Stem cells to restore insulin production and cure diabetes.

BACKGROUND: The advancement of knowledge in the field of regenerative medicine is increasing the therapeutic expectations of patients and clinicians on cell therapy approaches. Within these, stem cell therapies are often evoked as a possible therapeutic option for diabetes, already ongoing or possible in the near future. AIM: The purpose of this document is to make a point of the situation on existing knowledge and therapies with stem cells to treat patients with diabetes by focusing on some of the aspects that most frequently raise curiosity and discussion in clinical practice and in the interaction with the patient. In fact, at present there are no clinically approved treatments based on the use of stem cells for the treatment of diabetes, but several therapeutic approaches have already been evaluated or are being evaluated in clinical trials. DATA SYNTHESIS: It is possible to identify three large potential application fields: 1) the reconstruction of the ß cell mass; 2) the immunomodulation in type 1 diabetes (T1D); 3) the treatment of complications. In this study we will limit the discussion to approaches that have the potential for clinical translation, deliberately omitting aspects of basic biology and preclinical data. Also, we intentionally omit the treatment of the complications that will be the subject of a future document. Finally, an overview of the Italian situation regarding the storage of cord blood cells for the therapy of diabetes will be given.

Human skin-derived fibroblasts used as a 'Trojan horse' for drug delivery.

BACKGROUND: Drug toxicity currently represents the main challenge of tumour chemotherapy. Our group recently developed a new method for drug delivery inspired by the 'Trojan Horse' concept. Human mesenchymal stem cells (hMSCs) have been shown to play the role of new 'horses' in delivering anti-tumour agents, without involving any genetic manipulation. As human stromal dermal fibroblasts (hSDFs) represent an interesting alternative to hMSCs, being easy to isolate, they could be an ideal candidate for this kind of procedure. AIM: To investigate whether hSDFs can take up and deliver paclitaxel (PTX) in sufficient concentrations to inhibit a very aggressive melanoma tumour (IgR39) in vitro. METHODS: hSDFs were primed with high doses of PTX, and then the effect of drug delivery on IgR39 melanoma proliferation in vitro was evaluated using several assays (antiproliferation, transwell cocultures, rosette assays and colony growth assays). Furthermore, the cell cycle and PTX uptake/release mechanism of hSDFs were studied both under both normal and hypoxic conditions. RESULTS: hSDFs incorporated PTX and then released it with unaffected pharmacological activity, inhibiting human IgR39 melanoma growth in vitro. The hypoxic conditions did not induce changes in cell cycle pattern and the uptake-release mechanism with PTX was not affected. CONCLUSIONS: hSDFs can be used as a Trojan horse, as the released drug was functionally active. These results indicated that these cells could be used for clinical treatment as the drug was released into the cellular environment and the primed cells underwent apoptosis.

[Does treatment improve prognosis of heart failure with preserved ejection fraction?]. / Insuffisance cardiaque à fraction d'éjection préservée: le traitement améliore-t-il le pronostic?

Heart failure with preserved ejection fraction (HF-PEF) represents half of all heart failure. Morbi-mortality for HF-PEF is similar to that of reduced ejection fraction HF (HF-REF). Diagnosis of HF-REF is difficult because of the lack of highly specific criteria. It is based on the presence of signs and symptoms of heart failure, associated with a preserved or moderately decreased left ventricular function, the absence of left ventricular dilatation, and the presence of relevant structural disease such as left ventricular hypertrophy. Despite the use of prognosis modifying drugs commonly used for HF-REF, no therapeutic strategy has been shown to reduce morbi-mortality of HF-PEF. Evidence based guidelines are limited. Management of HF-PEF therefore resides in treatment of high blood pressure and cardiac rate, that of comorbidities, and the use of diuretics in case of congestion.

Thiophene-based compounds as fluorescent tags to study mesenchymal stem cell uptake and release of taxanes.

