Phosphatidylcholine-associated aspirin accelerates healing of gastric ulcers in rats

In this double-blind study, we administered lumbar epidural bupivacaine or bupivacaine plus verapamil to investigate the possible role of the calcium channel blocker, verapamil, in postoperative pain. One hundred patients (ASA physical class I or II) scheduled for lower abdominal surgery were randomly assigned to one of four groups. Group 1 received 10 mL of 0.5% epidural bupivacaine injected 15 min before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 2 received 10 mL of epidural normal saline injected before incision, followed by 10 mL of 0.5% epidural bupivacaine 30 min after incision. Group 3 received 10 mL of 0.5% epidural bupivacaine plus 5 mg of verapamil injected before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 4 received the same drugs as Group 3, in the reverse order. Pain and mood numeric rating scores, sedation scores, Prince Henry scores, patient-controlled cumulative postoperative analgesic consumption, and the incidence of side effects were assessed 2, 6, 12, 24, and 48 h after the operation in each group. Cumulative postoperative analgesic consumption in Groups 3 and 4 was significantly lower (P < 0.05) than that in Groups 1 and 2 24 and 48 h after surgery. There were no differences in the pain, mood, and sedation scores and the incidence of side effects among the four groups. We conclude that epidural verapamil decreases postoperative pain, possibly by interfering with normal sensory processing and by preventing the establishment of central sensitization. Implications: Calcium plays an important role in pain physiology at the spinal cord level. We examined the effect of bupivacaine plus verapamil (calcium channel blocker) and of bupivacaine alone. We demonstrated that the combination, administered epidurally, resulted in less postoperative analgesic consumption than bupivacaine alone.     

Role of cyclooxygenase-2 in the healing of gastric ulcers in rats

Extracellular activity was recorded from single spinal dorsal horn neurons in both chronic cat and acute rat models. This was done to define the effects of anesthesia on the processing of sensory information elicited by nonnoxious tactile stimulation of peripheral receptive fields (RFs). In the chronic cat model, baseline data were obtained in physiologically intact, awake, drug-free animals before anesthetic administration (halothane 1.0-2.0%). This made it possible to compare and contrast activity of each cell in the drug-free and anesthetized state. Halothane effects were confirmed in the acute rat model (anesthetized, spinally transected, and in some cases decerebrate). In addition, the gamma-aminobutyic acid-A (GABAA)-receptor antagonist picrotoxin (2 mg/kg) was administered intravenously to verify that the observed halothane effect on spinal dorsal horn neurons was mediated by an interaction with GABAA-receptor systems. Halothane effects on three separate measures of response to nonnoxious tactile stimuli were observed in the chronic cat model. Halothane produced a significant, dose-dependent reduction in the low-threshold RF area of the neurons studied. Halothane also caused a significant reduction in neuronal response to RF brushing (dynamic stimulus) and to maintained contact with the RF (static stimulus). A dose dependency was not observed with these latter two effects. Neurons with a predominant rapidly adapting response seemed to be less susceptible to halothane suppression than slowly adapting cells. In the acute rat model an increase in halothane caused a reduction in neuronal response similar to that seen in the cat. The intravenous administration of 2 mg/kg of picrotoxin by itself caused no significant change in RF size or response to brushing. However, the same amount of picrotoxin did cause a 50% reversal of the halothane-induced reduction in RF size without causing a significant change in the halothane effect on response to RF brushing. In contrast to work recently reported in a chronic sheep model, halothane causes a significant reduction in spinal dorsal horn neuronal response to tactile stimulation of peripheral RFs. This effect is caused by, in part, but not exclusively, to GABAA-neurotransmitter systems. However, the relative influence of GABAA systems may vary with the nature of the stimulus.     

Influence of healing on the disturbed blood flow regulation in venous ulcers

The respiratory exchange ratio (R) during steady-state exercise is equivalent to whole-body respiratory quotient (RQ), but does not represent muscle metabolism alone. If steady-state values of carbon dioxide production (VCO2) and oxygen uptake (VO2) are plotted for different work rates, the slope of the line fitting these points should estimate muscle RQ. Twelve cyclists randomly performed five 8-min, constant work rate tests of 40, 80, 120, 160 and 200 W. Whole-body R, averaged over the final 2 min of each exercise bout, increased with increasing work rate. When VCO2 was plotted as a function of VO2, the regression lines through the five points displayed excellent linearity, had negative y-intercepts, and a slope of 0.915 (0.043) [mean (SD)], which was greater than the whole-body R at any individual work rate [range 0.793 (0.027) at 40 W to 0.875 (0.037) at 200 W]. This slope was comparable to the lower slope of the VCO2 versus VO2 plot of an increasing work rate (ramp) protocol [0.908 (0.054)]. We conclude that, during mild and moderate exercise of relatively short duration, contracting muscle has a high and constant RQ, indicating that carbohydrate is the predominant metabolic substrate. Whole-body R does not accurately reflect muscle substrate utilization and probably underestimates muscle RQ at a given work rate.     

