GIP mediates the incretin effect and glucose tolerance by dual actions on α cells and ß cells.

Glucose-dependent insulinotropic polypeptide (GIP) communicates nutrient intake from the gut to islets, enabling optimal levels of insulin secretion via the GIP receptor (GIPR) on ß cells. The GIPR is also expressed in α cells, and GIP stimulates glucagon secretion; however, the role of this action in the postprandial state is unknown. Here, we demonstrate that GIP potentiates amino acid-stimulated glucagon secretion, documenting a similar nutrient-dependent action to that described in ß cells. Moreover, we demonstrate that GIP activity in α cells contributes to insulin secretion by invoking paracrine α to ß cell communication. Last, specific loss of GIPR activity in α cells prevents glucagon secretion in response to a meal stimulus, limiting insulin secretion and driving glucose intolerance. Together, these data uncover an important axis by which GIPR activity in α cells is necessary to coordinate the optimal level of both glucagon and insulin secretion to maintain postprandial homeostasis.

Sustained release of a GLP-1 and FGF21 dual agonist from an injectable depot protects mice from obesity and hyperglycemia.

There is great interest in identifying a glucagon-like peptide-1 (GLP-1)-based combination therapy that will more effectively promote weight loss in patients with type 2 diabetes. Fibroblast growth factor 21 (FGF21) is a compelling yet previously unexplored drug candidate to combine with GLP-1 due to its thermogenic and insulin-sensitizing effects. Here, we describe the development of a biologic that fuses GLP-1 to FGF21 with an elastin-like polypeptide linker that acts as a sustained release module with zero-order drug release. We show that once-weekly dual-agonist treatment of diabetic mice results in potent weight-reducing effects and enhanced glycemic control that are not observed with either agonist alone. Furthermore, the dual-agonist formulation has superior efficacy compared to a GLP-1/FGF21 mixture, demonstrating the utility of combining two structurally distinct peptides into one multifunctional molecule. We anticipate that these results will spur further investigation into GLP-1/FGF21 multiagonism for the treatment of metabolic disease.

Cystamine potently suppresses in vitro HIV replication in acutely and chronically infected human cells.

We have investigated the effects of cystamine on the replication of human immunodeficiency virus (HIV) in human lymphocytes and macrophages, the natural targets of HIV in vivo. Treatment of chronically infected macrophages with cystamine, at a concentration (500 microM) that did not show any cytotoxic or cytostatic effects, strongly decreased (> 80%) HIV-p24 antigen production and completely abolished the production of infectious viral particles. Cystamine does not affect viral transcription, translation or protein processing; indeed, all HIV proteins are present in a pattern similar to that of nontreated cells. Instead, cystamine interferes with the orderly assembly of HIV virions, as shown by electron microscopy analysis, that reveals only defective viral particles in treated cells. Moreover, suppression of HIV replication, due to the inhibition of proviral DNA formation was observed in acutely infected lymphocytes and macrophages pretreated with cystamine. These results show that cystamine potently suppresses HIV replication in human cells by contemporaneously blocking at least two independent steps of the viral life cycle, without affecting cell viability, suggesting that this compound may represent a new possibility towards the treatment of HIV-1 infection.

Fourteen years of hemodialysis with a central venous catheter: mechanical long-term complications.

