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Objectives: To evaluate associations of preoperative total prostate specific antigen (PSA) to free testosterone (FT), the PSA/FT index ratio, with features of pathology prostate cancer (PCA) and to investigate its prognostic potential in clustering the PCA population. Patients and methods: After excluding criteria, the records of 220 patients who underwent radical prostatectomy (RP) were retrospectively reviewed. Serum samples of PSA, total testosterone (TT) and FT were collected at 8.00 A.M., one month after biopsies and before RP. The PSA/FT ratio was computed in the population of patients who were clustered in groups according to ranking intervals of the PSA/FT ratio which identified at least 4 clusters which were coded as A, B, C, and D. The independent associations of the PSA/FT index ratio were assessed by statistical methods and a two-sided P < 0.05 was considered to indicate statistical significance. Results: TT correlated to FT which was a significant predictor of PSA in the population of patients who were subsequently clustered, according to increasing interval values of the PSA/FT index ratio, in groups that showed a stronger linear association of FT with PSA. The PSA/FT index ratio significantly associated with pathology features of prostate cancer such as pathology Gleason score (pGS), invasion of the seminal vesicles (pT3b), proportion of positive cores (P+) and proportion of cancer involving the volume of the prostate. In the population of patients, TT, PSA/FT index ratio and P+ independently associated with pGS ≥ 7 and pT3b; moreover, the odds ratio (OR) of the PSA/FT index ratio resulted 9.11 which was stronger than TT (OR = 1.11) and P+ (OR = 8.84). In the PCA population, TT, PSA/FT index ratio and P+ also independently associated with pT3b PCA; interestingly, the OR of PSA/FT index resulted 54.91 which was stronger than TT (OR = 1.31) and P+ (26.43). Conclusions: Preoperative PSA/FT index ratio is an independent strong factor which directly associates with aggressive features of pathology PCA; moreover, it might express prognostic potential for clustering the patient population in risk classes. Confirmatory studies are required.

Aldosterone and renin measurement is a cornerstone for primary aldosteronism (PA) diagnosis, but different thresholds are used according to different assays. A fully automated chemiluminescence (CL) immunoassay for renin and aldosterone was recently proposed, showing good performance for PA screening by aldosterone to renin ratio (ARR). This study aimed to define the accuracy of this assay in the screening and in the most popular confirmatory test of autonomous aldosterone production, the intravenous saline loading test (ivSLT). We compared aldosterone results obtained by CL vs radioimmunoassay (RIA) in hypertensive patients investigated for PA (102 baseline and 85 after ivSLT). An excellent correlation was observed between RIA and CL in the entire population for aldosterone (r=0.922) and ARR (r=0.977). For ARR, Deming regression proved a good accordance between methods and, consistent with the fit model, our previous institutional ARR cut-off of 32 (pg ml−1)/(pg ml−1) corresponded to 20 pg ml−1 mU−1 l−1 in CL assay. However, the correlation was weaker in the low end of aldosterone concentrations (r=0.676 for aldosterone

Background and Objective: Prostate cancer is an endocrine-dependent tumor which is still under-investigated for physiopathology factors related to its natural history. The association of pretreatment total testosterone (TT) serum levels with prostate cancer is still a controversial topic. The objective of this study was to investigate potential associations and functional relationships of preoperative TT serum level and pathology-detected Gleason score (pGS). Materials and Methods: Pretreatment and pathological variables of 220 patients operated with radical prostatectomy were retrospectively reviewed. Age, prostate-specific antigen (PSA), percentage of positive biopsy cores (P+), biopsy Gleason score (bGS), pGS, TT and free testosterone were the continuous variables, while clinical stage (cT: cT1c, cT2/3), biopsy Gleason pattern (bGP: ≤3+3, 3+4, >3+4), pathology Gleason pattern (pGP: ≤3+3, 3+4, >3+4), pathology stage (pT: pT2, pT3a, pT3b), pathology nodal staging (pN: pN0, pN1, pNx) and surgical margin invasion by cancer (R-, R+) were the categorical variables. Statistical methods were computed for assessing associations of TT and pGS; moreover, simple and multiple linear regression analysis (SLRA and MLRA) were used for assessing functional relationships of TT and pGS. Results: High-grade tumors (pGS ≥8.0) were associated with bGS >6.0 (p < 0.0001), pGP ≥3+4 (p < 0.0001), P+ >0.31% (p = 0.006), cT2/3 (p = 0.01), TT >15.5 nmol/l (p = 0.0004) and, to a lesser extent, PSA >6.27 μg/l (p = 0.06). The odds ratio (OR) ranked as follows: 2.01 (PSA >6.27 μg/l), 2.88 (cT2/3), 3.23 (P+ >0.31%), 5.53 (TT >15.5 nmol/l) and 12.09 (pGP ≥3+4 and pGS ≥8.0). On SLRA, pGS variation was significantly predicted by bGS (p < 0.0001), P+ (p < 0.0001), PSA (p = 0.0005) and TT (p = 0.02); on MLRA, pGS variation was still significantly predicted by bGS (p < 0.0001), P+ (p = 0.04), PSA (p = 0.03) and TT (p = 0.002). When bGS, P+, PSA and TT were dichotomized to their median value, only bGS (p < 0.0001) and TT (p = 0.001) showed independence in predicting pGS variation. The best model for predicting pGS variations was by dichotomizing TT above its median (>15.5 nmol/l) because the predictive coefficient increased to 0.32, which means that patients with TT >15.5 have a significantly higher estimated risk for high-grade pGS than patients with TT ≤15.5 nmol/l (OR = 1.31). Conclusion: In a patient population undergoing radical prostatectomy, increased pretreatment serum measurements of TT are associated with and functionally related to high-grade pGS; moreover, baseline TT together with bGS and PSA are important factors for predicting pGS and assessing high-grade tumors. Baseline TT serum levels might have prognostic potential for assessing treatment response for continuous as well as intermittent androgen deprivation therapy.

