Absence of inhibition by lipoprotein (a) inhibition of tPA induced thrombolysis in a patient's plasma milieu

The increase in Lp(a) is strongly correlated with premature coronary artery disease. The Apo(a) has striking homology to plasminogen. It was found in an in vitro purified system that Lp(a) competes with both plasminogen and tissue-type plasminogen activator (tPA) for fibrin binding sites, thus resulting in a decrease in fibrin-dependent plasminogen activation. In this study, plasma fibrinolysis was studied in a young patient who had a consistently high level of Lp(a) (198 mg/dl) and had suffered from cerebral thrombophlebitis 12 months previously. The patient had normal levels of plasma plasminogen and fibrinogen. The euglobulin lysis time before and after venous occlusion was not prolonged, and after the addition of tPA to the patient's plasma or whole blood, the clot lysis time was normal. The same result was obtained when the patient's plasma was depleted of Lp(a) before clotting. When the patient's plasma serpins were inhibited, plasminogen activation by tPA in the presence of several fibrin concentrations was normal, suggesting that the formation of the ternary complex tPA - plasminogen - fibrin was not inhibited by the presence of high levels of Lp(a). It is concluded that a consistently high level of Lp(a) in this patient did not inhibit tPA-dependent fibrinolysis, and the thrombotic episode was not therefore related to deficient thrombolysis.     

Evaluation of nuclear matrix protein 22 as a tumour marker in the detection of transitional cell carcinoma of the bladder.

OBJECTIVES: To evaluate the sensitivity and specificity of urinary nuclear matrix protein-22 (NMP22) in detecting bladder cancer, to compare the diagnostic performance of NMP22 alone and when corrected by urinary creatinine level, and to correlate NMP22 level with the histological and clinical characteristics of bladder cancer. PATIENTS, SUBJECTS AND METHODS: The study included 267 patients classified into five groups: group 1 comprised 111 patients with active transitional cell carcinoma (TCC) of the bladder; group 2 included 76 patients who had had bladder TCC but were being followed and were free of disease, as confirmed by cystoscopy; group 3 comprised 25 patients with benign urological diseases; group 4 included 25 patients with other malignant pathological conditions; group 5 constituted a control group of 30 healthy subjects free of urological diseases. Urinary NMP22 was measured using an enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curves were constructed to obtain the thresholds which gave optimal sensitivity and specificity for combinations of NMP22 alone and when corrected by urinary creatinine level. Stage, grade, tumour size, pattern of growth, focality and the presence of recurrence were recorded and their associations with NMP22 evaluated. RESULTS: The mean levels of NMP22 were 122.8, 5.1, 3.7, 2.3 and 0.3 U/mL for groups 1-5, respectively; overall, these values were significantly different (P<0.001). The mean (95% CI) optimal combination of 78.2% (69.3-85.5) sensitivity and 95.5% (87.3-99.0) specificity was obtained from the ROC analysis with a threshold value of 13.7 U/mL NMP22. When values were corrected by urinary creatinine levels, the threshold given by the best combination of sensitivity and specificity, at 73.2% (63.2-81.7) and 97.0% (89.6-99.5), respectively, was 3.0 U/mg creatinine. NMP22 level was statistically associated with stage, grade, tumour size and focality. CONCLUSIONS: Urinary NMP22 appeared to be a potential tumour marker for detecting TCC of the bladder; when corrected by urinary creatinine level, it might provide a better interpretation than when used alone. NMP22 correlated with the most relevant variables in bladder cancer. As a noninvasive adjunct, NMP22 might have a role in guiding urologists about the need for cystoscopy in such patients.     

Myths about vitamin B12 deficiency.

Neurologic manifestations of vitamin B12 deficiency are protean, including neuropathy, depression, and dementia. We present evidence to dispel confounding myths about vitamin B12 deficiency. Hematologic indices are normal in up to 30% of patients with vitamin B12 deficiency, and results of the Schilling test may be normal in patients with symptoms of deficiency. Isolated neuropathy or myelopathy may occur independently, but often appear concurrently. The neuropathy is primarily axonal and predominantly sensory. Myelopathy is caused by demyelinated areas in posterior and lateral columns. After therapy, recovery from neuropathy is incomplete or may extend for several years. Vitamin B12 replacement should not be withheld from patients with borderline vitamin B12 levels, since the consequences of allowing myelopathy, neuropathy, dementia, and mental disorders to worsen clearly outweigh any disadvantage of therapy.     