Human mesenchymal stem cells (hMSC) are multipotent cells that display the unique ability to home and engraft in tumor stroma. This remarkable tumor tropic property has generated a great deal of interest in many clinical settings. Recently, we showed that hMSC represent an excellent base for cell-mediated anticancer therapy since they are able to internalize paclitaxel (PTX) and to release it in an amount sufficient to inhibit tumor cell proliferation. In order to shed light on the dynamics of drug uptake and release, in the present paper we describe the synthesis of two novel thiophene-based fluorophore-paclitaxel conjugates, namely PTX-F32 and PTX-F35, as tools for in vitro drug tracking. We aimed to study the ability of these novel derivatives to be efficiently internalized by hMSC and, in a properly engineered coculture assay, to be released in the medium and taken up by tumor cells. In order to ensure better stability of the conjugates toward enzymatic hydrolysis, the selected oligothiophenes were connected to the taxol core at the C7 position through a carbamate linkage between PTX and the diamino linker. Antiproliferative experiments on both tumor cells and stromal cells clearly indicate that, in good correlation with the parent compound, cells are sensitive to nanomolar concentrations of the fluorescent conjugates. Moreover, in the coculture assay we were able to monitor, by fluorescence microscopy, PTX-F32 trafficking from hMSC toward glioblastoma U87 tumor cells. Our work paves the way for novel possibilities to perform extensive and high quality fluorescence-based analysis in order to better understand the cellular mechanisms involved in drug trafficking, such as microvescicle/exosome mediated release, in hMSC vehicle cells.

Serum uric acid and its relationship with metabolic syndrome and cardiovascular risk profile in patients with hypertension: insights from the I-DEMAND study.

BACKGROUND AND AIMS: The independent role of serum uric acid (SUA) as a marker of cardio-renal risk is debated. The aim of this study was to assess the relationship between SUA, metabolic syndrome (MS), and other cardiovascular (CV) risk factors in an Italian population of hypertensive patients with a high prevalence of diabetes. METHODS AND RESULTS: A total of 2429 patients (mean age 62 ± 11 years) among those enrolled in the I-DEMAND study were stratified on the basis of SUA gender specific quartiles. MS was defined according to the NCEP-ATP III criteria, chronic kidney disease (CKD) as an estimated GFR (CKD-Epi) <60 ml/min/1.73 m(2) or as the presence of microalbuminuria (albumin-to-creatinine ratio ≥2.5 mg/mmol in men and ≥3.5 mg/mmol in women). The prevalence of MS, CKD, and positive history for CV events was 72%, 43%, and 20%, respectively. SUA levels correlated with the presence of MS, its components, signs of renal damage and worse CV risk profile. Multivariate logistic regression analysis revealed that SUA was associated with a positive history of CV events and high Framingham risk score even after adjusting for MS and its components (OR 1.10, 95% CI 1.03-1.18; P = 0.0060; OR 1.28, 95% CI 1.15-1.42; P < 0.0001). These associations were stronger in patients without diabetes and with normal renal function. CONCLUSIONS: Mild hyperuricemia is a strong, independent marker of MS and high cardio-renal risk profile in hypertensive patients under specialist care. Intervention trials are needed to investigate whether the reduction of SUA levels favorably impacts outcome in patients at high CV risk.

Adipose tissue-derived stromal cells primed in vitro with paclitaxel acquire anti-tumor activity.