Aim: To investigate the potential of preoperative serum total testosterone (TT) in contributing to the definition of separate prostatectomy Gleason score (pGS) groups of the prostate cancer (PCa) population. Materials and Methods: The data of 220 patients operated on for PCa were retrospectively reviewed. No patient had previously received 5α-reductase inhibitor, luteinizing hormone-releasing analogs or testosterone replacement treatment. The patient population was grouped according to the pGS as 6 = 3+3, 7 = 3+4, 7 = 4+3 and 8-10. Eight variables were simultaneously investigated in each group: prostate-specific antigen (PSA), TT, free testosterone, age, percentage of positive prostate biopsy cores (P+), biopsy Gleason score (bGS), overall cancer volume estimated as percentage of prostate volume (V+) and prostate weight (Wi). Univariate analysis of variance (ANOVA), multivariate analysis of variance (MANOVA) and multivariate discriminant analysis (MDA) were the statistical methods used for evaluating the data. Results: There were 89 patients in pGS 6 = 3+3, 84 in pGS 7 = 3+4, 24 in pGS 7 = 4+3 and 23 in pGS 8-10. ANOVA showed that bGS (p < 0.0001), P+ (p < 0.0001), V+ (p < 0.0001), PSA (p = 0.0001), Wi (p = 0.0002) and TT (p = 0.01) were significantly different in the four pGS groups. MANOVA tests showed that only bGS (p < 0.0001), V+ (p = 0.0003), TT (p = 0.001) and, to a lesser extent, PSA (p = 0.06) were the significant variables that individually and independently contributed a significant amount to separation of the four pGS groups of the PCa population. MDA showed that the independent variables ranked as bGS (p < 0.0001), TT (p = 0.001), V+ (p = 0.001) and PSA (p = 0.06). Conclusions: Serum TT is a significant preoperative variable that independently contributes to separating the PCa population into pGS score groups. Pretreatment baseline serum TT levels should be measured and their inclusion in neural networks predicting PCa natural history be considered in the patient population diagnosed with PCa.

Purpose: The study aims to investigate the potential associations between preoperative plasma levels of total testosterone (TT) and biopsy Gleason score (bGS) upgrading in prostate cancer (PCA) patients undergoing radical prostatectomy (RP). Materials and Methods: Exclusion criteria were treatment with 5α-reductase inhibitors, LH-releasing hormone analogues or testosterone replacement. Criteria of bGS upgrading were as follows: (i) bGS 6 to pathological Gleason score (pGS) >6, (ii) bGS 7 with pattern 3 + 4 to pGS 7 with pattern 4 + 3 or to pGS >7, (iii) bGS 7 with pattern 4 + 3 to pGS >7. Patients who showed bGS >7 were excluded from the cohort. Results: The study included 209 patients. Tumor upgrading was assessed in 76 (36.4%) cases of the entire cohort, in 51 out of 130 cases (39.2%) of the bGS 6 group and 25 out of 79 patients (31.6%) in the bGS 7 cluster. Logistic regression models showed that independent clinical covariates predicting the risk of bGS upgrading included TT (OR 1.058; p = 0.027) and prostate-specific antigen (PSA) density (OR 23.3; p = 0.008) as well as TT (OR 1.057; p = 0.029) with PSA (OR 1.061; p = 0.023). The model suggests that 1 unit increase in TT plasma levels increases the odds of bGS upgrading by 5.8 or 5.7%. Conclusions: In summary, we have determined that high TT preoperative plasma levels independently predict bGS upgrading in men with PCA undergoing RP. Preoperative plasma levels of TT might be included as a potential marker for assessing the risk bGS upgrading.

Background The appropriate therapeutic management of patients with wasp-induced allergic reactions necessitates an accurate allergologic workup, entailing differentiation between sensitization against Vespula or Polistes venoms. Materials and methods We studied 52 consecutive adult subjects diagnosed with hypersensitivity to wasp venoms. Cap inhibition was performed using UniCAP Specific IgE. The concentration of serum IgE against two recombinant constituents of Antigen 5 (rVes v 5 and rPol d 5) was also measured using Immuno CAP 250. The ratio between values of specific IgE against recombinant allergens was calculated and a percentage difference > 50% was considered significant for specific immunization against one of the two venoms. Results The diagnostic agreement between recombinant allergens testing and CAP inhibition was 54% (kappa statistics, 0.34; 95% CI, 0.18–0.50) in the whole study population. In the 24 patients with recombinant allergens ratio > 50% and non dubious results of CAP inhibition assay the diagnostic agreement was perfect (100%; kappa of agreement, 1.00; 95% CI; 1.00–1.00). Discussion The results of this study show that the assessment of specific IgE against rVes v 5 and rPol d 5 may be regarded as a low-cost screening, providing valuable diagnostic information for differentiating the sensitization against Vespula or Polistes venoms. In patients with suggestive clinical history and ratio > 50% between specific IgE against rVes v 5 and specific IgE against and rPol d 5, the CAP inhibition assay may be safely withheld, thus allowing to achieve an early diagnosis at lower cost.

Aim: A preceding exploratory analysis has shown that follicle-stimulating hormone (FSH) was significantly correlated to and predicted by prostate-specific antigen (PSA) in a prostate cancer population. The aim of the study was to evaluate FSH physiopathology along the pituitary-testicular-prostate (PTP) axis at the time of initial diagnosis of prostate cancer in an operated population clustered according to the FSH/PSA ratio. Patients and Methods: The study included 93 patients who underwent standard radical prostatectomy. Age, percentages of positive cores at transrectal ultrasound scan biopsy (TRUSB) (P+), biopsy Gleason score (bGS), pathology Gleason score (pGS), luteinizing hormone (LH), FSH, prolactin hormone (PRL), total testosterone (TT), free testosterone (FT), estradiol (ESR) and PSA were the continuous variables. Category variables were pT and biopsy/pathology Gleason pattern I/II (b/pGPI/II). The population was clustered according to the FSH/PSA ratio which was computed from empirical data and then ranked for clustering the population as groups A (range 0.13 ≤ FSH/PSA ≤ 0.20), B (range 0.20 < FSH/PSA ≤ 0.50), C (range 0.50 < FSH/PSA ≤ 0.75), D (range 0.75 < FSH/PSA ≤ 1.00), E (range 1.00 < FSH/PSA ≤ 1.25), F (range 1.25 < FSH/PSA ≤ 2.00), G (range 2.00 < FSH/PSA ≤ 2.25), H (range 2.25 < FSH/PSA ≤ 6.40) and I (range 6.40 < FSH/ PSA ≤ 19.40). The model was assessed by simple linear regression analysis and differences between the groups were investigated by analysis of variance (ANOVA) for continuous variables and by contingency tables for category variables. Results: FSH was significantly correlated to and predicted by PSA in groups A (p = 0.04), B (p < 0.0001), C (p < 0.0001), D (p < 0.0001), E (p < 0.0001), F (p < 0.0001), G (p < 0.0001), H (p = 0.0001) and I (p = 0.001). Also, clusters (A–I) differed significantly for mean values of FSH (p < 0.0001), LH (p < 0.0001), TT (p = 0.04), PSA (p < 0.0001), bGS (p = 0.005), pGS (p = 0.01) and PSA/FT ratio (p < 0.0001); moreover, the nine groups showed significant different frequency distributions of pGPI (p = 0.02), pGPII (p = 0.0002) and bGPI (p = 0.04). Conclusion: The ranking FSH/PSA ratio significantly clustered, along the PTP axis, an operated population diagnosed with prostate cancer. Also, the ranking FSH/PSA ratio selected prostate cancer clusters expressing different levels of hormonal disorder along the PTP axis and prognostic potential with different risks of progression. As a theory, in the current advancing world, the ranking FSH/PSA model might be considered as an interesting and effective tool for prostate cancer study as well as individualized, risk-adapted approaches of the disease. However, confirmatory studies are needed.

