Novel Hydrophilic Camptothecin Derivatives Conjugated to Branched Glycerol Trimer Suppress Tumor Growth without Causing Diarrhea in Murine Xenograft Models of Human Lung Cancer.

Camptothecin possesses broad antitumor spectra on various cancers. In spite of its marked tumor-suppressing potency, camptothecin is too hydrophobic to be solved in water and therefore not currently in clinical use. CPT-11 (irinotecan) is one of the hydrophilic analogues of camptothecin and widely prescribed. However, its water solubility is still low and furthermore evokes severe diarrhea. Therefore, we designed and synthesized novel highly hydrophilic camptothecin derivatives by conjugating SN38 with branched glycerol trimer (SN38-BGL), which we have been developing as a unique strategy to endow hydrophobic molecule with much hydrophilicity, to maximize the benefit of CPT-11 and minimize the adverse effects. The SN38-BGLs exhibited equivalent or slightly stronger tumor-suppressing effects in murine xenograft human lung cancer models compared to CPT-11. However, neither early- nor late-onset diarrhea was observed when SN38-BGL was administered. Heights of villi in jejunum and ileum were bigger than those from CPT-11-treated mice, indicating that SN38-BGL is less harmful than CPT-11. Ex vivo digestion by liver microsome did not yield SN38 but a couple of other molecules against our expectations, which suggests the involvement of other active metabolites than SN38 and may explain the differences. Hence, SN38-BGLs can be a novel hydrophilic camptothecin derivative without causing severe diarrhea.

Endovascular repair with contralateral external-to-internal iliac artery bypass grafting: a case series.

BACKGROUND: To report a technique of keeping unilateral blood flow in the internal iliac artery in cases of an abdominal aortic aneurysm in achieving successful Endovascular abdominal aortic aneurysm repair using an external-to-internal artery bypass. CASE PRESENTATION: 6 japanese patients with infra-renal abdominal aortic aneurysms were treated using the retroperitoneal approach via a left (right) paramedian incision followed by an external-to-internal artery bypass. Endovascular abdominal aortic aneurysm repair was conducted on mean postoperative day 29 ± 18 and was performed because the contralateral internal iliac artery, which was not involved in the external-to-internal artery bypass, was treated with a coil embolization. No complications developed during the postoperative follow-up period (17 ± 1.5 months). In all 6 patients, patent grafts were evident on computed tomography angiography scans even after 1-3 months. CONCLUSIONS: Endovascular abdominal aortic aneurysm repair with unilateral internal iliac artery embolization and contralateral external-to-internal artery bypass is feasible with a relatively low risk. It is a safe procedure and reduces the incidence of postoperative complications.

Extended thymectomy via videothoracoscopy-assisted stepwise-access sternotomy.

A method of videothoracoscopy-assisted extended thymectomy procedure performed through a movable small access window is introduced. The access window can be moved stepwise and longitudinally alongside full sternotomy to be upon the dissection site. The majority of the thymectomy procedure can be directly viewed and operated from the moving window. However, partial and complete thoracoscopic maneuvers are required for dissection of the lateral-most region near the phrenic nerve and the upper poles of the thymus, respectively.

Inverted intercostal hernia of soft tissue manifested as slow-growing chest wall tumor after thoracotomy.

An 80-year-old woman had an asymptomatic chest wall tumor. She had undergone thoracotomy to treat a benign lesion 11 years previously. Chest computed tomography revealed a convex lens-shaped mass 7 cm in diameter in the chest wall. Positron emission tomography demonstrated mild accumulation of F-deoxyglucose. We performed an exploratory thoracotomy; however, no mass lesion was found. Therefore, we thought that the soft tissue of the back was drawn into the pleural cavity through the widened intercostal space during the previous thoracotomy. We simply aligned the ribs using heavy surgical sutures. The patient has experienced good recovery, with no recurrence since the surgery.

Changes in the prevalence of Helicobacter pylori infection and gastrointestinal diseases in the past 17 years.