The ideal dialysis access ensures adequate blood flow for dialysis, has a long life, and is associated with a low complication rate. Although no current type of access fulfills all these criteria, the native arteriovenous fistula (AVF) is close to doing so. Unfortunately, various kinds of vascular access (VA) are becoming more and more necessary to enable hemodialysis (HD). The central venous catheter (CVC), which is associated with higher morbidity and mortality, could be the only viable option to maintain permanent VA. We report an unusual complication in a patient, a 74-year-old female, who had been undergoing HD via a CVC for 14 yrs. A polyurethane CVC with a double lumen was inserted into the right internal jugular vein because an AVF was not feasible, and a polytetrafluoroethylene (PTFE) prosthesis was obstructed. In 2003, the CVC was removed due to stenosis and occlusion of the superior vena cava. A new CVC, also made of polyurethane and with a double lumen, was inserted into the left femoral vein. In January 2005, the patient reported a small rupture of about 3-4 mm located under the cuff of the CVC. For this reason, the left femoral vein had to be used, replacing the Optiflow one with a 40-cm long Tesio CVC, and the second catheter was inserted into the right femoral artery by conventional surgery. After 10 months, the patient returned once more, after the CVC in the left femoral vein had been removed because of malfunction and that the at-tempts to cannulate the same vein again had failed. Currently, two 70-cm long Tesio catheters implanted in the right femoral vein (whose tips almost reach the diaphragm) are used for dialysis sessions. The number of CVC implants has progressively increased amongst HD patients who are elderly, diabetic or who have been on long-term HD. The patient described in this case report is currently using a 70-cm long double Tesio catheter (single Tesio CVC in SPI silicon) placed in the right femoral vein. She has resumed therapy with dicumarol anticoagulants, maintaining INR within the 2.5-3.5 range. In conclusion, both the increase in the use of venous catheters for HD and in the survival of dialysis patients contribute towards the observation of rare complications associated with CVC use.

Quinoxalinylethylpyridylthioureas (QXPTs) as potent non-nucleoside HIV-1 reverse transcriptase (RT) inhibitors. Further SAR studies and identification of a novel orally bioavailable hydrazine-based antiviral agent.

Quinoxalinylethylpyridylthioureas (QXPTs) represent a new class of human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs) whose prototype is 6-FQXPT (6). Docking studies based on the three-dimensional structure of RT prompted the synthesis of novel heteroarylethylpyridylthioureas which were tested as anti-HIV agents. Several compounds proved to be potent broad-spectrum enzyme inhibitors and significantly inhibited HIV-1 replication in vitro. Their potency depends on the substituents and the nature of the heterocyclic skeleton linked to the ethyl spacer, and structure-activity relationships are discussed in terms of the possible interaction with the RT binding site. Although the new QXPTs analogues show potent antiviral activity, none of the compounds tested overcome the pharmacokinetic disadvantages inherent to ethylpyridylthioureidic antiviral agents, which in general have very low oral bioavailability. Through an integrated effort involving synthesis, docking studies, and biological and pharmacokinetic evaluation, we investigated the structural dependence of the poor bioavailability and rapid clearance within the thioureidic series of antivirals. Replacing the ethylthioureidic moiety with a hydrazine linker led to a new antiviral lead, offering promising pharmacological and pharmacokinetic properties in terms of antiviral activity and oral bioavailability.

Macrophage-colony stimulating factor (M-CSF) stimulation induces cell death in HIV-infected human monocytes.

We show here that HIV-infected monocyte-macrophages stimulated by macrophage-colony stimulating factor (M-CSF) undergo massive syncytia formation and die. The M-CSF-stimulated HIV-infected monocyte-macrophages (M/M) destroy themselves by blebbing out particles (resembling apoptotic bodies) which may contain condensed and marginated chromatin. The death of monocyte-macrophages is also characterized by the expression of "Tissue" Transglutaminase (tTG) which is one of the genes specifically expressed and activated in apoptising cells. Noteworthy, when the syncytia formation and consequently death is prevented, infected monocyte-macrophages remain viable and produce large amounts of virus for an extended period. The concentrations of M-CSF (1000 U/ml) used in this work are similar to those that stimulate macrophages in vivo. This suggests that HIV killing of M/M in the presence of M-CSF could lead, in vivo, to a greater than expected loss of immune cells and may contribute to explain the complex derangement of the immune function observed in HIV-infected patients.

Selective inhibition of HIV replication by adriamycin in macrophages but not in lymphocytes.

