Candidate colorectal cancer predisposing gene variants in Chinese early-onset and familial cases

AIM: To investigate whether whole-exome sequencing may serve as an efficient method to identify known or novel colorectal cancer(CRC) predisposing genes in early-onset or familial CRC cases.METHODS: We performed whole-exome sequencing in 23 Chinese patients from 21 families with nonpolyposis CRC diagnosed at ≤ 40 years of age, or from multiple affected CRC families with at least 1 firstdegree relative diagnosed with CRC at ≤ 55 years of age.Genomic DNA from blood was enriched for exome sequences using the Sure Select Human All Exon Kit, version 2(Agilent Technologies) and sequencing was performed on an Illumina Hi Seq 2000 platform.Data were processed through an analytical pipeline to search for rare germline variants in known or novel CRC predisposing genes.RESULTS: In total, 32 germline variants in 23 genes were identified and confirmed by Sanger sequencing.In 6 of the 21 families(29%), we identified 7 mutations in 3 known CRC predisposing genes including MLH1(5 patients), MSH2(1 patient), and MUTYH(biallelic, 1 patient), five of which were reported as pathogenic.Inthe remaining 15 families, we identified 20 rare and novel potentially deleterious variants in 19 genes, six of which were truncating mutations.One previously unreported variant identified in a conserved region of EIF2AK4(p.Glu738_Asp739insA rgA rg) was found to represent a local Chinese variant, which was significantly enriched in our early-onset CRC patient cohort compared to a control cohort of 100 healthy Chinese individuals scored negative by colonoscopy(33.3% vs 7%, P 0.001).CONCLUSION: Whole-exome sequencing of early-onset or familial CRC cases serves as an efficient method to identify known and potential pathogenic variants in established and novel candidate CRC predisposing genes.     

Little girl who conquered the ALPPS’’

An insufficient future liver remnant(FLR)is associated with post-hepatectomy liver failure.Associating liver partition and portal vein ligation for stage hepatectomy(ALPPS)has been shown to be effective for the induction of rapid FLR hypertrophy so as to improve the resectability in patients with insufficient FLR.We hereby report our experience of this novel approach for a 6-year-old patient with hepatoblastoma.Computed tomography showed a hepatoblastoma measuring12.5 cm×9.9 cm×11.7 cm in the right liver(Couinaud segmentⅣ,ⅤandⅧ).Volumetric assessment of the FLR i.e.,left lateral section was 112.6 mL i.e.,21.2%of the estimated total liver volume.In view of the small-for-size FLR,ALPPS was contemplated.An anterior approach was adopted for the in-situ parenchymal split without mobilisation of the right liver.FLR volumetry on the seventh postoperative day was 160.7 mL,which represented a 46.1%gain in volume,and a FLR/ESLV ratio of 30.2%.A right trisectionectomy was performed on the eighth postoperative day.Postoperative recovery was uneventful.Patient was discharged on day 16 after the first operation.To our knowledge,this was the first report that showed the applicability of ALPPS to a paediatric patient.     

Pancreaticoduodenectomy with vascular reconstruction for adenocarcinoma of the pancreas with borderline resectability

AIM: To analyze whether pancreaticoduodenectomy with simultaneous resection of tumor-involved vessels is a safe approach with acceptable patient survival.METHODS: Between January 2001 and March 2012, 136 patients received pancreaticoduodenectomy for adenocarcinoma at our hospital. Seventy-eight patients diagnosed with pancreatic head carcinoma were included in this study. Among them, 46 patients received standard pancreaticoduodenectomy (group 1) and 32 patients received pancreaticoduodenectomy with simultaneous resection of the portal vein or the superior mesenteric vein or artery (group 2) followed by reconstruction. The immediate surgical outcomes and survivals were compared between the groups. Fifty-five patients with unresectable adenocarcinoma of the pancreas without liver metastasis who received only bypass operations (group 3) were selected for additional survival comparison.RESULTS: The median ages of patients were 67 years (range: 37-82 years) in group 1, and 63 years (range: 35-86 years) in group 2. All group 2 patients had resection of the portal vein or the superior mesenteric vein and three patients had resection of the superior mesenteric artery. The pancreatic fistula formation rate was 21.7% (10/46) in group 1 and 15.6% (5/32) in group 2 (P = 0.662). Two hospital deaths (4.3%) occurred in group 1 and one hospital death (3.1%) occurred in group 2 (P = 0.641). The one-year, three-year and five-year overall survival rates in group 1 were 71.1%, 23.6% and 13.5%, respectively. The corresponding rates in group 2 were 70.6%, 33.3% and 22.2% (P = 0.815). The one-year survival rate in group 3 was 13.8%. Pancreaticoduodenectomy with simultaneous vascular resection was safe for pancreatic head adenocarcinoma.CONCLUSION: The short-term and survival outcomes with simultaneous resection were not compromised when compared with that of standard pancreaticoduodenectomy.     

