DPPA3 facilitates genome-wide DNA demethylation in mouse primordial germ cells.

BACKGROUND: Genome-wide DNA demethylation occurs in mammalian primordial germ cells (PGCs) as part of the epigenetic reprogramming important for gametogenesis and resetting the epigenetic information for totipotency. Dppa3 (also known as Stella or Pgc7) is highly expressed in mouse PGCs and oocytes and encodes a factor essential for female fertility. It prevents excessive DNA methylation in oocytes and ensures proper gene expression in preimplantation embryos: however, its role in PGCs is largely unexplored. In the present study, we investigated whether or not DPPA3 has an impact on CG methylation/demethylation in mouse PGCs. RESULTS: We show that DPPA3 plays a role in genome-wide demethylation in PGCs even before sex differentiation. Dppa3 knockout female PGCs show aberrant hypermethylation, most predominantly at H3K9me3-marked retrotransposons, which persists up to the fully-grown oocyte stage. DPPA3 works downstream of PRDM14, a master regulator of epigenetic reprogramming in embryonic stem cells and PGCs, and independently of TET1, an enzyme that hydroxylates 5-methylcytosine. CONCLUSIONS: The results suggest that DPPA3 facilitates DNA demethylation through a replication-coupled passive mechanism in PGCs. Our study identifies DPPA3 as a novel epigenetic reprogramming factor in mouse PGCs.

Effects of transgene insertion loci and copy number on Dnmt3L gene silencing through antisense transgene-derived PIWI-interacting RNAs.

PIWI-interacting RNAs (piRNAs), which are germ cell-specific small RNAs, are essential for spermatogenesis. In fetal mouse germ cells, piRNAs are synthesized from sense and antisense RNAs of transposable element sequences for retrotransposon silencing. In a previous study, we reported that transgenic mice expressing antisense-Dnmt3L under the control of the Miwi2 promoter (Tg-Miwi2P-asDnmt3L) exhibited piRNA-mediated DNMT3L down-regulation. In this study, two transgene integration loci (B3 and E1) were identified on chromosome 18 of the Tg-Miwi2P-asDnmt3L mice; these loci were weak piRNA clusters. Crossbreeding was performed to obtain mice with the transgene cassette inserted into a single locus. DNMT3L was silenced and spermatogenesis was severely impaired in mice with the transgene cassette inserted at the B3 locus (Tg-B mice). In contrast, spermatogenesis in mice bearing the transgene at the E1 locus (Tg-E mice) was normal. The number of piRNAs for Dnmt3L in Tg-B mice was eightfold higher than that in Tg-E mice. Therefore, both gene silencing and impaired spermatogenesis depended on the transgene copy number rather than on the insertion loci. Additionally, the endogenous Dnmt3L promoter was not methylated in Tg mice, suggesting that Dnmt3L silencing was caused by post-transcriptional gene silencing. Based on these data, we discuss a piRNA-dependent gene silencing mechanism against novel gene insertions.

Tet1 regulates epigenetic remodeling of the pericentromeric heterochromatin and chromocenter organization in DNA hypomethylated cells.

Pericentromeric heterochromatin (PCH), the constitutive heterochromatin of pericentromeric regions, plays crucial roles in various cellular events, such as cell division and DNA replication. PCH forms chromocenters in the interphase nucleus, and chromocenters cluster at the prophase of meiosis. Chromocenter clustering has been reported to be critical for the appropriate progression of meiosis. However, the molecular mechanisms underlying chromocenter clustering remain elusive. In this study, we found that global DNA hypomethylation, 5hmC enrichment in PCH, and chromocenter clustering of Dnmt1-KO ESCs were similar to those of the female meiotic germ cells. Tet1 is essential for the deposition of 5hmC and facultative histone marks of H3K27me3 and H2AK119ub at PCH, as well as chromocenter clustering. RING1B, one of the core components of PRC1, is recruited to PCH by TET1, and PRC1 plays a critical role in chromocenter clustering. In addition, the rearrangement of the chromocenter under DNA hypomethylated condition was mediated by liquid-liquid phase separation. Thus, we demonstrated a novel role of Tet1 in chromocenter rearrangement in DNA hypomethylated cells.