Wheat [Triticum aestivum (T.a.)] ingestion can cause a specific allergic reaction, which is called wheat-dependent exercise-induced anaphylaxis (WDEIA). The major allergen involved is ω-5 gliadin, a gluten protein coded by genes located on the B genome. Our aim was to study the immunoreactivity of proteins in Triticum monococcum (einkorn, T.m.), a diploid ancestral wheat lacking B chromosomes, for possible use in the production of hypoallergenic foods. A total of 14 patients with a clear history of WDEIA and specific immunoglobulin E (IgE) to ω-5 gliadin were enrolled. Skin prick test (SPT) with a commercial wheat extract and an in-house T.a. gluten diagnostic solution tested positive for 43 and 100% of the cases, respectively. No reactivity in patients tested with solutions prepared from four T.m. accessions was observed. The immunoblotting of T.m. gluten proteins performed with the sera of patients showed different IgE-binding profiles with respect to T.a., confirming the absence of ω-5 gliadin. A general lower immunoreactivity of T.m. gluten proteins with scarce cross-reactivity to ω-5 gliadin epitopes was assessed by an enzyme-linked immunosorbent assay (ELISA). Given the absence of reactivity by SPT and the limited cross-reactivity with ω-5 gliadin, T.m. might represent a potential candidate in the production of hypoallergenic bakery products for patients sensitized to ω-5 gliadin. Further analyses need to be carried out regarding its safety.

Patients with Systemic Mastocytosis (SM) need a highly sensitive diagnostic test for D816V detection of the KIT receptor gene.Along with histology/cytology and flow cytometry evaluation, bone marrow (BM) from 110 consecutive adult patients referred with a suspicion of SM to Multidisciplinary Outpatient Clinic for Mastocytosis in Verona were tested both by Amplification Refractory Mutation System Reverse Transcriptase quantitative real time Polymerase Chain Reaction (ARMS-RT-qPCR) and RT-PCR. +. Restriction Fragment Length Polymorphism (RFLP) followed by Denaturing-High Performance Liquid Chromatography (D-HPLC) and Sanger sequencing.ARMS-RT-qPCR identified D816V mutation in 77 patients, corresponding to 100% of cases showing CD25+ mast cells (MCs) whereas RT-PCR+RFLP/D-HPLC+sequencing revealed D816V mutations in 47 patients.According to the 2008 WHO criteria 75 SM, 1 Cutaneous Mastocytosis (CM), 1 monoclonal MC activation syndrome (MMAS), and 1 SM Associated with Haematologic Non-Mast Cell Disorder (SM-AHNMD) were diagnosed. Seventeen out 75 SM patients (23%) would have not satisfied sufficient WHO criteria on the basis of the sole RT-PCR+RFLP: these patients had significantly lower serum tryptase levels and amount of CD25+ MCs.Therefore, ARMS-RT-qPCR might result particularly useful, in patients that do not fulfil major BM histological criterion, for the recognition of indolent SM with a very low MC burden.

Background Systemic mastocytosis (SM) may be associated with hymenoptera allergy. In such cases, immunotherapy is a life-saving treatment, but a circumstantiated diagnosis is needed for its prescription. Patients with SM and previous reactions to stings, but with negative tests represent a diagnostic dilemma. The basophil activation test (BAT) may be helpful in refining the diagnosis. Objective We assessed the usefulness of BAT in subpopulations of mastocytosis patients, including those with negative tests for insect allergy. Methods Within a population of patients with mastocytosis and previous stings, we studied by BAT and augmented intradermal test (IDT) (10 µg/ml) two groups: (1) with reactions to stings and negative tests; (2) without reactions and negative tests. Basophil activation test was performed with different venoms, assessing at flow cytometry basophils’ activation. Results Sixty-three patients had mastocytosis and 52 had reactions to previous hymenoptera stings. Of them, seven proved negative to diagnostic tests. In six of seven of those patients, BAT was negative with all venoms, and in one, basophils resulted activated also with the negative control. In six patients without previous reactions and negative tests, BAT was totally negative in five of six patients and weakly positive to Hornet in one. Finally, the IDT at 10 µg/ml venom produced nonspecific positive results in most cases. Conclusion In patients with mastocytosis, the negative results of standard tests are reliable, because BAT and IDT at higher concentration do not add useful information.

To investigate, along the pituitary- testis- prostate axis, the potential of preoperative serum TT in contributing to defining separate prostatectomy Gleason score (pGS) groups of the prostate cancer (PC) population.The data of 126 patients operated on for PC were retrospectively reviewed. No patient had previously received 5α-reductase inhibitor, luteinizing hormone (LH)-releasing hormone analogs or testosterone replacement treatment. The patient population was grouped according to the prostatectomy Gleason score (pGS) as 6=3+3, 7=3+4, 7=4+3 and 8-10. Twelve variables were simultaneously investigated in each group: age, prolactin (PRL), follicle stimulating hormone (FSH), LH, total testosterone (TT), free testosterone (FT), estradiol (Er), prostate specific antigen (PSA), percentage of prostate biopsy positive cores (P+), biopsy Gleason score (bGS), overall cancer volume estimated as percentage of prostate volume (V+) and prostate weight (Wi). Univariate analysis of variance (ANOVA), multivariate analysis of variance (MANOVA) and multivariate discriminant analysis were the statistical methods used for evaluating the data.There were 38 patients in pGS 6=3+3, 57 in pGS 7=3+4, 15 in pGS 7=4+3 and 16 in pGS 8-10. ANOVA showed that bGS (p0.0001), P+ (p0.0001), V+ (p0.0001), PSA (p=0.02), Wi (p=0.001) and TT (p=0.04) were significantly different in the four pGS groups. MANOVA tests showed that only bGS (p0.0001) and TT (p=0.005) were the significant variables that individually and independently contributed a significant amount to separation of the four pGS groups of the PC population. Multivariate discriminant analysis confirmed that TT (p=0.005) and bGS (p0.0001) were the only variables that independently and significantly contributed to separating the pGS groups.along the pituitary- testis- prostate axis, serum TT is a significant preoperative variable that independently contributes to separating the prostate cancer population into pGS score groups. Pretreatment baseline serum TT levels should be measured for their inclusion in nomograms and future neural networks to be considered in the patient population diagnosed with PC.

