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The Asian soybean rust caused by the fungus Phakopsora pachyrhizi was cited for the first time in Argentina during the 2002-2003 growing season (3). During 2003-2004, the disease spread to other northern provinces and was also observed in north-central Santa Fe, the main producing soybean province of the country. Because the disease appeared at the end of the crop growing season (late March to early April) it had little or no impact on crop yields. The objectives of this study were to characterize morphologically and pathometrically the disease on soybean and check the presence of P. pachyrhizi on volunteer soybean plants that could eventually carry the disease to the next growing season. The study was conducted in the San Justo Department, Santa Fe Province (between 30 and 31°S latitude), where the presence of the soybean rust was molecularly confirmed by Sistema Nacional Vigilancia y Monitoreo (on-line publication at www.sinavimo.gov.ar ). Three field locations were sampled and identified as M1, M2, and M3. Transversal cuts of soybean leaves through rust lesions and histo-pathological staining were used for micromor-phologic characterization of the developmental stages of P. pachyrhizi. The disease incidence was estimated as the proportion of affected soybean plants and leaves. Average severity, expressed as the percentage of leaf area affected, including chlorosis, was measured on the terminal leaflet of leaves sampled from the lower one-third of the canopy. Three replicates of 10 plants, randomly chosen, were used. The number of uredinia per square centimeter and per lesion (symptomatic foliar area showing chlorosis and necrosis caused by the fungus) was measured on the undersides of the sampled leaflets at ×40 magnification (1). Typical signs and symptoms of P. pachyrhizi coexisted on soybean leaves with brown spot (Septoria glycines), downy mildew (Peronospora manshurica), anthracnose (Colletotrichum truncatum), and blight and leaf spot (Cercospora kikuchii) and also with bacteria (Pseudomonas and Xanthomonas spp.). Uredinia and telia of the P. pachyrhizi cycle were observed. Uredinia were also observed on soybean petioles. The average size of urediniospores (n = 60) was 23.3 × 16.6 μm. Telia were located adjacent to the uredinia. These telia were dark and crusty with four stacked layers of teliospores. Rust incidence in plants was 100% for the three fields, while the incidence in leaves was 100% for M1 and M2 and 60% for M3. Average disease severity was 50.3, 25.6, and 14.8% for M1, M2, and M3, respectively. The mean number of uredinia per square centimeter was 327, 179, and 177, for M1, M2, and M3, respectively. The number of uredinia per lesion ranged from 1 to 6. P. pachyrhizi was also found on volunteer soybean plants that emerged shortly after harvest. On 40 leaflets, the foliar incidence was 25%, showing one to two lesions with one to two uredinios per leaflet (2). The volunteer soybean plants could constitute a potential early source of inoculum. References: (1) M. Marcchetti et al. Phytopathology. 66:461, 1976. (2) R. Pioli et al. La roya asiática en Santa. Fe, Arg. XII Cong. AAPRESID, II Sem. Internac. Soja, Arg. 283-290, 2004. (3) R. L. Rossi. Plant Dis. 87:102, 2003.

The aim of this preliminary case-control study was to compare, in patients with migraine and PFO, transcatheter closure of PFO vs. medical treatments. Twelve patients were treated with antimigraine drugs and twelve underwent percutaneous transcatheter closure. All patients were followed-up for 12 months. Our preliminary results seem to confirm that, compared to medical treatment, PFO closure is by far more effective in reducing both frequency, duration and intensity of migraine attacks. Furthermore, the occurrence of prodromal aura is almost abolished.