Relationship between prognostic impact of N3 lymph node metastasis at the root of the feeding artery and location of colon cancer.

PURPOSE: To determine whether N3 nodal involvement predicts outcomes and whether its prognostic implications vary with tumor location in patients with Stage III colon cancer (CC). METHODS: We defined N3 as lymph node metastases near the bases of the major feeding arteries. We retrospectively examined recurrence rates and patterns by tumor location and sites of lymph node metastases in 57 patients with N3 CC who had undergone curative resections between January 2000 and March 2019. Survival analysis was performed to compare the prognoses of patients with and without N3 lymph node metastasis. RESULTS: Most N3 patients had large tumors (T ≥ 3); five had T2 disease. Recurrence occurred quickly in one patient with T2N3M0 disease. Multivariate survival analysis demonstrated that N3 lymph node metastasis is an independent predictor of poor prognosis in Stage III CC patients (P < 0.001). Categorizing N3 patients according to UICC-TNM staging system does not stratify risk of recurrence (P = 0.970). To investigate the impact of tumor location on recurrence risk, we classified N3 CC into two subtypes according to tumor location: metastasis at the base of the superior mesenteric artery in right-sided CC and inferior mesenteric artery in left-sided CC. The former was found to have a statistically significant poorer prognosis than the latter (P = 0.091). CONCLUSION: N3 is a robust prognostic marker in CC patients. Recurrence risk varies by tumor location. N3 right-sided CCs with lymph node metastasis at the base of the superior mesenteric artery have poorer prognoses than do N3 left-sided CCs.

[Perioperative Nutritional and Rehabilitation Therapy for Esophagectomy Cancer Patients].

The combination of nutritional therapy and rehabilitation in the perioperative period is expected to have synergistic effects on nutrition, muscle mass, inflammation, and other systemic conditions. It is important to form a perioperative team composed of members from other professions in order to implement a nutritional rehabilitation program efficiently and explain it in an easy-to-understand manner to patients. Nutritional guidance by a dietitian is provided from the preoperative outpatient visit, and a target daily nutritional intake is established. A feeding tube or percutaneous endoscopic gastrostomy (PEG) may be considered for patients with inadequate oral intake. Products containing branched-chain amino acids should be administered after exercise. Preoperative upper and lower limb muscle strengthening training is provided by physical and occupational therapists, and postoperative coughing and standing exercises are performed at the same time to facilitate the introduction of postoperative training. Postoperative nutritional management is primarily enteral nutrition through a tube enterostomy tube. Oral intake is resumed after fluoroscopy on day 7. The patient will be trained in bed for joint mobility, sitting on the edge of the bed, and standing on day 1. Gait training is started on day 2. After the third day, gait training is performed in the ward, and stretching, strength training, bicycle ergometer, and other exercises are performed in the training room. It is important to provide seamless nutritional rehabilitation therapy from preoperative to postoperative outpatient.

Comparison of CEA and CA19-9 as a predictive factor for recurrence after curative gastrectomy in gastric cancer.

BACKGROUND: Our aim of was to compare importance of the tumor markers (TMs) serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in prediction of recurrence after curative gastrectomy for gastric cancer. METHODS: We reviewed retrospectively the clinical records of 149 patients who underwent curative gastrectomy for stage I-III gastric cancer and whose CEA and CA19-9 levels were determined once preoperatively and for more than 3 years postoperatively. We investigated whether the clinicopathological characteristics of patients including age, sex, pathological disease stage, operative approach, type of gastrectomy, and degree of lymph node dissection as well as preoperative positivity of CEA and CA19-9 were risk factors for recurrence in univariate and multivariate analyses. Rate of recurrence was compared between patients positive and negative for postoperative CEA or CA19-9. We also calculated sensitivity, specificity, positive and negative predictable values of postoperative positivity of CEA and CA19-9 for recurrence. The lead time was compared between CEA and CA19-9 that was defined as the time of the first detection of increases in tumor markers and confirmation of recurrence on imaging modalities. RESULTS: The number of patients positive for preoperative CEA was 25 (17%) and for CA19-9 was 11 (7%). Recurrence was confirmed in 29 (19%) patients. Stage III disease, preoperative positivity for CA19-9 but not CEA, and total gastrectomy were risk factors for recurrence in univariate analysis, but stage III disease was the only risk factor for recurrence in multivariate analysis. Forty and 15 patients were positive for postoperative CEA and CA19-9, respectively. The recurrence rate of 47% (7/15) in patients positive for postoperative CA19-9 was greater than that in negative patients (22/134 = 16%), but it did not differ between patients who were positive or negative for postoperative CEA. Specificity for CA19-9 was greater than that for CEA (P < 0.05). The lead time of CEA (3.9 ± 4.7 months) was not different from that of CA19-9 (6.1 ± 7.1 months). CONCLUSIONS: These results indicate that CA19-9 rather than CEA is likely to be more useful for the detection of recurrence after curative gastrectomy for gastric cancer.

