Ofer Landau

Antiproliferative and differentiating effects of benzodiazepine receptor ligands on B16 melanoma cells

In this study, we evaluated the effect of several ligands active at the central-type and peripheral-type benzodiazepine receptor (BzR) (clonazepam, diazepam, PK11195 and Ro5-4864) on the growth and differentiation of B16 melanoma cells. All tested BzR ligands were able to suppress proliferation of the cells at the micromolar range and in a concentration-dependent manner. However, agents selectively active at the peripheral-type BzR (PK11195 and Ro5-4864) exhibited more potent antiproliferative activity. In addition, the BzR ligands were demonstrated to affect the cell cycle by reducing the percent of cells in the S phase and increasing the percent in the G2/M phase. BzR ligands induced cellular phenotypic alterations, which have been previously shown to be associated with melanoma cell differentiation. These alterations included: marked morphological changes, enhancement of melanogenesis, lipid accumulation and increase in the activity of gamma glutamyl transpeptidase. All BzR ligands induced a marked reduction in the concentration of UTP and most of them did the same in GTP and CTP, while ATP levels were not significantly altered. In summary, BzR ligands (clonazepam, diazepam, PK11195 and Ro5-4864) were found to exert antitumor effects in B16 melanoma cells. These findings encourage further studies of a possible therapeutic potential of BzR ligands in treatment of melanoma.

Acute Acalculous Cholecystitis versus Acute Calculous Cholecystitis: Review 1970-1988

Ultrasonography has led to an increase in the incidence of acute acalculous cholecystitis (AAC). Fifty-three patients with AAC are compared to 521 patients with acute calculous cholecystitis (ACC), bo

Rejuvenation of the Face and Neck: A Combination of Exoderm Peel and Neck Liposuction

Exoderm Peel is a modified phenol-based peel, utilized worldwide for the treatment of facial skin conditions such as rhytids, acne scars, and dyschromias in patients with fair and dark skin. The major disadvantage of Exoderm peel is its inadequacy on the neck skin. In recent years we have introduced neck liposuction as a complementary rejuvenation method. Combination of these two relatively noninvasive techniques creates a natural-looking cosmetic improvement of both neck and face.

Gangrenous Cholecystitis: Seventeen Years of Experience

Background: Gangrenous cholecystitis is a potentially lethal disease. We evaluated the magnitude of this complication from the aspect of pre- and postoperative findings and examined

Surgery for Acute Cholecystitis in the Elderly (> 80 Years)

In the last 15 years we operated on 618 patients for acute cholecystitis, of whom 60 were 80 years of age or more. Most of the ever-increasing number of patients within the hospital population who suf

Amino acid alcohols: growth inhibition and induction of differentiated features in melanoma cells

The effects of a series of D- and L-amino acid alcohols on the proliferation and phenotypic expression of B16 mouse melanoma cells were evaluated. B16 melanoma cells were incubated for different time intervals in the presence of D- or L-phenylalaninol (PHE), D- or L-alaninol (AL), D- or L-leucinol (LE), L-histidinol (HIS), L-tyrosinol (TYR) and L-methioninol (MET). All agents, including the D or L configuration, induced an anti-proliferative effect, although of considerably different magnitude. D-PHE was the most active growth inhibitor. The growth inhibitory effects were accompanied by phenotypic alterations, which included morphological changes and enhancement in the activities of NADPH cytochrome c reductase and tau-glutamyl transpeptidase. These phenotypic alterations correlated with the growth inhibitory effects of the different agents and seem to reflect a higher differentiated state.

Hemodynamic effects of laparoscopic radiofrequency ablation of liver tumors versus laparoscopic hepatic ultrasound examination

STUDY OBJECTIVE To compare the hemodynamic changes that occur during laparoscopic radiofrequency ablation of liver metastases with those occurring during laparoscopic ultrasound hepatic examination alone. DESIGN Prospective, observational study. SETTING Operating rooms of a university-affiliated hospital. PATIENTS 40 ASA physical status 2 and 3 patients with liver metastases. INTERVENTIONS 20 patients underwent laparoscopic radiofrequency ablation of liver tumors following laparoscopic ultrasound examination, and 20 had laparoscopic ultrasound examination alone. The anesthetic technique was standardized. MEASUREMENTS The primary endpoint of the study was the number of episodes of mean arterial pressure (MAP) < 70 mmHg. Secondary endpoints were significant differences between the groups in MAP, heart rate, cardiac index, ejection fraction (EF; both measured with thoracic bioimpedance), calculated systemic vascular resistance index (SVRI), and central venous pressure. MAIN RESULTS The number of episodes of MAP < 70 mmHg did not differ between groups: there were 9 episodes in the ultrasound alone group and 7 in the radiofrequency group (P = 0.668). Cardiac index, EF, and SVRI were similar between groups. Central venous pressure was slightly higher in the radiofrequency group [11.99 (10.8-13.2) mmHg vs. 10.3 (9.2-11.4) mmHg, P = 0.04]. CONCLUSIONS Hemodynamic profiles were similar when comparing laparoscopic radiofrequency ablation of liver metastases with laparoscopic ultrasound hepatic examination alone.

Incarcerated Hernia: Are You Sure, Doctor?

Groin and abdominal wall hernias constitute a frequent condition and contribute substantially to both elective and emergency surgery. Incarcerated hernias, given their dangerous potential, are usually

Incidental Cholecystectomy Does Not Increase the Risk of Surgery for Gastrointestinal Malignancy

From 1975 to 1994, 291 incidental cholecystectomies were performed in our department, 143 of them during surgery for gastrointestinal tumors. The number of incidental cholecystectomies has increased gradually each year, mainly after preoperative sonographic screening of the gallbladder became routine in our department. We have found that mortality, morbidity and duration of surgery were not significantly influenced by the addition of incidental cholecystectomy. The risk of the gallbladder becoming symptomatic during the expected survival of the patients who were operated upon for gastrointestinal tumors is higher than the added risk, morbidity or mortality as well as additional cost of incidental cholecystectomy. Therefore, the authors recommend the performance of incidental cholecystectomy during elective laparotomies for gastrointestinal tumors.

Gallstone Disease in Pregnancy: Mere Coincidence or Physiologic Response?

Albeit there have been numerous reports, but it has still not been completely clarified what the exact role (if any) of pregnancy is in the development of gallstone disease, or its influence in previo