Sensor Noise in LISA Pathfinder: In-Flight Performance of the Optical Test Mass Readout.

We report on the first subpicometer interferometer flown in space. It was part of ESA's Laser Interferometer Space Antenna (LISA) Pathfinder mission and performed the fundamental measurement of the positional and angular motion of two free-falling test masses. The interferometer worked immediately, stably, and reliably from switch on until the end of the mission with exceptionally low residual noise of 32.0_{-1.7}^{+2.4} fm/sqrt[Hz], significantly better than required. We present an upper limit for the sensor performance at millihertz frequencies and a model for the measured sensitivity above 200 mHz.

LISA Pathfinder Performance Confirmed in an Open-Loop Configuration: Results from the Free-Fall Actuation Mode.

We report on the results of the LISA Pathfinder (LPF) free-fall mode experiment, in which the control force needed to compensate the quasistatic differential force acting on two test masses is applied intermittently as a series of "impulse" forces lasting a few seconds and separated by roughly 350 s periods of true free fall. This represents an alternative to the normal LPF mode of operation in which this balancing force is applied continuously, with the advantage that the acceleration noise during free fall is measured in the absence of the actuation force, thus eliminating associated noise and force calibration errors. The differential acceleration noise measurement presented here with the free-fall mode agrees with noise measured with the continuous actuation scheme, representing an important and independent confirmation of the LPF result. An additional measurement with larger actuation forces also shows that the technique can be used to eliminate actuation noise when this is a dominant factor.

MpMRI of the prostate: is there a role for semi-quantitative analysis of DCE-MRI and late gadolinium enhancement in the characterisation of prostate cancer?

AIM: To assess whether there is a significant difference in perfusion parameters between benign and malignant prostatic lesions, focusing on semi-quantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and presence of late gadolinium enhancement (LGE). MATERIAL AND METHODS: Three hundred and thirteen patients who underwent multiparametric MRI (mpMRI) of the prostate and with available corresponding histology (prostatectomy or biopsy) were selected retrospectively for this study. The MRI protocol consisted of multiplanar T2-and diffusion-weighted imaging, DCE and delayed axial T1 images. Images were reviewed independently by two radiologists for LGE assessment and Prostate Imaging - Reporting and Data System (PI-RADS) scoring. For each lesion, semi-quantitative analysis of DCE-MRI was performed and the following data were evaluated: time to peak, wash-in rate, wash-out rate, brevity of enhancement, and area under the curve. The presence or absence of LGE in delayed axial T1 images was assessed qualitatively. MRI results were compared to histology. The presence of significant prostate cancer was based both on Epstein criteria (SPC) and Gleason score (GS ≥7). RESULTS: SPC and Gleason score ≥7 tumours showed significant lower time to peak and brevity of enhancement (p<0.001) with higher wash-in rate (p=0.001). LGE was observed in 152/313 (49%) cases; among them 103/152 (68%) did not show SPC whereas 49/152 (32%) had SPC (p<0.001). The presence of LGE determined a risk reduction of SPC resulting as an independent predictor at multivariate analysis (logOR=-0.78, SE 0.33, p=0.02). CONCLUSION: Semi-quantitative perfusion analysis and LGE may help to predict the presence/absence of a significant prostate tumour and represent a promising tool to improve mpMRI diagnostic performance.

Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 µHz.

In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 µHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05) fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10 fm s^{-2}/sqrt[Hz] at 20 µHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.

Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder.

We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0 fm s^{-2} Hz^{-1/2} across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results.

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1 fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15} g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3) fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5 mHz we observe a low-frequency tail that stays below 12 fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

GastroPanel® test for non-invasive diagnosis of atrophic gastritis in patients with dyspepsia.

