Intussusception of the bowel is defined as the telescoping of a proximal segment of the gastrointestinal tract within the lumen of the adjacent segment. This condition is frequent in children and presents with the classic triad of cramping abdominal pain, bloody diarrhea and a palpable tender mass. However, bowel intussusception in adults is considered a rare condition, accounting for 5% of all cases of intussusceptions and almost 1%-5% of bowel obstruction. Eight to twenty percent of cases are idiopathic, without a lead point lesion. Secondary intussusception is caused by organic lesions, such as inflammatory bowel disease, postoperative adhesions, Meckel’s diverticulum, benign and malignant lesions, metastatic neoplasms or even iatrogenically, due to the presence of intestinal tubes, jejunostomy feeding tubes or after gastric surgery. Computed tomography is the most sensitive diagnostic modality and can distinguish between intussusceptions with and without a lead point. Surgery is the definitive treatment of adult intussusceptions. Formal bowel resection with oncological principles is followed for every case where a malignancy is suspected. Reduction of the intussuscepted bowel is considered safe for benign lesions in order to limit the extent of resection or to avoid the short bowel syndrome in certain circumstances.

Intussusception of the bowel in adults: a review.

Context:Among persons diagnosed as having diabetes mellitus, the prevalence of foot ulcers is 4%to 10%, the annual population-based incidence is 1.0%to 4.1 %, and the lifetime incidence may be as high as 25%. These ulcers frequently b ecome infected, cause great morbidity, engender considerable financial costs, an d are the usual first step to lower extremity amputation. Objective:To systemat ically review the evidence on the efficacy of methods advocated for preventing d iabetic foot ulcers in the primary care setting. Data Sources, Study Selection, and Data Extraction:The EBSCO, MEDLINE, and the National Guideline Clearinghous e databases were searched for articles published between January 1980 and April 2004 using database-specific keywords. Bibliographies of retrieved articles wer e also searched, along with the Cochrane Library and relevant Web sites. We revi ewed the retrieved literature for pertinent information, paying particular atten tion to prospective cohort studies and randomized clinical trials. Data Synthesi s:Prevention of diabetic foot ulcers begins with screening for loss of protecti ve sensation, which is best accomplished in the primary care setting with a brie f history and the Semmes-Weinstein monofilament. Specialist clinics may quantif y neuropathy with biothesiometry, measure plantar foot pressure, and assess lowe r extremity vascular status with Doppler ultrasound and ankle-brachial blood pr essure indices. These measurements, in conjunction with other findings from the history and physical examination, enable clinicians to stratify patients based o n risk and to determine the type of intervention. Educating patients about prope r foot care and periodic foot examinations are effective interventions to preven t ulceration. Other possibly effective clinical interventions include optimizing glycemic control, smoking cessation, intensive podiatric care, debridement of c alluses, and certain types of prophylactic foot surgery. The value of various ty pes of prescription footwear for ulcer prevention is not clear. Conclusions:Sub stantial evidence supports screening all patients with diabetes to identify thos e at risk for foot ulceration. These patients might benefit from certain prophyl actic interventions, including patient education, prescription footwear, intensi ve podiatric care, and evaluation for surgical interventions.

Preventing foot ulcers in patients with diabetes

Stem cell ageing underlies the ageing of tissues, especially those with a high cellular turnover. There is growing evidence that the ageing of the immune system is initiated at the very top of the haematopoietic hierarchy and that the ageing of haematopoietic stem cells (HSCs) directly contributes to changes in the immune system, referred to as immunosenescence. In this Review, we summarize the phenotypes of ageing HSCs and discuss how the cell-intrinsic and cell-extrinsic mechanisms of HSC ageing might promote immunosenescence. Stem cell ageing has long been considered to be irreversible. However, recent findings indicate that several molecular pathways could be targeted to rejuvenate HSCs and thus to reverse some aspects of immunosenescence.

The ageing haematopoietic stem cell compartment

Intracoronary bone marrow-derived progenitor cells in acute myocardial infarction

In the past few years, microfluidic-based technology has developed microscale models recapitulating key physical and biological cues typical of the native myocardium. However, the application of controlled physiological uniaxial cyclic strains on a defined three-dimension cellular environment is not yet possible. Two-dimension mechanical stimulation was particularly investigated, neglecting the complex three-dimensional cell-cell and cell-matrix interactions. For this purpose, we developed a heart-on-a-chip platform, which recapitulates the physiologic mechanical environment experienced by cells in the native myocardium. The device includes an array of hanging posts to confine cell-laden gels, and a pneumatic actuation system to induce homogeneous uniaxial cyclic strains to the 3D cell constructs during culture. The device was used to generate mature and highly functional micro-engineered cardiac tissues (μECTs), from both neonatal rat and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), strongly suggesting the robustness of our engineered cardiac micro-niche. Our results demonstrated that the cyclic strain was effectively highly uniaxial and uniformly transferred to cells in culture. As compared to control, stimulated μECTs showed superior cardiac differentiation, as well as electrical and mechanical coupling, owing to a remarkable increase in junction complexes. Mechanical stimulation also promoted early spontaneous synchronous beating and better contractile capability in response to electric pacing. Pacing analyses of hiPSC-CM constructs upon controlled administration of isoprenaline showed further promising applications of our platform in drug discovery, delivery and toxicology fields. The proposed heart-on-a-chip device represents a relevant step forward in the field, providing a standard functional three-dimensional cardiac model to possibly predict signs of hypertrophic changes in cardiac phenotype by mechanical and biochemical co-stimulation.