We systematically assessed bone mineral density (BMD), bone turnover markers (BTM), and fractures in a large cohort of patients with Indolent Systemic Mastocytosis (ISM).Eighty-two patients (mean age 48 years, 37 women) with ISM were studied. BMD was measured by dual X-ray absorptiometry at the lumbar spine and proximal hip. The serum markers of bone turnover included bone-specific alkaline phosphatase, C-telopeptides of type I collagen, and serum osteocalcin. Previous clinical fractures were registered and spine X-ray was obtained from all patients.Three women were excluded for concomitant diseases associated to osteoporosis. Osteoporosis according with the WHO classification (T-score-2.5) was found in 16 patients (20.0%) (7 females and 9 men). Mastocytosis-related low BMD (Z-score at either the spine or the hip-2) was found in 3 women (9%) and 13 men (28%). The BMD was generally lower at the spine than at the hip. No significant correlation was observed between serum tryptase levels and T or Z-score BMD. One or more moderate or severe vertebral fractures were found in 17 patients (12 men); in 11 of them Z-score values were-2 or not valuable at the spine. No significant difference was found in the prevalence of mastocytosis-related low BMD and/or vertebral fractures between patients with or without skin involvement. Two patients had radiographic and densitometric osteosclerosis-like characteristics. In osteoporotic patients higher, normal or lower serum BTM were found, without correlations with serum tryptase levels, while in patients with osteosclerosis both BTM and serum tryptase values were particularly increased.Vertebral osteoporosis and fractures are frequent in patients with ISM. Spine X-ray and densitometric examination are warranted in all patients, also without skin involvement and particularly in males; Z-score other than T-score BMD must be evaluated. Patients with idiopathic osteoporosis should be evaluated for mast cell disease. Both high than low BTM can be observed in patients with osteoporosis while osteosclerosis is characterized by high bone turnover and serum tryptase levels.

Aim: To evaluate the physiopathology of follicle-stimulating hormone (FSH) along the pituitary-testicular-prostate axis at the time of initial diagnosis of prostate cancer in relation to the available clinical variables and to the subsequent cluster selection of the patient population. Patients and Methods: The study included 98 patients who were diagnosed with prostate cancer. Age, percentages of positive cores (P+) at transrectal ultrasound scan biopsy, biopsy Gleason score (bGS), luteinizing hormone (LH), FSH, total testosterone, free testosterone (FT) and prostate-specific antigen (PSA) were the continuous clinical variables. All patients had not previously received hormonal manipulations. FSH correlation and multiple linear analyses were computed in the population. The FSH/PSA ratio was computed and then ranked for clustering the population as groups A (0.13≤FSH/PSA≤0.57), B (0.57Results: In the patient population, FSH correlated to LH (p < 0.0001), FT (p = 0.007) and age (p = 0.004). FSH was independently predicted by both LH (p < 0.0001) and PSA (p = 0.04). PSA predicted FSH/PSA A (p < 0.0001), B (p < 0.0001) and C (p = 0.04). On multiple regression analysis, FSH/PSA A was predicted by PSA (p < 0.0001), P+ (p = 0.03) and bGS (p = 0.04); FSH/PSA B by LH (p = 0.002) and PSA (p < 0.0001); FSH/PSA C by LH (p < 0.0001) and PSA (p < 0.0001). Moreover, FSH/PSA A, B and C differed for mean values of FSH (p < 0.0001), LH (p < 0.0001), PSA (p < 0.0001) and PSA/FT ratio (p < 0.0001). FSH/PSA clusters showed features of decreasing aggressive disease as the FSH/PSA ratio progressed from A to C. Conclusion:At the diagnosis of prostate cancer and along the pituitary-testis-prostate axis in a patient population FSH significantly correlated to LH, FT and age, and FSH was independently and significantly predicted by both LH and PSA. Because of the independent prediction of PSA by FSH, the prostate cancer population at diagnosis was clustered and ranked according to the FSH/PSA ratio in groups A, B and C. Also, the predictive model of PSA on FSH for the different groups proved to be effective at selecting potential prognostic clusters in which the risk of progression might be assessed as low (group C), intermediate (group B) and high (group A). The FSH/PSA model might be considered as a tool for prostate cancer study and for use in individualized, risk-adapted approaches. However, confirmatory studies are needed.

Objectives: To explore, in operated prostate cancer patients, functional relationships of total testosterone (tt) predicting free testosterone (ft) and total PSA. Patients and Methods: 128 operated prostate cancer patients were simultaneously investigated for tt, ft and PSA before surgery. Patients were not receiving 5α-reductase inihibitors, LH-releasing hormone analogues and testosterone replacement treatment. Scatter plots including ft and PSA versus tt were computed in order to assess the functional relationship of the variables. Linear regression analysis of tt predicting ft and PSA was computed. Results: tt was a significant predictor of the response variable (ft) and different subsets of the patient population were assessed according to the ft to tt ratio. PSA was related to tt according to a nonlinear law. tt was a significant predictor of PSA according to an inversely nonlinear law and different significant clusters of the patient population were assessed according to the different constant of proportionality computed from experimental data. Conclusions: In our prostate cancer population, ft was significantly predicted by tt according to a linear law, and the ft/tt ratio was a significant parameter for assessing the different clusters. Also, tt was a significant variable predicting PSA by a nonlinear law and different clusters of the patient population were assessed by the different constants of proportionality. As a theory, we explain the nonlinear relation of tt in predicting PSA as follows: (a) the number of androgen-independent prostate cancer cells increases as tumor volume and PSA serum levels rise, (b) the prevalence of androgen-independent cells producing a substance which inhibits serum LH, and (c) as a result lower levels of serum tt are detected.