[Idiopathic and Iatrogenic Esophageal Rupture].

One of the most common indications for emergency surgery is full-layer rupture of the esophagus. Iatrogenic injury to the esophagus is the most frequent cause of esophageal rupture, followed by spontaneous rupture. If the patient is not treated promptly, mediastinitis can develop into a serious and life-threatening condition. Diagnosis and treatment must be initiated as soon as possible. Spontaneous esophageal rupture often requires emergency surgical intervention. Various surgical techniques for esophageal rupture have been reported, including transabdominal or transthoracic, open or thoracoscopic surgery, drain placement, and surgical position. There have been reports of thoracoscopic primary closure of esophageal tear and thoracic drainage in the prone or lateral decubitus position. On the other hand, iatrogenic esophageal rupture is often treated conservatively, those patients require fasting, administration of antibiotics and proton pump inhibitors, suctioning and decompression using nasogastric tube, and chest drainage if necessary. In addition, close follow-up should be maintained so that the opportunity for surgery is not missed when necessary. Although esophageal rupture is relatively rare and is not an everyday occurrence, it is an urgent condition that requires prompt diagnosis and treatment, so it is necessary to have prior knowledge and to respond promptly.

Ribosomal stress induces 2-cell embryo-like state transition of the mouse ESCs through p53 activation.

Embryonic stem cells (ESCs) maintain a pluripotent state and genome integrity in long-term culture. A rare population of ESCs showing 2-cell embryo-specific gene expression is believed to play critical roles in sustainable pluripotency and genome stability. However, the molecular mechanism controlling this transition to a 2-cell embryo-like (2CL) state remains unclear. We carried out screening to search for the factors involved in 2CL state induction and found a ribosomal RNA processing factor, Pum3 to be a candidate. Increased 2CL state population accompanied with an accumulation of pre-ribosomal RNA and activated p53 in the Pum3-KO ESC. Furthermore, the increase of 2CL state cells in the Pum3-KO ESCs was completely abrogated by the deletion of p53. The DNA damage induced by the Ultraviolet light (UV) irradiation and Zeocin promoted the transition to a 2CL state in a p53-dependent manner. Thus, our study provides new insights into a 2CL state transition mechanism through stress-dependent p53 activation of ESCs.

High frequency of bone recurrence as an initial recurrence site after radical surgery in T1N3 gastric cancer: a propensity score matching analysis.

PURPOSE: T1 gastric cancer (GC) with seven or more metastatic lymph nodes is extremely rare, and very few clinical studies have been conducted to evaluate the clinicopathological features of their recurrence. METHODS: We retrospectively analyzed the outcomes of T1 GC and T2-4 GC patients who had multiple nodal metastases after radical surgery from 2006 to 2020. Propensity score matching was performed to compare the two groups of patients. RESULTS: After propensity score matching, 18 of 22 patients in the T1 group and 36 of 144 patients in the T2-4 group were selected. Recurrence occurred in six patients (33.3%) in the T1 group. In the T1 group, the most common site of initial recurrence was bone (15.0%). The prevalence of bone recurrence was significantly higher in the T1 group than in the T2-4 group (P = 0.02). The median interval time between radical surgery and bone recurrence was 24 months, and the median survival time after bone recurrence was 14 months. CONCLUSION: Bone recurrence was more frequently identified as an initial recurrence site in T1 GC cases with multiple metastases after radical surgery compared with that in T2-4 GC cases. Careful attention should be paid to postoperative bone recurrence in the long-term postoperative course of these patients.