The relationship between CR3 deficiency and neutrophil actin assembly

Polymorphonuclear leukocytes (PMN) with a deficiency of the complement receptor type 3 (CR3) membrane glycoprotein family have impairments in the ability to adhere to surfaces as well as chemotactic and phagocytic defects, processes that require a functional contractile apparatus. PMN from the patient with neutrophil actin dysfunction (NAD) displayed similar functional characteristics to those with CR3 deficiency suggesting the two disorders may be the same disease. In order to evaluate the relationship between CR3 deficiency and actin assembly, actin filament assembly was measured in PMN from six previously reported homozygotes (two severe and four moderate CR3-deficient patients) as well as five heterozygotes for CR3 deficiency. PMN from all patients had normal unstimulated concentrations of F-actin and after exposure to the chemotactic peptide FMLP (5 x 10(-7) mol/L for 5 to 40 seconds at 25 degrees C) assembled actin normally. Pretreatment of normal PMN with concentrations of monoclonal anti-alpha CR3 antibody, capable of blocking PMN adherence, also failed to impair FMLP- induced actin filament assembly. CR3 glycoprotein expression was measured in PMNs from the mother, father, and older sister of the NAD patient (N Engl J Med 291:1093, 1974). Actin filament assembly was recently shown to be defective in PMNs from all three family members. The total concentrations of the alpha and beta CR3 subunits were below normal in PMN detergent extracts from the mother (25% of simultaneous controls) and older sister (56% of control). PMN surface expression of these two subunits was also found to be depressed (mother, 50%; older sister, 63% of control). These findings suggest these two NAD family members are heterozygote carriers for CR3 deficiency as well as NAD. Simultaneous studies of the father, however, demonstrated normal total concentrations of both the alpha and beta CR3 subunits (126% of controls) as well as normal surface expression of both subunits after phorbol myristate acetate stimulation and incubation at 37 degrees C (mean, 112% of controls) but slightly lower than normal levels after FMLP stimulation (mean, 83%). These findings indicate that CR3 deficiency generally is not associated with defective actin filament assembly and support the conclusion that NAD represents a unique kindred in which PMN actin function differs from previously reported genotypes of CR3 deficiency.     

Hemorrhagic tumor necrosis during a pilot trial of tumor necrosis factor-alpha and anti-GD3 ganglioside monoclonal antibody in patients with metastatic melanoma

Hemorrhagic tumor necrosis is an inflammatory event that leads to selective destruction of malignant tissues, with both potentially toxic and beneficial consequences. A pilot clinical trial was undertaken combining tumor necrosis factor-alpha (TNF-alpha) with the monoclonal antibody R24 (MoAb R24) against GD3 ganglioside in patients with metastatic melanoma. Patients received MoAb R24 to recruit leukocytes to the tumor followed by low doses of recombinant TNF-alpha to activate leukocytes. Eight patients were treated and seven patients had mild toxicity. One patient with extensive metastatic melanoma developed tumor lysis syndrome within hours after treatment with almost complete necrosis of bulky tumors in multiple visceral sites. To our knowledge, this is the first documented case of hemorrhagic tumor necrosis in a patient with metastatic cancer in multiple visceral sites.     

Nylon-fiber-induced neutrophil fragmentation

We have investigated the effects of mechanical elution of neutrophils from nylon-wool fiber (NWF) using the scanning electron microscope and biochemical analysis of elution fractions. We have determined that mechanical removal of neutrophils from nylon-wool fiber disrupts neutrophils adherent to nylon-wool fiber and augments release of granules, release of peripheral cytoplasmic fragments, and release of lactic dehydrogenase, a soluble cytoplasmic enzyme. Mechanical shearing of the adherent cell, and not adherence per se, causes the fragmentation. The extent of fragmentation is proportional to the NWF surface area available to neutrophils and is maximal at the temperature for optimal adherence and spreading. Agents that decrease cell spreading (n-ethylmaleimide and cold) diminish fragmentation. Cytochalasin B, an agent that destabilizes the neutrophil cortex, increases fragmentation. Fragmentation may be an important contributing cause of the abnormal morphology, function, and in vivo survival of nylon-wool-fiber procured human neutrophils. The prevention of fragmentation would appear to be necessary to insure the procurement of optimally functioning cells. Elution of NWF-adherent neutrophils in the cold might be a practical way to diminish neutrophil damage during clinical filtration leukapheresis.     

Genetic heterogeneity among Saint Louis encephalitis virus isolates of different geographic origin

A series of 57 Saint Louis encephalitis (SLE) virus isolates from humans, birds, rodents, and mosquitoes showed extensive variability in their RNase T₁ oligonucleotide fingerprints. The fingerprints of virion RNA did not contain an obvious poly(A) tract and were identical when the virus was grown in either mosquito or mammalian cells. Analysis and comparison of long oligonucleotides, representing approximately 10% of the genome of SLE isolates from the Central and Atlantic states, indicated the viruses share at least 80% of their long oligonucleotides. Analysis of the large T₁-resistant oligonucleotides by RNase A digestion revealed chemical similarities in the composition of common oligonucleotides derived from the genomes of four isolates. Analysis of 57 SLE strains from North America indicated that on the basis of the similarity of the oligonucleotide fingerprints, SLE isolates could be divided into genotypic sets representing different geographic regions in North America. These geographic varieties, designated “topotypes,” represent isolates from: (1) the Central/Atlantic states, (2) Florida, (3) and the Western United States. Variants of each “topotype” have been characterized whose oligonucleotide fingerprints are similar to that of the “topotype” but are sufficiently distinct to permit separation of the highly and less virulent SLE strains.