Anti-RhoA and anti-RhoC siRNAs inhibit the proliferation and invasiveness of MDA-MB-231 breast cancer cells in vitro and in vivo.

Overexpression of RhoA or RhoC in breast cancer indicates a poor prognosis, due to increased tumor cell proliferation and invasion and tumor-dependent angiogenesis. Until now, the strategy of blockage of the Rho-signaling pathway has used either GGTI or HMG-CoA reductase inhibitors, but they are not specific to RhoA or RhoC inhibition. In this study, a new approach with anti-RhoA and anti-RhoC siRNAs was used to inhibit specifically RhoA or RhoC synthesis. Two transfections of either RhoA or RhoC siRNA (8.5 nM) into MDA-MB-231 human breast cancer cells or HMEC-1 endothelial cells induced extensive degradation of the target mRNA and led to a dramatic decrease in synthesis of the corresponding protein. In vitro, these siRNAs inhibited cell proliferation and invasion more effectively than conventional blockers of Rho cell signaling. Finally, in a nude mouse model, intratumoral injections of anti-RhoA siRNA (100 microl at 85 nM) every 3 days for 20 days almost totally inhibited the growth and angiogenesis of xenografted MDA-MB-231 tumors. One may infer from these observations that specific inhibition of the Rho-signaling pathway with siRNAs represents a promising approach for the treatment of aggressive breast cancers.     

Systemic delivery of antiangiogenic adenovirus AdmATF induces liver resistance to metastasis and prolongs survival of mice

Systemic administration of Ad5-based recombinant adenovirus leads to preferential transduction of the liver. Using this property, we have assessed the potential of venous viral injection to deliver a recombinant antiangiogenic adenovirus to treat cancer dissemination and improve survival. The results demonstrate that venous injection of adenovirus AdmATF, which encodes a secretable mouse ATF (amino-terminal fragment of urokinase) known to inhibit angiogenesis, suppressed angiogenesis induced by colon cancer metastasis growth in mice liver and improved survival. Nude mice were injected intravenously with 5 X 10(9) PFU of AdmATF and subsequently challenged after a 3-day interval by intrasplenically injected human colon carcinoma cells (LS174T, 3 x 10(6)) that home to liver. Microscopic inspection revealed that, within the AdmATF-pretreated mice (n = 8), the size and number of liver-metastasized nodules on day 30 were remarkably reduced (80% in number, p < 0.05) compared with control mice (n = 7) pretreated in parallel with a control adenovirus. Metastatic growth-related liver weight gain was also inhibited up to 90%. AdmATF-specific capability that offers liver resistance to the apparition and growth of liver metastasis was shown to correlate with the inhibition of peritumoral and intratumoral angiogenesis (reduced by 79%, p < 0.01 as shown by anti-vWF immunostaining of liver sections) and a twofold increase in tumor necrotic area and an eightfold increase in apoptotic tumor cell number. This protective effect was still observed when the mice were challenged 10 days after venous AdmATF injection (visible metastasis nodules: 6.3+/-3.1, n = 7 for control mice versus 2.7+/-2.9, n = 10 for treated mice, p < 0.05). More importantly, the mean survival has been prolonged from 45.1 days (n = 9) to 83.3 days (n = 10, p < 0.05). Altogether, the high efficacy, although transient, in this experimental mice model strongly advocates the plausibility of transforming the liver into a dissemination resistant organ by antiangiogenic gene therapy through systemic delivery approach.     

Micro-ureteroscopy vs. ureteroscopy: effects of miniaturization on renal vascularization and intrapelvic pressure

Purpose

Ureteroscopy (URS) is related to complications, as fever or postoperative urinary sepsis, due to high intrapelvic pressure (IPP) during the procedure. Micro-ureteroscopy (m-URS) aims to reduce morbidity by miniaturizing the instrument. The objective of this study is to compare IPP and changes in renal haemodynamics, while performing m-URS vs. conventional URS.