Zinc deficiency delays gastric ulcer healing in rats

Zinc is an important element in wound healing. Zinc compounds hasten the healing of gastric ulcers, by an unknown mechanism(s). We studied the effect of the induction of zinc deficiency on gastric ulcer healing. Rats were given a control or zinc-deficient diet for six weeks and then subjected to the induction of acetic acid-induced chronic gastric ulcers. Four days later, zinc-deficient rats were divided into two groups. In the first group, the zinc-deficient diet was continued. In the second group, the diet was changed to the control diet. Zinc-deficient rats had a mean serum zinc concentration approximately 70% of that in controls. Zinc deficiency did not affect the formation of gastric ulcers; however, it reduced cell proliferation by day 4 and delayed ulcer healing. Zinc supplementation brought zinc to control levels within a week, but failed to reverse the delay in ulcer healing. We conclude that zinc is crucial for healing of gastric ulcers, especially at the early stage.     

Development of gastric ulcers in rats following stress termination.

Observed gastric ulcer formation in groups of female albino Charles River unrestrained rats (N = 123) sacrificed at varying intervals following the end of a single, 6-hr shock-stress session. Significant ulcer production was not found unless Ss experienced a minimum of 2 hr poststress rest prior to sacrifice. Findings with appropriate control groups implicate the sudden reversal from stressful to "safe" (home cage) conditions, rather than delay per se, as the major ulcerogenic factor. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Central effect of melatonin against stress-induced gastric ulcers in rats

We investigated the role of melatonin in the induction of gastric lesions induced by water immersion restraint stress or centrally administered thyrotropin-releasing hormone (TRH). Melatonin (0.1-1 ng) injected intracisternally (i.c) 30 min prior to stress dose-dependently inhibited the induction of gastric lesions by water immersion restraint stress, while 100 micrograms/kg, i.p. failed to protect the gastric mucosa. Preadministration of melatonin (1 ng, i.c.) significantly reduced (83%) the severity of gastric lesions induced by a TRH analogue (500 ng, i.c.). Serum melatonin concentrations 30 min after administration of 1 ng melatonin i.c. did not differ from those of rats receiving i.c. vehicle. These results suggest that melatonin plays a protective, anti-stress, role in the gastric mucosa via a mechanism involving the central nervous system.     

Effect of age and sex on histamine-induced gastric secretion in laboratory rats

Rats pretreated by daily depot injections of pentagastric for 24 days, responded with a significant increase of gastric secretion volume, and HC1 concentration and output, when infused intravenously with bethanechol chloride. In these rats, the total weight of the stomach and the height of the fundic mucosa were also increased. Pretreatment with histamine had no effect on rat gastric tissue or gastric secretion, under identical conditions of stimulation.     

Zinc counteracts experimentally-induced cirrhotic changes in rats

In the present study, cirrhosis was induced in rats by administration of carbon tetra chloride for 8 weeks. In these animals ZnSo4 (equivalent to 100 and 200 micrograms of zinc) was administered orally and liver function tests and plasma zinc (Zn) estimations were carried out after 2 and 4 week intervals. The results revealed that Zn supplement counteracts cirrhotic changes in liver.     

Rapid expression and specific localization of tenascin in gastric ulcer healing in rats

This study was done to investigate the gene expression and localization of tenascin in ulcerated gastric tissues during the healing process with Northern blot analysis and immunohistochemical technique. Gastric ulcers in rats were produced by acetic acid. Tenascin mRNA levels in the ulcerated tissue were significantly increased in a biphasic manner (12 h and day 5), preceding the increase in collagen type IV and laminin mRNA levels, and returned to control levels on day 11. In intact tissues, tenascin was mainly localized in the basement membrane above the proliferative zone, in contrast to the predominant localization of collagen type IV and laminin below the proliferative zone. On the ulcer margin from 12 h to day 5, tenascin was abundantly observed in the lamina propria around nonproliferating new epithelial cells, but collagen type IV and laminin were not seen in this lamina propria. On day 7, tenascin, expressed in the lamina propria, was replaced by collagen type IV and laminin. Thus, the rapid expression and unique localization of tenascin suggest the important role of tenascin in gastric ulcer healing.     

Influence of Aloe vera on collagen turnover in healing of dermal wounds in rats

Treatment of full-thickness wounds with A. vera, on rats resulted in increased biosynthesis of collagen and its degradation. A corresponding increase in the urinary excretion of hydroxyproline was also observed. Elevated levels of lysyl oxidase also indicated increased crosslinking of newly synthesised collagen. The results suggest that A. vera influences the wound healing process by enhancing collagen turnover in the wound tissue.     