Summary Background: Cross-reactions between venoms may be responsible for multiple diagnostic positivities in hymenoptera allergy. There is limited data on the cross-reactivity between Vespula spp and Vespa crabro, which is an important cause of severe reactions in some parts of Europe. We studied by CAP-inhibition assays and immunoblotting the cross-reactivity between the two venoms. Methods: Sera from patients with non discriminative skin/CAP positivity to both Vespula and Vespa crabro were collected for the analyses. Inhibition assays were carried out with a CAP method, incubating the sera separately with both venoms and subsequently measuring the specific IgE to venoms themselves. Immunoblotting was performed on sera with ambiguous results at the CAP-inhibition. Results: Seventeen patients had a severe reaction after Vespa crabro sting and proved skin and CAP positive also to vespula. In 11/17 patients, Vespula venom completely inhibited IgE binding to VC venom, whereas VC venom inhibited binding to Vespula venom only partially (

Objectives: To explore the significance of the pretreatment total prostate-specific antigen (PSA) to free testosterone (FT) ratio (PSA/FT) as a marker for assessing the pathologic Gleason sum (pGS) and levels of tumor extension (pT) in prostatectomy specimens. Patients and Methods: 128 of 135 consecutive patients diagnosed with prostate cancer underwent radical prostatectomy. Simultaneous pretreatment serum samples were obtained to measure serum total testosterone, FT and total PSA levels. The statistical design of the study included 2 sections: the first part trying to explore the role of the PSA/FT ratio in clustering patients with different pathologic prognostic factors, and the second to investigate the PSA/FT ratio distribution in different groups of patients according to the pathologic stage and pGS of the specimen after radical prostatectomy. Results: The average age was 65.80 (range 51.21–77.26) years, mean PSA was 8.88 (range 1.22–44.27) µg/l, mean FT was 35.32 (range 13.70–69.30) pmol/l, and the mean PSA/FT ratio was 0.27 (range 0.04–1.48). The PSA/FT ratio significantly clustered both the pT and pGS groups. Analysis of variance for the distribution of the PSA/FT ratio was significant for the pT model groups. The mean PSA/FT ratio increased as the tumor extended and grew through the prostate gland (high-stage disease). Analysis of variance for the different distributions of the PSA/FT ratio was significant for all model pGS groups. In our investigation we also found (data not shown) that a PSA/FT ratio of ≧0.40 was strongly correlated with large extensive (pT3b+pT4) and high-grade cancers (pGS8+pGS9). Conclusions: Prostate cancer patients may be classified into 3 different pathologic prognostic groups according to the PSA/FT ratio: low risk (PSA/FT ≤0.20), intermediate risk (PSA/FT >0.20 and ≤0.40), and high risk (PSA/FT >0.40 and ≤1.5). The PSA/FT ratio may be considered as the marker expressing different biology groups of prostate cancer patients, and it is strongly associated with pT and pGS.

Scombroid syndrome (histamine fish poisoning--HFP) is a complex of symptoms caused by biogenic amines, mainly histamine, contained in seafood. The diagnosis of HFP is quite difficult as the symptoms of this particular condition are similar to the symptoms of a normal allergic syndrome.We have collected 10 cases (3 male and 7 female) of HFP and 50 non-HFP patients (35 female and 15 male) with allergic disorders, all from the Emergency Department of Ospedale Civile Maggiore in Verona.As expected, tryptase serum concentrations of most of the patients with allergic or anaphylactic disorders were increased above normal value (24.4+/-8.0 ng/mL mean+/-SD, normal value11 ng/mL), whereas the tryptase serum concentrations of all the 10 patients with HFP were within the normal range (8.1+/-1.8 ng/mL).Our data suggest that tryptase serum concentrations can discriminate between the allergic and HFP syndromes. As the tryptase half-life is 90-120 min, blood samples must be taken 1-2 h from the beginning of symptoms.Finding a biomarker could help physicians to formulate a correct diagnosis and thus in choosing the best therapeutic strategy. In this work, we analyzed the role of tryptase serum concentrations to differentiate real allergic syndromes from the HFP syndrome, which causes similar histamine-mediated effects by a different mechanism.

Objectives: Prostate cancer is an interesting tumor for endocrine investigation. The prostate-specific antigen/free testosterone (PSA/FT) ratio has been shown to be effective in clustering patients in prognostic groups as follows: low risk (PSA/FT ≤0.20), intermediate risk (PSA/FT >0.20 and ≤0.40) and high risk (PSA/FT >0.40 and ≤1.5). In the present study we explored the total PSA and FT distributions, and linear regression of FT predicting PSA in the different groups (PSA/FT, pT and pG) and subgroups (pT and pG) of patients according to the prognostic PSA/FT ratio. Patients and Methods: The study included 128 operated prostate cancer patients. Pretreatment simultaneous serum samples were obtained for measuring free testosterone (FT) and total PSA levels. Patients were grouped according to the total PSA/FT ratio prognostic clusters (≤0.20, >0.20 and ≤0.40, >0.40), pT (2, 3a and 3b+4) and pathological Gleason score (pG) (≤6, = 7 >3 + 4, ≧7 >4 + 3). The pT and pG sets were subgrouped according to the prognostic PSA/FT ratio. Linear regression analysis of FT predicting total PSA was computed according to the different PSA/FT prognostic clusters for the: (1) total sample population, (2) pT and pG groups, (3) intraprostatic (pT2) and extraprostatic disease (pT3a/3b/4), and (4) low-intermediate grade (pG ≤6) and high-grade (pG ≧7) prostate cancer. Results: Analysis of variance always showed highly significant different PSA distributions for (1) the different PSA/FT, pT and pG groups; and (2) the pT and pG prognostic subgroups. Significant FT distributions were detected for the (1) PSA/FT and pT groups; and (2) the pT2, pT3a and pG ≤6 prognostic PSA/FT subgroups. Correlation, variance and linear regression analysis of FT predicting total PSA was significant for (1) the PSA/FT prognostic clusters, (2) all the pT2 and pT3a subgroups, and (3) the pT3b/4 subgroup with PSA/FT >0.20 and ≤0.40, and (4) all the pG subsets. Linear regression analysis showed that the slopes of the predicting variable (FT) were always highly significant for patients with (1) intraprostate and extraprostate disease, and (2) low-grade and high-grade prostate cancer. Conclusions: According to the prognostic PSA/FT ratio, significantly lower levels of FT are detected in prostate cancer patients with extensive and high-grade disease. Also, significant linear correlations of FT predicting PSA are assessed in the different groups and subgroups of patients clustered according to the prognostic PSA/FT ratio. Confirmatory studies are needed.

