Molecular Engineering of Ghfp, the Gonococcal Orthologue of Neisseria meningitidis Factor H Binding Protein.

Knowledge of the sequences and structures of proteins produced by microbial pathogens is continuously increasing. Besides offering the possibility of unraveling the mechanisms of pathogenesis at the molecular level, structural information provides new tools for vaccine development, such as the opportunity to improve viral and bacterial vaccine candidates by rational design. Structure-based rational design of antigens can optimize the epitope repertoire in terms of accessibility, stability, and variability. In the present study, we used epitope mapping information on the well-characterized antigen of Neisseria meningitidis factor H binding protein (fHbp) to engineer its gonococcal homologue, Ghfp. Meningococcal fHbp is typically classified in three distinct antigenic variants. We introduced epitopes of fHbp variant 1 onto the surface of Ghfp, which is naturally able to protect against meningococcal strains expressing fHbp of variants 2 and 3. Heterologous epitopes were successfully transplanted, as engineered Ghfp induced functional antibodies against all three fHbp variants. These results confirm that structural vaccinology represents a successful strategy for modulating immune responses, and it is a powerful tool for investigating the extension and localization of immunodominant epitopes.

The adjuvant MF59 induces ATP release from muscle that potentiates response to vaccination.

Vaccines are the most effective agents to control infections. In addition to the pathogen antigens, vaccines contain adjuvants that are used to enhance protective immune responses. However, the molecular mechanism of action of most adjuvants is ill-known, and a better understanding of adjuvanticity is needed to develop improved adjuvants based on molecular targets that further enhance vaccine efficacy. This is particularly important for tuberculosis, malaria, AIDS, and other diseases for which protective vaccines do not exist. Release of endogenous danger signals has been linked to adjuvanticity; however, the role of extracellular ATP during vaccination has never been explored. Here, we tested whether ATP release is involved in the immune boosting effect of four common adjuvants: aluminum hydroxide, calcium phosphate, incomplete Freund's adjuvant, and the oil-in-water emulsion MF59. We found that intramuscular injection is always associated with a weak transient release of ATP, which was greatly enhanced by the presence of MF59 but not by all other adjuvants tested. Local injection of apyrase, an ATP-hydrolyzing enzyme, inhibited cell recruitment in the muscle induced by MF59 but not by alum or incomplete Freund's adjuvant. In addition, apyrase strongly inhibited influenza-specific T-cell responses and hemagglutination inhibition titers in response to an MF59-adjuvanted trivalent influenza vaccine. These data demonstrate that a transient ATP release is required for innate and adaptive immune responses induced by MF59 and link extracellular ATP with an enhanced response to vaccination.

Lytic failure in the current pharmacointensive ST-elevated acute myocardial infarction care: insights from a pilot real-world study.

BACKGROUND: Thrombolysis remains a very acceptable reperfusion option for ST-elevated acute myocardial infarction (STEMI); however, it fails relatively frequently and unpredictably. AIM AND METHODS: To investigate correlates of lytic failure (according to the standard ST resolution criterion) in current pharmacointensive STEMI care (dual antiplatelets with antithrombin), we analyzed retrospectively clinical data and echocardiographic left ventricular systolic function before initiation of reperfusion treatment in Killip I-III STEMI patients admitted to our 'spoke' intensive cardiac care unit between 1 January and 31 December 2010. RESULTS: Of the 53 STEMI patients enrolled, 28% failed thrombolysis. Patients who did not reperfuse were less frequently active smokers (P < 0.05, odds ratio 4.33) and had a higher prevalence of hemodynamic instability [heart rate/SBP (i.e. shock index) >0.75; P < 0.05, odds ratio 13.45) and left ventricular systolic dysfunction (ejection fraction <45%; P < 0.005, odds ratio 11.14). In an exploratory multivariable logistic regression analysis, those variables were the only discriminators independently associated with lytic failure (adjusted odds ratio 8.74, 230.10, and 18.22, respectively, all P < 0.05). Moreover, the combined variables had a high accuracy for prediction of failed thrombolysis (all discriminators positive, 99% specificity and 83% positive predictive value). CONCLUSION: Our pilot study indicates that thrombolysis still fails in about one-third of STEMI patients despite the current pharmacointensive approach and suggests that failed ST resolution might be independently associated with nonsmoking habit and pretreatment hemodynamic instability and left ventricular systolic dysfunction. Larger trials are needed to verify the potential clinical implications of our preliminary observation.