Many strategies, including those based on genetically modified Mesenchymal Stromal Cells (MSCs), have been developed in recent years in order to obtain high concentrations of anticancer drugs effective on tumor mass. In previous studies, we showed that human and murine bone marrow-derived MSCs (BM-MSCs) and human skin-derived stromal fibroblasts (hSDFs) acquired strong anti-tumor capacity, both in vitro and in vivo, once primed with Paclitaxel (PTX). In this report we investigate whether adipose tissue-derived MSCs (AT-MSCs) behave similarly to BM-MSCs in their uptake and release of PTX in sufficient amounts to inhibit tumor proliferation in vitro. According to a standardized procedure, PTX primed AT-MSCs (AT-MSCsPTX) were washed and then subcultured to harvest their conditioned medium, which was then tested to evaluate its in vitro anti-tumor potential. We observed that AT-MSCsPTX were able to uptake PTX and release it in a time-dependent manner and that the released drug was active in vitro against proliferation of leukemia, anaplastic osteosarcoma, prostatic carcinoma and neuroblastoma cell lines. These data confirm that AT-MSCs, as well as BM-MSCs, can be loaded in vitro with anti-cancer drugs. While the harvesting of BM-MSCs requires invasive procedures, AT-MSCs can be prepared from fat samples taken with little patient discomfort. For this reason, this source of stromal cells represents an important alternative to BM-MSCs in developing new tools for carrying and delivering anti-cancer drugs into tumor microenvironments.

Glycaemic fall after a glucose load. A population-based study.

BACKGROUND AND AIMS: A blood glucose (BG) fall after an oral glucose load has never been described previously at a population level. This study was aimed at looking for a plasma glucose trend after an oral glucose load for possible blood glucose fall if any, and for its impact on coronary mortality at a population level. METHODS AND RESULTS: In subjects from an unselected general population, BG and insulin were detected before and 1 and 2h after a 75-g oral glucose load for insulin sensitivity and ß-cell function determination. Blood pressure, blood examinations and left ventricular mass were measured, and mortality was monitored for 18.8±7.7 years. According to discriminant analysis, the population was stratified into cluster 0 (1-h BG < fasting BG; n=497) and cluster 1 (1-h BG ≥ fasting BG; n=1733). To avoid any interference of age and sex, statistical analysis was limited to two age-gender-matched cohorts of 490 subjects from each cluster (n=940). Subjects in cluster 0 showed significantly higher insulin sensitivity and ß-cell function, lower visceral adiposity and lower blood pressure values. Adjusted coronary mortality was 8 times lower in cluster 0 than 1 (p<0.001). The relative risk of belonging to cluster 1 was 5.40 (95% CI 2.22-13.1). CONCLUSION: It seems that two clusters exist in the general population with respect to their response to an oral glucose load, independent of age and gender. Subjects who respond with a BG decrease could represent a privileged sub-population, where insulin sensitivity and ß-cell function are better, some risk factors are less prevalent, and coronary mortality is lower.

Oxidative stress-related proteins in a Conn's adenoma tissue. Relevance for aldosterone's prooxidative and proinflammatory activity.

BACKGROUND AND AIM: Angiotensin II (Ang II) induces oxidative stress (OxSt), which is essential for cardiovascular remodeling. Aldosterone also induces fibrosis and remodeling through direct effect on non-classical mineralocorticoid (MR) target tissues. However, studies on the role of aldosterone on OxSt and related factors in humans are lacking. MATERIALS AND METHODS: We assessed gene and protein expression of p22phox (RT-PCR and Western blot), NAD(P)H oxidase subunit essential for superoxide production and gene expression of transforming growth fator (TGF) beta, plasminogen activator inhibitor (PAI)-1, and heme oxygenase (HO)-1, effectors of OxSt (RT-PCR), in a Conn's adenoma, removed from a patient with primary hyperaldosteronism. Ang II type 1 (AT1R) and MR receptors expression were also evaluated (RT-PCR). The normal adrenal tissue adjacent to the adenoma was used as control. RESULTS: p22phox gene and protein expression were higher (31% and 53%, respectively) in the adrenal adenoma. TGFbeta, PAI-1, and HO-1 gene expression were also higher (25%, 129%, and 25%, respectively) in the adrenal adenoma while AT1R gene expression was similar (8%). The expression of MR in the adenoma was documented. CONCLUSIONS: This report demonstrates in a human model that the increased aldosterone production has effects on enzyme systems related to OxSt, enhancing the systemic fibrogenic effects of aldosterone excess through TGFbeta and PAI-1 expression which was previously demonstrated only indirectly in vitro and in animal models. The presence of MR expression in the adenoma may link the hormone with the adenoma growth. Therefore, the results of this study derived from a single case might represent an important working hypothesis for further research in a larger number of cases to clarify the role of aldosterone overproduction on OxSt and its clinical relevance.