Background and Purpose: Transcatheter closure of patent foramen ovale (PFO) is increasingly being performed and monitored with transthoracic or transesophageal echocardiography, whereas contrast-enhanced transcranial Doppler (ce-TCD), which probably represents the most suitable tool to quantify right-to-left shunt (RLS) in the brain vessels, has been systematically overlooked. Our goal is to prospectively assess efficacy and safety of PFO transcatheter closure using ce-TCD., Methods: A total of 140 consecutive patients (mean age, 46+/-13 years; male/female ratio, 63/77) with PFO-related large RLS and no other recognized cause of focal cerebral ischemia underwent transcatheter closure. TCD was done preoperatively and 1 month after the procedure in all patients, after 3 months in 120, after 6 months in 112, and after 1 year in 104 patients., Results: Implantation was successful in all patients. During Valsalva strain, a large shunt was still detectable in 31 of 140 (22%), 15 of 120 (13%), 9 of 112 (8%), and 9 of 104 (9%) patients at the 1-, 3-, 6-, and 12-month visits, respectively. Periprocedural and postprocedural complications included atrial fibrillation in 8% and scintillating scotomata in 6% of patients. During the 1-year follow-up period, only 1 transient ischemic attack was recorded in a patient with paroxysmal atrial fibrillation and complete PFO closure., Conclusions: Transcatheter PFO closure in patients with cryptogenic stroke and large RLS may be less successful than reported previously. TCD appears the ideal tool to follow up the closure process and to identify early, during follow-up, those patients who will be left with a significant shunt. Atrial fibrillation is more common than believed previously and may underlie the occurrence of further cerebrovascular events despite complete PFO closure. Irritative visual phenomena may occur as a consequence of nickel toxicity.

Fusarium graminearum, a pathogen of wheat and corn, was reported recently as a saprophytic fungus colonizing soybean (Glycine max L. Merr.) fruits and seeds at R7 in Argentina (2). To evaluate the capacity of F. graminearum obtained from stem and seeds of symptomatic soybean plants that cause disease on soybean seedlings, isolates were obtained during the 2001 to 2002 growing season from: (i) the basal one-third of stems from field-grown soybean plants, collected at R5, with light brown external and internal discoloration and leaves with interveinal chlorosis; and (ii) soybean seeds with pink tegument. The pathogen was isolated on potato glucose agar acidified with 0.2% lactic acid (PGAA). Isolates were identified as F. graminearum on the basis of growth rate and pigmentation of colonies on PGAA, lack of microconidia (1), and morphology and size of typical macroconidia in sporodochia developed on Spezieller Nährstoffarmer Agar (3). Isolates of F. graminearum, CE135 and CE136 (from wheat) and CE137 (from corn) deposited in the Centro de Referencia en Micología (CEREMIC), Fac. Farmacia y Bioquímica, UNR, Argentina, were used as references in identifying the soybean isolates. Plants (14-day-old) were inoculated separately with stem and seed isolates in the greenhouse at 26 ± 2 and 20 ± 2°C day/night temperature by inserting a piece of mycelium into a wound made with a scalpel in the hypocotyl. A completely randomized block design (RCB) was utilized with four replicate pots with four plants per pot. Plants wounded but without mycelium served as controls. This test was conducted twice (experiments 1 and 2). Another test was completed by burying a thin layer of wheat caryopsis colonized by fungal mycelium of the stem isolate CE170 in the soil of pots. Plants in pots with soil without inoculum served as controls (4). The experiment was conducted twice (experiments 3 and 4) in an RCB with five replications, four plants per replication. The progress of symptoms in experiments 1 and 2 were stem with light brown discoloration around the inoculation point that extended progressively along the stem, interveinal chlorosis or loss of turgence of unifoliate leaves, and interveinal chlorosis of trifoliate leaves followed by plant wilting and death. Twenty-one days after inoculation, average percentages of dead plants (%DP) was 42 and 21% for stem and seed isolates, respectively. For experiments 3 and 4, %DP was 56%, 45 days after emergence. These plants had roots with light brown, necrotic areas. Control plants remained healthy. The pathogen was reisolated from the stem (100%) and root (57%) tissues of symptomatic plants but not from similar tissues of control plants. To our knowledge, this is the first report of a pathogenic relationship between F. graminearum and soybean. References: (1) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, PA, 1983. (2) R.N. Pioli et al. Fitopatología 35(2):111, 2000. (3) B. A. Summerell et al. Plant Dis. 87:117, 2003. (4) C. E. Windels. Fusarium. Pages 115-128 in: Methods for Research on Soilborne Phytopathogenic Fungi. L. L. Singleton, J. D. Mihail, and C. M. Rush, eds. The American Phytopathological Society, St. Paul, MN, 1992.