Role of p16(INK4a) cytology testing as an adjunct to enhance the diagnostic specificity and accuracy in human papillomavirus-positive women within an organized cervical cancer screening program.

OBJECTIVE: We evaluated the performance of cytologic p16(INK4a) (p16) immunostaining within a cervical cancer screening program for the categories of atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LS after triage with high-risk human papillomavirus (HR-HPV) testing and atypical squamous cells, cannot exclude high-grade intraepithelial squamous lesion (ASC-H) and high-grade squamous intraepithelial lesion (HSIL). We also verified whether the routine introduction of p16 staining might enhance the specificity and positive predictive value (PPV) for cervical intraepithelial neoplasia grade 2 or higher (CIN2+) lesions predicted by a cytological screening test. STUDY DESIGN: Performance of the p16 cytology test was estimated in 578 cytological samples, of which 213 were HR-HPV+ ASC-US, 186 were HR-HPV+ LSIL, 74 were ASC-H, 56 were HSIL-CIN2 and 49 were HSIL-CIN3. All samples had histological follow-up. RESULTS: In the ASC-US category, p16 sensitivity was 91% for CIN2+ and 100% for CIN3, while specificity was 64 and 58%, respectively, negative predictive value (NPV) was 96 and 100%, respectively, and PPV was 39%. In the LSIL category, sensitivity was 77 and 75%, respectively, for CIN2+ and CIN3, while specificity was 64 and 57%, NPV was 93 and 98% and PPV was 30%. Sensitivity for ASC-H and HSIL-CIN3 was 100% for CIN2+ and CIN3, while for HSIL-CIN2 it was 91 and 95%, respectively; NPV for ASC-H was 100%, and for HSIL-CIN2 it was 43 and 86%, respectively. Follow-up examinations of 8 cases diagnosed as p16+ ASC-H and HSIL-CIN3, but histologically negative or CIN1 on the first biopsy, showed 4 CIN2 and 4 CIN3 lesions. CONCLUSIONS: Sensitivity, specificity, PPV and NPV confirm the importance of the utilization of p16 in the categories ASC-US and LSIL after triage with an HR-HPV test. In the ASC-H and HSIL-CIN3 lesions, p16 was shown to be an excellent marker for picking up CIN2+ lesions, especially in cases with cytohistological discordance.

UbcH10 expression on thyroid fine-needle aspirates.

BACKGROUND: Thyroid fine-needle aspiration (FNA) samples belonging to the follicular neoplasm/suspicious for malignancy classes are controversial. The authors identified UbcH10 as a marker useful in the diagnosis of several neoplasms, including thyroid cancer. Here, analysis of UbcH10 expression by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry was applied to FNAs. METHODS: A series of 84 follicular neoplasm/suspicious for malignancy FNAs with histological follow-up (30 malignant) was prospectively collected. UbcH10 immunostaining was performed on cell blocks and compared with that of the proliferation marker Ki-67. At the mRNA level, UbcH10 was compared with CCND2 and PCSK2 expression, these latter being the best performing components of the previously reported 3-gene assay; to determine the diagnostic accuracy, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for each gene individually and in combination was evaluated. RESULTS: UbcH10 and Ki-67 shared a similar pattern; although UbcH10 expression was higher in malignant than in benign lesions (P < .001), staining was sporadic, and the cutoff value derived by the ROC analysis was too low (1.25%) for routine application. Conversely, UbcH10 expression assessment by quantitative RT-PCR was effective. UbcH10 mRNA levels associated with malignant histology were significantly higher than those associated with benign histology (P = .02). The AUC was 0.74 for UbcH10, 0.81 for CCDN2, 0.62 for PCSK2, and 0.84 for UbcH10 and CCND2 combination. CONCLUSIONS: UbcH10 quantitative RT-PCR analysis, rather than immunohistochemistry, is useful to increase the detection of malignancy in thyroid FNAs. UbcH10 may be added as a panel component in quantitative RT-PCR-based assays.