AIM: Atrophic gastritis (AG), first step in the cascade leading to gastric adenocarcinoma, is related to Helicobacter pylori (H. pylori) infection. Currently, the gold standard for the diagnosis of AG is esophagogastroduodenoscopy (EGD) with histological examination of the biopsy specimens. However, since the latter are taken in random order and the distribution of AG is often patchy, histology is only representative of mucosal status. Considering this limitation, a test named GastroPanel®, that measures the blood concentrations of pepsinogen I and II, gastrin-17 and H. pylori antibodies, has been developed as a potential non-invasive biopsy. Aim of this study has been to assess the accuracy of GastroPanel® in patients with AG. METHODS: Forty-seven dyspeptic patients (24 males, mean age 52.2±9.3 years), in follow-up for antral or diffuse AG, were enrolled. All underwent at least two EGDs with random biopsies and blood collection for GastroPanel® parameters examination. RESULTS: Of the 47 patients, 16 (34.1%) had histological diagnosis of antral and 31 (65.9%) multifocal AG; 17 (36.2%) patients had mild and 30 (63.8%) had moderate-severe AG. H. pylori was detected in 39 (82.9%) and intestinal metaplasia was found in all patients. GastroPanel® showed 82.9% sensitivity for the diagnosis of AG and 53.8% for the diagnosis of H. pylori infection. The prediction of advanced atrophy was not sufficiently accurate, neither in patients with antral nor in those with multifocal AG. CONCLUSION: GastroPanel® can be useful for detecting patients with AG. However, it does not reflect the severity of atrophy.

Hymovis MO.RE. in the treatment of knee and ankle chondropathy in elite athletes: preliminary results of the CHAMPS (Cohort study about HYADD4-G Administration for Pain relief on Soccer players) prospective clinical study.

OBJECTIVE: This study evaluated single intra-articular injections of Hymovis MO.RE., a hyaluronic acid hexadecyl derivative (HYADD4-G), to manage post-traumatic or degenerative knee or ankle chondropathy in professional soccer players. PATIENTS AND METHODS: Twenty-five players affected by knee (n = 12) or ankle (n = 13) chondropathy were prospectively enrolled and treated by two single Hymovis MO.RE. (32 mg/4 ml) injections at the beginning of the football season (V0, baseline) and at mid-season (V1, 19-20 weeks thereafter), and were followed-up until the end of the season (V2, after further 19-20 weeks). Knee cases were evaluated using the 2000 IKDC knee subjective examination form and the modified Lysholm scoring system. Ankle cases were evaluated using the American Orthopaedic Foot Ankle Society (AOFAS) ankle-hindfoot score. Patients were also evaluated using a VAS Likert scale and a four-category scale recording both the patient's and the doctor's assessment on joint mobility in degrees and overall treatment efficacy. Adverse events, patient withdrawals and local reaction to injections were also assessed. RESULTS: In knee patients, the 2000 IKDC subjective score improved from 46.8 ± 11.4 at V0 to 83.1 ± 12.5 at V2. Their modified Lysholm score improved from 58.8 ± 8.9 at V0 to 90.6 ± 8.3 at V2. In the ankle patients, the AOFAS score improved from 52.2 ± 5.6 at V0 to 96.4 ± 4.5 at V2. VAS Likert values and subjective evaluations improved at V1 and were maintained at V2. No side effects were recorded. CONCLUSIONS: A single Hymovis MO.RE. (32 mg/4 ml) intra-articular injection, repeated after 19-20 weeks, may be a viable option to improve symptoms and function in professional soccer players suffering from knee and ankle chondropathy.

Attentional networks efficiency in preterm children.

Recent studies have reported specific executive and attentional deficits in preterm children. However, the majority of this research has used multidetermined tasks to assess these abilities, and the interpretation of the results lacks an explicit theoretical backdrop to better understand the origin of the difficulties observed. In the present study, we used the Child Attention Network Task (Child ANT; Rueda et al. 2004) to assess the efficiency of the alerting, orienting and executive control networks. We compared the performance of 25 preterm children (gestational age < or = 32 weeks) to 25 full-term children, all between 5(1/2) and 6(1/2) years of age. Results showed that, as compared to full-term children, preterm children were slower on all conditions of the Child ANT and had a specific deficit in executive control abilities. We also observed a significantly higher correlation between the orienting and executive control networks in the preterm group, suggesting less differentiation of these two networks in this population.