PNLDC1, mouse pre-piRNA Trimmer, is required for meiotic and post-meiotic male germ cell development.

PIWI-interacting RNAs (piRNAs) are germ cell-specific small RNAs essential for retrotransposon gene silencing and male germ cell development. In piRNA biogenesis, the endonuclease MitoPLD/Zucchini cleaves long, single-stranded RNAs to generate 5' termini of precursor piRNAs (pre-piRNAs) that are consecutively loaded into PIWI-family proteins. Subsequently, these pre-piRNAs are trimmed at their 3'-end by an exonuclease called Trimmer. Recently, poly(A)-specific ribonuclease-like domain-containing 1 (PNLDC1) was identified as the pre-piRNA Trimmer in silkworms. However, the function of PNLDC1 in other species remains unknown. Here, we generate Pnldc1 mutant mice and analyze small RNAs in their testes. Our results demonstrate that mouse PNLDC1 functions in the trimming of both embryonic and post-natal pre-piRNAs. In addition, piRNA trimming defects in embryonic and post-natal testes cause impaired DNA methylation and reduced MIWI expression, respectively. Phenotypically, both meiotic and post-meiotic arrests are evident in the same individual Pnldc1 mutant mouse. The former and latter phenotypes are similar to those of MILI and MIWI mutant mice, respectively. Thus, PNLDC1-mediated piRNA trimming is indispensable for the function of piRNAs throughout mouse spermatogenesis.

[Surgery and Perioperative Management of Esophageal Cancer Patients with Malnutrition].

The incidence of postoperative morbidity and mortality are higher in patients with preoperative malnutrition in esophageal cancer patients. Oral intake tends to decrease during preoperative chemotherapy, and nutritional status is likely to worsen. When nutrition intake decreases, catabolism increases and muscle mass can decrease. It has been reported that related to preoperative sarcopenia and the onset and prognosis of postoperative complications. It has been reported to be associated with preoperative sarcopenia and the incident of postoperative complications and prognosis. Early nutritional assessment and interventions should improve nutritional status before surgery. Amino acid intake and exercise therapy improve exercise capacity such as walking. It is expected that a synergistic effect on the improvement of long-term prognosis by nutrition therapy and exercise therapy. Our hospital has introduced a enhanced preoperative nutrition rehabilitation program for undernourished patients. Immuno-nutrition therapy, exercise therapy, and postexercise branched-chain amino acid preparations are administered. During surgery for such malnourished patient, it is necessary to minimize the surgical invasion and to avoid complications. It is important to have continuous nutritional evaluation, intervention and rehabilitation by various occupations from the initial diagnosis to the perioperative period as well as during outpatient follow-up after discharge.

GPAT2 is required for piRNA biogenesis, transposon silencing, and maintenance of spermatogonia in mice†.

PIWI-interacting RNAs (piRNAs), a subclass of germ cell-specific noncoding small RNAs, are essential for de novo DNA methylation of retrotransposon genes in embryonic testes. PIWIL2/MILI, one of three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably via piRNA, and normal spermatogenesis. In vitro analysis using germline stem cells (GS cells) revealed that glycerol-3-phosphate acyltransferase 2 (GPAT2), which is a mitochondrial outer membrane protein involved in generation of lysophosphatidic acid (LPA) and highly expressed in testes, plays important roles in spermatogenesis. Namely, GPAT2 binds to PIWIL2 and is closely involved in the biogenesis of piRNAs; this process is independent of its enzymatic activity on LPA. However, GS cells recapitulate only a limited phase of spermatogenesis and the biological functions of GPAT2 remain largely unknown. In this study, we generated GPAT2-deficient mice and conducted comprehensive analyses. The deficient mice showed defective piRNA production and subsequent de-silencing of IAP and Line-1 retrotransposons in fetal testes. In addition, apoptosis of pachytene spermatocytes was observed. These abnormalities were all common to the phenotype of PIWIL2-deficient mice, in which piRNA production was impaired. GPAT2-deficient mice exhibited apoptosis in spermatogonia at the neonatal stage, which was not observed in PIWIL2-deficient mice. These data show that GPAT2 plays a critical role in preventing apoptosis in spermatogonia.

Billroth-I reconstruction using an overlap method in totally laparoscopic distal gastrectomy: propensity score matched cohort study of short- and long-term outcomes compared with Roux-en-Y reconstruction.