Identifying a higher throughput assay for metabolism dependent inhibition (MDI).

A higher throughput method of screening for the metabolism dependent inhibition of 56 marketed drugs was evaluated and compared data from the PHLM assay (using midazolam as probe) with Cypex assay (using diethoxyfluoresin (DEF) as probe) for CYP3A4 by using 96 well plate. Also 27 marketed drugs were selected to evaluate the reproducibility of Cypex assay using 7-benzyloxyquinoline (7-BQ) as second probe substrate for CYP3A4. Furthermore Cypex CYP2D6 was used to evaluate the reproducibility of this system using 4-methylaminomethyl-7-methoxycoumarin (MMC) as probe substrate with 15 marketed drugs. The fold change was estimated using the fold change obtained from triplicates experiments in same day or different days. All replicates in agreement (i.e. all positive or all negative) for >80% of compounds. The IC50 values for the two assays closely matched only for 13 compounds (23%). Only 5 of the variant 56 compounds had higher IC50 values with the recombinant enzymes, whereas 38 had lower IC50 values with the recombinant cypex CYP3A4 enzyme. The Cypex assay is comparable to PHLM assay in terms of predictivity and reproducibility. The Cypex assay therefore offers a higher throughput, reproducible alternative to PHLM for placement earlier in the lead optimisation process. In conclusion, the results obtained from a fluorescence-based method using Cypex CYP3A4 reflect mostly those obtained from conventional assay using human liver microsomes. This method provides more rapid and reliable detection of MDI inhibitors and may be useful in drug discovery.

Novel wall motion score-based method for estimating global left ventricular ejection fraction: validation by real-time 3D echocardiography and global longitudinal strain.

AIMS: To evaluate the reliability of a regional wall motion score index (WMSI)-based method for assessment of left ventricular (LV) ejection fraction (EF). METHODS AND RESULTS: Two-dimensional (2D) echocardiography was used to assess a LV 16-segment-based regional wall motion. Each segment received a score based on contractility status: 4, normal kinesis; 3, mild; 2.5, moderate; and 1.5, severe hypo-kinesis; 0, akinesis; -1, dyskinesis; 3.5 and 4.5 were used for low-normal and high-normal kinesis; 5 for hyper-kinesis. Hence, WMSI-based EF was derived by summing the score assigned to each segment. Contextually, EF was evaluated by real-time three-dimensional (3D) echocardiography and by traditional Simpson's method (2D). Global longitudinal strain (GLS) by speckle-tracking method was derived as a volume-independent indicator of LV chamber contractility sensitive to regional wall motion abnormalities. In 40 subjects with 3D-EF ranging from 14 to 80%, including clinically healthy hypertensive and patients with Stage B-D congestive heart failure with global or segmental wall motion abnormalities, on average, WMSI-EF did not differ from EF measured by 3D or 2D (all P > 0.5). By intraclass correlation coefficients, reliability of WMSI-EF vs. 3D method was as good as the reliability of 2D method vs. 3D method. GLS correlated with WMSI-EF as strongly as with 3D-EF (both r(2) = 0.90). Moderate-severe mitral regurgitation was associated with increased difference between WMSI-EF and 3D-EF, independent to potential confounders. Intra-observer and inter-observer reproducibility of WMSI-EF was comparable to the reproducibility of EF estimated by 3D echocardiography. Feasibility (WMSI, 3D, 2D, and GLS all available) was 78%; however, feasibility of WMSI per se was approximately 92% in clinical series. CONCLUSION: Trained readers may rapidly estimate EF by a novel WMSI system, which was found to be accurate compared with 3D method and GLS.

Cyclin D1 and D3 overexpression predicts malignant behavior in thyroid fine-needle aspirates suspicious for Hurthle cell neoplasms.