Analysis of the accuracy of actuation electronics in the laser interferometer space antenna pathfinder.

The Laser Interferometer Space Antenna Pathfinder (LPF) main observable, labeled Δg, is the differential force per unit mass acting on the two test masses under free fall conditions after the contribution of all non-gravitational forces has been compensated. At low frequencies, the differential force is compensated by an applied electrostatic actuation force, which then must be subtracted from the measured acceleration to obtain Δg. Any inaccuracy in the actuation force contaminates the residual acceleration. This study investigates the accuracy of the electrostatic actuation system and its impact on the LPF main observable. It is shown that the inaccuracy is mainly caused by the rounding errors in the waveform processing and also by the random error caused by the analog to digital converter random noise in the control loop. Both errors are one order of magnitude smaller than the resolution of the commanded voltages. We developed a simulator based on the LPF design to compute the close-to-reality actuation voltages and, consequently, the resulting actuation forces. The simulator is applied during post-processing the LPF data.

Soluble transferrin receptor values in top level soccer players and skiers: comparison with sedentary people and pitfalls of laboratory methods.

AIM: Hematological assessment is crucial in athletes: the risk of sports' anemia should be monitored with hematological parameters and iron metabolism tests. The aim of this study was to evaluate soluble transferrin receptor (sTfR) efficacy, as it is highly sensitive and specific and usually utilized in sport medicine for monitoring iron metabolism. METHODS: sTfR was studied using two immunological methods (IDeA Orion, and Biokit) on a group of professional athletes, together with hematological and iron metabolism parameters. Values have been compared with those of sedentary people, before and during competitive season. Athletes were 76 professional male soccer players plus 20 males and 14 females of the alpine ski Italian National Teams. RESULTS: The sTfR values in athletes are similar to those found in sedentary people. Different results have been observed between the two different methods: a bias of 0.37 mg/L was found comparing them. A significant correlation between sTfR and iron, transferrin saturation, and reticulocytes was found in skiers; there was no correlation with hemoglobin, erythrocytes, ferritin. In soccer players significant differences have been retrieved among different teams' distribution of data. CONCLUSIONS: The principal limit for using sTfR in sports medicine, but also in the general population, is the lack of standardization among methods. The quantitative differences in athletes between the two methods are high, although the behavior of the parameter is similar from the quality point of view. The differences between measured concentrations could influence the thresholds used in antidoping context.

Pituitary cotransplantation significantly improves the performance, insulin content, and vascularization of renal subcapsular islet grafts.

Because the pituitary contains hormones with beta-cell trophic activity, we evaluated whether cotransplantation of pituitary tissue with pancreatic islets might be beneficial for islet graft function and survival. Streptozotocin diabetic nude mice were transplanted under the kidney capsule with 150 handpicked islets alone or mixed with two diced pituitaries and were then followed for 4 weeks. Mice transplanted with mixed islet/pituitary grafts had higher levels of circulating prolactin (PRL) than mice transplanted with islets only, while serum cortisol, growth hormone, and follicle-stimulating hormone were similar in the two groups. After transplantation, recipients of mixed islet/pituitary grafts showed a more pronounced decrease in glycemic levels and higher systemic insulin levels than mice transplanted only with islets. Mixed islet/pituitary grafts were macroscopically characterized by an excellent vascularization and were biochemically characterized by higher insulin and PRL content than pure islet grafts. Histologically, posttransplantation remodeling originated a hybrid organ in which healthy, well-vascularized islets were adjacent to pituitary cell clusters. Transplantations performed to address the specific effect of the anterior versus the intermediate pituitary lobes indicated the former as responsible for the improved function of cotransplanted islets. Mixed islet/pituitary grafts composed of anterior lobes were also the best vascularized and were histologically characterized by the presence of many folliculo-stellate cells. In conclusion, we obtained evidence that pituitary cotransplantation significantly improves the function, insulin content, and vascularization of suboptimal islet grafts. Evidence suggesting that ectopically produced PRL and/or locally released angiogenic peptides might play a causal role is provided.