BACKGROUND AND AIMS: The aim of the study was to examine whether the change in the prevalence of Helicobacter pylori infection had influenced upper gastrointestinal diseases in a recent 17-year period. METHODS: The prevalence of H. pylori infection was examined by serum H. pylori antibody tests in the subjects undergoing annual health checks at the Social Insurance Shiga Hospital in 1998 and 2005 (142 and 242 subjects, respectively). The prevalence of H. pylori infection in 1988 was estimated by parallel translation from the prevalence in 1998. A total of 2833 records of endoscopy performed in 1988 and 2005 at Otsu Municipal Hospital were studied. The age-adjusted prevalence of peptic ulcer, gastric cancer and reflux esophagitis were compared between 1988 and 2005. RESULTS: The age-adjusted prevalence of H. pylori infection significantly decreased in 2005 compared with 1988 (70.5-52.7%). The endoscopic records of 937 and 1246 patients in 1988 and 2005, respectively, were included in the analysis. The age-adjusted prevalence of peptic ulcer significantly decreased 0.34-fold in both men and women in 2005 compared with 1988. The age-adjusted prevalence of gastric cancer significantly decreased 0.44-fold in men, but did not change in women (0.99-fold), and overall significantly decreased 0.56-fold. The age-adjusted prevalence of reflux esophagitis significantly increased 6.6-, 2.7- and 4.8-fold in men, women and total, respectively. The increase was dominant in men aged 30-69 years. CONCLUSION: Over the 17-year period, accompanying the decreasing prevalence of H. pylori infection, the age-adjusted prevalence of peptic ulcer and gastric cancer decreased, but that of reflux esophagitis increased.

Mitral valve replacement for extensive calcification: half and half technique.

A 50-year-old woman who had been undergoing hemodialysis for 18 years underwent mitral valve replacement because of mitral valve stenosis. Her mitral valve leaflet and annulus were highly calcified, and it was impossible to remove the posterior leaflet from the ventricular wall. At the time of surgery, noneverted horizontal mattress sutures were placed from the left ventricle to the left atrium on the anterior half of the mitral annulus and everted horizontal mattress sutures on the left atrial wall close to the calcified posterior annulus. A 25-mm St. Jude valve was seated successfully at a supra-annular position. The St. Jude valve is suitable for this technique because its leaflets protrude less into the left ventricle.

Exposure of the mitral valve using flexible self-retaining retractors and an atrial hook.

We hereby present our technique for using the self-retaining flexible arm retractor and its attachments for mitral valve exposure. The Aortic Valve Assistant, which was developed for aortic valve exposure, is also very useful for exposure of the inferior wall of the left atrium. Our modified atrial hook provides excellent exposure of the anterior mitral annulus. Extensive dissection and the combined use of the flexible arm and attachments allows us comfortable access for mitral valve operations.

Natriuretic peptides up-regulate aquaporin 3 in a human colonic epithelial cell line.

Several specialized channels termed aquaporins (AQPs) facilitate water transport in the gastrointestinal tract. AQP3 localizes to epithelial cells in the human small intestine and colon. However, the regulatory mechanisms responsible for AQP3 function in the gastrointestinal tract are not well understood. To characterize the regulation of AQP3 expression by atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), we studied mRNA expression by Northern blotting, protein expression by Western blotting and DNA binding activity by electrophoretic mobility shift assay (EMSA) in the human colonic epithelial cell line HT-29. We also used several inhibitors to investigate signal transduction. AQP3 mRNA was up-regulated in addition to ANP (>100 nM) and BNP (>10 nM). The expression of AQP3 protein was enhanced at 1 h after the addition of ANP and BNP. The combination of protein kinase-A (PK-A) and protein kinase-G (PK-G) inhibitors completely inhibited the expression of AQP3 mRNA enhanced by ANP or BNP to its basal level. The EMSA of the cyclic-AMP response element (CRE) in HT-29 cells revealed a single band. These results indicate that ANP and BNP up-regulated the expression of AQP3 mRNA and protein, and both PK-A and PK-G dependent pathways mediated this effect.

The effects of lectins on indomethacin-induced small intestinal ulceration.

Growth factors, such as epidermal growth factor and keratinocyte growth factor, have considerable therapeutic potential for repairing mucosal injury in the intestine when given systemically. Recently, several lectins have been shown to have trophic effects on the intestine when given orally. We examined the effects of phytohaemagglutinin (PHA) and concanavalin A (Con-A) on indomethacin-induced intestinal injury in rat. Five-week-old rats were randomized to four groups (n=5), and intestinal injury was induced by indomethacin injection in three of these groups. Elemental diet (ED) feeding was then commenced. The groups were thus ED feeding/indomethacin untreated (control group), ED feeding/indomethacin treated (ED group), 0.1% PHA-supplemented ED feeding/indomethacin treated (PHA group) and 0.1% Con-A-supplemented ED feeding/indomethacin treated (Con-A group). After 7 days of feeding, macroscopic inflammatory scores, mucosal permeability, myeloperoxidase (MPO) activities and cell proliferation were determined. Macroscopic inflammatory scores, mucosal permeability and MPO activities were significantly lower in both lectin groups than that in control group. Twenty-four hour excretion rate of phenolsulphonphthalein was significantly lower in both lectin groups than that in ED group. Cell proliferation of the small intestine was significantly increased by both lectins. Lectin supplementation can induce ulcer healing following indomethacin-induced damage.