BACKGROUND: Thyroid fine-needle aspiration (FNA) samples that feature a follicular-patterned, monotonous Hurthle (oncocytic) cell population cannot be diagnosed reliably. The authors of this report recently identified cyclin D3 overexpression on histologic sections of Hurthle cell carcinoma. In this study, they assessed the diagnostic value of cyclin D3 immunohistochemistry added to routine cytology. METHODS: Fifty-one FNA samples that were suspicious for Hurtle cell neoplasia and that had histologic follow-up (19 malignant cases) were examined. Cyclin D3 expression levels were evaluated in cell block preparations and were compared with levels of the closely related cyclin D1 protein. RESULTS: Greater than 25% positive cells were used as the cutoff point, as suggested by previous studies. Cyclin D1 and cyclin D3 were highly specific (100% for both) and fairly accurate (75% and 92%, respectively) in distinguishing between benign and malignant oncocytic lesions; the positive predictive value (PPV) for each was 100%. However, both cyclins D1 and D3 had low sensitivity (32% and 79%, respectively) and low negative predictive value (NPV) (71% and 89%, respectively). In contrast, by adopting balanced receiver operating characteristic-derived positive cutoff values, cyclin D1 (>or=6.5%) and cyclin D3 (>or=7.5%) were found to be highly sensitive (100% for both) and accurate (90% and 94%, respectively); and the NPV was 100% for both. In contrast, cyclins D1 and D3 had low specificity (84% and 91%, respectively) and a low PPV (79% and 86%, respectively); however, these values improved in samples that were positive for both cyclins (sensitivity, 100%; specificity, 94%; PPV, 90%; NPV, 100%; and accuracy, 96%). CONCLUSIONS: Cyclin D3 increased the suspicion of malignancy in indeterminate oncocytic lesions; its diagnostic performance depended on the cutoff point used and was enhanced further when combined with cyclin D1.

Changes in components of left ventricular mechanics under selective beta-1 blockade: insight from traditional and new technologies in echocardiography.

AIMS: Myocardial inotropism is considered to be reduced under beta-1 adrenoreceptor blockage (beta1-block). However, relationships between components of left ventricular (LV) systolic mechanics under beta1-block accounting for physiological correlates are only partially explored. METHODS AND RESULTS: Hypertensive outpatient without previous cardiovascular events and with normal LV ejection fraction (EF) at rest underwent echocardiographic evaluations of LV size and systolic function by standard, tissue-Doppler, and speckle-tracking methods before and after 2 weeks of treatment with bisoprolol to obtain change in LV systolic mechanics at a stable heart rate reduction (-20 +/- 10% from baseline) without significant change in LV mass. In the study sample (n = 26, 62% women, mean age 52 +/- 10 years), under bisoprolol, afterload [i.e. circumferential (CESS) and meridional (MESS) end-systolic stress], LV mass, left atrial volume, and EF did not change significantly; LV chamber contractility [i.e. CESS/LV end-systolic volume index (CESS/ESVi) as well as MESS/ESVi] and relative wall thickness (RWT) decreased; stroke volume increased (all P < 0.05). Circumferential LV contractility (i.e. stress-corrected midwall shortening) increased, whereas regional longitudinal strain and strain rate, and global longitudinal strain decreased (all P < 0.05). Peak velocities of the systolic displacement of the lateral and medial mitral anulus did not change under bisoprolol. Parameters of longitudinal LV systolic function did not correlate with preload, afterload, RWT, or with stoke volume. CONCLUSION: In hypertensive subjects with preserved LV EF, parameters of longitudinal LV systolic mechanics may not reflect the LV myocardial contractility status in steady-state conditions under short-term treatment with beta1-block.

UbcH10 expression in human lymphomas.