Antisense transcription at the TRPM2 locus as a novel prognostic marker and therapeutic target in prostate cancer.

Overwhelming evidence indicates that cancer is a genetic disease caused by the accumulation of mutations in oncogenes and tumor suppressor genes. It is also increasingly apparent, however, that cancer depends not only on mutations in these coding genes but also on alterations in the large class of non-coding RNAs. Here, we report that one such long non-coding RNA, TRPM2-AS, an antisense transcript of TRPM2, which encodes an oxidative stress-activated ion channel, is overexpressed in prostate cancer (PCa). The high expression of TRPM2-AS and its related gene signature were found to be linked to poor clinical outcome, with the related gene signature working also independently of the patient's Gleason score. Mechanistically, TRPM2-AS knockdown led to PCa cell apoptosis, with a transcriptional profile that indicated an unbearable increase in cellular stress in the dying cells, which was coupled to cell cycle arrest, an increase in intracellular hydrogen peroxide and activation of the sense TRPM2 gene. Moreover, targets of existing drugs and treatments were found to be consistently associated with high TRPM2-AS levels in both targeted cells and patients, ultimately suggesting that the measurement of the expression levels of TRPM2-AS allows not only for the early identification of aggressive PCa tumors, but also identifies a subset of at-risk patients who would benefit from currently available, but mostly differently purposed, therapeutic agents.

Insights from a successful case of intrahepatic islet transplantation into a type 1 diabetic patient.

We report a case of long-term (>4 yr) successful intrahepatic islet transplantation into a type 1 diabetic patient chronically immunosuppressed for a prior kidney graft. The exogenous insulin requirement decreased progressively after transplantation, and insulin treatment was withdrawn at 6 months. Glycosylated hemoglobin levels were in the normal range at 1 and 2 yr (5.3%) and increased slightly above the upper normal limit at 3 and 4 yr (6.3% and 6.4%). Fasting C peptide levels remained stable during the entire follow-up, but the proinsulin to insulin ratios increased dramatically at yr 3. Glycemic levels after an oral glucose tolerance test showed a diabetic profile at 1 yr, a normal profile at 2 yr, and an impaired glucose tolerance profile at 3 yr. Intravenous glucose tolerance test-induced first phase insulin release, present at 1 and 2 yr, disappeared at 3 yr. Diabetes-related autoantibodies (islet cell antibodies, glutamic acid decarboxylase antibodies, and tyrosine phosphatase-like protein antibodies) were undetectable before transplantation and remained so during the entire follow-up. The patient died of myocardial infarction 50 months after transplantation while she was still in good metabolic control (glycosylated hemoglobin, <6.8%) in the absence of exogenous insulin administration. The autoptic liver showed well granulated islets, richly vascularized and without evidence of lympho-mononuclear cell infiltration. The morphometrically extrapolated intrahepatic beta-cell mass was 99.9 mg. In conclusion, this successful islet graft showed a bell-shaped clinical effect, maximal at 2 yr after transplantation, followed by a slow progressive decline. The absence of allo- and autoreactivities against the transplanted islets points to a nonimmune-mediated beta-cell loss as the cause of graft functional deterioration.

Combination of intravesical chemotherapy and hyperthermia for the treatment of superficial bladder cancer: preliminary clinical experience.

The prevalence of superficial transitional cell carcinoma of the bladder (STCCB) is still increasing in spite of improved adjuvant chemotherapeutic and/or immunoprophylaxis approaches. Thus, there is certainly an urgent need to improve our ability to control this disease. Local hyperthermia has a therapeutical potential for the treatment of many solid tumors, especially when used in combination with other treatments, such as radiation and chemotherapy. In particular, a synergistic or, at least, supra-additive anti-tumor cell killing effect was documented when local hyperthermia was administered in combination with selected cytostatic drugs. Recently, advances in miniaturized technology have allowed the development of a system specifically designed for delivering an endovesical thermo-chemotherapy regimen in humans. In preliminary clinical experiences, insofar mainly carried out as mono-institutional investigations, the combined treatment using this system was demonstrated to be feasible, minimally invasive and safe when performed on out-patient basis. Moreover, the anti-tumoral efficacy seemed to be significantly enhanced when compared with that obtained using intravesical chemotherapy alone for both adjuvant (prophylaxis) and neo-adjuvant (ablative) approaches to superficial bladder cancer.