Alteration of aquaporin mRNA expression after small bowel resection in the rat residual ileum and colon.

BACKGROUND: Diarrhea occurring after small bowel resection gradually improves due to intestinal adaptation. It is known that several water channels, termed aquaporins (AQP), are expressed in the gastrointestinal tract and facilitate water transport. However, the changes of AQP after bowel resection remain unclear. In the present paper, the alterations in AQP mRNA expression were investigated after a massive small bowel resection in the rat residual ileum and colon. METHODS: The 6-week-old male Sprague-Dawley rats (n = 15) underwent an 80% distal small bowel resection. The residual ileum and colon were dissected on postoperative day 1, 3, 5 or 7 (n= 3 on each day). Total RNA was purified from each mucosa, and the expressions of AQP and sodium-dependent glucose transporter (SGLT1) mRNA were analyzed by northern blot. The plasma vasoactive intestinal polypeptide (VIP) concentrations on the preoperative day and postoperative day 1 were assayed. RESULTS: In the residual small intestine, the expression of AQP-1 and AQP-3 mRNA increased significantly on postoperative day 1. The AQP-7 mRNA increased on postoperative day 3, but the AQP-4 mRNA did not change after the bowel resection. The SGLT1 mRNA gradually decreased after the bowel resection. In the colon, the expression of AQP-3 increased on postoperative day 1 and 7, but AQP-4 mRNA did not change after surgery. The AQP-8 mRNA levels increased slightly on postoperative day 7. Plasma VIP concentration did not change between preoperative day and postoperative day 1. CONCLUSIONS: These results indicate that several AQP, except for AQP-4, were up-regulated after a massive small bowel resection, and that AQP might play important roles during adaptation.

Effects of the soluble fibre pectin on intestinal cell proliferation, fecal short chain fatty acid production and microbial population.

AIM: Although pectin, a dietary fibre, has been suggested to possess some trophic effects on the intestine, the mechanisms involved remain unclear. This study aimed to evaluate the effects of pectin on rat intestinal cell proliferation and the intraluminal environment. METHODS: Control and pectin-fed rats were given a fibre-free elemental diet (ED) and an ED containing 2.5% pectin, respectively. On the 15th day, the length, weight and number of Ki-67-positive cells from each intestinal segment, and the short chain fatty acids (SCFAs) and microbial population in the caecum were measured. Plasma glucagon-like peptide-2 (GLP-2) concentration and GLP-2 receptor (GLP-2R) mRNA levels in the epithelium were also determined. RESULTS: Pectin supplementation resulted in significant increases in the length, weight, and number of Ki-67-positive cells in the ileum, caecum and colon. Although pectin supplementation did not affect the caecal microbial flora that produced SCFAs, the caecal SCFA content was significantly increased. Pectin supplementation also induced an increase in the plasma GLP-2 concentration, but did not affect the GLP-2R mRNA levels in the small intestine. CONCLUSIONS: The increases in the caecal SCFAs and plasma GLP-2 levels induced by pectin supplementation may cause mucosal proliferation in the lower intestinal tract.

Dynamical aspects of in vitro conditioning in Hermissenda type B photoreceptor.

Dynamics of changes in physiology and morphology were studied in Hermissenda photoreceptors after in vitro conditioning with paired light and vibration. An increase in input resistance of the type B photoreceptor was observed following 5 paired presentations of light and vibration. It peaked at 10 min after in vitro conditioning, then decreased to a level twice the pre-conditioning level for more than 60 min. Contraction of the terminal branches along centro-lateral direction was initiated 5 min after conditioning and reached its final state at 10 min after conditioning. The pairing specific contraction of the axon terminal was not observed in ASW containing anisomycin. The dynamics in physiology and morphology were completely parallel 30 min after conditioning. These findings suggested that in vitro conditioning induced contraction was dependent on protein synthesis dependent process initiated within 5 min after training trials and that the change of cell morphology is a form of short-term synaptic plasticity that involves changes in macromolecular synthesis. Present findings that functional remodeling at the terminal branch of the type B photoreceptor occurred within 10 min after conditioning was the fastest modification process reported so far.

Mucosal permeability regulates receptor binding of luminal epidermal growth factor in the adult rat intestine.