AIMS: The UbcH10 ubiquitin-conjugating enzyme plays a key role in regulating mitosis completion. We have previously reported that UbcH10 overexpression is associated with aggressive thyroid, ovarian and breast carcinomas. The aim of this study was to investigate UbcH10 expression in human lymphomas. METHODS AND RESULTS: Cell lines and tissue samples of Hodgkin's lymphoma (HL) and of non-Hodgkin's lymphoma (NHL) were screened for UbcH10 expression at transcriptional and translational levels. UbcH10 expression was related to the grade of malignancy. In fact, it was low in indolent tumours and high in a variety of HL and NHL cell lines and in aggressive lymphomas. It was highest in Burkitt's lymphoma, as shown by quantitative real-time polymerase chain reaction and by tissue microarray immunohistochemistry. Flow cytometry of cell lines confirmed that UbcH10 expression is cell-cycle dependent, steadily increasing in S phase, peaking in G(2)/M phase and dramatically decreasing in G(0)/G(1) phases. We also showed that UbcH10 plays a relevant role in lymphoid cell proliferation, since blocking of its synthesis by RNA interference inhibited cell growth. CONCLUSIONS: Taken together, these results indicate that UbcH10 is a novel lymphoid proliferation marker encompassing the cell cycle window associated with exit from mitosis. Its overexpression in aggressive lymphomas suggests that UbcH10 could be a therapeutic target in this setting.

Impact of resistance to thyroid hormone on the cardiovascular system in adults.

BACKGROUND: The clinical manifestations of resistance to thyroid hormone (RTH) are highly variable, and the impact of RTH on the cardiovascular system has been poorly investigated. AIM: The objective of the study was to evaluate the cardiovascular characteristics of 16 untreated and asymptomatic patients with RTH compared with 16 euthyroid healthy controls to define the cardiovascular involvement in RTH syndrome. PATIENTS AND METHODS: Sixteen untreated and asymptomatic RTH patients (eight males; aged 33 +/- 12 yr, range 21-45 yr) and 16 controls (nine males; aged 33 +/- 5 yr, range 24-42 yr) were enrolled. Clinical data, thyroid status, and echocardiographic results were recorded. RESULTS: Heart rate was comparable with that of controls, whereas arterial pressure was higher than controls. Mean interventricular septum diastolic thickness and mean left ventricular (LV) posterior wall diastolic thickness were significantly lower in RTH patients than controls with a consequent significant decrease of the mean LV mass and LV mass indexed by body surface area. Patients also had abnormalities of myocardial relaxation as indicated by a significant increase of peak A and consequent reduction of the early to late ratio. Finally, systemic vascular resistance was significantly higher in RTH patients than controls. CONCLUSIONS: Our results suggest the presence of cardiovascular alterations in asymptomatic and untreated RTH patients similar to those reported in hypothyroid patients. Our strict selection likely created a bias in the inclusion of a particular type of RTH patients, who could represent a minority of patients with RTH. However, no correlation was found between the type of mutation and cardiovascular characteristics of RTH patients.

Effects of growth hormone on exercise capacity and cardiopulmonary performance in patients with chronic heart failure.

BACKGROUND: Because GH exerted beneficial effects in various experimental models of heart failure, we investigated the effects of GH on physical exercise capacity and cardiopulmonary performance in patients with dilated cardiomyopathy and chronic heart failure (CHF). METHODS: Twenty-two patients with CHF (New York Heart Association functional class II-III) underwent spirometry and a symptom-limited, cardiopulmonary exercise testing before and after 3 months of GH (n = 11; seven males; seven idiopathic; 57 +/- 11 yr; 4 IU sc every other day) or placebo (n = 11; eight males; six idiopathic; 54 +/- 10 yr) administration, in a randomized, double-blind trial. Background CHF therapy remained unchanged. RESULTS: GH, but not placebo, increased IGF-I serum concentration (from 144 +/- 35 to 293 +/- 58 ng/ml; P < 0.005) and improved New York Heart Association functional class (from 2.4 +/- 0.5 to 1.8 +/- 0.4; P < 0.005), exercise duration (from 831 +/- 273 to 925 +/- 266 sec; P < 0.005), peak power output (from 245 +/- 127 to 280 +/- 132 W; P < 0.05), peak minute ventilation (from 52.5 +/- 16.1 to 61.3 +/- 17.3 liters/min; P < 0.05), peak oxygen consumption (from 19.8 +/- 5.6 to 25.1 +/- 5.6 ml/kg.min; P < 0.005), and anaerobic threshold (from 14.9 +/- 4.8 to 20.0 +/- 4.5 ml/kg.min; P < 0.005) without affecting lung function parameters. Furthermore, the slope of the relationship between minute ventilation and pulmonary carbon dioxide production (ventilatory efficiency) decreased from 34.7 +/- 5.1 to 31.7 +/- 5.3 (P < 0.005), whereas the slope of the relation between percent predicted heart rate reserve used and percent observed metabolic reserve used (chronotropic index) rose from 0.57 +/- 0.20 to 0.69 +/- 0.18 (P < 0.005). CONCLUSION: Given the predictive value of physical exercise capacity and cardiopulmonary performance in CHF progression, these data provide additional insights into the mechanisms by which GH may potentially benefit CHF patients.