Assessment of human herpesvirus-6 infection in mesenchymal stromal cells ex vivo expanded for clinical use.

Infection or reactivation of human herpesvirus (HHV)-6 represents a potentially serious complication (often involving the central nervous system) in patients receiving either solid organ or hematopoietic stem cell transplantation. The objective of this study was to assess the risk of HHV-6 infection/reactivation in mesenchymal stromal cells (MSCs). MSCs are multipotent cells displaying immunomodulatory properties that have been already successfully used in the clinical setting to enhance hematopoietic stem cell engraftment and to treat steroid-refractory acute graft-versus-host disease. We analyzed 20 samples of ex vivo expanded MSCs, at different passages of culture, isolated both from bone marrow and from umbilical cord blood. Through Western blotting and immunocytochemistry techniques, we investigated the presence of the HHV-6 receptor (CD46) on cell surface, whereas the presence of HHV-6 DNA was evaluated by nested polymerase chain reaction assay. All of the MSC samples tested were positive for the virus receptor (CD46), suggesting their potential susceptibility to HHV-6. However, none of the MSC samples derived from cultures, performed in the perspective of clinical use, was found to harbor HHV-6. This preliminary observation on a consistent number of MSC samples, some of them tested at late in vitro passages, indicates a good safety profile of the product in terms of HHV-6 contamination. Nevertheless, it remains important to set up in vitro experimental models to study MSCs' susceptibility to HHV-6 (and HHV-7) infection, to verify their capacity to integrate the virus into cellular DNA, and to investigate which experimental conditions are able to induce virus reactivation.

Application of human CFU-Mk assay to predict potential thrombocytotoxicity of drugs.

Megakaryocytopoiesis gives rise to platelets by proliferation and differentiation of lineage-specific progenitors, identified in vitro as Colony Forming Unit-Megakaryocytes (CFU-Mk). The aim of this study was to refine and optimize the in vitro Standard Operating Procedure (SOP) of the CFU-Mk assay for detecting drug-induced thrombocytopenia and to prevalidate a model for predicting the acute exposure levels that cause maximum tolerated decreases in the platelets count, based on the correlation with the maximal plasma concentrations (C max) in vivo. The assay was linear under the SOP conditions, and the in vitro endpoints (percentage of colonies growing) were reproducible within and across laboratories. The protocol performance phase was carried out testing 10 drugs (selected on the base of their recognised or potential in vivo haematotoxicity, according to the literature). Results showed that a relationship can be established between the maximal concentration in plasma (C max) and the in vitro concentrations that inhibited the 10-50-90 percent of colonies growth (ICs). When C max is lower than IC10, it is possible to predict that the chemicals have no direct toxicity effect on CFU-Mk and could not induce thrombocytopenia due to bone marrow damage. When the C max is higher than IC90 and/or IC50, thrombocytopenia can occur due to direct toxicity of chemicals on CFU-Mk progenitors.

High angiotensin II state without cardiac remodeling (Bartter's and Gitelman's syndromes): are angiotensin II type 2 receptors involved?