Adriamycin (ADR) is an anticancer drug commonly used in the treatment of HIV-related cancers. Due to its effect on DNA metabolism, ADR might be able to modulate HIV replication in monocyte-macrophages (M/M), resting cells potentially less sensitive to the toxic effect of this drug. Thus, we assessed the efficacy of ADR against HIV replication in both lymphocytes and M/M. We further investigated the mechanism(s) of action of ADR and its potential synergistic activity with zidovudine (AZT) or alpha-interferon (IFN alpha). ADR consistently inhibited viral replication in M/M: 50% viral inhibition was obtained with 0.005 micrograms/ml ADR, while greater 90% viral inhibition was obtained with 0.05 micrograms/ml ADR. No cell toxicity was seen in M/M at concentrations up to 0.5 micrograms/ml. No anti-HIV activity was shown by ADR in lymphocytes at concentrations up to 0.05 micrograms/ml, that is also the toxic dose 50% (TCID50 for these cells). ADR neither inactivates HIV virions nor affects HIV binding with CD4 receptors. No inhibition of HIV reverse transcriptase by ADR was found at concentrations at least 2,000-fold greater than the 50% HIV inhibitory concentration in M/M. Molecular analysis by polymerase chain reaction (PCR) suggests that ADR substantially affects virus DNA production at concentrations that inhibit viral replication. Finally, late stages of HIV replication were not affected by ADR. At least additive effects of the association ADR + AZT and ADR + IFN alpha were obtained against de novo HIV infection of M/M.(ABSTRACT TRUNCATED AT 250 WORDS)

A tetrazolium-based colorimetric assay for quantification of HIV-1-induced cytopathogenicity in monocyte-macrophages exposed to macrophage-colony-stimulating factor.

A sensitive assay was developed for in vitro evaluation of anti-HIV agents in monocyte-macrophage cells (M/M) (a crucial target of HIV in the body). Monocyte-macrophage cells are usually poorly sensitive to the cytopathic effect induced by HIV. However, when fresh adherent monocyte-macrophage cells are cultured at relatively high density in the presence of macrophage-colony stimulating factor (M-CSF), they undergo cytolysis and die in 2-3 weeks. HIV-mediated cell-killing can thus be assessed with a method based on the reduction of the yellow colored 3-(4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) by metabolically active cells to a blue formazan, which can be measured spectrophotometrically. HIV-mediated cytopathic effect of M-CSF-exposed monocyte-macrophage cells was consistently achieved in all experiments performed under the conditions described herein. Anti-HIV activity of zidovudine (AZT) was also comparatively evaluated in M-CSF- and normal monocyte-macrophage cells both using the MTT assay and by measuring HIV-p24 antigen production in supernatants of monocyte-macrophage cells cultures, and similar results obtained with both methods. These results support the use of this colorimetric assay for broad screening of anti-HIV agents in monocyte-macrophage cells.

[Role of surgery in the multidisciplinary treatment of lithiasis of the common bile duct]. / Il ruolo della chirurgia nel trattamento multidisciplinare della litiasi della via biliare principale (VBP).

The efficacy of surgery was evaluated in 32 patients with common bile duct stones. Twenty-two patients have not undergone a previous cholecystectomy. In 13 cases an endoscopic approach was attempted before surgery. In 13 patients biliary-intestinal anastomoses were performed for large stones or bile duct strictures. In 19 cases common bile exploration with biliary drainage insertion was performed for uncomplicated biliary stones. We had no mortality and morbidity was 9%. We conclude that surgery is the treatment of choice in patients with gallbladder in situ or in cases of endoscopic failure. Endoscopic sphincterectomy may be preferred in poor-risk patients.

[Schwannoma of the ultimate ileal loop. Case report and review of the literature]. / Schwannoma dell'ultima ansa ileale. Case report e review della letteratura.

The paper reports a rare case of malignant ileal schwannoma. A review of the most recent literature confirms the diagnostic and therapeutic procedures used by the authors. Minimal resection or necessary resection in relation to the site and local situation are the only real therapy apart from palliative surgery. It is vital to identify any possible polycentric manifestation since schwannoma is often associated with Recklinghausen's disease. Radiotherapy and chemotherapy are completely ineffective. Responses were obtained in around 30% of cases in the most common trials; the gastrointestinal localization also appears to be even less responsive. The most active drugs are decarbazine, doxorubicin and ifosfamide, associated with CIVADIC or MAID polychemotherapy protocols. It is often difficult to diagnose malignancy; the overall survival rate (taking grading into account) is 7-10% after 10 years and 50% after 5 years for those forms with the lowest degree of malignancy. Antoni classified schwannoma into: type A with a solid component, and type B with a microcystic component. Treatment and prognosis are identical.

[Breast carcinoma in the elderly patient: which treatment?]. / Carcinoma mammario nell'anziano: quale trattamento?