Epidermal growth factor (EGF) stimulates repair in the damaged intestine, but its role in the normal intestine is not clear. Because EGF receptors are found on the basolateral surface but not the luminal surface, we hypothesized that mucosal permeability regulates EGF binding. Adult male rats were divided into 3 groups, one that was fed normal chow (the control), one that was starved for 4 days, and one that was given methotrexate (MTX) intragastrically (10 mg/kg/day for 3 days). The rats were sacrificed and everted sacks of the jejunum were made and incubated in EGF solution. Western blot analysis of mucosal homogenates showed that the amount of phosphotyrosyl EGF receptor in the starved and MTX-treated groups was, respectively, about 1.5 times and 2 times that in the control group. The mucosal permeability in the starved and MTX treated groups also increased and varied directly with the amount of phosphotyrosyl EGF receptor. These results suggest that in the adult rat intestine, luminal EGF may play a role only under tissue damage, where enhanced permeability permits the EGF to pass through the mucosa and bind to its receptor on the basolateral membrane.

Alteration in expression of polyamine and glucose-related enzyme mRNA after small bowel resection in the rat residual ileum.

The adaptive hyperplasia of the residual intestine after a massive bowel resection is not fully understood. We investigated the alterations in polyamine and glucose-related enzyme mRNA expression during intestinal adaptation. Six-week-old male Wistar rats underwent an 80% resection of the small intestine. The residual ileum was removed on the preoperative day (control) and on postoperative day (POD) 1, 3, 5 and 7. The total RNA was extracted from the mucosa, and a Northern blot analysis was performed. In the residual small intestine, the expression of polyamine synthesis enzymes, ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) mRNAs were increased on POD 1. The expression of polyamine degradation enzymes diamine oxidase (DAO) and spermidine/spermine N1-acetyltransferase (SSAT) mRNA did not change dramatically. Antizyme-1 (AZ-1) mRNA was significantly increased on POD 1. The mRNA expression of glucose absorption and metabolism-related proteins, including the Na+-dependent D-glucose cotransporter (SGLT1), fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P,2-kinase/Fru-2,6-Pase) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were only slightly changed on POD 1. The enzymes responsible for polyamine biosynthesis but not catabolism were upregulated at the translational level in enterocytes after a small bowel resection. The expression of glucose transport and glycolysis enzyme mRNAs did not increase after a small bowel resection.

In vitro conditioning induces morphological changes in Hermissenda type B photoreceptor.

Short- and long-term synaptic plasticity are considered to be cellular substrates of learning and memory. The mechanisms underlying synaptic plasticity especially with respect to morphology, however, are not known. In vitro conditioning in molluscan preparations is a well established form of short-term synaptic plasticity. Five paired presentations of light and vestibular stimulation to the isolated nervous system of Hermissenda results in an increase in excitability of the identified neuron, the type B photoreceptor, indicated by 2 measures, an increase in the input resistance and a cumulative depolarization after the cessation of light stimulus recorded from the cell soma. The terminal branches of type B photoreceptors iontophoretically injected with fluorescent dye were analyzed using computer-aided 3-dimensional reconstruction of images obtained using a confocal microscope under 'blind' conditions. The terminal branches contracted along the centro-lateral axis within an hour after conditioning, paralleling the increase in neuronal excitability. These data suggest that in vitro conditioning in Hermissenda is a form of short-term synaptic plasticity that involves changes in macromolecular synthesis.

Associative learning acquisition and retention depends on developmental stage in Lymnaea stagnalis.

Associative learning dependent on visual and vestibular sensory neurons and the underlying cellular mechanisms have been well characterized in Hermissenda but not yet in Lymnaea. Three days of conditioning with paired presentations of a light flash (conditional stimulus: CS) and orbital rotation (unconditional stimulus: UCS) in intact Lymnaea stagnalis results in a whole-body withdrawal response (WBWR) to the CS. In the current study, we examined the optimal stimulus conditions for associative learning, including developmental stage, number of stimuli, interstimulus interval, and intertrial interval. Animals with a shell length longer than 18 mm (sexually mature) acquired and retained the associative memory, while younger ones having a shell length shorter than 15 mm acquired but did not retain the memory to the following day. For mature animals, 10 paired presentations of the CS and UCS presented every 2 min were sufficient for the induction of a WBWR to the CS. Furthermore, animals conditioned with the UCS presented simultaneously with the last 2 s of the CS also exhibited a significant WBWR in response to the CS. Blind animals did not acquire the associative memory, suggesting that ocular photoreceptors, and not dermal photoreceptors, detected the CS. These results show that maturity was key to retention of associative learning.