Contrast-enhanced ultrasonography of peripheral soft-tissue tumors: Feasibility study and preliminary results

OBJECTIVES

To determine the diagnostic value of contrast-enhanced ultrasonography, to differentiate benign and malignant soft-tissue tumors and to assess the feasibility and interest of modelling enhancement curves.

PATIENTS AND METHODS

This retrospective study includes 118 patients with soft-tissue tumors, examined with ultrasound after injection of SonoVue(®), a contrast product. The raw data were treated with CHI-Q acquisition software to model the enhancement curves. We analyzed tumor uptake of the contrast product visually and studied the enhancement curves, characterized by five parameters: peak intensity, time to peak, mean transit time, initial slope, and area under the curve.

RESULTS

There were 81 benign and 37 malignant tumors. For a diagnosis of benign tumor, the absence of contrast uptake had a sensitivity of 60%, a specificity of 68%, a positive predictive value of 50% and a negative predictive of 83%. Study of the 70 curves obtained (48 benign and 22 malignant tumors) showed that the parameters of area under the curve (Chi(2)=8.6 and P<0.005), slope (Chi(2)=8.12 and P=0.004), and peak intensity (Chi(2)=7.55, P=0.005) differed significantly between the two populations.

CONCLUSION

Absence of contrast uptake suggests a benign lesion. The study of enhancement curves showed significant differences between the different tumor populations.

Modulation of serum uric acid levels by inosine in patients with multiple sclerosis does not affect blood pressure

The role of uric acid (UA) in human physiology is subject to controversy. Either it is an important radical scavenger, a mostly neutral, waste metabolic product that may cause gout and kidney stones if elevated, or it is involved in the causation of hypertension, vascular and renal diseases. Recently we conducted a clinical trial to determine whether raising the serum UA levels through the oral administration of inosine is well tolerated and may benefit patients with multiple sclerosis. An important aspect of the safety profile is whether raising the serum UA levels elevates blood pressure. During the 1-year trial, blood pressure and serum UA levels were monitored in 16 patients. Both parameters were recorded throughout the trial that included 69 visits by patients at baseline and during the placebo phase as well as 138 visits while receiving inosine treatment. We have observed that although the serum UA levels increased significantly during the inosine treatment phase of the trial, from 4.2+/-0.8 to 7.1+/-1.7 mg per 100 ml, blood pressure remained unchanged, averaging 123+/-15/78+/-9. Our findings indicate that raising the serum UA levels to upper normal physiological levels for a period of up to 1-year does not influence blood pressure significantly.

S6K1 deficiency protects against apoptosis in hepatocytes

The mammalian target of rapamycin (mTOR)/S6K1 signaling pathway controls cell growth and proliferation. To assess the importance of S6K1 in the balance between death and survival in the liver, we have generated immortalized hepatocyte cell lines from wild-type and S6K1-deficient (S6K1(-/-)) mice. In S6K1(-/-) hepatocytes, caspase-8 and the pro-apoptotic protein Bid were constitutively down-regulated as compared with wild-type. Moreover, S6K1(-/-) hepatocytes failed to respond to the apoptotic trigger of death receptor activation. Neither caspase-8 activation nor FLIP(L) degradation in response to tumor necrosis factor alpha (TNF-alpha) or anti-Fas antibody (Jo2) was observed in cells lacking S6K1. Downstream events such as Bid cleavage, cytochrome C release, caspase-3 activation, DNA laddering, as well as the percentage of apoptotic cells were attenuated as compared with wild-type. In addition, the anti-apoptotic protein Bclx(L) was down-regulated in TNF-alpha-treated or Jo2-treated wild-type hepatocytes, but this response was abolished in S6K1(-/-)cells. In vivo, S6K1-deficient mice were protected against concanavalin A-induced apoptosis. The withdrawal of growth factors strongly induced apoptosis in wild-type, but not in S6K1(-/-) hepatocytes. S6K1 deficiency did not decrease Bclx(L)/Bim ratio on serum withdrawal, thereby protecting cells from cytochrome C release and DNA fragmentation. At the molecular level, the lack of S6K1-mediated negative feedback decreased insulin receptor substrate-1 (IRS-1) serine phosphorylation, resulting in activation of survival pathways mediated by phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase (ERK). However, S6K1(-/-) hepatocytes underwent apoptosis on serum withdrawal in combination with phosphatidylinositol 3-kinase (PI3K) or ERK inhibitors.