BACKGROUND/AIMS: While Angiotensin II (Ang II) is a major factor in the development of cardiomyocyte hypertrophy and a pivotal role for Ang II signals via ERK1/2 has been identified, mechanism(s) responsible are still unclear. As Bartter's and Gitelman's syndrome patients (BS/GS) have increased Ang II, and yet normo/hypotension, hyporesponsiveness to pressors and blunted Ang II signaling via type 1 receptors (AT1R), this study assesses BS/GS's left ventricular (LV) mass and structure as well as Ang II induced ERK1/2 phosphorylation compared with essential hypertensive patients (EH) and normotensive healthy subjects (C) to gain insight into Ang II mediated processes. METHODS: Indices of cardiac hypertrophy were determined by M-mode, two-dimensional echo Doppler and ERK phosphorylation by Western blot. RESULTS: None of BS/GS exhibited LV remodelling; LV mass, LV end-diastolic volume and mass/volume ratio were unchanged vs C (60+/-14 g/m2 vs 64+/-12, 64+/-12 ml/m2 vs 60+/-8 and 0.95+/-0.2 vs 1.0+/-0.2, respectively) and reduced vs EH (119+/-15, p<0.001, 78+/-9, p<0.05 and 1.52+/-0.15, p<0.01). Despite BS/GS's higher plasma renin activity and aldosterone and unchanged level of AT1R, Ang II induced ERK1/2 phosphorylation was reduced vs both C and EH: 0.64 d.u.+/-0.08 vs 0.90+/-0.06 in C, p<0.006, and vs 1.45+/-0.07 in EH, p<0.001. CONCLUSION: The data point to a direct cardioremodeling role for Ang II and support a role of Ang II type 2 receptor (AT2R) signaling as involved in the lack of cardiovascular remodeling in BS/GS. However, further studies using more direct approaches to demonstrate the effects of AT2R signaling must be pursued.

Myocardial perfusion defects in Bartter and Gitelman syndromes.

BACKGROUND: Normotensive hypokalaemic tubulopathies (Bartter and Gitelman syndromes (BS/GS)) are genetic diseases that are considered benign. However, QT prolongation, left ventricular dysfunction and reduction of cardiac index upon exercise leading to arrhythmias and sudden cardiac death have been reported in these patients. Hence, we aimed to verifying whether an isometric exercise could represent a useful tool for the identification of patients at risk for future cardiac events. PATIENTS AND METHODS: Myocardial function (MF) and perfusion, evaluated as myocardial blood flow (MBF) of 10 BS/GS patients and 10 healthy controls, were investigated at rest and during isometric exercise. MF and MBF were evaluated using quantitative two-dimensional and myocardial contrast echocardiography. RESULTS: BS/GS patients had normal baseline MF and MBF. During exercise in BS/GS patients, corrected QT (QTc) was prolonged to peak value of 494 +/- 9.1 ms (P < 0.001). In controls, MF increased from resting to peak exercise (left ventricular ejection fraction: 65 +/- 4% to 78 +/- 5%, P < 0.003) while in seven BS/GS patients (Group 1) it declined (64 +/- 5% to 43 +/- 9%, P < 0.001). Myocardial perfusion increased upon exercise in controls as shown by changes of its markers: beta (a measure of myocardial flow velocity; 0.89 +/- 0.12 vs. 0.99 +/- 0.12, P < 0.001) and myocardial blood volume (14.4 +/- 2 vs. 20.2 +/- 0.25, P < 0.001), while in Group 1 BS/GS it decreased (0.87 +/- 0.15 vs. 0.67 +/- 0.15, P < 0.001; and 14.5 +/- 1.9 vs. 8.3 +/- 0.22, P < 0.001, respectively). CONCLUSIONS: Our results document for the first time that exercise induce coronary microvascular and myocardial defects in BS/GS patients. Therefore, this may challenge the idea that BS/GS are benign diseases. In addition, the diagnostic approach to these syndromes should include an in-depth cardiac assessment in order to identify patients at higher risk.

Primary aldosteronism - part I: prevalence, screening, and selection of cases for adrenal vein sampling.

Over the last few years compelling evidence has been gathered to support the view that primary aldosteronism (PA) is far more prevalent than usually held: its prevalence rate among consecutive newly diagnosed hypertensive patients referred to hypertension centers can be as high as 11.2%. Moreover, about 4.8% of cases are a surgically curable endocrine form of hypertension, and the majority of cases do not exhibit hypokalemia at the time of clinical presentation. The impact of these results on the strategy to be used in the clinical investigation of patients with hypertension is discussed in light of novel information on the optimal screening strategy to be used for pinpointing the PA patients from the vast array of hypertensive patients.