To show that prostate cancer biology is related to serum levels of both free testosterone (FT) and prostate-specific antigen (PSA), that PSA level is linearly related to FT and that the PSA to FT ratio may be considered as the growth rate parameter expressing cancer phenotype biology.The study includes 135 consecutive patients diagnosed with prostate cancer. Pretreatment simultaneous serum samples for analyzing total testosterone (TT), FT and total PSA levels were obtained. The study was assessed according to a multidimensional approach of the five continuous variables including TT, FT, PSA, AGE and percentage of positive biopsies (=P+). The all sets of data were considered as one--sample with no groupings among the observations. Multivariate analysis included factor analysis (FA) and principal component analysis (PCA). Multivariate inferential statistics for comparing different groups of patients according to the PSA to free testosterone ratio (PSA/FT) included Hotteling's multivariate two-sample T²-Test for comparing two mean vectors as well as Box's M-Test with the chi-square approximation for comparing multiple covariance matrices when patients were sampled in more than two groups.Factor analysis showed the two natural grouping of variables, FT-TT and PSA-P+. PCA assessed FT and PSA as the two variables with large variances having a notable influence on the first two principal components. Multiple linear regression analysis showed that all the income variables, except age, significantly predicted the PSA/FT ratio. Patients were first sampled according to the PSA/FT ratio in group 1 (PSA/FT ≤ 0.20) and group 2 (PSA/FT0.20), and Hotteling's multivariate two sample T²-Test was significant (P0.01). Patients were then sampled according to the PSA/FT ratio in group 1 (PSA/FT ≤ 0.20), group 2 (PSA/FT0.20 and ≤ 0.40), and group 3 (PSA/FT0.40), and Box's M-Test comparing the covariance matrices of the 3 groups differed significantly (P0.001). Finally, patients were sampled according to the PSA/FT ratio in 6 groups, and Box's M-Test was again significant (P0.001).The PSA to FT ratio is the growing rate parameter expressing different biology patterns and assessing different groups of prostate cancer patients. In our opinion, the results of the present study might have wide applications in understanding, assessing and planning prostate cancer studies including basic science, screening, assessing risk of the disease, predicting disease stage as well natural history after a planned treatment involving biochemical recurrence, progression, hormone refractory prostate cancer and disease-specific survival.

Background: The preferential association of mastocytosis with hymenoptera sting reactions is well known, but there is no data on the prevalence of clonal mast cell disorders in subjects with severe systemic reactions due to foods or drugs. Methods: Patients with food- or drug-induced severe systemic reactions, including anaphylaxis, and increased serum tryptase were studied for the presence of mastocytosis, and compared with a population of patients with hymenoptera allergy. The aetiological role of foods or drugs was assessed according to current recommendations. Systemic reactions were graded in severity according to the procedure described by Mueller. Serum tryptase was considered increased if the level was >11.4 ng/ml. Subjects with increased tryptase had dermatological evaluation and Bone marrow(BM) aspirate-biopsy, which included histology/cytology, flow cytometry and detection of KIT mutations. Results: A total of 137 subjects (57 male, mean age 42 years) were studied. Of them, 86 proved positive for drugs and 51 for foods. Overall, out of 137 patients, only nine (6.6%) had a basal tryptase >11.4 ng/ml, and only two (1.5%) were diagnosed with mastocytosis. This was clearly different from patients with hymenoptera allergy, where 13.9% had elevated tryptase and 11.1% had a clonal mast cell disorder. Conclusion: The association of clonal mast cell disorders with hymenoptera allergy seems to be more specific than that with food- or drug-induced systemic reactions.

Background: Data about food-induced anaphylaxis in Italy are missing. Objective: It was the aim of this study to detect the main foods/food allergens causing anaphylaxis in Italy. Methods: The frequency of anaphylaxis and the relative importance of many offending foods were assessed in 1,110 adult patients with food allergy diagnosed by common criteria at 19 allergy centres scattered throughout Italy from 1 January to 31 December 2007. Results: Fifty-eight of 1,110 (5%) food-allergic patients experienced at least 1 episode of anaphylaxis. On average, they were older than other food-allergic patients (34 vs. 31 years; p < 0.05). The majority of anaphylactic episodes occurred in patients sensitized to lipid transfer protein (LTP; n = 19), followed by shrimp (n = 10), tree nuts (n = 9), legumes other than peanut (n = 4), and seeds (n = 2); peanut, spinach, celery, buckwheat, wheat, avocado, tomato, fish, meat, and Anisakis caused an anaphylactic reaction in single patients. Among LTP-hypersensitive patients, peach caused 13/19 anaphylactic episodes. Shrimp-allergic patients were significantly older than other patients with food-induced anaphylaxis (p < 0.05), whereas patients allergic to LTP experienced their anaphylactic episodes at a younger age (p < 0.001). The frequency of anaphylaxis among patients sensitized to LTP, shrimp or tree nuts did not differ between northern and central/southern Italy. Conclusion: LTP is the most important allergen causing food-induced anaphylaxis in Italy, peach being the most frequently offending food. Peanut-induced anaphylaxis seems very uncommon. Geographic and environmental differences both between Italy and other countries and within Italy seem to play a relevant role in the pattern of sensitization to foods.

Background Anaphylaxis after Hymenoptera stings has been reported in subjects with mastocytosis, but few data exist regarding disease prevalence in populations allergic to these insects. Objective The incidence of clonal mast cell (MC) disorders in subjects with both systemic reactions to Hymenoptera stings and increased serum baseline tryptase (sBT) levels was assessed by using bone marrow (BM) aspirates and biopsy specimens. Methods Subjects with a history of a systemic reaction caused by a Hymenoptera sting underwent the standard diagnostic work-up for Hymenoptera allergy, and sBT levels were measured. Subjects with an increased sBT level had BM evaluation that included histology/cytology, flow cytometry, and detection of KIT mutations. Results Forty-four (11.6%) of 379 subjects with systemic reactions had increased sBT levels (>11.4 ng/mL), and 31 (70.5%) of these had a history of anaphylaxis. Thirty-four subjects with increased sBT levels underwent a BM analysis. Histology detected diagnostic or subdiagnostic MC infiltrates in 22 (65%) of 34 patients. Abnormal MCs were identified by means of flow cytometry and cytology in 26 (78.8%) of 33 and 20 (58.8%) of 34 subjects, respectively. A KIT mutation was detected in 17 (54.8%) of 31 subjects. The diagnosis was indolent systemic mastocytosis in 21 (61.7%) of 34 subjects and monoclonal MC activation syndrome in 9 (26.5%) of 34 subjects. All subjects with anaphylaxis had one of those 2 disorders. Conclusion The concomitant presence of systemic reactions (especially anaphylaxis) after Hymenoptera stings and increased sBT levels strongly suggests that a BM examination is indicated for the diagnosis of clonal MC disease.

