Short- and long-term outcomes of self-expanding metallic stent placement vs. emergency surgery for malignant colorectal obstruction

The European Society of Gastrointestinal Endoscopy does not recommend self-expanding metal stent (SEMS) placement as a bridge to surgery (BTS) for malignant colorectal obstruction (MCRO). However, no universally accepted consensus has been determined. The present study aimed to evaluate the short- and long-term outcomes of SEMS placement vs. emergency surgery (ES) for MCRO. Surgical resection of colorectal cancer was performed in 3,840 patients between April 2001 and June 2016. Of these, 93 patients had MCRO requiring emergency decompression. Only patients in whom the colorectal lesion was ultimately resected were included; thus, the present study included 62 patients treated with MCRO via SEMS placement as a BTS (n=25) or via ES (n=37). The rates of laparoscopic surgery, primary anastomosis, stoma formation, lymph node dissection, adverse events, 30-day mortality and disease-free survival were evaluated. The clinical success rate of SEMS placement was 92.0% (23/25). Compared with the ES group, the SEMS group had higher rates of laparoscopic surgery (68.0 vs. 2.7%; P<0.001) and primary anastomosis (88.0 vs. 51.4%; P=0.003), a greater number of dissected lymph nodes (30 vs. 18; P=0.001), and lower incidences of stoma formation (24.0 vs. 67.6%; P=0.002) and overall adverse events (24.0 vs. 62.2%; P=0.004). The 30-day mortality and disease-free survival of the SEMS group were not significantly different to that of the ES group (0 vs. 2.7%; P=1.000; log-rank test; P=0.10). In conclusion, as long as adverse events such as perforation are minimized, SEMS placement as a BTS could be a first treatment option for MCRO. The present study is registered in the University Hospital Medical Network Clinical Trials Registry (UMIN R000034868).

Clinicopathological features of T1 colorectal carcinomas with skip lymphovascular invasion

With recent advances in endoscopic treatment, many T1 colorectal carcinomas (CRCs) are resected endoscopically with a negative margin. However, some lesions exhibit skip lymphovascular invasion (SLVI), which is defined as the discontinuous foci of the tumor cells within the colon wall. The aim of the present study was to reveal the clinicopathological features of T1 CRCs with SLVI and validate the Japanese guidelines regarding SLVI. A total of 741 patients with T1 CRCs that were resected surgically between April 2001 and October 2016 in our hospital were divided into two groups: With SLVI and without SLVI. Clinicopathological features compared between the two groups were patient's gender, age, tumor size, location, morphology, lymphovascular invasion, tumor differentiation, tumor budding and lymph node metastasis. The incidence of T1 CRCs with SLVI was 0.9% (7/741). All cases with SLVI were found in the sigmoid colon or rectum. T1 CRCs with SLVI showed significantly higher rates of lymphovascular invasion than those without SLVI (P<0.01). In conclusion, lymphovascular invasion was a significant risk factor for SLVI in T1 CRCs, and for which surgical colectomy was necessary. The Japanese guidelines are appropriate regarding SLVI. Registered in the University Hospital Medical Network Clinical Trials Registry (UMIN000027097).

Artificial intelligence may help in predicting the need for additional surgery after endoscopic resection of T1 colorectal cancer

BACKGROUND AND STUDY AIMS

Decisions concerning additional surgery after endoscopic resection of T1 colorectal cancer (CRC) are difficult because preoperative prediction of lymph node metastasis (LNM) is problematic. We investigated whether artificial intelligence can predict LNM presence, thus minimizing the need for additional surgery.

PATIENTS AND METHODS

Data on 690 consecutive patients with T1 CRCs that were surgically resected in 2001 - 2016 were retrospectively analyzed. We divided patients into two groups according to date: data from 590 patients were used for machine learning for the artificial intelligence model, and the remaining 100 patients were included for model validation. The artificial intelligence model analyzed 45 clinicopathological factors and then predicted positivity or negativity for LNM. Operative specimens were used as the gold standard for the presence of LNM. The artificial intelligence model was validated by calculating the sensitivity, specificity, and accuracy for predicting LNM, and comparing these data with those of the American, European, and Japanese guidelines.

