Impact of bacterial contamination of the abdominal cavity during pancreaticoduodenectomy on surgical-site infection

Background

Several risk factors for complications after pancreaticoduodenectomy have been reported. However, the impact of intraoperative bacterial contamination on surgical outcome after pancreaticoduodenectomy has not been examined in depth.

Methods

This retrospective study included patients who underwent pancreaticoduodenectomy and peritoneal lavage using 7000 ml saline between July 2012 and May 2014. The lavage fluid was subjected to bacterial culture examination. The influence of a positive bacterial culture on surgical-site infection (SSI) and postoperative course was evaluated. Risk factors for positive bacterial cultures were also evaluated.

Results

Forty-six (21·1 per cent) of 218 enrolled patients had a positive bacterial culture of the lavage fluid. Incisional SSI developed in 26 (57 per cent) of these 46 patients and in 13 (7·6 per cent) of 172 patients with a negative lavage culture (P < 0·001). Organ/space SSI developed in 32 patients with a positive lavage culture (70 per cent) and in 43 of those with a negative culture (25·0 per cent) (P < 0·001). Grade B/C pancreatic fistula was observed in 22 (48 per cent) and 48 (27·9 per cent) respectively of patients with positive and negative lavage cultures (P = 0·010). Postoperative hospital stay was longer in patients with a positive lavage culture (28 days versus 21 days in patients with a negative culture; P = 0·028). Multivariable analysis revealed that internal biliary drainage, combined colectomy and a longer duration of surgery were significant risk factors for positive bacterial culture of the lavage fluid.

Conclusion

Intraoperative bacterial contamination has an adverse impact on the development of SSI and grade B/C pancreatic fistula following pancreaticoduodenectomy.

Cell-free and concentrated ascites reinfusion therapy (CART) for management of massive malignant ascites in gastric cancer patients with peritoneal metastasis treated with intravenous and intraperitoneal paclitaxel with oral S-1

BACKGROUND

Massive malignant ascites originating from peritoneal metastasis of gastric cancer is difficult to control and resistant to chemotherapy. Cell-free and Concentrated Ascites Reinfusion Therapy (CART) is one of the types of apheresis therapy, by which filtered and concentrated ascites containing albumin and globulin is reinfused intravenously to patients. We retrospectively studied the feasibility of intraperitoneal (IP) chemotherapy combined with CART in gastric cancer patients with massive malignant ascites.

METHODS

Paclitaxel (PTX) was administered via an IP access port implanted in the subcutaneous space. If patient had massive ascites at the start of treatment, paracentesis was performed through a percutaneous IP catheter and then CART was performed. PTX was administered through the catheter until the ascites diminished.

RESULTS

A total of 127 CART procedures in 30 patients were analyzed. The average volume of processed ascites was 3.1 L, which was concentrated to 0.33 L containing 85.5 g protein on average. Significant increases in urine volume, serum total protein and albumin level were found after the CART. Increase in body temperature (0.3°C), decrease in platelet count (3.8 × 10(4)/μl), and changes in blood pressure (2 mm Hg) were found after the CART procedure, but no clinically significant adverse event was experienced. The median survival time and 1-year survival of 30 patients who received IP chemotherapy combined with the CART procedure was 10.2 months and 43.3% respectively.

CONCLUSIONS

IP chemotherapy combined with CART might be a promising strategy for patients with massive malignant ascites originating from peritoneal metastasis of gastric cancer.

Macrophage deficiency in osteopetrotic (op/op) mice inhibits activation of satellite cells and prevents hypertrophy in single soleus fibers

Effects of macrophage on the responses of soleus fiber size to hind limb unloading and reloading were studied in osteopetrotic homozygous (op/op) mice with inactivated mutation of macrophage colony-stimulating factor (M-CSF) gene and in wild-type (+/+) and heterozygous (+/op) mice. The basal levels of mitotically active and quiescent satellite cell (-46 and -39% vs. +/+, and -40 and -30% vs. +/op) and myonuclear number (-29% vs. +/+ and -28% vs. +/op) in fibers of op/op mice were significantly less than controls. Fiber length and sarcomere number in op/op were also less than +/+ (-22%) and +/op (-21%) mice. Similar trend was noted in fiber cross-sectional area (CSA, -15% vs. +/+, P = 0.06, and -14% vs. +/op, P = 0.07). The sizes of myonuclear domain, cytoplasmic volume per myonucleus, were identical in all types of mice. The CSA, length, and the whole number of sarcomeres, myonuclei, and mitotically active and quiescent satellite cells, as well as myonuclear domain, in single muscle fibers were decreased after 10 days of unloading in all types of mice, although all of these parameters in +/+ and +/op mice were increased toward the control values after 10 days of reloading. However, none of these levels in op/op mice were recovered. Data suggest that M-CSF and/or macrophages are important to activate satellite cells, which cause increase of myonuclear number during fiber hypertrophy. However, it is unclear why their responses to general growth and reloading after unloading are different.