Beating heart on a chip: a novel microfluidic platform to generate functional 3D cardiac microtissues

Stem cell therapies have been clinically employed to repair the injured heart, and cardiac stem cells are thought to be one of the most potent stem cell candidates. The beating heart is characterized by dynamic mechanical stresses, which may have a significant impact on stem cell therapy. The purpose of this study is to investigate how mechanical stress affects the growth and differentiation of cardiac stem cells and their release of paracrine factors. In this study, human cardiac stem cells were seeded in a silicon chamber and mechanical stress was then induced by cyclic stretch stimulation (60 cycles/min with 120% elongation). Cells grown in non-stretched silicon chambers were used as controls. Our result revealed that mechanical stretching significantly reduced the total number of surviving cells, decreased Ki-67-positive cells, and increased TUNEL-positive cells in the stretched group 24 hrs after stretching, as compared to the control group. Interestingly, mechanical stretching significantly increased the release of the inflammatory cytokines IL-6 and IL-1β as well as the angiogenic growth factors VEGF and bFGF from the cells in 12 hrs. Furthermore, mechanical stretching significantly reduced the percentage of c-kit-positive stem cells, but increased the expressions of cardiac troponin-I and smooth muscle actin in cells 3 days after stretching. Using a traditional stretching model, we demonstrated that mechanical stress suppressed the growth and proliferation of cardiac stem cells, enhanced their release of inflammatory cytokines and angiogenic factors, and improved their myogenic differentiation. The development of this in vitro approach may help elucidate the complex mechanisms of stem cell therapy for heart failure.

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The effects of mechanical stress on the growth, differentiation, and paracrine factor production of cardiac stem cells.

A 44-year-old woman was admitted to our hospital for investigation and treatment of sudden abdominal pain and distention. Plain abdominal radiography and abdominal computed tomography (CT) findings were suggestive of sigmoid volvulus. She underwent an emergency colonoscopy, and the scope passed easily through the sigmoid colon and reached the ascending colon quickly. However, stenosis with concentricity of the fold was observed in the cecum, which was shifted upward and to the left. Based on these findings, we diagnosed cecal volvulus caused by mobile cecum syndrome. The patient’s symptoms resolved quickly after colonoscopic reduction and elective laparoscopic surgery was performed 18 days after admission. Perioperative examination revealed a mobile cecum caused by an elongated ascending colon. We sutured the cecum and ascending colon to the lateral peritoneum laparoscopically with interrupted sutures. The patient recovered well and was discharged on postoperative day 7. An unfixed intestine can be detected easily during laparoscopic surgery, which is minimally invasive and cosmetically, physically, and economically beneficial. Thus, we recommend laparoscopic cecopexy for mobile cecum syndrome.

Laparoscopic cecopexy for mobile cecum syndrome manifesting as cecal volvulus: Report of a case

A 63-year-old woman was admitted to our hospital for investigation of upper abdominal pain and vomiting. Ultrasonography (US) showed a hyperechoic mass in the right lower abdomen, and computed tomography (CT) showed a low-density mass and intestinal invagination. Thus, we made a diagnosis of intestinal lipoma with intussusception and performed laparoscopic partial resection of the ileum, including the tumor. The resected specimen contained a round tumor, 25 × 22 × 20 mm, which was identified as an intestinal lipoma histopathologically. Our experience supports earlier reports that US and CT are effective tools in the diagnosis of bowel lipoma. Laparoscopic surgery is the treatment of choice for benign tumors of the small intestine because it is minimally invasive, with cosmetic, physical, and economic benefits.

Laparoscopic resection of an ileal lipoma: Report of a case.

Background: Hypoxic preconditioning of bone marrow cells (BMCs) from young healthy individuals can enhance the cells' therapeutic potential. Considering that the response to hypoxia may differ according to the quality of the cells, we assessed the effect of hypoxic preconditioning on BMCs from aged mice and compared the difference in response between BMCs from aged and young mice. Methods and Results: BMCs from young (3 months) and aged (20-22 months) mice were subjected to hypoxic preconditioning by culture for 24h in 2% O2. Compared with BMCs from young mice, those from aged mice showed significantly fewer CD34- or c-kit-positive stem cells, higher expression of p53, and lower telomerase activity. Adhesion, survival and angiogenic potency were also lower in BMCs from aged mice, indicating an aging-related impairment. Hypoxia-preconditioned BMCs from aged mice showed enhanced adhesion, survival, and angiogenic potency with the in vitro assessments, as well as the in vivo implantation into ischemic hindlimbs. All the enhancements by hypoxic preconditioning were comparable between BMCs from aged and young mice, although the angiogenic potential of BMCs with and without hypoxic preconditioning was lower in old mice compared with young mice. Conclusions: Similar responses to hypoxia by BMCs from both aged and young mice suggest that hypoxic preconditioning could be a useful method of enhancing the angiogenic potential of BMCs. (Circ J 2012; 76: 986-994)

Hiroshi Kurazumi

Papers

The effects of mechanical stress on the growth, differentiation, and paracrine factor production of cardiac stem cells.

Laparoscopic cecopexy for mobile cecum syndrome manifesting as cecal volvulus: Report of a case

Laparoscopic resection of an ileal lipoma: Report of a case.

Hypoxic Preconditioning Enhances Angiogenic Potential of Bone Marrow Cells With Aging-Related Functional Impairment

Predictors of late aortic events after Stanford type B acute aortic dissection