The importance of patent foramen ovale (PFO) in stroke of unknown cause remains disputed, as PFO may be present in up to 20% of normal people and in a high proportion of patients with non-vascular disorders. Recent evidence suggests that the amount of right-to-left shunt (RLS) may be the crucial factor for stroke occurrence and relapse. The aim of the study was to assess predictors of recurrence in PFO-related stroke patients with particular emphasis on amount of shunting. Patients less than 61 years old who had been admitted for a PFO-related stroke within the previous 5 years, were re-evaluated on a follow-up visit. The clinical syndrome, residual disability, vascular risk factors and number of relapses as the index event were assessed. RLS sizing was semi-quantitatively performed with saline-enhanced transcranial Doppler (TCD), by assuming a cut-off of more or less 10 bubbles recorded in the cerebral vessels as a criterion to discriminate large versus small shunt, respectively. Thereafter patients were prospectively followed-up for a median time of 23 months. Total follow-up was 61 months. Fifty-nine patients (M/F = 23/36, mean age 43 +/- 13) were studied. Overall there were 23 relapses in 13 patients. The amount of shunting was the only significant independent variable associated with relapse: at the end of the follow-up period the recurrence rate was 0.66 and 8.2% per patient per year in patients with small and large shunt, respectively. This difference was statistically significant (chi2 = 10.39, P = 0.0012; OR 17.05, 95% CI 2.10-755.22). In patients with PFO-related stroke, the amount of RLS as assessed with TCD is the only independent predictor of relapse. PFO sizing is mandatory in patients with PFO.

The purpose of this study was to assess the safety and feasibility of percutaneous interventional closure of patent foramen ovale (PFO) with or without atrial septal aneurysm (ASA) in symptomatic patients. Between June 1999 and June 2002, we performed transcatheter closure of PFO in 256 consecutive symptomatic patients (female/male = 1.45; mean age 48 +/- 16 years; range 14-75): ischemic stroke (n = 101), transient ischemic attack (n = 144), peripheral and coronary arterial embolism (n = 17); multiple events (n = 23); platypnea-orthodeoxia syndrome (n = 2); refractory hypoxemia (n = 1); and migraine aura (n = 27). The implanted devices were an Amplatzer PFO Occluder (n = 248), a Gore-HELEX Septal Occluder (n = 4), and PFO STAR (n = 4). Most procedures (n = 176.69%) were done under two-dimensional intracardiac echocardiography (ICE) guidance alone; in the last 30 patients, 3D/4D ICE reconstruction (TomTec Imaging Systems) 6mbH was obtained. In 30 cases, ICE and contrast enhanced-TCD have been used simultaneously in the catheterization laboratory. The devices were placed correctly in all patients. Mean fluoroscopy time was 9.45 +/- 5 minutes (range = 2.5-35 minutes); mean procedural time was 57 +/- 21 minutes (range = 15-135 minutes). Total occlusion rate at follow-up (mean 19 months, range 1-33) was 98.1%. No significant recurrent neurological events were observed. Transcatheter closure of PFO with or without ASA is a safe and effective, minimally invasive procedure that ensures high closure rate and avoids life-long anticoagulation. Mid-term follow-up results appear favorable with respect to recurrent thromboembolic events.