Electric-field-induced modification of the magnon energy, exchange interaction, and curie temperature of transition-metal thin films

The electric-field-induced modification in the Curie temperature of prototypical transition-metal thin films with the perpendicular magnetic easy axis, a freestanding Fe(001) monolayer and a Co monolayer on Pt(111), is investigated by first-principles calculations of spin-spiral structures in an external electric field (E field). An applied E field is found to modify the magnon (spin-spiral formation) energy; the change arises from the E-field-induced screening charge density in the spin-spiral states due to p-d hybridizations. The Heisenberg exchange parameters obtained from the magnon energy suggest an E-field-induced modification of the Curie temperature, which is demonstrated via Monte Carlo simulations that take the magnetocrystalline anisotropy into account.

The real impact of telaprevir dosage on the antiviral and side effects of telaprevir, pegylated interferon and ribavirin therapy for chronic hepatitis C patients with HCV genotype 1

Triple therapy with telaprevir, pegylated interferon and ribavirin has been reported to improve antiviral efficacy but have potentially severe adverse effects in patients with chronic hepatitis C. To avoid the severe effects of telaprevir, lowering the dose has been suggested. However, impact of dosage changes on antiviral and adverse effects remains unclear. One hundred and sixty-six Japanese patients with HCV genotype 1 were treated with triple therapy. The drug exposure of each medication was calculated by averaging the dose actually taken. The overall SVR rate was 82%. The telaprevir discontinuation rate was 26%. The factors associated with discontinuation were an older age (≥65 y.o.) and a higher average dose during treatment. The telaprevir discontinuation rates were 42%, 25% and 14% in patients at ≥35, 25-35 and <25 mg/kg/day of telaprevir and 58% in older patients at ≥35 mg/kg/day of TVR. The factors associated with SVR were treatment-naïve, relapse to previous treatment, higher average telaprevir dose during treatment and completion of treatment. The SVR rate was higher, at 91%, in patients at 25-35 mg/kg/day of telaprevir than the 71% and 78% observed in those at <25 and ≥35 mg/kg/day of drug. In Japanese patients, a mean telaprevir dose of 25-35 mg/kg/day during treatment can augment its efficacy in triple therapy for patients with HCV genotype 1.

Publisher's note. Identification of a novel synonymous mutation in the human β-ureidopropionase gene UPB1 affecting pre-mRNA splicing

β-Ureidopropionase is the third enzyme of the pyrimidine degradation pathway and it catalyzes the conversion of N-carbamyl-β-alanine and N-carbamyl-β-aminoisobutyric acid to β-alanine and β-aminoisobutyric acid, respectively, and ammonia and CO2. To date, only 16 genetically confirmed patients with a complete ß-ureidopropionase deficiency have been reported. Here, we report the clinical, biochemical, and molecular analysis of a newly identified patient with β-ureidopropionase deficiency. Mutation analysis of the UPB1 gene showed that the patient was compound heterozygous for a novel synonymous mutation c.93C>T (p.Gly31Gly) in exon 1 and a previously described missense mutation c.977G>A (p.Arg326Gln) in exon 9. The in silico predicted effect of the synonymous mutation p.Gly31Gly on pre-mRNA splicing was investigated using a minigene approach. Wild-type and the mutated minigene constructs, containing the entire exon 1, intron 1, and exon 2 of UPB1, yielded different splicing products after expression in HEK293 cells. The c.93C>T (p.Gly31Gly) mutation resulted in altered pre-mRNA splicing of the UPB1 minigene construct and a deletion of the last 13 nucleotides of exon 1. This deletion (r.92 104delGCAAGGAACTCAG) results in a frame shift and the generation of a premature stop codon (p.Lys32SerfsX31). Using a minigene approach, we have thus identified the first synonymous mutation in the UPB1 gene, creating a cryptic splice-donor site affecting pre-mRNA splicing.

