Sabino Zani

Expression of nifH genes in natural microbial assemblages in Lake George, New York, detected by reverse transcriptase PCR.

ABSTRACT A modified nested reverse transcriptase PCR (RT-PCR) method was used to detect the expression of nitrogenase genes in meso-oligotrophic Lake George, New York. Net (>20-μm pore size) plankton samples collected from two sites (Dome Island and Hague Marina) were extracted for total RNA and genomic DNA to determine the identity of diazotrophic organisms that were present and those that were actively expressing nitrogenase genes. Phylogenetic analysis of individual sequences cloned from PCR amplifications showed that there were phylogenetically diverse groups of bacteria that possessed a nifH gene, including representatives of unicellular and filamentous cyanobacteria, the α- and γ-subdivisions of the division Proteobacteria (α- and γ-proteobacteria), and a previously undefined group of bacteria. The phylotypes cloned from RT-PCR amplifications, which were actively expressing nifH transcripts, clustered with the unicellular and filamentous cyanobacteria, α-proteobacteria, and the novel bacterial cluster. No bacterial sequences were found which clustered with sequences from cluster II (alternative nitrogenases), III (nitrogenases in strict anaerobes), or IV (nifH-like sequences). These results indicate that there were several distinct groups of nitrogen-fixing microorganisms in the net plankton from both sampling sites and that most of the groups had representative phylotypes that were actively expressing nitrogenase genes.

Diversity and Detection of Nitrate Assimilation Genes in Marine Bacteria

ABSTRACT A PCR approach was used to construct a database of nasAgenes (called narB genes in cyanobacteria) and to detect the genetic potential for heterotrophic bacterial nitrate utilization in marine environments. A nasA-specific PCR primer set that could be used to selectively amplify the nasA gene from heterotrophic bacteria was designed. Using seawater DNA extracts obtained from microbial communities in the South Atlantic Bight, the Barents Sea, and the North Pacific Gyre, we PCR amplified and sequencednasA genes. Our results indicate that several groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments.

Modest advances in survival for patients with colorectal-associated peritoneal carcinomatosis in the era of modern chemotherapy

The treatment of metastatic colorectal cancer (CRC) has evolved rapidly over the last decade, with combination chemotherapy and targeted biologic agents leading to significant improvements in survival. Despite these advances, little is known about their effectiveness in CRC‐associated peritoneal carcinomatosis. The purpose of this study was to evaluate outcomes in patients with CRC‐associated PC treated in the era of modern chemotherapy.

Safety and Feasibility of Minimally Invasive Inguinal Lymph Node Dissection in Patients With Melanoma (SAFE-MILND): Report of a Prospective Multi-institutional Trial

Background: Minimally invasive inguinal lymph node dissection (MILND) is a novel approach to inguinal lymphadenectomy. SAFE-MILND (NCT01500304) is a multicenter, phase I/II clinical trial evaluating the safety and feasibility of MILND for patients with melanoma in a group of surgeons newly adopting the procedure. Methods: Twelve melanoma surgeons from 10 institutions without any previous MILND experience, enrolled patients into a prospective study after completing specialized training including didactic lectures, participating in a hands-on cadaveric laboratory, and being provided an instructional DVD of the procedure. Complications and adverse postoperative events were graded using the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events Version 4.0. Results: Eighty-seven patients underwent a MILND. Seventy-seven cases (88.5%) were completed via a minimally invasive approach. The median total inguinal lymph nodes pathologically examined (SLN + MILND) was 12.0 (interquartile range 8.0, 14.0). Overall, 71% of patients suffered an adverse event (AE); the majority of these were grades 1 and 2, with 26% of patients experiencing a grade 3 AE. No grade 4 or 5 AEs were observed. Conclusions: After a structured training program, high-volume melanoma surgeons adopted a novel surgical technique with a lymph node retrieval rate that met or exceeded current oncologic guidelines and published benchmarks, and a favorable morbidity profile.

