoor P. camembertii concentration and the patient's symptoms.

The Mirizzi syndrome is often undiagnosed before surgery and can carry a high risk of iatrogenic damage to the common bile duct when encountered during open or, especially, laparoscopic surgery. Endoscopic management has recently been reported, but this treatment can be performed only when there is a high index of suspicion based on clinical criteria that the condition is present and therefore suggests the indication for endoscopic retrograde cholangiopancreatography (ERCP). This is not always the case. Consequently, in a considerable percentage of patients, the syndrome is discovered only after the bile ducts have been damaged during surgery. Three cases of Mirizzi's syndrome were observed in our experience of 896 laparoscopic cholecystectomies (0.3%). All patients were without typical symptoms, and the syndrome was unsuspected in spite of preoperative intravenous cholangiography. All patients required conversion to an open procedure, with two injuries of the common bile duct (a complete transection and a tear) being promptly repaired. We conclude that when this syndrome is suspected or found during surgery, the surgeon should follow these guidelines: (1) perform intraoperative cholangiography when possible, even through the gallbladder wall; and (2) dissect the gallbladder from above and, if necessary, open it to extract the stone. Dissection of Calot's triangle should never be attempted. Great expertise is required to complete the operation laparoscopically. The reported cases in the literature refer to a high percentage of conversion, underlining the technical difficulties and making this syndrome, when undiagnosed and unsuspected, a real challenge for laparoscopic surgeons.

Wollastonite fibers were tested in vitro for their ability to produce reactive oxygen species (ROS) with two different systems: a cell-free reactive mixture containing deoxyribose and a polymorphonuclear leukocyte suspension. After adding the fibers, we measured the thiobarbituric acid-reactive substances produced by deoxyribose degradation and luminol-enhanced chemiluminescence, respectively. Compared with asbestos, wollastonite fibers produced higher ROS levels both in the PMN suspensions and in the cell-free reactive mixtures. A large amount of these ROS were not hydroxyl radicals. Indeed we obtained remarkable differences in ROS generation between unground and ground wollastonite fibers and negative results with fibers modified with ferric chloride and dithionite. In addition, ROS generation was partially inhibited (by 46-54%) in the reactions performed in the presence of 1,3-dimethyl-2-thiourea (DMTU), a strong hydroxyl radical scavenger. Wollastonite fibers were also analyzed for their ability to lyse erythrocytes and activate complement. Hemolytic potency was about twice that of chrysotile and half that of crocidolite. The levels of complement activation (via the alternate pathway) were about four-fifths of those measured in zymosan-activated plasma (a typical stimulus used to activate the alternate pathway), equal to those obtained with crocidolite, and two-thirds of those found with chrysotile. The addition of DMTU markedly reduced both these activities. Since asbestos fiber toxicity is mainly due to hydroxyl radical generation, our results indicate that wollastonite fibers are probably less toxic than asbestos fibers.

Background and Aims: The scarce availability of organs and the excellent results obtained using living donors, due to the improved degree of compatibility between donor and recipient, the short period of organ storage and the possibility of choosing the ideal surgical "timing", in the authors' opinion justify the use of living donors from a clinical and ethical-moral point of view., Methods: Between April 1986 and December 1996 a 406 renal transplants were performed; of these, 10 patients received grafts from living donors. Preliminary screening consisted in a careful clinical and immunological evaluation to evaluate the operating risk, good compatibility with the recipient and the perfect bilateral function of the kidney., Results: The 10 donors had no postoperative mortality or morbidity, no alterations of renal function, and no onset of hypertension and/or proteinuria in the immediate post-operative period or at a distance. The organ and patient survival rate (including a follow-up of between 2 and 54 months, mean 25 months) was 100%., Conclusions: The authors suggest that living donors represent a valid alternative in uremic patients. This therapeutic act must be carried out in complete respect for ethical, moral and legislative principles and must be based on a careful clinical selection to minimise the risks of donation and to guarantee the maximum benefit for the recipient. It is to be hoped that further improvements are made in immunodepressive treatment, and above all an appropriate increase in transplants from cadaveric donors, making the use of living donors superfluous since this practice maims a perfectly healthy individual.

Background: The incidence of malignancies after transplantation is higher when compared with expected cancer in control patients, particularly skin and female genital cancer, non-Hodgkin's disease and Kaposi's sarcoma. The aim of this study is to evaluate the frequency and the efficacy of the treatment of cancer following renal transplantation., Methods: A retrospective analysis of 404 recipients was performed and it showed the onset of 15 cancers (8 skin cancers, 3 Kaposi's sarcomas, 2 renal carcinomas, 1 urotelioma and 1 colon cancer) in 11 patients (3.7%). At the time of diagnosis, the mean period of immunosuppressive therapy (7 cases of double therapy, 4 cases of triple therapy) was 44.8 months. Skin cancer (53.3%) and Kaposi's sarcoma (20%) were the most frequent in personal experience as reported in literature. Neither lymphomas, nor female genital cancers were detected., Results: All the cases were surgically treated, except patients with Kaposi's sarcoma, whose immunosuppressive therapy was reduced without alteration of renal function. Death-rate was 0.25% (1 case), the remaining patients show no signs of local recurrence or metastasis with preserved renal function except for the patient with renal carcinoma of the transplanted kidney, who underwent nephrectomy and returned in replacement therapy., Conclusions: The conclusion is drawn that the research of relationship between type of immunosuppressive therapy and cancer incidence and careful clinical and instrumental examination of transplant patients may contribute to reduce the onset of neoplastic degenerations and lead to an early diagnosis.