Background: Hymenoptera venom allergy can be effectively cured with specific immunotherapy, thus the correct identification of the allergen is essential. In the case of multiple skin and serum positivities it is important to know if a cross-reaction among venoms is present. We studied by CAP-inhibition assays the degree of cross-reactivity between Vespula vulgaris and Polistes dominulus. Methods: Serum samples were obtained from consecutive patients with a clinical history of grade III–IV reactions to hymenoptera sting and with nondiscriminative skin/CAP positivity to both Vespula and Polistes. Inhibition assays were carried out with a CAP method, incubating the sera separately with both venoms and subsequently measuring the specific immunoglobulin E (IgE) to venoms themselves. Results: Forty-five patients (33 male, mean age 40 years, age range 12–74, total serum IgE 242 ± 168 kU/l) were included. Their specific IgE to Vespula and Polistes were 12.03 ± 5.70 kU/l and 10.7 ± 2.0 kU/l (P = NS), respectively. At the CAP-inhibition assays, in 25 patients a >75% heterologous inhibition by P. dominulus venom against V. vulgaris-specific IgE was found. In six subjects V. vulgaris venom effectively inhibited the P. dominulus-specific IgE. In the remaining 14 cases the CAP-inhibition test provided intermediate and not discriminative results. Conclusion: In 31/45 patients, the double sensitizations to venoms were probably the result of cross-reactions and the CAP-inhibition allowed identifying the true double sensitizations. This approach may be helpful for the correct prescription of immunotherapy in the case of V. vulgaris and P. dominulus double positivity.

To evaluate the sensitivity of selective sampling from the inferior petrosal sinuses in the differential diagnosis of ACTH-dependent hypercortisolism with non-diagnostic pituitary imaging.Between 1987 and 2001, 17 patients (14 women and 3 men, aged 18-63 years) with ACTH-dependent hypercortisolism and negative X-ray of the sellar region, underwent simultaneous bilateral sampling from the inferior petrosal sinuses with ACTH measurement, at baseline and after stimulation with CRH (100 micro i.v.). Baseline samplings were also carried out at the level of the infrarenal and suprarenal inferior vena cava, of the adrenal and suprahepatic veins, of the superior vena cava, of the jugular veins, and of a peripheral vein. A central/peripheral gradient2 at baseline and/or one3 after stimulation with CRH was considered indicative of the pituitary origin of ACTH. Bilateral femoral venous catheterization was performed in an angiographic room using 5-French introducers after local anaesthesia. Selective catheterization of the inferior petrosal sinuses was achieved with 100 cm-long, steam-bent (45 degrees) 5-French catheters, without lateral holes.Twelve patients exhibited ACTH central/ peripheral gradients indicating the pituitary origin of the hormonal hyperincretion; this was confirmed by surgical exploration of the hypophysis in 10 patients, whereas 2 refused surgery and were therefore "lost". Of the five patients without ACTH central/peripheral gradients, one had an adrenal metastasis from ACTH-secreting lung neoplasia (with ACTH gradient in the blood flowing back from the adrenal gland), one had a hepatic CRHoma (with high levels of CRH in the suprahepatic veins), whereas the origin of the hyperincretion remained indeterminate in three.Bilateral simultaneous selective sampling from the inferior petrosal sinuses for ACTH measurements proved to be highly sensitive and free of complications in the differential diagnosis of ACTH-dependent forms of hypercortisolism.

In patients with chronic congestive heart failure (CHF), aldosterone production may occur despite the administration of angiotensin-converting enzyme (ACE) inhibitors. This phenomenon has been termed aldosterone "escape"; its relation to the severity of the disease is unknown. We sought to assess whether aldosterone escape might be related to disease severity or functional impairment in patients with CHF. One hundred forty-one consecutive patients with CHF who received ACE inhibitors (> 6 months) underwent an evaluation of neurohormonal activation and body composition, an echo-Doppler examination, and a cardiopulmonary exercise test. Aldosterone escape was defined as plasma levels of aldosterone above the normal range in our laboratory (> 0.42 nmol/L). Fourteen patients (10%) had aldosterone escape. There were no differences between patients with and without aldosterone escape with regard to age, New York Heart Association class, neurohormonal activation, ACE inhibitor dose, hemodynamics, or skeletal muscle bulk. In contrast, mean peak oxygen consumption (14.2 +/- 3.5 vs 17.3 +/- 4.9 ml/min/kg, p < 0.05) and the slope of the relation between ventilation and carbon dioxide production (41 +/- 7 vs 36 +/- 6, p

The relationship between exposure to cat/dog in domestic environments and development of allergic sensitization to pet allergens is still controversial.To test the role of indirect exposure to cat, we aimed to evaluate the amounts of cat specific IgE in sensitized subjects with or without cat at home.Three hundred six adult patients with a previous diagnosis of allergic sensitization to cat allergens (by skin prick test) were enrolled for this study. Among 306 men and women sensitized to cat (and other allergens), 150 owned a cat for at least 10 years ( direct exposure) and 156 had never owned this animal (indirect exposure). An internal questionnaire specifically designed for the study was completed by the same allergists during the screening consultation: the results of skin prick tests, personal and clinical data, periods of symptoms and characteristics of cat ownership were carefully recorded. Specific IgE to cat extract was determined by the Pharmacia CAP System FEIA (Pharmacia Diagnostics, Uppsala, Sweden) and Immulite 2000 (Diagnostic Products Corporation, Los Angeles, USA) RESULTS: Although specific IgE to cat allergen were significantly higher in patients with cat at home (F = 42.77; p0.001), high amounts of these antibodies were found also in sera of subjects indirectly exposed to cats.The results of our study demonstrate that the degree of serological sensitization to cat allergens may be relevant also in subjects without any direct contact with cats (indirect exposure).