Isolated left ventricular diastolic dysfunction: implications for exercise left ventricular performance in patients without congestive heart failure.

OBJECTIVE: Clinical relevance of left ventricular (LV) diastolic dysfunction in the absence of congestive heart failure (CHF) and LV systolic dysfunction is not fully established. METHODS: Asymptomatic outpatients, sedentary, with cardiovascular risk factors but no history of cardiovascular events, underwent echocardiographic evaluation of LV structure and function by standard Doppler, color M-mode, and Doppler tissue methods, and exercise testing with simultaneous noninvasive assessment of LV stroke index and cardiac index. LV ejection fraction less than 50% and significant valvular disease or stress test suggestive of coronary disease were additional exclusion criteria. RESULTS: In 70 patients selected (40 +/- 10 years old, 63% men, 34% hypertensive, 34% diabetic, 4% diabetic and hypertensive, 11% with LV hypertrophy), LV diastolic dysfunction was detected in 26%, which was associated with hypertension, higher LV mass index, lower systolic function, lower peak exercise heart rate, and chronotropic reserve (all P < .05), and with lower peak exercise stroke index and cardiac index (both covariates adjusted P < .05), but not with lower peak exercise metabolic equivalents (P > .5). Abnormal LV relaxation was independently correlated with lower peak exercise cardiac index and stroke index (both P < .05). Peak exercise systolic and cardiac indices were comparable between patients with CHF risk factors (74%) versus those without. CONCLUSIONS: Isolated LV diastolic dysfunction was independently associated with lower peak exercise LV systolic performance in patients without CHF. Its diagnosis may provide a target for aggressive CHF risk management.

Association between post-ischemic forearm blood flow and blood pressure response to maximal exercise in well trained healthy young men.

BACKGROUND: The relationship between peripheral circulation and blood pressure (BP) response to maximal exercise is an intriguing and not yet well defined topic. AIMS: Aims of the present study were to investigate in well trained young healthy males the possible relationships between the endothelial or the smooth muscle component of the peripheral circulation and 1) the BP response to physical exercise on treadmill 2) the body mass composition. SUBJECTS AND METHODS: Fifteen subjects (18-36 years), regularly performing physical activity 3 times weekly underwent the following examinations: body composition by bioelectrical impedance analysis; measurement of the forearm blood flow (FBF) at rest and during post-ischemic hyperemia by strain-gauge plethysmography at the upper arm; measurement of brachial artery diameter (BAD) at rest and after 4-min ischemia by echography; BP response to maximal exercise on treadmill with the determination of maximal oxygen consumption and the measurement of lactic acid serum concentration. RESULTS: BAD was significantly increased during post-ischemic hyperemia up to the 4th minute of observation with a peak at 60 s (+8.5%); FBF increased at 30 s after ischemia (+210%) and returned to baseline levels at the 2nd minute. In the linear correlation analysis, systolic BP increase at the end of the maximal exercise was significantly and inversely related to the increase in FBF (r=-0.663, p<0.01) and to the early FMD (r=0.503, p<0.05). In the multiple regression analysis, however, only FBF independently affected SBP increase during exercise (t=-3.268, p<0.02). Systolic BP increase at the end of the maximal exercise was significantly related to the increase in FBF but not to that of BAD. Among parameters of body composition, fat-free mass was closely related to changes only in BAD. CONCLUSIONS: These data indicate that FBF, which depends on the smooth muscle component of the peripheral circulation, is closely related to BP response to exercise while the endothelial function, which has been determined as changes in BAD, is related to the fat-free mass of the body, possibly through the peripheral insulin sensitivity.