Transcranial Doppler (TCD) is a very sensitive tool for detecting microembolic signals (MES) in the brain vessels after injection of air-mixed saline in case of right-to-left shunt (RLS). Patent foramen ovale (PFO) can be found in nearly one-half of migraineurs with aura, and, reciprocally, the prevalence of migraine in patients with stroke with PFO is exceedingly high. We aimed to monitor the passage of MES in the brain vessels during transcatheter closure of PFO and to subsequently follow-up patients for both the efficacy of the procedure and the severity of migraine. Seventeen patients suffering from migraine with aura (MA+, n = 8) or without aura (MA-, n = 9) scheduled to undergo transcatheter closure of PFO with Amplatzer PFO occluder devices for paradoxical cerebral embolism were monitored with contrast TCD (DWL, Germany) before, during, and after the procedure to estimate the magnitude of the shunt. Spontaneous embolization to the brain was also recorded. The patients were thereafter followed-up at 1, 3, and 6 months. A composite score of migraine severity, which included frequency, duration, and intensity of the attacks in the previous 3 months (range 0-10), was obtained at the time of the procedure and at the follow-up visits. Complete occlusion of PFO was achieved in all patients after 1 month in most cases. Preoperatively, the migraine score was 6.75 in MA+ and was 6 in MA--patients. After closure, the score dropped to 2.5 in MA+ and to 4.2 in MA--patients at the 6-month follow-up visit, the difference being statistically highly significant in both groups. Overall, 5 of 17 patients no longer complained of migraine, 10 of 17 were substantially improved, and two of 17 were unchanged at 6 months. Migraine aura disappeared in six of eight patients. Closure rate was very satisfactory, from a preoperative average bubble count of 42 to an average of 4 bubbles in the four patients in whom a small residual shunt was still detectable at the 6-month follow-up visit. TCD monitoring provides the most accurate assessment of RLS at the brain level. Closure of PFO with transcatheter devices results in the substantial relief of migraine in patients with stroke with large RLS.

0157:H7 is a known etiologic agent of hemorrhagic colitis. The clinical and histologic picture of colitis is largely similar to that of ischemic colitis, with areas of submucosal hemorrhage and edema, erosions, and ulcerations. We present a case report and review of the literature. A 52-year-old HIV-positive man, in apparently good immunologic condition, developed severe hemorrhagic colitis characterized by the onset of multiple colonic perforations and an unfavorable outcome. The diagnosis of 0157:H7 colitis should therefore be considered in all patients with indeterminate hematic diarrhea. Further studies are warranted to verify whether HIV infection may play a determinant role in the clinical course of 0157:H7 infection.

The first report of soybean stem canker (SSC) caused by Diaporthe phaseolorum var. caulivora in South America was published in 2001, and was based on an isolate obtained in 1999 at Oliveros, Santa Fe (32°33'S, 60°51'W), Argentina (2). During the 2001 to 2002 growing season, isolates of D. phaseolorum var. caulivora were obtained from stems of field-grown soybeans (Glycine max L.) exhibiting SSC symptoms. Isolates were collected in three localities of the main soybean-producing region of Argentina: Marcos Juárez, Córdoba (32°66'S, 62°10'W); Salto, Buenos Aires (34°20'S, 60°33'W); and Diego de Alvear, Santa Fe (34°21'S, 62°10'W), and disease incidence in the fields was 10 to 60%, 5 to 15%, and 10 to 20%, respectively. The pathogen was isolated on potato glucose agar acidified with 0.2% lactic acid cultured in the dark at 25 ± 1°C. White colonies with compact and tufted mycelium were produced and turned yellow and light tan after 6 days. Appressed and fluffy mycelia were observed in old cultures. Stromata (2 mm diameter) were produced but pycnidia were not detected. After 20 days in culture at 25 ± 1°C under a 12-h light and 12-h dark regime, clustered perithecia developed on stem segments. For each isolate, 10 perithecia, 90 asci, and 30 bicellular, biguttulate ascospores were measured. Averages of asci length and width were 28.3 ± 2.3 and 5.9 ± 0.7 μm, respectively. Averages of ascospores mean length and width were 8.4 ± 0.6 and 2.5 ± 0.4 μm, respectively. These measures were similar to the measures obtained previously (2). Based on these features, the new isolates were classified as D. phaseolorum var. caulivora (Athow & Caldwell). Clustered perithecia, smaller asci and ascospores, and the development of fluffy mycelia with age were the main characteristics that distinguished D. phaseolorum var. caulivora from D. phaseolorum var. meridionalis (1). Pathogenicity trials were performed on cvs. Tracy M, Crockett, Hutchenson, and RA 702 in the greenhouse by placing a small amount of mycelium in soybean seedling hypocotyls wounds made with a scalpel. The pathogen was reisolated from stem portions of the symptomatic plants. Control plants remained healthy. The results reported here show that D. phaseolorum var. caulivora is widely disseminated in the main soybean-producing region of Argentina, where it coexists with D. phaseolorum var. meridionalis (2). The coexistence of both varieties indicates pathogen variability in the region is higher than previously recognized. References: (1) R. N. Pioli et al. Plant Dis. 83:1071, 1999. (2) R. N. Pioli et al. Plant Dis. 85:95, 2001.