To evaluate estradiol (E(2)) physiopathology along the pituitary-testicular-prostate axis at the time of initial diagnosis of prostate cancer (PC) and subsequent cluster selection of the patient population.Records of the diagnosed (n=105) and operated (n=91) patients were retrospectively reviewed. Age, percentage of positive cores at-biopsy (P+), biopsy Gleason score (bGS), E(2), prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (TT), free-testosterone (FT), prostate-specific antigen (PSA), pathology Gleason score (pGS), estimated tumor volume in relation to percentage of prostate volume (V+), overall prostate weight (Wi), clinical stage (cT), biopsy Gleason pattern (bGP) and pathology stage (pT), were the investigated variables. None of the patients had previously undergone hormonal manipulations. E(2) correlation and prediction by multiple linear regression analysis (MLRA) was performed. At diagnosis, the log E(2)/log bGS ratio clustered the population into groups A (log E(2)/log bGS ≤ 2.25), B (2.25log E(2)/log bGS ≤ 2.48) and C (2.48log E(2)/log bGS ≤ 2.59). The operated population was clustered according to the log E(2)/log pGS ratio into groups A (log E(2)/log pGS ≤ 2.25), B (2.25log E(2)/log pGS ≤ 2.48) and C (2.48log E(2)/log pGS ≤ 2.59). Simple linear regression analysis of bGS and pGS predicting E(2) was computed; differences between the clusters were assessed by analysis of variance (ANOVA) and by contingency tables.At diagnosis, E(2) was correlated to TT (r=0.32, p=0.0006) and FT (r=0.25, p=0.0009); moreover, E(2) was independently-predicted by TT (p=0.009) and bGS (p=0.04) on MLRA. The bGS significantly predicted E(2) in all groups. Groups A, B and C differed in mean values for E(2) (p0.0001), TT (p=0.005), FT (p=0.05), P+ (p=0.01) and bGS (p=0.003); moreover, the frequencies of the different bGPs were significantly different in the three groups (p=0.004). Interestingly, groups A, B, and C were associated with high-, intermediate- and low-bGS tumor grade, as well as with low-, intermediate- and high-serum levels of E(2), TT and FT, respectively. In the operated population, E(2) significantly correlated to FSH (r=-0.20, p=0.04), TT (r=0.34, p=0.0008), FT (r=0.29, p=0.003), bGS (r=0.22, p=0.03) and V+ (r=0.26, p=0.01); moreover, E(2) was independently-predicted by TT (p=0.05) and bGS (p=0.03) on MLRA. The pGS significantly predicted E(2) in all groups that differed for mean values of E(2) (p0.0001), TT (p=0.004), FT (p=0.002) and pGS (p=0.007), as well as for pT (p0.0001) and pGS (p=0.008) frequencies. Interestingly, clusters A, B, and C were associated with high-, intermediate- and low-pGS-pT frequencies as well as with low-, intermediate- and high-mean serum levels of E(2), TT and FT, respectively.In a diagnosed- and operated-PC population, E(2) serum levels were functionally related along the pituitary-testis-prostate cancer axis; also the log E(2)/log bGS and log E(2)/log pGS ratio, clustered the population in three groups where the risk of progression might be ranked as high (group A), intermediate (group B) and low (group C). However, further confirmatory studies are needed.

Epinephrine is the treatment of choice for acute food-allergic reactions but existing guidelines state that it should be prescribed uniquely to patients who already experienced at least one food-induced anaphylactic episode.We investigated whether in Italy epinephrine auto-injector is prescribed uniquely following the existing guidelines only, or is allergen-informed as well (i.e., based on the potential risk associated with sensitization to certain food allergens), and hence preventive.1110 adult patients (mean age 31 years; M/F 391/719) with food allergy seen at 19 allergy outpatient clinics were studied. Patients with a history of probable anaphylaxis were identified. Subjects were classified as having primary (type 1) and/or secondary (type 2) food allergy and were divided into several subgroups based on the offending allergen/food. Epinephrine prescriptions were recorded and analyzed both as a whole and by sensitizing allergen.Epinephrine was prescribed to 138/1100 (13%) patients with a significant difference between subjects with type-1 and type-2 food allergy (132/522 [25%] vs. 6/629 [1%]; p0.001). The epinephrine group included most patients with a history of anaphylaxis (55/62 [89%]) or emergency department visits 106/138 (77%). In some specific subsets, namely fish-, tree nuts-, and lipid trasfer protein (LTP)-allergic patients, epinephrine was prescribed to patients without a history of systemic allergic reactions.Italian allergy specialists prescribe epinephrine auto-injectors both on the basis of clinical history of severe reactions and on a critical analysis of the hazard associated with the relevant protein allergens, which suggests a good knowledge of allergens as well as acquaintance with the guidelines for prescription of emergency medication.

Glucose toxicity (i.e., glucose-induced reduction in insulin secretion and action) may be mediated by an increased flux through the hexosamine-phosphate pathway. Glucosamine (GlcN) is widely used to accelerate the hexosamine pathway flux, independently of glucose. We tested the hypothesis that GlcN can affect insulin secretion and/or action in humans. In 10 healthy subjects, we sequentially performed an intravenous glucose (plus [2-3H]glucose) tolerance test (IVGTT) and a euglycemic insulin clamp during either a saline infusion or a low (1.6 micromol x min(-1) x kg(-1)) or high (5 micromol x min(-1) x kg(-1) [n = 5]) GlcN infusion. Beta-cell secretion, insulin (SI*-IVGTT), and glucose (SG*) action on glucose utilization during the IVGTT were measured according to minimal models of insulin secretion and action. Infusion of GlcN did not affect readily releasable insulin levels, glucose-stimulated insulin secretion (GSIS), or the time constant of secretion, but it increased both the glucose threshold of GSIS (delta approximately 0.5-0.8 mmol/l, P < 0.03-0.01) and plasma fasting glucose levels (delta approximately 0.3-0.5 mmol/l, P < 0.05-0.02). GlcN did not change glucose utilization or intracellular metabolism (glucose oxidation and glucose storage were measured by indirect calorimetry) during the clamp. However, high levels of GlcN caused a decrease in SI*-IVGTT (delta approximately 30%, P < 0.02) and in SG* (delta approximately 40%, P < 0.05). Thus, in humans, acute GlcN infusion recapitulates some metabolic features of human diabetes. It remains to be determined whether acceleration of the hexosamine pathway can cause insulin resistance at euglycemia in humans.