BACKGROUND: Delta-shaped anastomosis is an established procedure for intracorporeal Billroth-I reconstruction (B-I). However, this procedure has several technical and economic problems. The aim of the current study was to present the technique of B-I using an overlap method (overlap B-I), which is a side-to-side intracorporeal gastroduodenostomy in laparoscopic distal gastrectomy (LDG), and to evaluate the short- and long-term outcomes of this overlap B-I procedure. METHODS: We retrospectively reviewed the medical records of 533 patients who underwent LDG with overlap B-I (n = 247) or Roux-en-Y reconstruction (R-Y) (n = 286). Patients with overlap B-I were propensity score matched to patients with R-Y in a 1:1 ratio. Short- and long-term outcomes of the two procedures were compared after matching. RESULTS: In the total cohort, anastomosis-related complications occurred in 2.4% of patients with overlap B-I, and 3.2% of those with R-Y (P = 0.794). Morbidity rate, including anastomosis-related complications, and postoperative course were comparable after overlap B-I performed by qualified versus general surgeons. Of 247 patients with overlap B-I, 169 could be matched. After matching, morbidity rate and postoperative course were comparable between the two procedures. Median operation time was significantly shorter for overlap B-I (205 min) than R-Y (252 min; P < 0.001). The incidence of readmission due to gastrointestinal complications was significantly lesser after overlap B-I (2.4%) compared with R-Y (21.9%; P < 0.001). The main causes of readmission after R-Y were bowel obstruction (7.3%) and gallstones (8.0%). Regarding the development of common bile duct (CBD) stones, 11 patients (3.8%) who underwent R-Y were readmitted due to CBD stones, whereas no patients who underwent B-I developed CBD stones. CONCLUSIONS: Overlap B-I is feasible and safe, even when performed by general surgeons. B-I was superior to R-Y concerning operation time and readmission due to gastrointestinal complications.

Roles of MIWI, MILI and PLD6 in small RNA regulation in mouse growing oocytes.

The mouse PIWI-interacting RNA (piRNA) pathway produces a class of 26-30-nucleotide (nt) small RNAs and is essential for spermatogenesis and retrotransposon repression. In oocytes, however, its regulation and function are poorly understood. In the present study, we investigated the consequences of loss of piRNA-pathway components in growing oocytes. When MILI (or PIWIL2), a PIWI family member, was depleted by gene knockout, almost all piRNAs disappeared. This severe loss of piRNA was accompanied by an increase in transcripts derived from specific retrotransposons, especially IAPs. MIWI (or PIWIL1) depletion had a smaller effect. In oocytes lacking PLD6 (or ZUCCHINI or MITOPLD), a mitochondrial nuclease/phospholipase involved in piRNA biogenesis in male germ cells, the piRNA level was decreased to 50% compared to wild-type, a phenotype much milder than that in males. Since PLD6 is essential for the creation of the 5΄ ends of primary piRNAs in males, the presence of mature piRNA in PLD6-depleted oocytes suggests the presence of compensating enzymes. Furthermore, we identified novel 21-23-nt small RNAs, termed spiRNAs, possessing a 10-nt complementarity with piRNAs, which were produced dependent on MILI and independent of DICER. Our study revealed the differences in the biogenesis and function of the piRNA pathway between sexes.

Dysregulated YAP1/TAZ and TGF-ß signaling mediate hepatocarcinogenesis in Mob1a/1b-deficient mice.

