Sentinel lymph node biopsy in melanoma: Which hot nodes should be harvested and is blue dye really necessary?

OBJECTIVES: The '10% rule' has become widely accepted by surgeons performing sentinel lymph node biopsy (SLNB) for melanoma. The purpose of this study was to compare the '10% rule' with alternative node harvesting criteria. In particular, we were interested to see whether the use of blue dye had any impact on the sensitivity of the test and whether it is necessary to remove all hot nodes. METHODS: We reviewed 537 SLNBs performed for primary melanoma from 2009-2015. SLNB was offered to all patients with 1-4 mm Breslow thickness melanoma and sentinel nodes were harvested according to the '10% rule'. RESULTS: One hundred sixteen patients (22%) had at least one positive sentinel node and there were 45 positive nodal basins from which more than one sentinel node had been harvested. Excluding blue dye and sampling only hot nodes would have enabled a 5% reduction in nodes harvested, without any compromise in the sensitivity of the test. However, applying harvesting criteria whereby not all hot nodes are taken was associated with a loss of sensitivity, with positive sentinel nodes being missed and patients understaged. CONCLUSIONS: Our data do not support the continued use of blue dye in SLNB for melanoma, as it does not improve the sensitivity of the test. This series adds to growing evidence, suggesting that the '10% rule' with the inclusion of blue nodes should be reconsidered and that radiocolloid tracer alone is sufficient for sentinel node localisation.

Development of an aquatic pathogen database (AquaPathogen X) and its utilization in tracking emerging fish virus pathogens in North America.

The AquaPathogen X database is a template for recording information on individual isolates of aquatic pathogens and is freely available for download (http://wfrc.usgs.gov). This database can accommodate the nucleotide sequence data generated in molecular epidemiological studies along with the myriad of abiotic and biotic traits associated with isolates of various pathogens (e.g. viruses, parasites and bacteria) from multiple aquatic animal host species (e.g. fish, shellfish and shrimp). The cataloguing of isolates from different aquatic pathogens simultaneously is a unique feature to the AquaPathogen X database, which can be used in surveillance of emerging aquatic animal diseases and elucidation of key risk factors associated with pathogen incursions into new water systems. An application of the template database that stores the epidemiological profiles of fish virus isolates, called Fish ViroTrak, was also developed. Exported records for two aquatic rhabdovirus species emerging in North America were used in the implementation of two separate web-accessible databases: the Molecular Epidemiology of Aquatic Pathogens infectious haematopoietic necrosis virus (MEAP-IHNV) database (http://gis.nacse.org/ihnv/) released in 2006 and the MEAP- viral haemorrhagic septicaemia virus (http://gis.nacse.org/vhsv/) database released in 2010.

Synthesis and pharmacological activity of metabolites of the 5-HT(4) receptor antagonist SB-207266.

Three metabolites of N-[(1-butyl-4-piperidinyl)methyl]-3,4-dihydro-2H-[1,3]-oxazino[3,2_a]indole-10-carboxamide (SB-207266) (1) were synthesised and their pharmacological activity determined.

Characterisation using FLIPR of human vanilloid VR1 receptor pharmacology.

A full pharmacological characterisation of the recently cloned human vanilloid VR1 receptor was undertaken. In whole-cell patch clamp studies, capsaicin (10 microM) elicited a slowly activating/deactivating inward current in human embryonic kidney (HEK293) cells stably expressing human vanilloid VR1 receptor, which exhibited pronounced outward rectification (reversal potential -2.1+/-0.2 mV) and was abolished by capsazepine (10 microM). In FLIPR-based Ca(2+) imaging studies the rank order of potency was resiniferatoxin>olvanil>capsaicin>anandamide, and all were full agonists. Isovelleral and scutigeral were inactive (1 nM-30 microM). The potencies of capsaicin, olvanil and resiniferatoxin, but not anandamide, were enhanced 2- to 7-fold at pH 6.4. Capsazepine, isovelleral and ruthenium red inhibited the capsaicin (100 nM)-induced Ca(2+) response (pK(B)=6.58+/-0.02, 5.33+/-0.03 and 7.64+/-0.03, respectively). In conclusion, the recombinant human vanilloid VR1 receptor stably expressed in HEK293 cells acted as a ligand-gated, Ca(2+)-permeable channel with similar agonist and antagonist pharmacology to rat vanilloid VR1 receptor, although there were some subtle differences.