Bayesian modeling of virus removal efficiency in wastewater treatment processes

Left-censored datasets of virus density in wastewater samples make it difficult to evaluate the virus removal efficiency in wastewater treatment processes. In the present study, we modeled the probabilistic distribution of virus removal efficiency in a wastewater treatment process with a Bayesian approach, and investigated how many detect samples in influent and effluent are necessary for accurate estimation. One hundred left-censored data of virus density in wastewater (influent and effluent) were artificially generated based on assumed log-normal distributions and the posterior predictive distribution of virus density, and the log-ratio distribution were estimated. The estimation accuracy of distributions was quantified by Bhattacharyya coefficient. When it is assumed that the accurate estimation of posterior predictive distributions is possible when a 100% positive rate is obtained for 12 pairs of influent and effluent, 11 out of 144, 60 out of 324, and 201 out of 576 combinations of detect samples gave an accurate estimation at the significant level of 0.01 in a Kruskal-Wallis test when the total sample number was 12, 18, and 24, respectively. The combinations with the minimum number of detect samples were (12, 9), (16, 10), and (21, 8) when the total sample number was 12, 18, and 24, respectively.

Preparation of metal oxide thin films from organic-additive-free aqueous solutions by low-speed dip-coating

Transparent, crack-free SnO₂ and TiO₂ precursor films were obtained from organic-additive-free aqueous solutions by low-speed dip-coating. The precursor films were crystallized to SnO₂ and TiO₂ by the heat treatment at 700 °C for 10 min in air.

Doublecortin marks a new population of transiently amplifying muscle progenitor cells and is required for myofiber maturation during skeletal muscle regeneration

Muscle satellite cells are indispensable for muscle regeneration, but the functional diversity of their daughter cells is unknown. Here, we show that many Pax7+MyoD− cells locate both beneath and outside the basal lamina during myofiber maturation. A large majority of these Pax7+MyoD− cells are not self-renewed satellite cells, but have different potentials for both proliferation and differentiation from Pax7+MyoD+ myoblasts (classical daughter cells), and are specifically marked by expression of the doublecortin (Dcx) gene. Transplantation and lineage-tracing experiments demonstrated that Dcx-expressing cells originate from quiescent satellite cells and that the microenvironment induces Dcx in myoblasts. Expression of Dcx seems to be necessary for myofiber maturation because Dcx-deficient mice exhibited impaired myofiber maturation resulting from a decrease in the number of myonuclei. Furthermore, in vitro and in vivo studies suggest that one function of Dcx in myogenic cells is acceleration of cell motility. These results indicate that Dcx is a new marker for the Pax7+MyoD− subpopulation, which contributes to myofiber maturation during muscle regeneration.

Anisotropy of the superconducting gap in the iron-based superconductor BaFe2(As(1-x)P(x))2

We report peculiar momentum-dependent anisotropy in the superconducting gap observed by angle-resolved photoemission spectroscopy in BaFe₂(As_1-xP_x)₂ (x = 0.30, T_c = 30 K). Strongly anisotropic gap has been found only in the electron Fermi surface while the gap on the entire hole Fermi surfaces are nearly isotropic. These results are inconsistent with horizontal nodes but are consistent with modified s_± gap with nodal loops. We have shown that the complicated gap modulation can be theoretically reproduced by considering both spin and orbital fluctuations.

Narrow-margin excision is a safe, reliable treatment for well-defined, primary pigmented basal cell carcinoma: an analysis of 288 lesions in Japan

BACKGROUND

Complete excision is the most promising treatment for basal cell carcinoma (BCC) and a surgical margin of at least 4 mm is recommended. However, little is known about the appropriate surgical margin of pigmented BCC.

OBJECTIVE

To investigate the reliability of narrower margin excision of well-defined, pigmented BCC.

METHODS

We identified a total of 263 patients with 288 well-defined, primary pigmented BCC at the Department of Dermatology, Kyushu University (Fukuoka, Japan), between January 2006 and December 2013. All lesions were surgically excised with 1-6-mm margins and analysed. For 30 recent lesions out of the 288 lesions, border gaps between dermoscopy and histopathology were assessed.

RESULTS

Of the 288 lesions, 218 (75.7%) were excised with a narrow margin (≤ 3 mm) and 60 lesions (24.3%) with a wide margin (≥ 4 mm). Only two lesions (0.7%), which were excised with 2-mm margins, were associated with tumour-positive margins. Narrow-margin excision showed a complete removal rate of 99% (2-mm margins, 95.3%; 3-mm margins, 100%). Dermoscopically determined borders almost exactly corresponded to the histopathological ones; 71.2% of border gaps between dermoscopy and histopathology were within 1 mm and there were no cases in which tumours spread beyond 1 mm of their dermoscopic borders.

CONCLUSION

Surgical excision with a 2-3-mm margin is reliable treatment for well-defined, primary pigmented BCC, with a complete removal rate of 99%.