Background: The use of the ultrasonically activated scalpel (UAS) for vessel closure has attained widespread acceptance in many surgical fields. The aim of our study was to investigate the electron microscopic changes to the blood vessels after the application of UAS., Methods: We collected 10 arterial and 10 venous segments from vessels that had previously been closed by UAS during abdominal operations. The samples were then prepared for ultramicroscopic analysis. Pathological changes in the lumen and the three wall layers of the blood vessel were examined under scanning and transmission electron microscopy., Results: All of the vessel segments showed similar changes: the presence of a blood clot, endothelial cell condensation, coagulative necrosis of the wall, and charring of the vessel at its tip. The edge of the cut vessel were closed by the coagulation bond, which was tied up by collagen fibrils escaped from denaturation., Conclusion: When ultrasonic energy is applied to tissues, it changes their structure so as to make a new extracellular matrix.

Purpose: Hemorrhoids and rectal diseases are very frequent in HIV-positive patients, especially in those with homosexual habits. This study was designed to compare posthemorrhoidectomy healing time in such patients, and evaluate the role of various factors related to their HIV-positive status., Methods: The study involved a prospective series of 48 male patients (32 HIV-seropositive and 16 with acquired immunodeficiency syndrome) who underwent hemorrhoidectomy between 1992 and 1996; 20 age-matched and gender-matched seronegative patients were retrospectively identified as controls. Healing times, postoperative complications, and wound infections were recorded, and the delaying effect of CD4+, Karnofsky Index scores, and HIV-ribonucleic acid were evaluated. Between-group differences were analyzed using Cox's model, Student's t-test, chi-squared test, and Fisher's exact probability test. P values of <0.05 were considered statistically significant., Results: Cox's model revealed that HIV positivity and the presence of acquired immunodeficiency syndrome significantly delayed wound healing, which also correlated with the presence of infection. The healing rate in HIV-positive patients was 66 percent after 14 weeks and 100 percent after 32 weeks; the corresponding figures for patients with acquired immunodeficiency syndrome were 0 and 50 percent. All of the controls were healed after 14 weeks (P < 0.01 vs. both the patients with acquired immunodeficiency syndrome and HIV+ patients). Centers for Disease Control and Prevention HIV-positive status (including CD4+ counts) and the performance status proved to be of prognostic value., Conclusions: Our data suggest that the indications for hemorrhoidectomy in patients with acquired immunodeficiency syndrome need to be considered extremely carefully because of the high incidence of delayed wound healing.

The purpose of this paper is to report the clinical characteristics and treatment outcome following different therapeutic approaches in a large series of patients with primary low-grade MALT lymphoma of the stomach. A total of ninety-three patients (median age 63 years) were reviewed. The patients were treated by different modalities (local treatment alone, combined treatment, chemotherapy, antibiotics alone); seven patients refused any treatment. The antibiotic-treated group of patients was prospectively followed with regular endoscopic biopsies, and their responses were histologically evaluated. The 5-years projected overall survival is 82% (95% C.I.; 67%-91%) in the series as a whole. Second tumors were observed in 21.5% of the patients in this series (95% CI 14%v to 31%). There was no apparent difference in overall survival and event-free survival between patients who received different treatments. In the antibiotic-treated group histologic regression of MALT lymphoma was documented in 67% of patients (95% CI 51% to 80%). In conclusion the indolent nature of the disease justifies a conservative approach. The use of antibiotics as first-line therapy may avert or at least postpone the indication for surgical resection in the majority of patients.