Distribution and expression of TREK-1, a two-pore-domain potassium channel, in the adult rat CNS.

TREK-1 is a member of the two-pore-domain potassium channel family which is expressed predominantly in the CNS. Using an anti-peptide polyclonal antiserum, we have determined the distribution of TREK-1 in the brain and spinal cord of adult rats. Specificity of the antiserum was tested using a TREK-1-transfected cell line and confirmed with c-myc-tagged TREK-1. In thin tissue sections, immunoreactivity was widespread throughout the rat brain and spinal cord. TREK-1-like signals were observed in the cerebral cortex, basal ganglia, hippocampus, and various other subcortical nuclei in the hypothalamus, thalamus, mesencephalon and rhombencephalon. TREK-1 labelling appeared to be over the entire cell membrane, including the cell body and processes. Cells that morphologically resembled projection neurones and interneurones but not glial cells were labelled. As interneurones and known GABAergic projection neurones were the predominant population labelled, we investigated the possibility that TREK-1 is expressed in GABA-containing neurones using a specific anti-GABA antiserum. Expression of TREK-1 in GABA-containing neurones was observed in a number of areas, including the isocortex, hippocampus and thalamus. Thus, TREK-1 expression defines a unique and specific subset of interneurones and principal cells. These studies indicate a widespread distribution of TREK-1 potassium channels throughout the rat brain and spinal cord, with expression in a number of areas being demonstrated to be present on GABA-containing neurones.

Potent inhibition of a recombinant low voltage-activated Ca(2+) channel by SB-209712.

T-type Ca(2+) currents were recorded in 2 mM Ca(2+) from HEK293 cells stably expressing the low voltage-activated Ca(2+) channel sub-unit alpha(1I). These currents were inhibited by the known Ca(2+) channel antagonist mibefradil with an IC(50) close to 1 microM. SB-209712 (1,6,bis¿1-[4-(3-phenylpropyl)piperidinyl]¿hexane), a compound originally developed as a high voltage-activated Ca(2+) channel blocker, proved to be a more potent T-type channel antagonist, exhibiting an IC(50) in the region of 500 nM. The antagonism produced by SB-209712 was reversed following drug removal and the observed antagonism exhibited little or no voltage-dependence with respect to either holding or test potential. These data indicate that SB-209712 is amongst the most potent known non-peptide T-type channel antagonists and thus may have some use in understanding the role of these channels in cellular function.

Cross-modal selective attention: on the difficulty of ignoring sounds at the locus of visual attention.

In three experiments, we investigated whether the ease with which distracting sounds can be ignored depends on their distance from fixation and from attended visual events. In the first experiment, participants shadowed an auditory stream of words presented behind their heads, while simultaneously fixating visual lip-read information consistent with the relevant auditory stream, or meaningless "chewing" lip movements. An irrelevant auditory stream of words, which participants had to ignore, was presented either from the same side as the fixated visual stream or from the opposite side. Selective shadowing was less accurate in the former condition, implying that distracting sounds are harder to ignore when fixated. Furthermore, the impairment when fixating toward distractor sounds was greater when speaking lips were fixated than when chewing lips were fixated, suggesting that people find it particularly difficult to ignore sounds at locations that are actively attended for visual lipreading rather than merely passively fixated. Experiments 2 and 3 tested whether these results are specific to cross-modal links in speech perception by replacing the visual lip movements with a rapidly changing stream of meaningless visual shapes. The auditory task was again shadowing, but the active visual task was now monitoring for a specific visual shape at one location. A decrement in shadowing was again observed when participants passively fixated toward the irrelevant auditory stream. This decrement was larger when participants performed a difficult active visual task there versus fixating, but not for a less demanding visual task versus fixation. The implications for cross-modal links in spatial attention are discussed.

Pharmacological characterization of the vanilloid receptor in the rat dorsal spinal cord.