Prognostic significance of the histopathologic recognition of low- and high-grade components in stage I-II B-cell gastric lymphomas.

The prognostic value of histopathologic features was assessed in 83 patients with stage I-II gastric B-cell lymphomas (PGL). The following histotypes were considered: low-grade mucosa-associated lymphoid tissue (MALT)-type lymphoma (LGML; n = 35), diffuse large B-cell lymphoma with areas of MALT-type lymphoma (DLCLML; n = 20) and diffuse large B-cell lymphoma without areas of MALT-type lymphoma (DLCL; n = 28). Low-grade (LG) and high-grade (HG) components, lymphoepithelial lesions (LEL), size of cells giving rise to LEL, and amount and growth pattern of large cells (LC) were analyzed. Five-year cause-specific survival (CSS) for patients with LGML, DLCLML, and DLCL were 94%, 84%, and 64%, respectively (p = 0.05). LG component or LEL were associated with a significantly longer 5-year CSS, whereas the presence of an HG component, defined as clustered LC greater than 10% of neoplastic population, was significantly related to a shorter survival. Lymphomas with LC disposed in clusters were associated with a worse survival in comparison with cases with scattered LC. The presence of scattered LC 5%-10% appeared irrelevant in LGML. When analysis was limited to DLCLML/ DLCL patients, the presence of LG component or LEL was associated with a significantly longer 5-year CSS, whereas the existence of LEL formed by LC (HG LEL) did not modify survival. Multivariate analysis, adjusted by the main prognostic factors, confirmed the independent and significant association between histopathologic categorization and survival. Age, stage, lactate dehydrogenase (LDH) ratio, thrombocytopenia, and use of chemotherapy had independent prognostic value. In conclusion, histopathologic categorization is an independent prognosticator in PGL. The formation of compact clusters by LC, rather than their amount, is a true prognostic variable. The presence of scattered LC 5%-10% appears irrelevant in LGML. LG component and LEL are favorable predictors in HG lymphomas, helping to identify two subsets of DLCL with different prognosis.

Paradoxical release of insulin by adult pig islets in vitro. Recovery after culture in a defined tissue culture medium.

In this study, in vitro responsiveness to glucose of fresh and cultured islets from adult pigs was tested under both static (incubation) and dynamic (perifusion) conditions. Islets were isolated by an automated method from pancreases of 24-month-old animals and cultured overnight in CMRL 1066 and 10% FCS plus antibiotics; islets, perifused immediately after the overnight culture, showed a paradoxical decrease in insulin release when exposed to an acute glucose stimulus (16.7 mmol/L), and a normal response to acute glucose when isobutylmethylxanthine (IBMX) was added to the perifusing buffer. In addition, an acute reduction of glucose concentration in the perifusate elicited a paradoxical insulin release. At the microscope, islets appeared loose and irregularly shaped after the overnight culture; immunohistochemistry showed loss of peripheral A and other mantle cells. After the overnight culture, islets were divided into 5 groups and were cultured for a further 48 hr in different tissue culture media: CMRL 1066; RPMI 1640 (without glucose); RPMI 1640 (plus 11.1 mmol/L glucose); Ham's F12; and medium 199 (all media were supplemented with 10% FCS and antibiotics). During this period, insulin release was 11.4 +/- 1.1 pg/islet/min in islets cultured in CMRL 1066, 16.2 +/- 2.4 in islets cultured in RPMI 1640 (11.1 mmol/L glucose), 1.8 +/- 0.2 (P < 0.001 vs. all the other groups), and 9.0 +/- 0.6 and 8.4 +/- 0.9 pg/islet/min in islets cultured in RPMI 1640 (without glucose), Ham's F12, and medium 199, respectively. After the 48-hr culture in different media, the islets' responsiveness to an acute glucose stimulus (16.7 mmol/L; static incubation) was evaluated: islets cultured in CMRL 1066 and in RPMI 1640 (with and without glucose) showed no insulin response to the acute glucose stimulus; in contrast, insulin release rose from 0.42 +/- 0.06 to 0.60 +/- 0.12 pg/islet/min (NS) in islets cultured in Ham's F12, and from 0.24 +/- 0.06 to 0.48 +/- 0.06 pg/islet/min (P < 0.001) in islets cultured in medium 199. During perifusions, the paradoxical insulin release in response to an acute fall in glucose concentration disappeared, but a significant increase in response to high (16.7 mmol/L) glucose was observed only in islets previously cultured in medium 199. To assess the possible role of glucagon and of cAMP, additional perifusions were done in islets cultured for 48 hr in CMRL 1066 in the presence of glucagon (10 mumol/L) and IBMX (10 mumol/L); glucagon and IBMX were unable to modify the insulin response to 16.7 mmol/L glucose.(ABSTRACT TRUNCATED AT 400 WORDS)