RESULTS

Sensitivity was 100 % (95 % confidence interval [CI] 72 % to 100 %) in all models. Specificity of the artificial intelligence model and the American, European, and Japanese guidelines was 66 % (95 %CI 56 % to 76 %), 44 % (95 %CI 34 % to 55 %), 0 % (95 %CI 0 % to 3 %), and 0 % (95 %CI 0 % to 3 %), respectively; and accuracy was 69 % (95 %CI 59 % to 78 %), 49 % (95 %CI 39 % to 59 %), 9 % (95 %CI 4 % to 16 %), and 9 % (95 %CI 4 % - 16 %), respectively. The rates of unnecessary additional surgery attributable to misdiagnosing LNM-negative patients as having LNM were: 77 % (95 %CI 62 % to 89 %) for the artificial intelligence model, and 85 % (95 %CI 73 % to 93 %; P < 0.001), 91 % (95 %CI 84 % to 96 %; P < 0.001), and 91 % (95 %CI 84 % to 96 %; P < 0.001) for the American, European, and Japanese guidelines, respectively.

CONCLUSIONS

Compared with current guidelines, artificial intelligence significantly reduced unnecessary additional surgery after endoscopic resection of T1 CRC without missing LNM positivity.

A case of steroid-responsive organizing pneumonia in a patient with rheumatoid arthritis showing migratory infiltration and normal glucose levels in pleural effusions

A 59-year-old Japanese man with RA was referred to us with arthralgia and pulmonary infiltration. Chest roentgenogram showed migratory infiltration and pleural effusion, the glucose levels of the pleural fluid were not reduced. Transbronchial lung biopsy showed granulation tissue plugging the alveolar ducts, indicating organizing pneumonia and interstitial inflammation. These pathological findings were identical with those for cryptogenic organizing pneumonitis (COP). There was a good clinical and roentgenographic response and the pleural effusion responded well to corticosteroids. The characteristic migratory infiltration in rheumatoid lung disease responds well to corticosteroids.

Cell cycle control by Ca2+ in Saccharomyces cerevisiae

We established an experimental system suitable for study of cell cycle regulation by Ca2+ in the yeast Saccharomyces cerevisiae. Systematic cell cycle analysis using media containing various concentrations of Ca2+, a Ca2(+)-ionophore (A23187), and a Ca2(+)-chelator [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) revealed that simultaneous addition of 10 microM A23187 and 10 mM EGTA to cells growing in a Ca2(+)-deficient medium at 22 degrees C caused rapid decrease in intracellular Ca content and resulted in transient G1 arrest followed by block mostly at G2/M, as revealed by flow cytometry. Recovery from G1 arrest was not due to coordinated initiation of DNA synthesis and bud emergence: unbudded cells with S or G2/M DNA were observed. Examination of terminal phenotype suggested that Ca2+ was required at all the stages of the cell cycle except for the initiation of DNA synthesis. The intracellular cAMP level decreased within 10 min of addition of A23187 and EGTA. No significant transient G1 arrest was observed in cells incubated with 8-Br-cAMP, or RAS2val19 and delta bcy1 mutants, which produce a high level of cAMP and have constitutively activated cAMP-dependent protein kinase, respectively. These results indicate that Ca2+ is essential for cell cycle progression and suggest that Ca2+ may regulate the cAMP level. This system will be useful for genetic and molecular studies on cell cycle events regulated by Ca2+.

Essential role for induced Ca2+ influx followed by [Ca2+]i rise in maintaining viability of yeast cells late in the mating pheromone response pathway. A study of [Ca2+]i in single Saccharomyces cerevisiae cells with imaging of fura-2

We established an experimental system for measuring the cytosolic-free Ca2+ concentration ([Ca2+]i) in individual Saccharomyces cerevisiae cells using fura-2 as a Ca2(+)-specific probe in conjunction with digital image processing and examined changes in [Ca2+]i in response to alpha-factor in single cells of a mating type. The addition of alpha-factor to a cells raised [Ca2+]i to several hundred nanomolar in the cells from a basal level of approximately 100 nM, simultaneous with the induction of Ca2+ influx. When the cells were incubated with alpha-factor in a Ca2(+)-deficient medium, Ca2+ influx was greatly reduced, and the rise in [Ca2+]i was not detected. This indicates that the alpha-factor-induced rise in [Ca2+]i is generated by Ca2+ influx through the plasma membrane and not by release from internal stores. In the Ca2(+)-deficient medium, a cells died specifically after they had changed into cells with one projection on the cell surface. This indicates that the rise in [Ca2+]i is essential for the late response to alpha-factor. The duration of Ca2+ requirement for maintaining viability was limited to this stage, and the earlier and later stages were not affected by Ca2+ deprivation. Mating between a and alpha mating type cells was impaired in this medium due to cell death at and before the stage of conjugation. These findings are the first evidence for an essential role for mobilized Ca2+ in the yeast life cycle.