1. In the present study a novel 96-well plate assay system was used to characterize pharmacologically the vanilloid receptor in the dorsal spinal cord of the rat. When activated, this receptor stimulates release of calcitonin gene-related peptide (CGRP) from the central terminals of the afferent nerves. 2. Capsaicin, resiniferatoxin (RTX) and olvanil each evoked a concentration-dependent increase in CGRP release with pEC50 values of 6.55 +/- 0.07, 7.90 +/- 0.24 and 6.19 +/- 0.15 respectively. RTX and olvanil were partial agonists with respect to capsaicin. All concentration-effect curves were bell-shaped. 3. The vanilloid receptor antagonist, capsazepine (10 microM) had no effect on basal peptide release but inhibited the CGRP release evoked by all 3 agonists to a similar extent. These results suggest that the antagonistic effects of capsazepine were agonist-independent. 4. The capsaicin-sensitive cation channel blocker, ruthenium red (10 microM) had no effect on basal CGRP release, but antagonized the peptide release evoked by capsaicin, olvanil and RTX. 5. The pharmacology of the vanilloid receptor in the rat dorsal spinal cord is not identical to that previously found in other systems. The reason for these differences is unclear, but the possibility of multiple classes of receptor cannot at this stage be ruled out.

Diagnostic standards for acute pancreatitis.

An accurate history and thorough physical examination will often raise clinical suspicion of acute pancreatitis in the differential diagnosis of a patient presenting with acute abdominal pain. An accurate diagnosis is needed to eliminate etiologies of acute abdominal pain and to appropriately direct therapy. Confirmation of the diagnosis is most often made by evaluation of serum amylase and lipase levels. Although hyperamylasemia is found in the majority of patients with acute pancreatitis, other nonpancreatic acute abdominal conditions may be present with hyperamylasemia. CT scanning provides an accurate confirmation of clinical and laboratory findings and offers excellent anatomic and morphologic representation of the pancreas and peripancreatic tissue. The following article, written by the late John H.C. Ranson, presents a discussion of the modalities available for diagnosing acute pancreatitis.

Optimal management of the pancreatic remnant after pancreaticoduodenectomy.

OBJECTIVE: The authors evaluated methods of operative management of the pancreatic remnant after pancreaticoduodenectomy. SUMMARY BACKGROUND DATA: Despite reductions in mortality after pancreaticoduodenectomy, leakage from the pancreatic remnant still may cause significant morbidity. Patients with small, unobstructed pancreatic ducts or soft, friable pancreata are at particularly high risk. Although numerous surgical techniques have been described to avoid such complications, no single method is suitable for all patients. METHODS: The authors retrospectively reviewed the medical records of 114 consecutive patients who underwent pancreaticoduodenectomy. Sixty-nine patients were men (61%) and 45 were women (39%), with median age 66 years. Underlying disease was malignant in 87 (76%) and benign in 27 (24%). Patients were divided into groups based on risk for postoperative pancreatic fistula and on the operative management of the pancreatic remnant. Sixty-eight patients underwent end-to-side pancreaticojejunostomy, 13 of whom were high risk (group 1A) and 55 of whom were low risk (group 1B). Thirty-seven patients, all high risk, had either pancreatic duct closure by oversewing (N = 19, group 2) or end-to-end pancreaticojejunal invagination (N = 18, group 3). Nine patients underwent total pancreatectomy (group 4). Morbidity related to prolonged pancreatic drainage (PPD) of greater than 20 days was determined. RESULTS: Overall incidence of PPD was 17% and caused the only death. Patients considered high risk for postoperative pancreatic fistula had a 36% incidence of PPD compared with 2% in patients considered low risk (p < 0.0001). Prolonged pancreatic drainage frequency related to the method of pancreatic remnant management was as follows: group 1A, 15%; group 1B, 2%; group 2, 79%; and group 3, 6% (p < 0.001 for group 2 vs. other groups). No serious sequelae followed PPD in 15 patients (79%); however, 4 patients required reoperation for pseudocyst or abscess drainage; one in group 1A (who died) and three in group 2. Multivariate analysis revealed that operative technique (oversewing of the pancreatic duct) and male sex were significant factors predisposing a patient to the development of PPD. CONCLUSION: After pancreaticoduodenectomy, pancreatic remnant management by end-to-side pancreaticojejunostomy appeared safe in low-risk patients. In high-risk patients, end-to-end pancreaticojejunal invagination was the safest option. Morbidity was greatest after pancreatic duct closure without anastomosis.