Feeding jejunostomy during Whipple is associated with increased morbidity

BACKGROUND Placement of a feeding jejunostomy tube (FJ) is often performed during pancreaticoduodenectomy (PD). Few studies, however, have sought to determine whether such placement affects postoperative outcomes after PD. MATERIALS AND METHODS This is a retrospective analysis of the National Surgical Quality Improvement Program (NSQIP) database to determine the 30-d-postoperative mortality rate, major complication rate, and overall complication rate of jejunostomy tube placement at the time of PD. Univariate and multivariate comparison of postoperative outcomes between patients with and without FJ placement during PD was performed on a total of 4930 patients. RESULTS Thirty-day-postoperative mortality did not differ between the two groups (4.0% for patients with FJ versus 2.7% without, P = 0.13), whereas overall morbidity (43.3% with FJ versus 34.6% without, P < 0.0001) and serious morbidity (29.5% with FJ versus 22.8% without, P < 0.0001) were significantly higher in patients undergoing FJ placement during PD. The specific complications that occurred more frequently in FJ patients than patients without FJ included deep space surgical site infection, pneumonia, unplanned reintubation, acute renal failure, and sepsis. CONCLUSION Although FJ placement during PD is considered to be routine at many institutions, our analysis of data from NSQIP suggest that FJ placement may be associated with increased postoperative morbidity.

How the radiologist can add value in the evaluation of the pre- and post-surgical pancreas

Abstract Disease involving the pancreas can be a significant diagnostic challenge to the interpreting radiologist. Moreover, the majority of disease processes involving the pancreas carry high significant morbidity and mortality either due to their natural process or related to their treatment options. As such, it is critical for radiologists to not only provide accurate information from imaging to guide patient management, but also deliver that information in a clear manner so as to aid the referring physician. This is no better exemplified than in the case of pre-operative staging for pancreatic adenocarcinoma. Furthermore, with the changing healthcare landscape, it is now more important than ever to ensure that the value of radiology service to other providers is high. In this review, we will discuss how the radiologist can add value to the referring physician by employing novel imaging techniques in the pre-operative evaluation as well as how the information can be conveyed in the most meaningful manner through the use of structured reporting. We will also familiarize the radiologist with the imaging appearance of common complications that occur after pancreatic surgery.

ORGANIZATION OF THE nif GENES OF THE NONHETEROCYSTOUS CYANOBACTERIUM TRICHODESMIUM SP. IMS101

An approximately 16‐kb fragment of the Trichodesmium sp. IMS101 (a nonheterocystous filamentous cyanobacterium) “conventional”nif gene cluster was cloned and sequenced. The gene organization of the Trichodesmium and Anabaena variabilis vegetative (nif 2) nitrogenase gene clusters spanning the region from nif B to nif W are similar except for the absence of two open reading frames (ORF3 and ORF1) in Trichodesmium. The Trichodesmium nif EN genes encode a fused Nif EN polypeptide that does not appear to be processed into individual Nif E and Nif N polypeptides. Fused nif EN genes were previously found in the A. variabilis nif 2 genes, but we have found that fused nif EN genes are widespread in the nonheterocystous cyanobacteria. Although the gene organization of the nonheterocystous filamentous Trichodesmium nif gene cluster is very similar to that of the A. variabilis vegetative nif 2 gene cluster, phylogenetic analysis of nif sequences do not support close relatedness of Trichodesmium and A. variabilis vegetative (nif 2) nitrogenase genes.

Gangrenous cholecystitis: a contemporary review.