Primary aldosteronism: part II: subtype differentiation and treatment.

After discussing in Part I (Rossi et al, J Nephrol. 2008;21:447-454) the screening strategy to identify the hypertensive patients with primary aldosteronism (PA), we report here an update on the methodology for the further diagnostic work-up and treatment of PA patients. The most common forms of PA are aldosterone-producing adenoma (APA) and adrenocortical hyperplasia (BAH), which are unilateral or bilateral sources of aldosterone excess secretion, respectively. Since APA needs a surgical approach, in contrast to BAH which requires medical treatment, it is crucial to clearly delineate a diagnostic work-up aimed at discriminating the 2 forms. Clinical usefulness and accuracy of adrenal vein sampling, imaging tests (e.g., computed tomography and magnetic resonance) and mineralocorticoid adrenocortical scintigraphy are discussed in detail.

Endocrine arterial hypertension: therapeutic approach in clinical practice.

This review describes the therapeutic approach of endocrine arterial hypertension in clinical practice. In mineralocorticoid-related hypertension, adrenalectomy is the treatment of choice for aldosterone-producing adenomas and monolateral primary aldosteronism, whereas pharmacologic blood pressure (BP) control is indicated for the other forms of primary aldosteronism such as bilateral adrenal hyperplasia. Spironolactone is the drug of choice, but intolerable side effects limit its use; amiloride or eplerenone are a valid alternative. If BP remains uncontrolled, angiotensin converting enzyme inhibitors (ACE-I), angiotensin II receptor antagonists (AII-RA) and calcium channel blockers (CCB) may be added. Hypertension accompanying Cushing's syndrome can be approached with surgery, but antihypertensive treatment both pre- and postoperative is required as well. Eplerenone, AII-RA and ACE-I are indicated, while peroxisome proliferator activated receptor upsilon agonists may help for the insulin resistance syndrome. Drugs that suppress steroidogenesis should be used with care because of their serious side effects. Subjects with catecholamine-dependent hypertension due to a neuroendocrine neoplasm need to undergo preoperative alpha-adrenergic blockade with phenoxybenzamine or doxazozine. When adequate alpha-adrenergic blockade is achieved, beta-adrenergic blockade with low dose propranolol may be added. If target BP is not achieved, CCB and/or metyrosine are indicated. Laparoscopic adrenalectomy is the procedure of choice for solitary intra-adrenal neoplasms <8 cm. Acute hypertensive crises that may occur before or during surgery should be treated intravenously with sodium nitroprusside, phentolamine, nicardipine or labetalol. For malignant neoplasms, chemo- and radiopharmaceutical therapy may be considered.

Endocrine arterial hypertension: diagnostic approach in clinical practice.

Endocrine arterial hypertension (EAH) a condition in which hormone excess results in clinically significant hypertension is a rare cause of hypertension. However in the last years its prevalence has increased, mostly due to the improvement of diagnostic work-up. In clinical practice, hypertensive subjects with suspicion of EAH currently undergo hormonal screening of the renin-aldosterone and catecholamines and glucocorticoids excess. This paper reviews current understanding for earlier recognition of the main forms of EAH and discusses screening laboratory methods and localization techniques that have enhanced the clinician's ability to make the diagnosis of EAH. Primary aldosteronism (PA) has recently been recognised as the most frequent cause of EAH. The aldosterone to renin ratio (ARR) is a highly recommended screening test for PA. When ARR is increased, confirmatory tests as saline infusion or fludrocortisone suppression are required. Differential diagnosis of PA requires adrenal gland imaging by computed tomography (CT) or magnetic resonance imaging (MRI), biochemical testing of the aldosterone response to posture, and selective adrenal venous sampling to differentiate unilateral aldosterone-producing adenoma from bilateral hyperplasia. Hypertension is frequently found in endogenous Cushing's Syndrome (CS). Twenty-four-hour urinary free cortisol measurement is the gold standard for the diagnosis of CS, but it must be confirmed by the overnight dexamethasone suppression test. CT and MRI are the primary imaging studies to perform, while scintigraphy is a useful confirmatory method. The most specific and sensitive diagnostic test for catecholamine-producing neoplasms is determination of urinary metanephrine levels; the neoplasms can be located by CT, MRI and metaiodo-benzylguanidine scintigraphy.