Mps One Binder Kinase Activator (MOB)1A/1B are core components of the Hippo pathway that coactivate large tumor suppressor homolog (LATS) kinases. Mob1a/1b double deficiency in mouse liver (LMob1DKO) results in hyperplasia of oval cells and immature cholangiocytes accompanied by inflammatory cell infiltration and fibrosis. More than half of mutant mice die within 3 wk of birth. All survivors eventually develop liver cancers, particularly combined hepatocellular and cholangiocarcinomas (cHC-CCs) and intrahepatic cholangiocellular carcinomas (ICCs), and die by age 60 wk. Because this phenotype is the most severe among mutant mice lacking a Hippo signaling component, MOB1A/1B constitute the critical hub of Hippo signaling in mammalian liver. LMob1DKO liver cells show hyperproliferation, increased cell saturation density, hepatocyte dedifferentiation, enhanced epithelial-mesenchymal transition and cell migration, and elevated transforming growth factor beta(TGF-ß)2/3 production. These changes are strongly dependent on Yes-Associated Protein-1 (Yap1) and partially dependent on PDZ-binding motif (Taz) and Tgfbr2, but independent of connective tissue growth factor (Ctgf). In human liver cancers, YAP1 activation is frequent in cHC-CCs and ICCs and correlates with SMAD family member 2 activation. Drug screening revealed that antiparasitic macrocyclic lactones inhibit YAP1 activation in vitro and in vivo. Targeting YAP1/TAZ with these drugs in combination with inhibition of the TGF-ß pathway may be effective treatment for cHC-CCs and ICCs.

Importance of Barium Swallow Test and Chest CT Scan for Correct Diagnosis of Achalasia in the Primary Care Setting.

Esophageal achalasia is a disease characterized by the impaired esophageal peristalsis and non-relaxation of the lower esophageal sphincter muscle with unknown causes. Clinical manifestation of the disease is nonspecific (e.g., weight loss, vomiting, and persistent cough); namely, early diagnosis of the disease is often difficult. Delayed diagnosis of the disease is known to impair the patients' quality of life. Identifying the diagnostic factors that could cause diagnostic delay is needed. In this study, we collected data from 38 patients with achalasia and searched for diagnostic factors associated with delayed diagnosis (i.e., ≥ 6 months from the first hospital visit to diagnosis). The enrolled patients, diagnosed with achalasia based on esophageal manometry findings, had undergone surgical myotomy. As a result, the diagnosis of achalasia was likely to be delayed when the physician who had first contacted the patient did not perform a barium swallow test (p < 0.0001) or chest CT scan (p < 0.01) in a timely fashion. Among the patients with a delayed diagnosis (n = 15), none underwent a barium swallow test or chest CT within 6 months from their first hospital visit. The estimated sensitivities of diagnostic examinations for achalasia based on the enrolled 38 patients were higher than 80% for the barium swallow test and chest CT scan, but only 50-81% for endoscopy. To avoid the delayed diagnosis of achalasia, performing a barium swallow test or chest CT scan in a timely fashion, in addition to routine endoscopy, appears to be highly important.

Application of Large Electronic Medical Database for Detecting Undiagnosed Patients in the General Population.

Clinical application of accumulated medical big data is a hot topic in medical informatics. Not only for suggesting possible diagnoses in each individual, large medical database can be possibly used for detecting undiagnosed patients in the general population. In this study, we tried to develop a computerized system of detecting overlooked undiagnosed patients with rare chronic diseases in the community population by utilizing the uniformed national medical insurance record database. A cumulative total of 489,823 hospital visits at one tertiary medical center were collected for this project. As the target disease, we selected esophagogastric junction outflow obstruction (EGJOO), including achalasia, which is known to be easily overlooked without performing a barium swallow test. Patient selection software automatically picked out 17,814 individuals with the given suspected diagnoses that could be misdiagnosed in patients with the target disease, from which the software further picked out 526 individuals who underwent upper endoscopy but did not undergo barium swallow test. Of them, the hospital medical records suggested that 39 people still suffered from prolonged symptoms lasting for more than 6 months after the first hospital visit. Among them, 16 individuals agreed to undergo the barium swallow test. One of them was confirmed to suffer from EGJOO, possibly based on some undiagnosed connective tissue diseases. An automated computerized detection system with uniform big medical data would realize more efficient and less expensive screening system for undiagnosed chronic diseases in the general population based on symptoms and previously performed examinations in each individual.

Influence of age on postoperative complications especially pneumonia after gastrectomy for gastric cancer.