Pneumocystis carinii is a common cause of interstitial pneumonitis in AIDS patients: it affects 85% of patients with cell-mediated immunodeficiencies. Extrapulmonary infection is much more infrequent and it is observed only in these patients who receive aerosolized pentamidine prophylaxis because of minimal systemic distribution of the drug. No case of extrapulmonary disease was observed in patients receiving systemic prophylaxis for Pneumocystis carinii with cotrimoxazole. The pathogenesis of extrapulmonary infection is not clear: it is probably connected with hematogenous or lymphatic dissemination from the lung. In a small number of case is due to reactivation of extrapulmonary foci or to a new infection. The management of disseminated infection of Pneumocystis carinii is medical: only recently a combination of medical and surgical approach was proposed for a patient with extrapulmonary infection. We report a case of 29 years old patient with AIDS with a demonstrated pulmonary and splenic localisation of pneumocystis carinii submitted to surgical splenectomy. The surgical decision was taken for several reasons: no response to medical therapy, the relative good general condition of the patient despite the immunological status, the presence of thrombocytopenia and abdominal pain in the left upper quadrant, and the risk of rupture of spleen. The post-operative course was eventful. We support splenectomy for splenic infection of Pneumocystis carinii in very small selected cases and only with palliative intent.

The low-affinity nerve growth factor receptor p75NTR belongs to a membrane receptor superfamily whose members, in certain cell types, are able to transduce an apoptotic signal. To investigate the effect of p75NTR expression in neuroblastoma cells, we transfected the p75NTR cDNA into SK-N-BE cells, a neuroblastoma cell line that lacks expression of both p75NTR and TrkA. Cell clones expressing elevated levels of p75NTR showed a high degree of cell death by apoptosis, even in serum-supplemented medium. Moreover, the level of apoptosis correlated directly with the expression level of the receptor, indicating that p75NTR could activate the cell death program by itself. Clones expressing p75NTR showed a dramatic increase of cell death when switched into serum-free medium; these cultures rapidly extinguished. This apoptotic effect was greatly inhibited by NGF treatment. Our results support the hypothesis that p75NTR, when it is not bound by NGF, may play a role in neuronal selection during embryonic development and suggest that neuroblastomas may arise from immature neuroblasts that escape programmed cell death. Therefore, the loss of p75NTR expression in developing neural crest cells might be a primary event in the genesis of neuroblastoma.

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are abundant nuclear polypeptides, most likely involved in different steps of pre-mRNA processing. Protein A1 (34 kDa), a prominent member of the hnRNP family, seems to act by modulating the RNA secondary structure and by antagonizing some splicing factors (SR proteins) in splice-site selection and exon skipping/inclusion. A role of A1 in the nucleo-cytoplasmic transport of RNA has also been proposed. These activities might depend not only on the RNA-binding properties of the protein but also on specific protein-protein interactions. Here we report that A1 can indeed selectively interact, in vitro, both with itself and with other hnRNP basic "core" proteins. Such selective binding is mediated exclusively by the Gly-rich C-terminal domain, where a novel protein-binding motif constituted by hydrophobic repeats can be envisaged. The same domain is necessary and sufficient to promote specific interaction in vivo, as assayed by the yeast two-hybrid assay. Moreover, an in vitro interaction with some SR proteins was also observed. These observations suggest that diverse and specific protein-protein interactions might contribute to the different functions of the hnRNP A1 protein in mRNA maturation.