Cloning and analysis of the 5'-flanking region of rat Na+/K(+)-ATPase alpha 1 subunit gene

We cloned a 13.3 kilobase (kb) fragment of genomic DNA spanning at least the first two exons of the rat Na+/K(+)-ATPase alpha 1 subunit gene (NKAA1) and 1.5 kb of the 5'-flanking region. S1 nuclease mapping analysis of the 5' end of the Na+/K(+)-ATPase mRNA indicated that the transcription initiation site was located 262 base pairs (bp) upstream of the translation initiation codon. The transcription initiation site of the Na+/K(+)-ATPase alpha 1 subunit gene was identical among six tissues of adult rat (kidney, brain, heart, thyroid, liver and lung). A TATA-box-like sequence (at position -32), two Sp1 factor binding sequences (-137, -56), an active transcription factor consensus binding sequence (-71) and two glucocorticoid-responsive element half consensus sequences (-750, -481) were found in the 5'-flanking region. The sequence of the first exon and the 5'-flanking region of the rat NKAA1 was 63% homologous to that of the horse equivalent. Maximum homology (82%) between the two genes was observed in the region from 361 bp upstream of the translation initiation site to the 3' end of the first exon. The TATA-like box, Sp1 binding site and the active transcriptional factor (ATF) consensus site in this region were conserved in both rat and horse.

Regulation of Na+,K(+)-ATPase. II. Cloning and analysis of the 5'-flanking region of the rat NKAB2 gene encoding the beta 2 subunit

We cloned a 14.5-kb fragment of genomic DNA spanning at least the first two exons of the rat Na+,K(+)-ATPase (EC 3.6.1.3) beta 2 subunit-encoding gene and 5.5 kb of the 5'-flanking region. The transcription start point (tsp) is located 595 bp upstream from the start codon. The tsp was identical for adult rat brain and spleen, both of which produce the beta 2 isoform. The TATA sequence was found 29 bp upstream from the tsp and Sp1-binding sites at nucleotides (nt) -55 and -147. In addition, multiple consensus binding sites for a wide variety of regulatory proteins were present throughout the upstream and downstream tsp-flanking regions. Conserved sequence elements which may serve for coordinated expression of the alpha and beta subunits were found in the nt sequence of the 5'-flanking region.

Regulation of Na+,K(+)-ATPases. I. Cloning and analysis of the 5'-flanking region of the rat NKAA2 gene encoding the alpha 2 subunit

The nucleotide (nt) sequence of the genomic clone, spanning at least the first two exons of the rat Na+,K(+)-ATPase alpha 2 subunit-encoding gene and 6.5 kb of the 5'-flanking region, has been determined. S1 nuclease mapping analysis of the 5' end of the Na+,K(+)-ATPase mRNA indicated that the transcription start point (tsp) is located 105 bp upstream from the start codon. The tsp was identical among three adult-rat tissues (brain, skeletal muscle and heart) which produce the alpha 2 isoform. A TATA-like sequence was found 33 bp upstream from the tsp. In addition, multiple consensus binding sites for a wide variety of regulatory proteins were present throughout the upstream and downstream tsp-flanking regions. A remarkable conservation in the nt sequence of the 5'-flanking region was confirmed between the rat and human genes.

The Na,K-ATPase alpha 2 subunit gene displays restriction fragment length polymorphisms between the genomes of normotensive and hypertensive rats

The Na,K-adenosine triphosphatase (ATPase) alpha 2 subunit gene was found to display restriction fragment length polymorphisms (RFLPs) between the genomes of normotensive and hypertensive rats when digested with the restriction enzymes Bgl II and Hind III. In normotensive rats, we tested the spontaneously hypertensive rat (SHR) and its substrain, the stroke-prone spontaneously hypertensive rat (SHR-SP). Rat (SD) complementary (c) DNA encoding the alpha 2 subunit of Na,K-ATPase was used as a probe. When the probe was dissected these RFLPs were found to occur in the vicinity of the genomic locus encoding the middle part of the messenger (m) RNA for the alpha 2 subunit of Na,K-ATPase. A Northern blot analysis indicated that these RFLPs did not influence the alpha 2 subunit with regard to either size or amount of mRNA.