Intravenous thrombolysis in the emergency department for the treatment of acute ischaemic stroke.

BACKGROUND AND AIMS: Thrombolytic therapy with intravenous recombinant tissue plasminogen activator (rt-PA) improves outcome in patients with ischaemic stroke treated within 3 h of symptom onset, but its extended implementation is limited. A pilot study was designed to verify whether evaluation of patients with acute ischaemic stroke and their treatment with intravenous rt-PA in the emergency department (ED), followed by transportation to a semi-intensive stroke care unit, offers a safe and effective organisational solution to provide intravenous thrombolysis to acute stroke patients when a stroke unit (SU) is not available. METHODS: After checking for inclusion and exclusion criteria, ED doctors contacted the stroke team with a single page, located family members and urgently obtained computed tomography scan and laboratory tests. A stroke team investigator clinically assessed the patient, obtained written informed consent and supervised intravenous rt-PA in the ED. After treatment, the patient was transferred to the SU for rehabilitation and treatment of complications, under supervision of the same stroke team investigator. RESULTS: 52 patients were treated with intravenous rt-PA within 3 h of symptom onset. 20 patients (38%) improved neurologically after 24 h, the number increased to 30 (58%) after one week. At 3 months 22 patients had a favourable outcome (43%). The 3-month mortality rate was 12%. Symptomatic cerebral haemorrhage was observed in two patients (4%). CONCLUSIONS: Intravenous rt-PA administration in the ED is an effective organisational solution for acute ischaemic stroke when an SU is not established.

Mitochondrial function, apoptosis and cell cycle delay in the WEHI-3B leukaemia cell line and its variant Ciprofloxacin-resistant WEHI-3B/CPX.

OBJECTIVE: The susceptibility of two cell lines, WEHI-3B myelomonocytic leukaemia and its variant Ciprofloxacin-resistant WEHI-3B/CPX to undergo apoptosis induced by Ciprofloxacin was studied and compared. MATERIALS AND METHODS: Apoptosis was checked by measuring the DNA fragmentation and determining the ratio of apoptotic/necrotic cells. The relationship between the induction of apoptosis and G(1), S or G(2) block in the cell cycle has also been investigated and cytogenetical evaluation of chromosomal aberrations in both cell lines has been carried out. The regulation of expression of Bax and Bcl-2 was also checked by western blotting after Ciprofloxacin treatment. RESULTS: We observed that the resistance of the subline was caused by a small percentage of cells that underwent apoptosis during continuous exposure to Ciprofloxacin in comparison with the parental cell line, whereas the percentage of necrotic cells remained unchanged. The WEHI-3B cells showed a G(2) block and a higher degree of cytogenetic damage after drug exposure. The two cell lines expressed the same level of Bax and Bcl-2 following stimulation by Ciprofloxacin. Only in the resistant subclone, the ratio Bcl-2/Bax reversed in the anti-apoptotic gene expression. CONCLUSION: The resistance to ciprofloxacin observed is not related to mitochondrial function and although Bcl-2/Bax ratio behaviour does not fully explain the resistance of the WEHI3B/CPX subclone it is consistent with phenotypic character of resistance to CPX. The toxic effect on sensitive cells could be mediated by the cell cycle arrest whereas in the resistant clone, the prolonged G(2) phase could play a key role to favour cell cycle progression and proliferation.