Clinically significant ureteral obstruction caused by inflammatory complications of severe pancreatitis.

Clinically significant ureteral obstruction caused by the inflammatory complications of severe pancreatitis is rare with only eight previously reported cases. We present two additional cases and review the world literature. Clinically significant ureteral obstruction can affect either or both ureters and present simultaneously with an episode of pancreatitis or months later. If symptomatic ureteral obstruction is present, prompt urologic drainage is recommended. Definitive correction of the obstruction is frequently required and depends on the obstructive mechanism.

Pyrophosphate: fructose-6-phosphate 1-phosphotransferase and fructose 2,6-bisphosphate in the bundle sheath of maize leaves.

The aim of this work was to discover whether the cells of the bundle sheath of the leaves of maize (Zea mays) contained pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) and fructose 2,6-bisphosphate (Fru-2,6-P2). Physiologically active preparations of bundle sheath cells from leaves of 4- to 6-week-old plants showed activities of PFP, 6-phosphofructo-2-kinase (6-PF-2-K), and fructose-2,6-bisphosphatase (Fru-2,6-Pase) of 38, 1.8, and 15 nmol min-1 mg-1 chlorophyll, respectively, and contained 75 pmol mg-1 chlorophyll Fru-2,6-P2. For the above enzymes, and marker enzymes for the bundle sheath and for mesophyll cells, the ratios of the activities in leaf extracts to those in bundle sheath extracts were determined. The ratios for PFP, 6-PF-2-K, Fru-2,6-Pase, and Fru-2,6-P2 were intermediate between those found for the mesophyll markers and bundle sheath markers. The distribution of PFP activity after nonaqueous fractionation of leaves differed from that of the bundle sheath and mesophyll marker enzymes. It is argued that maize bundle sheaths can contain significant activity of PFP and amounts of Fru-2,6-P2.

Nutritional support for acute pancreatitis.

The current review has summarized current data relevant to the nutritional support of patients with acute pancreatitis. Selection of the most appropriate form of nutritional support for patients with acute pancreatitis is intimately linked to a thorough understanding of the effects of various forms of enteral and parenteral nutrition on physiologic exocrine secretory mechanisms. Two basic concepts have emerged from the multiple studies that have addressed these issues to date: 1, enteral feeds should have low fat composition and be delivered distal to the ligament of Treitz to minimize exocrine pancreatic secretion and 2, parenteral substrate infusions, alone or in combinations similar to those administered during TPN, do not stimulate exocrine pancreatic secretion. From a practical standpoint, most patients with acute pancreatitis are diagnosed by nonoperative means and will manifest some degree of paralytic ileus during the early phase of the disease. Therefore, jejunal feeds are usually not a therapeutic option early in the course of this disease. On the basis of the clinical studies reviewed herein we propose general guidelines for the nutritional support of patients with acute pancreatitis: 1, most patients with mild uncomplicated pancreatitis (one to two prognostic signs) do not benefit from nutritional support; 2, nutritional support should begin early in the course of patients with moderate to severe disease (as soon as hemodynamic and cardiorespiratory stability permit); 3, initial nutritional support should be through the parenteral route and include fat emulsion in amounts sufficient to prevent essential fatty acid deficiency (no objective data exist to recommend specific amino acid formulations); 4, patients requiring operation for diagnosis or complications of the disease should have a feeding jejunostomy placed at the time of operation for subsequent enteral nutrition using a low fat formula, such as Precision HN (Sandoz, 1.3 percent calories as fat), Criticare HN (Mead Johnson, 3 percent calories as fat) or Vivonex High Nitrogen (Norwich Eaton, 0.87 percent calories as fat), and 5, oral feedings should be low fat in composition and should be reinstituted using traditional clinical criteria, including the symptoms of the patient, physical examination and computed tomographic appearance of the pancreas (clinicians should bear in mind the well documented exocrine stimulatory effects of even low fat oral feeds and the risks of early refeeding). These general guidelines must be individualized to incorporate what is perhaps the most important clinical variable--the premorbid nutritional state of the patient.(ABSTRACT TRUNCATED AT 400 WORDS)

Long peritoneal lavage decreases pancreatic sepsis in acute pancreatitis.