Tadalafil improves quality of life and exercise tolerance in idiopathic pulmonary arterial hypertension.

Pulmonary arterial hypertension has a poor prognosis quoad vitam et valitudinem. Herein, we report on a middle-aged woman affected by idiopathic pulmonary arterial hypertension whose quality of life and exercise tolerance improved remarkably after a six-month course of treatment with the long-acting phosphodiesterase-5 inhibitor tadalafil.

Growth hormone- and pressure overload-induced cardiac hypertrophy evoke different responses to ischemia-reperfusion and mechanical stretch.

OBJECTIVE: To compare the molecular, histological, and functional characteristics of growth hormone (GH)- and pressure overload-induced cardiac hypertrophy, and their responses to ischemia-reperfusion and mechanical stretch. DESIGN: Four groups of male Wistar rats were studied: aortic banding (n=24, AB) or sham (n=24, controls) for 10 weeks, and GH treatment (n=24; 3.5mg/kg/day, GH) or placebo (n=24, controls) for 4 weeks. At 13 weeks, the rats were randomly subjected to: (i) assessment of basal left ventricular mRNA expression of sarcoplasmic reticulum calcium-ATPase (SERCA-2), phospholamban (PLB), and Na(+)-Ca(2+) exchanger (NCX) and collagen volume fraction (CVF) (Protocol A, 8 rats in each group); (ii) left ventricular no-flow ischemia with simultaneous evaluation of intracellular Ca(2+) handling and ATP, phosphocreatine (PCr) and inorganic phosphate (Pi) content (Protocol B, 12 rats in each group); or (iii) left ventricular mechanical stretch for 40 min with assessment of tumor necrosis-alpha (TNF-alpha) mRNA (Protocol C, 4 rats in each group). Protocol B and C were carried out in a Langendorff apparatus. RESULTS: In Protocol A, no difference was found as to myocardial mRNA content of Ca(2+) regulating proteins and CVF in GH animals vs controls. In contrast, in the AB group, myocardial mRNA expression of SERCA-2 and PLB was downregulated while that of NCX and CVF were increased vs. controls (p<0.05). In Protocol B, recovery of left ventricular function was significantly decreased in AB vs GH groups and controls and this was associated with 1.6-fold increase in intracellular Ca(2+) overload during reperfusion (p<0.05). Baseline ATP content was similar in the four study groups, whereas PCr and Pi was lower in AB vs GH rats and controls. However, the time courses of high-energy phosphate metabolic changes did not differ during ischemia and reperfusion in the four study groups. In Protocol C, no detectable TNF-alpha mRNA level was found in the left ventricular myocardium of GH treated rats and controls at baseline, while a modest expression was noted in AB animals. Mechanical stretch resulted in de novo myocardial TNF-alpha mRNA expression in GH group and controls, which was dramatically increased in AB animals ( approximately 5-fold above baseline, p<0.001). CONCLUSIONS: The data show that cardiac hypertrophy activated by short-term GH treatment confers cardioprotection compared with pressure overload with regard to molecular and histological characteristics, and responses to ischemia-reperfusion and mechanical stretch.

An exaggerated systolic blood pressure response to exercise is associated with cardiovascular remodeling in subjects with prehypertension.