We here describe our experience of the treatment of "breast cancer" in the elderly. The results in this group of patients (37 over 75 years) are like the younger group if: the local control is done; hormonotherapy is prescribed; chemotherapy is done even in the 70-80-year-old group. If a radical mastectomy isn't impossible in the patients over 80, even a simple mastectomy is safe. In this patients a conservative local treatment of the breast is not mandatory. Our over-75-year-old patients have no psychological problem related to mastectomy. They often don't accept obligatory radiotherapy after the conservative treatment of breast cancer, and moreover the breast cancer in the elderly is usual smaller, fibrotic and bigger than 3 cm. Lymph nodal status isn't important for overall survival, but only for the eventual chemotherapeutic treatment, so in patients over 80 year-old simple mastectomy is sufficient because we don't use chemotherapy for the general conditions of the same. The local control of axillary lymph nodes is obtained with radiotherapy if necessary. Screening for breast cancer must also include 70-75-year-old patients. Why is the breast cancer in elderly like the others patients? Some authors have seen that the immuno-reaction around the cancer in elderly is less than the same reaction observed in younger patients. So in the elderly there is a smaller production of "growth factors" important for the growth of the tumor and of "angiogenesis factor", fundamental for the initial growth of the cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

[Internal pancreatic fistulae. The authors' experience]. / Fistole pancreatiche interne. Nostra esperienza.

The paper describes the authors' personal experience of internal pancreatic fistulas. This is an uncommon pathology which should however be taken into account in the presence of ascites or pleural effusion without a clear cause. Essential diagnostic tests are chemical and physical examination and the assay of amylase in ascitic or pleural fluids. Medical treatment is sometimes efficient leading to the disappearance of the fistula. If medical therapy fails, surgery is necessary, based on pancreatic resection or the drainage of the cyst or interrupted pancreatic duct.

[Extranodal non-Hodgkin's lymphomas. Review and our experience]. / I linfomi non-Hodgkin extranodali. Review e nostra esperienza.

The authors report their experience concerning 12 cases of extranodal lymphoma (6 gastric, 1 duodenal, 2 ileal, 1 rectal, 1 splenic, 1 mammary). Extranodal lymphomas are increasing because of the high number of patients with AIDS and new extra-European immigration. Surgery is important not only for diagnosis, but above all for therapy. The great majority of extranodal lymphomas is diffuse rather nodular. Diffuse histiocytic type is the most commun pathologic feature. Prognosis of gastroenteric lymphomas is better than adenocarcinomas of gastrointestinal tract. The surgical techniques are the same as those used for the others tumors, and combined-modality therapy appears superior to local therapy alone for patients with extranodal disease characterized by unfavorable histology, site or stage. The classification is that of Ann Arbor, but for many authors the TNM system was an useful predictor of survival in patients treated with surgery.

[Cloacogenic carcinoma of the anus. Description of a clinical case]. / Carcinoma cloacogenico dell'ano. Descrizione di un caso clinico.

A clinical case of cloacogenic anal carcinoma is reported. These neoplasms, deriving from embryonal residuals at different levels of the ano-rectal junction, have a better prognosis than squamous carcinomas; the surgical alternative to abdomino-perineal resection is a simple local exeresis for small tumours that do not invade the muscular layer, with a good radical result as reported by the literature.

[Ano-rectal candidiasis]. / La candidosi ano-rettale.

The presence of candida and other fungi was investigated in 300 patients referred with anal problems of diverse aetiology. Candida was present in 13% and played a pathogenic role in about 50% of all positive cultures. It is concluded that cultural tests for fungal pathogens should always be performed in cases of anal itching or burning combined with other anal skin problems.

[Carcinoma of the parathyroid glands. Apropos of a case associated with thyroid struma]. / Carcinoma delle paratiroidi. A proposito di un caso associato a struma tiroideo.

The paper reports a case of carcinoma of the parathyroid associated with thyroid struma and underlines the difficulties of intraoperative diagnosis and the surgical approach which should be adopted on the basis of this finding. Often the diagnosis of the malignant nature of the neoplasia is based on the possible appearance of local or distant recurrence rather than histological examination.

The technique of reimplantation as it relates to bone defect.