Gene expression, localization, and characterization of endothelin A and B receptors in the human adrenal cortex.

Compelling evidence indicates that the endothelium-derived potent vasoconstrictor endothelin-1 (ET-1) stimulates aldosterone secretion by interacting with specific receptors. Although two different ET-1 receptors have been identified and cloned, the receptor subtype involved in mediating aldosterone secretion is still unknown. Accordingly, we wished to investigate whether the genes of ET-1 and of its receptors A and B are expressed in the normal human adrenal cortex. We designed specific primers for ET-1 and the ETA and ETB receptors genes and developed a reverse transcription polymerase chain reaction (RT-PCR) with chemiluminescent quantitation of the cDNA. In addition, we carried out 125I ET-1 displacement studies with cold ET-1, ET-3 and the specific ETA and ETB ligands BQ123 and sarafotoxin 6C. Localization of each receptor subtype was also investigated by autoradiography. Binding experiments were first individually analyzed by Scatchard and Hofstee plot and then coanalyzed by the nonlinear iterative curve fitting program Ligand. Histologically normal adrenal cortex tissue, obtained from kidney cancer patients (n = 7), and an aldosterone-producing adenoma (APA), which is histogenetically derived from the zona glomerulosa (ZG) cells, were studied. Results showed that the ET-1, ETA and ETB mRNA can be detected by RT-PCR in all adrenal cortices as well as in the APA. The best fitting of the 125I ET-1 displacement binding data was consistently provided by a two-site model both in the normal adrenal cortex (F = 22.1, P < 0.0001) and in the APA (F = 18.4, P < 0.0001). In the former the density (Bmax) of the ETA and ETB subtype was 2.6 +/- 0.5 pmol/mg protein (m +/- SEM) and 1.19 +/- 0.6, respectively. The dissociation constant (Kd) of ET-1, ET-3, S6C, and BQ-123 for each receptor subtype resulted to be within the range reported for human tissue for the ETA and ETB receptors. In the APA tissue the Bmax tended to be lower (1.33 and 0.8 pmol/mg protein, for the ETA and ETB, respectively) but the Kd were similar. Autoradiographic studies confirmed the presence of both receptor subtypes on the ZG as well as on APA cells. Thus, the genes of ET-1 and both its receptor subtypes ETA and ETB are actively transcribed in the human adrenal cortex. Furthermore, both receptor subtypes are translated into proteins in ZG and APA cells.

The Super-Magenstrasse and Mill operation with pyloroplasty: preliminary results.

BACKGROUND: Our strategy for performing various types of bariatric operations in order to make them suitable for the individual morbidly obese patient, has led us to take into account the original Magenstrasse and Mill (M&M) operation and modify it. This resulted in the so-called Super-Magenstrasse and Mill with pyloroplasty (SM&M-P). METHODS: In the past 3 years, 34 patients with mean BMI 48 and mean age 43 years underwent the SM&MP operation for morbid obesity. A digitoclasic pyloroplasty was performed and a 36-Fr bougie was used to calibrate the Magenstrasse. A 21-mm circular stapler was used to create a gastric window 10 cm proximal to the pylorus. The stapled division of the stomach to 3-4 cm from the pylorus and to the angle of His was performed first distally via the gastric window and then proximally from the window. RESULTS: 2 patients have reached 3 years since the operation: one could not be assessed due to the development of rectal cancer 1 year after surgery, and the other one has had an excellent outcome with 3-year BMI 26 kg/m2. 8 patients who underwent the surgery 2 years ago have a mean percent excess BMI loss (%EBL) of 69, and 19 patients who have reached 1 year have %EBL 64. All patients have experienced a clear reduction of appetite, with vomiting absent or rare. CONCLUSIONS: The SM&M-P procedure confers to this restrictive intervention some characteristics similar to gastric bypass, including rapid transit of the alimentary contents in the prepyloric "mill", scarse reflux into the gastric fundus, possible entero-endocrine effects and loss of interest in food.