BACKGROUND: Although many observers consider the cardiovascular risk associated with isolated prehypertension to be low and not worth pharmacological treating, the cardiovascular disease rate is increased among individuals within this blood pressure stratum. METHODS: We performed Doppler echocardiography and submaximal bicycle ergometry in 20 nonsmoking sedentary prehypertensive subjects and 20 age- and sex-matched nonsmoking sedentary normotensive subjects, and investigated the association between the systolic blood pressure response to exercise (SBPRE) and hypertensive target organ damage. An exaggerated SBPRE (E-SBPRE) and a normal SBPRE (N-SBPRE) were diagnosed using the mean +2 standard deviations of systolic blood pressure at 100 W in normotensives. RESULTS: Body mass index was similar in the two groups. Resting blood pressure and systemic vascular resistance were higher in prehypertensives. Almost half the latter had an E-SBPRE. There were no differences in age, gender, and body mass index between normotensives and prehypertensives with an E-SBPRE or a N-SBPRE. Resting blood pressure and systemic vascular resistance were similarly increased in prehypertensives with an E-SBPRE and a N-SBPRE vs normotensives. Compared with normotensives, prehypertensives with an E-SBPRE showed: (a) a significantly greater left ventricular relative wall thickness, mostly due to a smaller cavity, (b) a significantly longer left ventricular isovolumic relaxation time, and (c) a significantly greater global arterial stiffness, as estimated by the pulse pressure/left ventricular stroke volume ratio. CONCLUSIONS: Our findings suggest that an E-SBPRE is frequent among prehypertensive subjects and is associated with cardiovascular remodeling, which may herald cardiovascular disease.

Complex regulation of the cyclin-dependent kinase inhibitor p27kip1 in thyroid cancer cells by the PI3K/AKT pathway: regulation of p27kip1 expression and localization.

Functional inactivation of the tumor suppressor p27(kip1) in human cancer occurs either through loss of expression or through phosphorylation-dependent cytoplasmic sequestration. Here we demonstrate that dysregulation of the PI3K/AKT pathway is important in thyroid carcinogenesis and that p27(kip1) is a key target of the growth-regulatory activity exerted by this pathway in thyroid cancer cells. Using specific PI3K inhibitors (LY294002, wortmannin, and PTEN) and a dominant active AKT construct (myrAKT), we demonstrated that the PI3K/AKT pathway controlled thyroid cell proliferation by regulating the expression and subcellular localization of p27. Results obtained with phospho-specific antibodies and with transfection of nonphosphorylable p27(kip1) mutant constructs demonstrated that PI3K/AKT-dependent regulation of p27(kip1) mislocalization in thyroid cancer cells occurred via phosphorylation of p27(kip1) at T157 and T198 (but not at S10 or T187). Finally, we evaluated whether these results were applicable to human tumors. Analysis of 100 thyroid carcinomas indicated that p27(kip1) phosphorylation at T157/T198 and cytoplasmic mislocalization were preferentially associated with activation of the PI3K/AKT pathway. Thus the PI3/AKT pathway and its effector p27(kip1) play major roles in thyroid carcinogenesis.

Subclinical hyperthyroidism: clinical features and treatment options.

Subclinical hyperthyroidism appears to be a common disorder. It may be caused by exogenous or endogenous factors: excessive TSH suppressive therapy with L-thyroxine (L-T4) for benign thyroid nodular disease, differentiated thyroid cancer, or hormone over-replacement in patients with hypothyroidism are the most frequent causes. Consistent evidence indicates that 'subclinical' hyperthyroidism reduces the quality of life, affecting both the psycho and somatic components of well-being, and produces relevant signs and symptoms of excessive thyroid hormone action, often mimicking adrenergic overactivity. Subclinical hyperthyroidism exerts many significant effects on the cardiovascular system; it is usually associated with a higher heart rate and a higher risk of supraventricular arrhythmias, and with an increased left ventricular mass, often accompanied by an impaired diastolic function and sometimes by a reduced systolic performance on effort and decreased exercise tolerance. It is well known that these abnormalities usually precede the onset of a more severe cardiovascular disease, thus potentially contributing to the increased cardiovascular morbidity and mortality observed in these patients. In addition, it is becoming increasingly apparent that subclinical hyperthyroidism may accelerate the development of osteoporosis and hence increased bone vulnerability to trauma, particularly in postmenopausal women with a pre-existing predisposition. Subclinical hyperthyroidism and its related clinical manifestations are reversible and may be prevented by timely treatment.