Glucagon improves insulin secretion from pig islets in vitro.

It has been shown that peripheral glucagon secreting cells (A-cells) are lost during most of the isolation procedures employed for pig islets. Loss of A-cells decreases intra-islet glucagon levels and cAMP levels in B-cells and might reduce glucose-induced insulin release. This study was designed to test this hypothesis, by evaluating the effects of culture of porcine islets with exogenous glucagon on insulin secretion and on insulin and cAMP content in islets. Islets were isolated from adult 2-year old Large White pigs using an automated method. The number of A-cells was calculated by immunostaining for glucagon in islets before and after isolation and a significant decrease in A-cells was observed. After an overnight culture, islets were cultured for 48 h in a standard medium (CMRL 1066, 10% foetal calf serum, 1% antibiotics, 1% glutamine) alone or in the presence of glucagon at two different concentrations (1.0 and 10.0 microM); exposure to glucagon was either continuous or alternated with periods of incubation in CMRL 1066 alone. After the 48-h culture in standard medium, the islet glucagon response to arginine was almost negligible and significantly lower than that observed in human islets.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-secreting pituitary GH3 cells: a potential beta-cell surrogate for diabetes cell therapy.

In a companion article, we describe the engineering and characterization of pituitary GH3 cell clones stably transfected with a furin-cleavable human insulin cDNA (InsGH3 cells). This article describes the performance of InsGH3 (clones 1 and 7) cell grafts into streptozotocin (STZ)-induced diabetic nude mice. Subcutaneous implantation of 2 x 10(6) InsGH3 cells resulted in the progressive reversal of hyperglycemia and diabetic symptoms, even though the progressive growth of the transplanted cells (clone 7) eventually led to glycemic levels below the normal mouse range. Proinsulin transgene expression was maintained in harvested InsGH3 grafts that, conversely, lose the expression of the prolactin (PRL) gene. Elevated concentrations of circulating mature human insulin were detected in graft recipients, demonstrating that proinsulin processing by InsGH3 cells did occur in vivo. Histologic analysis showed that transplanted InsGH3 grew in forms of encapsulated tumors composed of cells with small cytoplasms weakly stained for the presence of insulin. Conversely, intense insulin immunoreactivity was detected in graft-draining venules. Compared to pancreatic betaTC3 cells, InsGH3 cells showed in vitro a higher rate of replication, an elevate resistance to apoptosis induced by serum deprivation and proinflammatory cytokines, and significantly higher antiapoptotic Bcl-2 protein levels. Moreover, InsGH3 cells were resistant to the streptozotocin toxicity that, in contrast, reduced betaTC3 cell viability to 50-60% of controls. In conclusion, proinsulin gene expression and mature insulin secretion persisted in transplanted InsGH3 cells that reversed hyperglycemia in vivo. InsGH3 cells might represent a potential beta-cell surrogate because they are more resistant than pancreatic beta cells to different apoptotic insults and might therefore be particularly suitable for encapsulation.