Bioassay-Guided Isolation of a Potent Platelet-Activating Factor Antagonist Alkenylresorcinol from Ardisia elliptica

In the course of our search for novel platelet-activating factor (PAF) antagonists from medicinal plants, the methanol extract of the leaves of Ardisia elliptica Thunb. was investigated for its inhibitory effects on PAF receptor binding to rabbit platelets using ³H-PAF as a ligand. The methanol extract showed inhibitory activity of 53.9% and its ethyl acetate, n-butanol, and methanol fractions exhibited 48.6%, 39.0%, and 22.0% inhibition, respectively. Bioassay-guided fractionation of the ethyl acetate fraction led to the isolation of a new alkenylresorcinol, 5-(Z-heptadec-4′-enyl)resorcinol, together with 5-pentadecylresorcinol. The alkenylresorcinol showed a strong inhibition with an IC₅₀ value of 7.1 µM. The structures of the compounds were elucidated by spectroscopic techniques.     

Interaction phenomena in graphene seen through quantum capacitance

Capacitance measurements provide a powerful means of probing the density of states. The technique has proved particularly successful in studying 2D electron systems, revealing a number of interesting many-body effects. Here, we use large-area high-quality graphene capacitors to study behavior of the density of states in this material in zero and high magnetic fields. Clear renormalization of the linear spectrum due to electron–electron interactions is observed in zero field. Quantizing fields lead to splitting of the spin- and valley-degenerate Landau levels into quartets separated by interaction-enhanced energy gaps. These many-body states exhibit negative compressibility but the compressibility returns to positive in ultrahigh B. The reentrant behavior is attributed to a competition between field-enhanced interactions and nascent fractional states.     

Management of Anorectal Melanoma: Report of 17 Cases and Literature Review

Background

Primary anorectal melanoma is a rare and aggressive disease. It accounts for 0.5% of all rectal tumors. They are very agressive tumors with poor prognosis. The aim of this study is to report the clinical and evolutionary profile and therapeutical approach of these tumors.

Patients and Methods

A retrospective study of 17 patients with anorectal melanoma diagnosed between January 1998 and December 2007 was performed. The signs and symptoms, diagnostic study, and surgical and medical treatments were analyzed.

Results

The average age was 58?years. Sex ratio was 12 men per five women. Patients had symptoms present for an average of 6?months. The most common symptom was rectal bleeding. According to Slingluff classification, five patients had stage I (localized tumor), four cases had stage II (regional nodes metastasis), and eight cases had stage III (distant metastasis). Seven patients have radical surgery. Only two patients received adjuvant immunotherapy. Eight patients received palliative chemotherapy based on dacarbazine or cisplatinum. The median survival was 8?months.

Conclusion

Prognosis of anorectal melanoma is still very poor. However, some patients when treated by radical resection may experience long-term survival. The use of adjuvant immunotherapy needs large collaborative studies in view of the rarity of the tumor.     

A liver transplant center experience with liver dialysis in the management of patients with fulminant hepatic failure: a preliminary report

Among extracorporeal liver support devices, liver dialysis is cleared by the U.S. Food and Drug Administration to be used for the management of fulminant hepatic failure (FHF). The outcomes of patients following liver dialysis need to be clearly evaluated. Among the 25 patients with FHF admitted to the Liver ICU between May 2000 and November 2002, 12 underwent liver dialysis, including 6 men and 6 women, of mean age 32 years. The causes of FHF were identified as acetaminophen (n = 10), herbal medications (n = 1) and autoimmune disease (n = 1). At presentation, the mean total bilirubin was 9.35 mg/dL (range, 0 to 1.3), mean ALT 3015 U/L (range, 0 to 48), mean AST 3457 (range, 0 to 42), mean ammonia 98 micromol/L (range, 10 to 60) and mean INR 1.88. A control group including 13 patients (2 men and 11 women), of mean age 27.8 years mean total bilirubin 5.66, mean ALT 3494, mean AST 3528, mean ammonia 113 and mean INR 3, were not treated with liver dialysis, due to the lack of machine availability or physician's choice. The causes of FHF were acute hepatitis B (n = 1), acetaminophen (n = 10) or unknown (n = 2). There was no statistically significant difference in the baseline characteristics of the two groups (P >.05). Among the liver dialysis group, 1 patient died, 2 underwent OLTx, and 9 were discharged home. Among the control group; 4 patients died, 2 underwent OLTx, and 7 were discharged home. Preliminary results seem to support survival benefit among patients who underwent liver dialysis compared to non-liver dialysis; however, further randomized control trials are warranted to verify this observation.     

Excisional biopsy of borderline lesions after large bore vacuum-assisted core needle biopsy- is it necessary?