BACKGROUND Despite the established superiority of laparoscopic cholecystectomy (LC) for acute cholecystitis, gangrenous cholecystitis (GC) is commonly treated with open cholecystectomy (OC). This study aimed to characterize outcomes of GC in the modern era and between LC or OC surgical approach. MATERIALS AND METHODS Patients with a diagnosis of GC were identified using the 2005-2011 National Surgical Quality Improvement Project Participant User File. Baseline patient and operative characteristics and 30-d outcomes were established for all patients. Patients were stratified by surgical approach (LC or OC), and groups were propensity matched with a nearest-neighbor matching algorithm. Primary outcomes were 30-d mortality and any 30-d complication. A nonparsimonious multiple logistic regression model was used in the matched subset to adjust for patient comorbidities, demographics, and laboratory values. RESULTS A total of 141,970 cholecystectomies were identified with 7017 having a diagnosis of GC. Overall 30-d mortality for the entire cohort was 0.8% (n = 239) and overall 30-d complication rate was 8.0% (n = 2485). For GC patients, the 30-d mortality was 1.2% (n = 84) and overall complication rate was 10.8% (n = 761). The multivariate logistic regression model demonstrated a significant decrease in overall (odds ratio = 0.46; P < 0.001) complication rates for LC patients but did not reveal a significant difference in 30-d mortality (odds ratio = 0.59; P = 0.12). CONCLUSIONS GC is associated with increased morbidity and mortality compared with that of acute cholecystitis. A LC approach is a safe option for patients with GC and is associated with decreased 30-d morbidity. Although LC should be used when possible for GC to minimize postoperative complications, OC should not be avoided if necessary to ensure patient safety.

Snowblower Injuries to the Hand : Epidemiology, Patterns of Injury, and Strategies for Prevention

Snowblowers injure approximately 5000 people a year and can cause devastating hand injuries. Even with added safety measures and warnings on modern snowblowers, hand injuries are still occurring at an alarming rate. We have reviewed our series of snowblower-related hand injuries to elucidate the epidemiology, patterns of injury, and strategies for prevention. Questionnaires and treatment records of 22 individuals with snowblower injuries to the hand between 2002 and 2005 were reviewed. All patients were treated by a single hand surgeon at Hartford Hospital in Hartford, CT. Eleven of the 22 held upper level educational degrees. Averaged results include operator experience of 15.17 years, machine age of 21.38 years, temperature of 29.05°F (−1.51°C), precipitation of 8.60 cm (3.38 in), and duration of use of 20.59 minutes excluding 3 outliers. Three patients consumed 1 alcoholic drink and 1 consumed 2 alcoholic drinks before injury. The majority of patients were aware of safety warnings (77.20%) and injured themselves with the machine running (82.35%) resulting in multiple digit injury (2.0 on average) on the dominant hand (68.18%). Operator inexperience, low operator intelligence, and excessive alcohol consumption do not seem to contribute to injury. Instead, significant experience, older machines, short durations of use before injury, characteristic weather patterns, and underlying misperceptions about snowblower design and function typically set the stage for injury. Injuries may be prevented in the future by improving snowblower design and/or by making brief public service announcements.

Training High-Volume Melanoma Surgeons to Perform a Novel Minimally Invasive Inguinal Lymphadenectomy: Report of a Prospective Multi-Institutional Trial

BACKGROUND Minimally invasive inguinal lymphadenectomy (MILND) is a novel procedure with the potential to decrease surgical morbidity compared with the traditional open approach. The current study examined the feasibility of a combined didactic and hands-on training program to prepare high-volume melanoma surgeons to perform this procedure safely and proficiently. STUDY DESIGN A select group of melanoma surgeons with no MILND experience were recruited. After completing a structured training program, surgeons enrolled patients with melanoma who required inguinal lymphadenectomy and performed the procedure in the minimally invasive fashion. A proficiency score composed of lymph node yield, operative time, and blood loss (or adverse events) was assigned for each case. After performing six cases, surgeons meeting a threshold score were considered proficient in the procedure. RESULTS Twelve surgeons from 10 institutions enrolled 88 patients. The majority of surgeons were deemed proficient within 6 cases (83%). No differences in operative time or lymph node yield were noted during the course of the study. The rate of conversion was higher during an individual surgeons early experience (9 of 49 [18%]), and only 1 procedure was converted in the 39 cases performed after a surgeon had performed 5 cases (late conversion rate, 3%; p = 0.038); however, this did not remain significant after controlling for surgeon. CONCLUSIONS After a structured training program, experienced melanoma surgeons adopted a novel surgical technique with acceptable operative times, conversions, and lymph node yield. Eighty-four percent of the surgeons who completed at least 6 MILND procedures were considered proficient based on our predetermined definition.