Evaluation of insulin independence using 11C-methionine positron emission tomography after living-donor and brain-dead donor pancreas transplantation

We recently reported that (11)C-methionine positron-emission tomography (PET) is clinically useful for the evaluation of the pancreatic function of the living donor. The objective of this study was to evaluate the postoperative insulin independence in 10 living donor (LD) and 10 brain-dead donor (BD) pancreas transplantations for 20 patients with type I diabetes mellitus by using (11)C-methionine PET. After 6 months, PET/computed tomography was performed 30 minutes after (11)C-methionine (370-740 MBq) injection. The uptake in the pancreas was expressed as the standardized uptake value (SUV). Patient survival rates were 100% at 5 years for LD transplantations and at 2 years for BD transplantations. Insulin independence was 60% for LD transplantations at 5 years and 75% for BD transplantations at 2 years. There were no major surgical complications such as vascular thrombosis, intra-abdominal abscess, and graft pancreatitis. The SUVs for LD and BD pancreas transplantations with insulin independence were 7.2 ± 1.8 and 10.4 ± 2.3, respectively. The SUVs for LD pancreas transplantations with insulin dependence and BD pancreas transplantations with graft failure were 3.6 ± 1.1 and 2.9 ± 1.0, respectively. At 5 years after transplantation, for the LD transplants, the insulin-independent rate was 100% for the graft recipients with an SUV higher than 5, and the median insulin independence duration of the graft recipients with an SUV less than 5 was 7 months (P < .01). The (11)C-methionine PET may be a potent modality to predict long-term insulin independence and the avoidance of pancreas graft failure.

Preferential infiltration of interleukin-4-producing CXCR4+ T cells in the lesional muscle but not skin of patients with dermatomyositis

Dermatomyositis (DM) and polymyositis (PM) are collectively termed autoimmune myopathy. To investigate the difference between muscle- and skin-infiltrating T cells and to address their role for myopathy, we characterized T cells that were directly expanded from the tissues. Enrolled into this study were 25 patients with DM and three patients with PM. Muscle and skin biopsied specimens were immersed in cRPMI medium supplemented with interleukin (IL)-2 and anti-CD3/CD28 antibody-conjugated microbeads. The expanded cells were subjected to flow cytometry to examine their phenotypes. We analysed the cytokine concentration in the culture supernatants from the expanded T cells and the frequencies of cytokine-bearing cells by intracellular staining. There was non-biased in-vitro expansion of tissue-infiltrating CD4(+) and CD8(+) T cells from the muscle and skin specimens. The majority of expanded T cells were chemokine receptor (CCR) type 7(-) CD45RO(+) effecter memory cells with various T cell receptor (TCR) Vβs. The skin-derived but not muscle-derived T cells expressed cutaneous lymphocyte antigen (CLA) and CCR10 and secreted large amounts of IL-17A, suggesting that T helper type 17 (Th17) cells may have a crucial role in the development of skin lesions. Notably, the frequency of IL-4-producing chemokine (C-X-C motif) receptor (CXCR)4(+) Th2 cells was significantly higher in the muscle-derived cells and correlated inversely with the serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) levels. stromal-derived factor (SDF)-1/CXCL12, a ligand for CXCR4, was expressed at a high level in the vascular endothelial cells between muscular fasciculi. Our study suggests that T cell populations in the muscle and skin are different, and the Th2 cell infiltrate in the muscle is associated with the low severity of myositis in DM.

Suppressive effects of neutrophil by Salp16-like salivary gland proteins from Ixodes persulcatus Schulze tick

Salp16, a 16-kDa tick salivary gland protein, is known to be the molecule involved in the transmission of Anaplasma phagocytophilum, an obligate intracellular pathogen causing zoonotic anaplasmosis, from its mammalian hosts to Ixodes scapularis. Recently, the presence of A. phagocytophilum was documented in Japan and Ixodes persulcatus was identified as one of its vectors. The purpose of this study was to identify Salp16 genes in I. persulcatus and characterize their function. Two cDNA clones encoding the Salp16-like sequences were obtained from the salivary glands of fed female I. persulcatus ticks and designated Salp16 Iper1 and Iper2. Gene expression analyses showed that the Salp16 Iper genes were expressed specifically in the salivary glands and were up-regulated by blood feeding. These proteins attenuated the oxidative burst of activated bovine neutrophils and inhibited their migration induced by the chemoattractant interleukin-8 (IL-8). These results demonstrate that Salp16 Iper proteins contribute to the establishment of blood feeding as an immunosuppressant of neutrophil, an essential factor in innate host immunity. Further examination of the role of Salp16 Iper in the transmission of pathogens, including A. phagocytophilum, will increase our understanding of the tick-host-pathogen interface.