BACKGROUND: The aim of this study was to investigate the influence of patients' age on postoperative morbidities including pneumonia. METHODS: We reviewed the clinical records of 211 patients with stages I - III gastric cancer undergoing curative distal gastrectomy (DG) or total gastrectomy (TG). Patients were classified into an elderly (≧80 y.o.) or a control (< 80 y.o.) group. We compared patient characteristics (sex ratio, disease stage, degree of lymph node dissection, number of retrieved lymph nodes, and type of reconstruction) and early postoperative outcomes (operation time, intra-operative blood loss, and postoperative morbidity including pneumonia, and mortality) between the two groups separately in DG and TG. RESULTS: There were 134 and 77 patients who underwent DG and TG, respectively. The numbers of patients in the elderly and control groups were 25 and 109 in DG and 12 and 65 in TG. The percentage of female patients in the elderly group was greater than that in the control group in both DG and TG. The extent of lymph node dissection did not differ between two groups in TG; in contrast in DG, the rate of a D1 dissection was greater in the elderly group than in the control group. There were no differences between the two groups in distribution of disease stage, number of retrieved lymph nodes, operation time, and blood loss in DG and in TG. Overall postoperative morbidity did not differ between two groups after DG and after TG. The rate of infectious complications in the elderly group was not different from that in the control group after DG and after TG. The incidence of pneumonia was more frequent in the elderly group compared to the control group after DG (8% vs. 1%, P < 0.05) but not after TG (17% vs. 5%). When patients were compared between the elderly and the control groups regardless of type of gastrectomy, the incidence of pneumonia in the elderly group (4/37 (11%)) was greater than that in the control group (4/174 (2%), P < 0.05). CONCLUSIONS: These results suggest that pneumonia is increased in patients older than 80 years after DG.

[Surgical Techniques of Spontaneous Esophageal Rupture].

Spontaneous esophageal rupture was first reported by Boerhaave in 1724 and typically occurs in conjunction with vomiting, retching, or swallowing a large food bolus. This condition is potentially life threatening and causes severe mediastinitis, empyema, and sepsis, unless appropriate and early treatment is initiated. Conventional surgical repair is recommended within 24 hours of initial onset. However, some reports recommend surgery regardless of the time interval since onset. Various surgical procedures, conservative to esophagectomy, have been utilized in clinical practice. These methods include open thoracotomy, thoracoscopic surgery, or the addition of laparotomy. In this chapter the basic method of chest drainage, esophageal repair and reinforcement of suture line by open thoracotomy or thoracoscopic surgery. Surgical results for the treatment of this condition with thoracoscopic surgery are similar to those with conventional thoracotomy. Any procedures should be considered as suitable when selecting the approach used to treat Boerhaave's syndrome with regard to patient condition, status of the esophageal tear, and the surgeon's skills. In any surgical methods, it is important to assess the area of esophageal tear, to suture the esophageal wall appropriately, and to have enough drainage and place chest tubes in the proper position.

Evaluation of the impact of psoas muscle index, a parameter of sarcopenia, in patients with esophageal squamous cell carcinoma receiving neoadjuvant therapy.

BACKGROUND: The impact of sarcopenia on digestive cancer is widely known. Muscle mass, defined as the psoas muscle index (PMI), is an important parameter of sarcopenia. However, the relationship between esophageal cancer and PMI has not been fully investigated, especially in patients receiving neoadjuvant therapy. METHODS: To elucidate the influence of the PMI on patients with esophageal squamous cell carcinoma receiving neoadjuvant therapy, the progression of sarcopenia defined by the PMI, the relationship between pretherapeutic/preoperative sarcopenia and patient characteristics, and patient survival were retrospectively investigated in 82 patients with esophageal squamous cell carcinoma who underwent neoadjuvant therapy. RESULTS: The PMI decreased by more than 20 mm2/m2 between the pretherapeutic and preoperative periods in 75.6% of the patients. Pretherapeutic sarcopenia (low PMI) correlated with the pathological therapeutic response, postoperative recurrence, and pretherapeutic body mass index. Neoadjuvant chemoradiotherapy was associated with the progression of sarcopenia. The pretherapeutic sarcopenia group (low PMI) had worse disease-free survival (DFS) than the non-sarcopenia group. Furthermore, pretherapeutic sarcopenia (low PMI) was an independent prognostic risk factor of DFS according to univariate and multivariate analyses. CONCLUSIONS: The PMI may decrease during neoadjuvant therapy, especially during neoadjuvant chemoradiotherapy. Pretherapeutic sarcopenic (low PMI) patients should be followed-up more carefully postoperatively because higher risks of recurrence and poorer rates of disease-free survival are associated with these patients.