Role of metalloproteinases in the development and healing of acetic acid-induced gastric ulcer in rats

The three main components involved in thrombosis and haemostasis are thrombin, platelets, and plasmin. Almost all inhibitors of thrombosis are focused either on the inhibition of thrombin or on the inhibition of platelets. We designed a construct using the fibrinolytic activity of staphylokinase, fused via a cleavable linker to an antithrombotic peptide of 29 amino acids. The peptide was designed to include three inhibitory regions: (1) the Arg-Gly-Asp (RGD) amino acid sequence to prevent fibrinogen binding to platelets; (2) a part of fibrinopeptide A, an inhibitor of thrombin; and (3) the tail of hirudin, a potent direct antithrombin. The amino acid sequence of the 29 amino acid peptide was reverse translated, and the gene was chemically synthesised and cloned into an expression vector as a 3' fusion to the staphylokinase gene. Gene expression was induced in E. coli Top 10 cells and the fusion protein, designated PLATSAK, was purified using metal affinity chromatography. The purified fusion protein significantly lengthened the activated partial thromboplastin time and thrombin time and inhibited the amidolytic activity of thrombin. The fibrinolytic activity was almost equal to that of recombinant staphylokinase as measured with a thrombelastograph. Platelet aggregation was not markedly inhibited by PLATSAK, probably due to the unfavourable three dimensional structure, with the Arg-Gly-Asp sequence buried inside. Our results confirm that it is feasible to design and produce a hybrid multifunctional protein that targets various components of the haemostatic process.     

A protective role for calcitonin gene-related peptide in water-immersion stress-induced gastric ulcers in rats

For over a century, Cincinnati, Ohio, has been at the center of the nation's efforts to control water pollution. Site and subject of PHS activities to understand, manage, and prevent pollution, Cincinnati now carries on this public health legacy as home to EPA's water pollution programs. From ante-bellum way station for primary care and the seat of early 20th century scientific contributions to vibrant center for the development of environmental health programs after World War II, the Queen City has truly provided a number of watershed developments in the history of public health.     

Four-layer bandaging and healing rates of venous leg ulcers

This paper reports the healing rates of venous leg ulcers in a community setting (Exeter and District Community Health Services NHS Trust) using the Charing Cross four-layer compression system. We report on 514 venous leg ulcers and show healing rates of 40% at 12 weeks, 50% at 17 weeks, 57% at 24 weeks and 80% predicted at 2 years. Patients were treated in one of 16 community leg ulcer clinics or in their homes. Nurses were allowed to use this system only after full training by the leg ulcer management service. Nurses had to prove their competence in leg ulcer assessment, Doppler measurement and the technique of four-layer compression. Even in patients whose leg ulcers did not heal, it was felt that the four-layer compression system was comfortable, convenient and cost effective with only weekly changes of bandages being necessary.     

History of perforated duodenal and gastric ulcers

Perforated peptic ulcer as a disease entity has been known since 167 BC. Surgical and nonsurgical treatment strategies for perforated peptic ulcer disease were not developed until the latter half of the nineteenth century. The history of the gradual evolution of the various forms of treatment adopted for the conditions over the last century and a half is described.     

Therapeutic indications in hemorrhaging duodenal and gastric ulcers

Ulcer complications including bleeding and perforation were increasingly observed during the last decade due to the greater life expectancy and the increased NSAID consumption. The unchanging mortality rate, which has been around 6-10% for several decades, could be explained by the fact that age and the prevalence of concurrent illness are important predictors of death. Rebleeding which is also an independent prognostic factor can be predicted by the presence of hypovolemic shock and of endoscopic stigmata such as active bleeding or a visible vessel. Endoscopic hemostatic therapy, specially injection therapy which is the most widely used method, has become the treatment of choice. It has been proven to significantly reduce rates of further bleeding, surgery and mortality. Surgical intervention is indicated in cases of immediate or secondary failure of endoscopic therapy (20%) and should not be delayed in high-risk patients. Once hemostasis has been achieved therapeutic goals are to heal the ulcer and to prevent the occurrence of further complications including bleeding and also perforation.     

Stimulation of healing of varicose ulcers by ultrasound

The local application of theraputic ultrasound has been shown, in a controlled trial, to stimulate the healing of chronic varicose ulcers. The change in ulcer size by the end of the period of treatment was noted. It was found that healing of insonated ulcers was significantly more marked than that exhibited by the controls.     

Effect of norepinephrine on gastric wound healing

Lavage of the stomach with norepinephrine has been suggested as a temporary means of controlling upper gastrointestinal tract bleeding. The effect of norepinephrine on the healing of a standard gastric incision in the rat was studied using irrigation topically. When compared with those rats in the control study that were irrigated with a saline solution alone, no significant difference was found in the tensile strength, local inflammatory response or synthesis of new collagen, as determined by the hydroxyproline-proline ratio. There would appear to be no adverse effect on gastric wound healing as a result of preliminary irrigation of the gastric mucosa with norepinephrine given topically in a concentration of 16 milligrams per liter.