Objective: The shortage of cobalt (Co) on the metal market forced the industry to add nickel (Ni) to Co as a binding agent for the sintering of hard metal. This change enabled us to study (1) the exposure to Ni powder and (2) the effect of Ni on Co uptake (and vice versa)., Methods: Equal amounts of Co and Ni were used in the mixture in a plant employing 50 workers. Both personal ambient-air samples and single-void urine samples were taken twice in the same week, i.e., on Monday and Thursday. Atomic absorption spectroscopy (AAS) was used for analyses., Results: The airborne availability of Ni (mean value 41.65 +/- 6.29 micrograms/m3) was 2-fold that of Co (mean value 21.85 +/- 24.25 micrograms/m3), although the two series of data (n = 20) were significantly correlated. Even if the Co and Ni urinary concentration values (n = 45) recorded on Monday morning and Thursday evening were significantly correlated, at the end of the week there was a 3-fold increase, specifically, from 7.3 to 22.28 micrograms/l, in Co elimination (a significant difference) and a 30% increase in Ni elimination from 11.98 to 15.83 micrograms/l. Moreover, on Monday morning, 90% of Ni urinary concentration values were higher than those of Co as opposed to only 33% on Thursday evening. In the six cases in which both airborne and urine determinations were performed on the 2 days, no significant relationship was found between external exposure and biological monitoring data., Conclusions: Although Ni uptake was variable, it was generally low, whereas Co uptake was substantial, as had previously been observed in the same plant when Co was the only binder under use. It was therefore possible to rule out any influence of Ni exposure on Co uptake and to suggest the contrary, as has been demonstrated in bacterial species and in rats using everted intestinal sacs.

A sample of silicon carbide dust taken in the field from a plant producing abrasives was studied in vitro. The SiC particles (part unmilled and part milled) were able to disturb the structure of erythrocyte membranes and to lead to blood red-cell lysis; they also either interfered with complement and activated the alternate pathway, or interacted with biological media and polymorphonuclear leucocyte membranes, thus eliciting reactive oxygen species production. These in vitro properties were detected both in original large particles and unmilled particles, over 40% of which were of respirable size. The ability of these SiC particles to produce complement activation in vitro lends support to the previous hypothesis, that the radiographic opacities found in two workers employed in the same area of the plant from which the dust tested was taken are due to a reaction by pulmonary interstitial structures to SiC particle inhalation. It is speculated that SiC particles could act like asbestos, the ability of which to activate complement through the alternate pathway is considered to be one of the mechanisms by which the initial asbestotic lesions and subsequent fibrotic inflammatory infiltrates are generated in the lung.

Objective: To increase the awareness of the successful use of horseshoe kidneys in renal transplantation., Patients and Methods: Two donors were found to have horseshoe kidneys; these were divided at the midline and transplanted into four recipients., Results: All four recipients had a delayed return of renal function; all eventually functioned with no complications related to the horseshoe kidney., Conclusion: Transplantation of horseshoe kidneys has been performed infrequently but they should be considered as suitable for transplants, considering the shortage of cadaver donors and, when possible, should be divided at the isthmus and the halves transplanted into two recipients.

Absorption and excretion of cobalt in the hard metal industry was investigated by means of ambient air and urine measurements in three factories with high levels of environmental cobalt pollution. In the presence of poor hygiene conditions and permission to smoking during work, there was no relationship between cobalt ambient air and cobalt urine concentrations. Such a finding was therefore attributed to a substantial skin contact. A simple experiment of skin exposure to freshly mixed or waste powder on volunteers identified a ten-fold increase of cobalt in urine in the post-exposure samples, thus confirming the contribution of dermal exposure as a route of entry. An improvement in the hygiene of the working conditions helped to investigate the relationship between exposure and excretion level. Cobalt uptake through the different routes of entry may be substantial, and requires a more prolonged exposure-free period so that the excretion rate can be reduced to the reference population level.

Anastomosis recovery still represents a problem in colon surgery, particularly when the resection is performed in emergency or on a suffering and not adequately prepared bowel. The authors describe a new technique successfully tested in the animal. The operation consists in a bowel resection followed by immediate reconstruction with a protective colostomy and an exclusion anastomosis obtained by a proximal suture in resorbable clips. Results in animals have been satisfactory, with a spontaneous and gradual resumption of physiological canalization, according to authors expectations. Technical details and several histological features are herein described.