Late infection of devitalized pancreatic and peripancreatic tissue has become the major cause of morbidity in severe acute pancreatitis. Previous experience found that peritoneal lavage for periods of 48 to 96 hours may reduce early systemic complications but did not decrease late pancreatic sepsis. A fortunate observation led to the present study of the influence of a longer period of lavage on late sepsis. Twenty-nine patients receiving primary nonoperative treatment for severe acute pancreatitis (three or more positive prognostic signs) were randomly assigned to short peritoneal lavage (SPL) for 2 days (15 patients) or to long peritoneal lavage (LPL) for 7 days (14 patients). Positive prognostic signs averaged 5 in both groups but the frequency of five or more signs was higher in LPL (71%) than in SPL (47%). Eleven patients in each group had early computed tomographic (CT) scans. Peripancreatic fluid collections were shown more commonly in LPL (82%) than in SPL (54%) patients. Longer lavage dramatically reduced the frequency of both pancreatic sepsis (22% LPL versus 40% SPL) and death from sepsis (0% LPL versus 20% SPL). Among patients with fluid collections on early CT scan, LPL led to a more marked reduction in both pancreatic sepsis (33% LPL versus 83% SPL) and death from sepsis (0% LPL versus 33% SPL). The differences were even more striking among 17 patients with five or more positive prognostic signs. In this group the incidence of pancreatic sepsis was 30% LPL versus 57% SPL and of death from sepsis 0% (LPL) versus 43% (SPL) (p = 0.05). In these patients, overall mortality was also reduced (20% LPL versus 43% SPL). When 20 patients treated by LPL were compared with 91 other patients with three or more positive prognostic signs who were treated without lavage or by lavage for periods of 2 to 4 days, the frequency of death from pancreatic sepsis was reduced from 13% to 5%. In those with five or more signs, the incidence of sepsis was reduced from 40% to 27% (p = 0.03) and of death for sepsis from 30% to 7% (p = 0.08). These findings indicate that lavage of the peritoneal cavity for 7 days may significantly reduce both the frequency and mortality rate of pancreatic sepsis in severe acute pancreatitis.

Eosinophilic cholangitis: a self-limited cause of extrahepatic biliary obstruction.

The first case of eosinophilic cholecystitis with radiographically documented biliary tract obstruction is presented. Differences between eosinophilic cholecystitis with and without obstruction in terms of gender predilection and the incidence of associated cholelithiasis suggest these may be two distinct disease processes. The dense eosinophilic infiltration of the porta hepatis seen in the present case has led us to believe that extrahepatic obstruction was due to "eosinophilic cholangitis." The self-limited nature of eosinophilic cholangitis makes it an essential consideration in the evaluation of presumed neoplasms of the porta hepatis.

The role of surgery in the management of acute pancreatitis.

Surgical intervention in acute pancreatitis may have varied goals. Early laparotomy may be required for diagnostic purposes. There is, however, no convincing evidence that attempts to reduce the morbidity of severe pancreatitis by early operative pancreatic drainage, early formal pancreatic resection, or early biliary procedures have been effective. In fact, they may be harmful. Peritoneal lavage by catheter induced under local anesthesia may ameliorate early cardiovascular and respiratory complications in some patients. Preliminary experience suggests that early operative debridement of devitalized pancreatic tissue with postoperative lavage may be helpful in selected patients. Patients with infections of devitalized pancreatic or peripancreatic tissue require operative debridement and drainage or packing. Other complications such as colonic necrosis or pseudocysts also require operative treatment. Rarely do patients require operation to relieve protracted pancreatitis. Patients with gallstone-associated pancreatitis should usually undergo surgical correction of their cholelithiasis as soon as their pancreatitis has subsided.