The current recommendation for borderline breast lesions after core needle biopsy is for surgical excision due to a high rate of pathologic underestimation. With the use of vacuum-assisted core needle (VACN) biopsy devices, upgrade rates have improved, but still average 20 per cent. We routinely use larger bore VACNs (7- and 8-gauge) than previously reported (9 to 11-gauge). The aim of this study is to evaluate the upgrade rate to malignancy in patients undergoing VACN using larger bore needles. VACN biopsies were performed in 902 patients. Of those, 87 were recommended excisional biopsy for borderline or noncorrelating lesions and 66 underwent the procedure. Two patients were upgraded to cancer, for an overall upstage rate of 3 per cent. Both of these underestimations were in patients that initially had atypical ductal hyperplasia. In the patients not excised, no patient developed further cancer. A 7- or 8-gauge needle was used in 57 per cent of patients, greater than 90 per cent removal of the initial lesion was accomplished in 53 per cent of cases, and there were no bleeding complications. This study suggests that upgrade rates decline with larger bore biopsy needles with near complete excision of the initial lesion, and that some borderline lesions may potentially be managed nonoperatively.     

The turmoil around the drug-eluting stents

Of 141 hospital survivors after intracardiac repair of tetralogy of Fallot, eight died suddenly 6–23 years later. Compared with the other 133 patients, these eight were older at operation, with higher post-repair systolic right ventricular pressure and more often complete atrioventricular block; ventricular arrhythmia was diagnosed before death in three cases. In follow-up totalling 2255 patient years, the linearized rate of sudden death was 0.35%/year. The instantaneous risk of sudden death showed continuous increase with the length of follow-up. Of 80 survivors electrocardiographically evaluated 13–26 (median 20) years postoperatively, none had complete block, but 79 had complete right bundle branch block, including seven with left anterior hemiblock. Ventricular extrasystoles were recorded in 1% at rest, in 34% during exercise and in 83% during 24-hour ambulatory monitoring, with Lown Grade ≥II in 27%. Old age and possibly presence of fibrosis and/or fibroelastosis in right ventricular outflow tract muscle correlated independently with high Lown Grade. A patient with Lown grade III died suddenly 2 years after our follow-up. Old age at repair thus was associated with increased risk of late sudden death and with frequent ventricular arrhythmia in long-term survivors.     

Congenital band of the vitelline artery remnant as a cause of chronic lower abdominal pain in an adult: Case report

INTRODUCTIONIntraabdominal bands of the vitelline vessel remnant are the rarest form of congenital mesodiverticluar bands which may or may not be associated with Meckel's diverticulum. In the majority of cases they cause an acute abdominal disease such as intestinal obstruction, especially in children.PRESENTATION OF CASEWe report a case of a 64 year old gentleman who experienced recurrent episodes of abdominal distension and bloating over two years. Computed tomography of his abdomen, colonoscopy, and barium follow through were all normal. Diagnostic laparoscopy revealed a single band adhesion stretching between the distal ileal mesentery and the anterior abdominal wall near the umbilicus.DISCUSSIONCongenital vascular bands are established causes of acute intestinal obstruction especially in children but are relatively uncommon. Their role in chronic abdominal pain is rare and diagnosis is difficult preoperatively. Pain in the patient was most likely due to recurrent partial twisting and untwisting of the bowel around the band.CONCLUSIONThis case not only highlights an unusual cause of chronic abdominal pain, but also the effectiveness of laparoscopy as a diagnostic tool in such patients.     

Secretory and serum immunoglobulin class-specific antibodies to poliovirus after vaccination

Immune responses in serum and saliva were studied in Pakistani children by enzyme-linked immunosorbent assay after natural exposure to poliovirus and vaccination with live or inactivated poliovirus vaccines. Swedish children unexposed to wild poliovirus who had almost 100% vaccination coverage with inactivated vaccine at 8, 9, and 18 months and at 5 years of age were analyzed for comparison. Natural exposure induced secretory IgA (SIgA) antibodies to poliovirus in the saliva of Pakistani infants at one month of age that reached adult levels at six months. No difference in levels of salivary antibody at eight months was observed between groups vaccinated with either live or inactivated vaccines. Vaccination with live or inactivated vaccine starting at 2 or 3 months of age resulted in high titers of IgG antibody to poliovirus in serum, the highest of which occurred after four doses of live vaccine. In Sweden, an increase of antibody in serum was observed after the third vaccination. IgA antibodies continued to increase subsequently, whereas IgG antibodies reached a plateau. The SIgA response in saliva initially appeared on the third vaccination, with a significant increase after the fourth. Repeated vaccination with inactivated poliovirus vaccine induces specific SIgA antibodies. Adults all had SIgA antibodies to poliovirus in saliva.