Silicon carbide (SiC) fibre generation is reported to occur during commercial SiC crystal production. Dust levels and fibre concentrations were measured by static sampling in an Italian plant operating 24 Acheson furnaces. X-ray Diffraction (XRD) was used to assess the quartz content in the dust collected. Optical microscopy (OM) and scanning electron microscopy (SEM) were used for fibre counting and identification of fibres. Only alpha-quartz was identified, but airborne concentrations were found to be higher than the concentration of crystalline silica reported in other similar studies. Two types of fibre, coarse and fine, were identified by OM and SEM: for both, only the peak of silicon (Si) was evident at energy dispersive X-ray analysis (EDXA). Coarse fibres are irregular in shape, with a diameter greater than 5 microns. Fine (respirable) fibres are straight, regular in shape, with a typical diameter between 1 and 2 microns. Fine fibre concentration does not appear to be related either to total dust or to total fibre concentration. It cannot therefore be predicted from the nature of the various processes involved.

Twenty-six workers in a hard metal manufacturing plant were monitored by cobalt urinary and ambient air measurements during the first month after summer holidays. Cobalt determinations were performed utilizing AAS, with a preliminary chelation and extraction procedure for urinary samples. Almost all personal ambient air samples turned out to be under the cobalt dust TLV of 0.1 mg/m3. When restarting work after the holidays, urinary values did not differ from the control group. At the end of the first working week, urinary cobalt had increased four fold, then decreased to the original values on the following Monday before restarting work. Thereafter, the weekend was no longer sufficient to reduce the levels to normal urinary cobalt values. The values rose to the same level observed before the holidays, and dit not substantially decrease even after the weekend. End-shift urinary cobalt values showed a good relationship with present as well as with mean past exposure on the first and the fifth weekday, but the third day did not. The correlation was better with present exposure on Monday and with mean past exposure on Friday. The observed differences may be explained by the minor influence of recent exposure on present exposure on Monday. The highest values were found on Wednesday. We suggest the utilization of end-shift urinary cobalt determination as a measure of the present exposure on Monday, and of mean recent or preceding exposure on Friday.

Intrasplenic hepatocytes transplantation was carried out in Wistar-Lewis strain inbred rats, after inducing acute hepatic failure by intravenous injection of Dimethylnitrosamine (DMNA) (30 mg/kg). Iso-, allo-(CDF-Fisher strain) and xenogeneic (New Zealand White rabbit) grafts were performed. Liver cells suspension was obtained by mechanical separation. The results demonstrated the efficacy of iso- and allotransplants, but not of xenogeneic hepatocytes, in improving significantly the survival rate compared to the control group. It is concluded that immunogenicity of liver cells is a factor which must be taken into consideration in hepatocyte transplantation. Moreover the absence of liver cells into the spleen at one week after the transplant seems to suggest that an intact liver cell is not necessary to improve survival.

Following a rapid review of equipment available for the depolluting of operating theatres, new equipment which does not interfere with anaesthesia circuit pressures is presented; experimental data obtained during use of this equipment are also reported and compared with standard data.

4 cases of oesophageal achalasia, 2 primary and 2 recurrences following multiple oesophagomyotomy are reported. The superiority of oesophagomyotomy carried out by the left transthoracic route (according to Ellis) in cases of primary achalasia is stressed. On the basis of the literature and reported experience, it is concluded that this approach is also preferable in recurrences when the previous operation was done by the abdominal route and the recurrence occurred within 6 months. In all other cases, particularly in the presence of an achalasic megaoesophagus, partial oesophagogastric resection with interposition of a jejunal loop (Merendino's operation) is the procedure of choice and the satisfactory results of using it are reported.

The authors present their experience of endoscopic sclerosis of esophageal varices in 56 patients in a period of about two and half year (February '83-July '85). 46% of the patients were of the group C according to Child's criteria and 48.2% showed a fourth degree varices according to Paquet's criteria. Twenty-nine patients (51.7%) were submitted to the sclerosis as emergency treatment, 17 patients (30.3%) had an elective procedure and 10 (17.8%) were treated by a prophylactic sclerosis. The hemorrhage was stopped in 25 cases (86%) among emergency treated patients. However a new hemorrhage was observed before the end of the cycle of treatment in 48%. On the contrary 17% of patients complained recurrent hemorrhage after completing the treatment. Thirty-five per cent of patients electively treated showed recurrent hemorrhage while 40% bled after prophylactic treatment. Thirty-eight patients had a follow up of one year with results very similar to these reported in the literature. As a conclusion, on the bases of the reported results the authors suggest to submit to this treatment all the patients with recent hemorrhage or in emergency. The sclerosis should be reserved as elective procedure only to the patients of the class C; class A should be reserved to surgery while patients of the class B are matter of debate. Moreover prophylactic treatment, theoretically very attractive, needs further evaluation, at least in their hand.