Methods

A porcine model involving 14 female pigs was used in this experimental study. Two surgeons performed 7 URS (8/9.8 Fr), for 45 min, and 7 m-URS (4.85 Fr), for 60 min, representing a total of 28 procedures in 14 animals. A catheter pressure transducer measured IPP every 5 min. Haemodynamic parameters were evaluated by Doppler ultrasound. The volume of irrigation fluid employed in each procedure was also measured.

Results

The range of average pressures was 5.08–14.1 mmHg in the m-URS group and 6.08–20.64 mmHg in the URS (NS). 30 mmHg of IPP were not reached in 90% of renal units examined with m-URS, as compared to 65% of renal units in the URS group. Mean peak diastolic velocity decreased from 15.93 to 15.22 cm/s (NS) in the URS group and from 19.26 to 12.87 cm/s in the m-URS group (p < 0.01). Mean resistive index increased in both groups (p < 0.01). Irrigation fluid volume used was 485 mL in the m-URS group and 1475 mL in the URS group (p < 0.001).

Conclusions

m-URS requires less saline irrigation volumes than the conventional ureteroscopy and increases renal IPP to a lesser extent.

     

Predictors of oncological outcomes in T1G3 patients treated with BCG who undergo radical cystectomy

Purpose

To evaluate the oncological impact of postponing radical cystectomy (RC) to allow further conservative therapies prior to progression in a large multicentre retrospective cohort of T1-HG/G3 patients initially treated with BCG.

Methods

According to the time of RC, the population was divided into 3 groups: patients who did not progress to muscle-invasive disease, patients who progressed before radical cystectomy and patients who experienced progression at the time of radical cystectomy. Clinical and pathological outcomes were compared across the three groups.

Results

Of 2451 patients, 509 (20.8%) underwent RC. Patients with tumors?>?3 cm or with CIS had earlier cystectomies (HR?=?1.79, p?=?0.001 and HR?=?1.53, p?=?0.02, respectively). Patients with tumors?>?3 cm, multiple tumors or CIS had earlier T3/T4 or N?+?cystectomies. In patients who progressed, the timing of cystectomy did not affect the risk of T3/T4 or N?+?disease at RC. Patients with T3/T4 or N?+?disease at RC had a shorter disease-specific survival (HR?=?4.38, p?<?0.001), as did patients with CIS at cystectomy (HR?=?2.39, p?<?0.001). Patients who progressed prior to cystectomy had a shorter disease-specific survival than patients for whom progression was only detected at cystectomy (HR?=?0.58, p?=?0.024)

Conclusions

Patients treated with RC before experiencing progression to muscle-invasive disease harbor better oncological and survival outcomes compared to those who progressed before RC and to those upstaged at surgery. Tumor size and concomitant CIS at diagnosis are the main predictors of surgical treatment while tumor size, CIS and tumor multiplicity are associated with extravesical disease at surgery.

     

Junctional communication of pancreatic beta cells contributes to the control of insulin secretion and glucose tolerance

Proper insulin secretion requires the coordinated functioning of the numerous beta cells that form pancreatic islets. This coordination depends on a network of communication mechanisms whereby beta cells interact with extracellular signals and adjacent cells via connexin channels. To assess whether connexin-dependent communication plays a role in vivo, we have developed transgenic mice in which connexin 32 (Cx32), one of the vertebrate connexins found in the pancreas, is expressed in beta cells. We show that the altered beta-cell coupling that results from this expression causes reduced insulin secretion in response to physiologically relevant concentrations of glucose and abnormal tolerance to the sugar. These alterations were observed in spite of normal numbers of islets, increased insulin content, and preserved secretory response to glucose by individual beta cells. Moreover, glucose-stimulated islets showed improved electrical synchronization of these cells and increased cytosolic levels of Ca(2+). The results show that connexins contribute to the control of beta cells in vivo and that their excess is detrimental for insulin secretion.