Normal-state charge dynamics in doped BaFe₂As₂: roles of doping and necessary ingredients for superconductivity

In high-transition-temperature superconducting cuprates and iron arsenides, chemical doping plays an important role in inducing superconductivity. Whereas in the cuprate case, the dominant role of doping is to inject charge carriers, the role for the iron arsenides is complex owing to carrier multiplicity and the diversity of doping. Here, we present a comparative study of the in-plane resistivity and the optical spectrum of doped BaFe₂As₂, which allows for separation of coherent (itinerant) and incoherent (highly dissipative) charge dynamics. The coherence of the system is controlled by doping, and the doping evolution of the charge dynamics exhibits a distinct difference between electron and hole doping. It is found in common with any type of doping that superconductivity with high transition temperature emerges when the normal-state charge dynamics maintains incoherence and when the resistivity associated with the coherent channel exhibits dominant temperature-linear dependence.

Identification of a novel synonymous mutation in the human β -Ureidopropionase Gene UPB1 affecting pre-mRNA splicing

β-Ureidopropionase is the third enzyme of the pyrimidine degradation pathway and it catalyzes the conversion of N-carbamyl-β-alanine and N-carbamyl-β-aminoisobutyric acid to β-alanine and β-aminoisobutyric acid, respectively, and ammonia and CO2. To date, only 16 genetically confirmed patients with a complete ß-ureidopropionase deficiency have been reported. Here, we report the clinical, biochemical, and molecular analysis of a newly identified patient with β-ureidopropionase deficiency. Mutation analysis of the UPB1 gene showed that the patient was compound heterozygous for a novel synonymous mutation c.93C >T (p.Gly31Gly) in exon 1 and a previously described missense mutation c.977G >A (p.Arg326Gln) in exon 9. The in silico predicted effect of the synonymous mutation p.Gly31Gly on pre-mRNA splicing was investigated using a minigene approach. Wild-type and the mutated minigene constructs, containing the entire exon 1, intron 1, and exon 2 of UPB1, yielded different splicing products after expression in HEK293 cells. The c.93C >T (p.Gly31Gly) mutation resulted in altered pre-mRNA splicing of the UPB1 minigene construct and a deletion of the last 13 nucleotides of exon 1. This deletion (r.92_104delGCAAGGAACTCAG) results in a frame shift and the generation of a premature stop codon (p.Lys32SerfsX31). Using a minigene approach, we have thus identified the first synonymous mutation in the UPB1 gene, creating a cryptic splice-donor site affecting pre-mRNA splicing.

Partial Sequence of Acid Phosphatase-11Gene(Aps-11)Linked to Nematode Resistance Gene (Mi) of Tomato

A partial amino acid sequence of acid phosphatase-1(1) (apase-1(1)), one of acid phosphatase isozymes of tomato, was identified. This information enabled us to synthesize degenerated primer pools of oligonucleotides for polymerase chain reactions (PCR) using cDNA for poly(A)+ RNA of tomato leaves as a template. As a result, a 135-bp, then a 467-bp PCR product were obtained. Nucleotide sequencing of these two PCR products gave a total of 522-bp sequence that was identified as a part of the Asp-1(1) gene judging from the amino acid sequence deduced from it. Using the 135-bp PCR product as a probe, we detected the restriction fragment length polymorphism (RFLP) in two different lines of tomato by genomic Southern blot analysis. We also did pulsed-field gel electrophoresis (PFGE) and Southern blot analysis to search for suitable fragments to clone into a YAC vector. As a result, a single band with a size that could be cloned into a YAC vector was detected when the genomic DNA was digested with some kinds of restriction enzymes.

The Structure of Zinc Chloride Complexes in Aqueous Solution

The structure of zinc chloride complexes with different ratios of chloride to zinc, formed in concentrated ZnCl2 aqueous solutions, were determined from large-angle X-ray scattering using concentrations of the chloride complexes estimated by complementary Raman spectroscopic measurements. The highest chloro complex, [ZnCl4]2-, is tetrahedral with a Zn-Cl bond length of 2.294(4) Å. The trichloro complex, [ZnCl3]-, which coordinates one water molecule, is pyramidal with the Cl-Zn-Cl angle 111°. The Zn-Cl and the Zn-H2O bonds are 2.282(4) and 1.9 Å, respectively. The two lower complexes, [ZnCl2] and [ZnCl]+ , cannot be separated by Raman spectra. The average Zn-Cl distance in these complexes is 2.24 Å, and the average Zn-H2O distance is 1.9 Å. In [Zn(H2O)6]2+ the Zn-H2O distance is 2.15 Å.