CONCLUSION

This finding might explain the mechanism of resistance to mTOR inhibitors in cancer treatments and strongly suggests that the inhibition of S6K1 could protect against acute liver failure and, in combination with inhibitors that abrogate the sustained activation of Akt and ERK, could improve the efficacy of hepatocarcinoma (HCC) treatment.

Weight Loss Comparison of Gastric Bypass and Silastictrade mark Ring Vertical Gastroplasty

Thirty-five patients who had undergone primary bariatric surgery between 14 January 1988 and 16 September 1990 were selected for retrospective analysis based on the availability of 3-month and 1-year (+/- 3 months) follow-up visit records. Fourteen patients had undergone a Roux-en-Y gastric bypass (RGB), and 21 patients had undergone a Silastictrade mark ring vertical gastroplasty (SRVG). Weight loss, pre- and postoperative body mass index (BMI), and the postoperative incidence of dumping syndrome, anemia, and food intolerance were compared. At 1 year (+/- 3 months), the average weight loss was 40 kg for the entire group. The RGB patients lost an average of 41.7 kg, while the SRVG patients lost an average of 39.4 kg (not significant). The average preoperative BMI was 46.4 kg/m(2) for both the RGB and SRVG patients. The 1-year postoperative BMI was 30.6 kg/m(2) for the RGB patients and 32.4 kg/m(2) for the SRVG patients (not significant). One RGB patient developed a dumping syndrome, and one RGB patient showed evidence of a nutritional anemia. Neither complication was incapacitating. The SRVG patients had far more difficulty in advancing the consistency and variety of their diet in the early postoperative period, with only 62% (13/21) of the SRVG patients demonstrating an ability to tolerate a regular consistency diet at the end of 1 year. Seventy-six percent (16/21) of the SRVG patients reported occasional vomiting at 1 year, compared to only 7% (1/14) of the RGB patients. This retrospective analysis documented comparable weight loss for the RGB and SRVG operations. A greater incidence of eating problems up to 1 year postoperatively was observed in patients following SRVG in comparison to RGB.

Cation activities in reversible ischemia of the cat brain

In normothermic anesthetized cats cerebral blood flow was interrupted completely for one hour by arterial clamping and induced hypotension. The effect of ischemia on the ionic gradients of the cerebral cortex was assayed by determining total cortical electrolytes and by recording the activities of extracellular potassium ([K+i1e) and subarachnoid sodium ions ([Na+])s) with ion-sensitive electrodes. During ischemia [K+]e increased from 3.3+/-0.3 to 56+/-5.4 mEq per liter (means+/-SE) and [Na+]s decreased from 133+/-3.8 to 53+/-5.8 mEq per liter. When the brains were recirculated with blood after one hour's ischemia, [K+]e and [Na+]a gradually returned to normal within 45 minutes. The calculated intracellular uptake of sodium during ischemia amounted to 139 mEq per kilogram dry weight, whereas the intracellular release of potassium was only 64 mEq per kilogram. The increase in intracellular cation was accompanied by a movement of water from the extracellular into the intracellular compartment, causing a reversible shrinkage of the extracellular space from 18.9 to 8.5 vol %. The changes in ionic gradients were related to the development and resolution of ischemic brain swelling, and to the elctrophysiological events during and after ischemia.

Using volunteer therapists to reduce hospital readmissions

Two aftercare programs using volunteers as therapists for former inpatients have been effective in reducing hospital readmissions. The volunteer therapists ensure that patients take medications, evaluate them for decompensation, help them find housing and jobs, and give them supportive counseling. In the first program the recidivism rate after one year for 36 chronic schizophrenic women was 11 per cent for the group treated by volunteers and 34 per cent for the control group receiving traditional aftercare. In the second program the recidivism rate after one year for 11 men and women with various types of schizophrenia was 9 per cent for the treatment group and 37 per cent for the control group.