Bone loss is the principal problem in hip prosthesis revision surgery; repair of this loss may identify the method itself of reimplantation. In light of thirteen years of hip reimplantation surgery the authors propose a classification of bone loss that correlates pathologic anatomy with surgical strategy. Thus, three types of acetabular bone loss and four types of femoral bone loss are distinguished, to which correspond just as many surgical strategies, aimed at an attempt to obtain stability of the revision implant and its longer duration in time.

[A rare complication in the suppression of a porto-systemic shunt in disabling encephalopathy]. / Considerazioni su una rara complicanza nella soppressione di shunt porto-sistemico per encefalopatia invalidante.

The authors describe an uncommon complication in a case of side-to-side portacaval shunt which was suppressed due to disabling portal-systemic encephalopathy; the patient was treated by esophageal transection with esophagogastric devascularization and nonoperative secondary occlusion of the shunt by external elastic traction on a Silastic catheter surrounding the anastomosis: a stenosis of the caval vein under traction required another operation in order to close the shunt.

[Enterohemorrhagic Escherichia coli O157:H7 infection]. / L'infezione da Escherichia coli entero-emorragico sierotipo O157:H7.

Infections in the digestive tract are due to multiple organism, which cause different syndromes. Escherichia coli O157:H7, already identified as a human pathogen in 1982, has been recognised as a major public health issue, being responsible for sporadic and epidemic cases of haemorrhagic colitis, often associated, in children and elderly, with the haemolytic uraemic syndrome. E. coli O157:H7 infection may occur everywhere, but is more frequent in North Europe, Canada, USA, Argentina and Japan, with annual incidence rates of 8 per 100,000 population. In Italy until 1997 the Italian National Institute of Health has identified 196 cases of haemolytic uraemic syndrome, in addition, an outbreak caused by E. coli O157:H7 occurred in 1993. In Italy the incidence of the haemolytic uraemic syndrome is 4-5 times lower than in Great Britain, Germany and other European countries. E. coli infection is more frequently associated with the ingestion of food from bovine and sheep origin and with infected water. The clinical spectrum includes an asymptomatic infection, non bloody diarrhoea, haemorrhagic colitis, haemolytic uraemic syndrome. When the E. coli infection is suspected, it is necessary to isolate the bacterium in a specialised laboratory. Treatment is essentially supportive in order to control anaemia and to maintain an adequate fluid and electrolyte balance, if necessary with the use of dialysis. The use of antimicrobial agents is currently under debate as there are controversial data on the risk of developing haemolytic uraemic syndrome.

A novel angiopoietin-derived peptide displays anti-angiogenic activity and inhibits tumour-induced and retinal neovascularization.

BACKGROUND AND PURPOSE: Pathological angiogenesis is associated with various human diseases, such as cancer, autoimmune diseases and retinopathy. The angiopoietin (Ang)-Tie2 system plays critical roles in several steps of angiogenic remodelling. Here, we have investigated the anti-angiogenic effect of a novel angiopoietin-derived peptide. EXPERIMENTAL APPROACH: Using computational methods, we identified peptides from helical segments within angiopoietins, which were predicted to inhibit their activity. These peptides were tested using biochemical methods and models of angiogenesis. The peptide with best efficacy, A11, was selected for further characterization as an anti-angiogenic compound. KEY RESULTS: The potent anti-angiogenic activity of A11 was demonstrated in a multicellular assay of angiogenesis and in the chorioallantoic membrane model. A11 bound to angiopoietins and reduced the binding of Ang-2 to Tie2. A11 was also significantly reduced vascular density in a model of tumour-induced angiogenesis. Its ability to inhibit Ang-2 but not Ang-1-induced endothelial cell migration, and to down-regulate Tie2 levels in tumour microvessels, suggests that A11 targets the Ang-Tie2 pathway. In a rat model of oxygen-induced retinopathy, A11 strongly inhibited retinal angiogenesis. Moreover, combination of A11 with an anti-VEGF antibody showed a trend for further inhibition of angiogenesis, suggesting an additive effect. CONCLUSIONS AND IMPLICATIONS: Our results indicate that A11 is a potent anti-angiogenic compound, through modulation of the Ang-Tie2 system, underlining its potential as a therapeutic agent for the treatment of ocular and tumour neovascularization, as well as other pathological conditions that are dependent on angiogenesis.