In 1984 we started a prospective controlled trial comparing endoscopic sclerotherapy (ES) with the distal splenorenal shunt (DSRS) in the elective treatment of variceal hemorrhage in cirrhotic patients. The study population included 40 patients with cirrhosis and portal hypertension referred to our department from October 1984 to March 1988. These patients were drawn from a pool of 173 patients who underwent either elective surgery or endoscopic sclerotherapy during this time. Patients were assigned to one of the two groups according to a random-number table: 20 to DSRS and 20 to ES. During the postoperative period, no DSRS patient died, while one ES patient died of uncontrolled hemorrhage. One DSRS patient had mild recurrent variceal hemorrhage despite an angiographically patent DSRS. Four ES patients suffered at least one episode of gastrointestinal bleeding: two from varices and two from esophageal ulcerations. Five ES patients developed transitory dysphagia. Long-term follow-up was complete in all patients. Two-year survival rates for shunt (95%) and ES (90%) groups were similar. One DSRS patient rebled from duodenal ulcer, while three ES patients had recurrent bleeding from esophagogastric sources (two from varices and one from hypertensive gastropathy). One DSRS and two ES patients have evolved a mild chronic encephalopathy; four DSRS and two ES patients suffered at least one episode of acute encephalopathy. Two ES patients had esophageal stenoses, which were successfully dilated. Preliminary data from this trial seem to indicate that DSRS, in a subgroup of patients with good liver function and a correct portal-azygos disconnection, more effectively prevents variceal rebleeding than ES. However no significant difference in the survival of the two treatment groups was noted.

A procedure is described for the efficient production of insulin-specific monoclonal antibodies, which involves primary and secondary immunization of BALB/c mice in the hind footpads with bovine or porcine insulin and fusion of lymphocytes from popliteal lymph nodes with a P3x63 murine myeloma line. With this protocol, over 200 positive hybrids were obtained from four separate fusions. Dissociation constants of 31 purified monoclonals, cross-reacting with human insulin, were determined by two different methods and ranged between 4 X 10(-10) and 2 X 10(-6) mol/l. 24 monoclonals were biotinylated, paired in all possible combinations and tested by ELISA for their capacity to simultaneously bind to human insulin in a two-site assay. More than 40 monoclonal pairs were found which formed a sandwich with the hormone. The development of a simple and rapid one-step enzyme immunoassay is described, which involves a first monoclonal bound to the wells of a microtiter plate and a second monoclonal conjugated to alkaline phosphatase. With this assay, insulin can be determined in a range between 0.08 and 7.5 ng/ml in 3-4 h.

Although immunosuppressive treatment with corticosteroids and azathioprine has become a widely employed and highly effective mode of therapy in a variety of conditions, its influence on cellular and humoral immunity is still somewhat intriguing and controversial. In order to further investigate the status of the immune system during various maintenance immunosuppressive treatments, we have studied a group of 32 long term survivors of kidney transplantation who were treated with different immunosuppressive regimens. The present investigation demonstrates the presence of a persistent defect of T and B peripheral lymphocytes in long term kidney transplant recipients. Moreover, it shows that the immune deficits are influenced by the time-dose schedule of the maintenance immunosuppressive therapy but not by the duration of the treatment. In particular methylprednisolone in a daily dose schedule (8 mg per day as a single oral dose in the morning) with or without azathioprine (1.5-3 mg/kg per day as a single oral dose in the morning) produces a global defect of T and B cell populations, while the same dosage of methylprednisolone administered every other day (16 mg every other day as a single oral dose in the morning) in association with daily doses of azathioprine exerts a sparing effect on T cell populations. The humoral parameters do not show definite abnormalities. The factors that may have contributed to the genesis of the immune imbalances we have detected are discussed.

To define the effect of different immunosuppressive treatments on survival of long-term kidney transplant recipients, we have followed, for a period of four years, a group of 18 long-term survivors (more than three years) of kidney transplantation who were subjected to two different corticosteroid regimens (daily or alternate day corticosteroids) plus azathioprine. THis study not only confirms that an alternate day corticosteroid treatment reduces the incidence of infectious episodes and of side effects, but also suggests that it may steadily improve the survival of these patients. One of the six patients who performed an alternate day corticosteroid regimen died and only one lost renal graft function. On the contrary, three of the twelve patients who received daily corticosteroids died of causes related to immunosuppressive treatment, while another five patients lost renal graft function. A very low level of peripheral blood lymphocytes, of early E rosette and E rosette-forming cells was detected in patients who died of causes related to immunosuppressive treatment.