Diabetes and the gastrointestinal tract

Gastrointestinal motility disorders are common in patients with diabetes. The entire gastrointestinal tract may be involved from the esophagus to the anal sphincter. Before instituting therapy, people with diabetes first require a careful diagnostic evaluation. Treatment includes tight glucose control and the use of antiemetics and prokinetic agents.     

AIDS and the gastrointestinal tract

Gastrointestinal disease in AIDS most often affects three major areas: the bowel, the esophagus, and the liver. Investigation should be tailored to identify treatable causes of disease, bearing in mind that multiple infections, superinfection, and untreatable diseases are common. Clinical decisions must be made regarding both the level of investigation necessary and the best testing procedures to use. Treatment is often only symptomatic, but in some cases a specific pathogen can be targeted.     

Healing in the gastrointestinal tract

Healing in the GI tract is rapid when free of complications: Unlike cutaneous healing, in which progress can be observed on a daily basis and intervention instituted early if necessary, healing of the intestinal anastomosis is anatomically obscured from inspection, allowing the surgeon only the patient's parameters of general well-being to judge the success of the operation. For the same reason, complications usually require re-operation, with the associated morbidity of a laparotomy and additional general anesthetic. This places a great responsibility on the surgeon to be cognizant of all the preoperative, intraoperative, and postoperative factors relating to anastomotic healing that might compromise the healing process. Bearing these in mind, along with attention to technical detail, should limit complications to an acceptable level. Patients most at risk are (1) those who perioperatively develop physiologic problems that lead to shock, hypoxia, and resultant anastomotic ischemia, (2) those with radiation-induced tissue injury, (3) those with sepsis, and (4) those with preoperative bowel obstruction. Malnourishment, malignancy, diabetes, steroids, and age also influence outcome to varying degrees. Future advancement in the field of GI healing lies in our ability to manipulate the early struggle between collagen synthesis and collagen breakdown. A profound understanding of the molecular and biochemical pathways and the factors that control them will bring us closer to this goal. Clinically, this may be accomplished by the introduction of wound healing enhancers into the anastomotic site, possibly by incorporating them into suture materials, biofragmentable anastomotic rings, or staple materials. Already much is known about the influence of different cytokines and growth factors on collagen regulation, knowledge that will help resolve many of the long-standing problems associated with GI surgery.     

Biomechanics of the gastrointestinal tract

As the function of the gastrointestinal tract is to a large degree mechanical, it has become increasingly popular to acquire distensibility data in motility research based on various parameters. Hence it is important to know on which geometrical and mechanical assumptions the various parameters are based. Currently, compliance and tone derived from pressure-volume curves are by far the most often used parameters. However, pressure-volume relations obtained in tubular organs must be carefully interpreted as they provide no direct measure of luminal cross-sectional area and other variables useful in plane stress and strain analysis. Thus, erroneous conclusions concerning tissue distensibility may be deduced. Other parameters, such as wall tension, stress and strain, give more useful information about mechanical behaviour. Distensibility data procure significance in fluid mechanics and in the study of tone, peristaltic reflexes, and mechanoreceptor kinematics. Such data are needed for the determination of the interaction between stimulus, electrical responses in neurons and the mechanical behaviour of the gut. Furthermore, from a clinical perspective, investigation of visco-elastic properties is important because GI diseases are associated with growth and remodelling. For example, prestenotic dilatation, increased collagen synthesis, dysmotility and altered distensibility are common features of obstructive diseases. The purpose of this review is to discuss the physiological and clinical importance of acquiring biomechanical data, distensibility parameters and interpretation of these results and their associated errors. We will also discuss some aspects of the relationship between morphology, growth and biomechanics. Finally, we will outline a number of techniques to study the mechanical properties of the GI tract.     

Duplications of the gastrointestinal tract

The pathology and clinical presentation of intestinal duplications are discussed. 8 assorted cases are presented. Spherical lesions of the small intestine were resected together with the stenosed segment of bowel while the cysts of the ileo-caecal region were dissected out. The rare tubular duplication of the rectum was managed with an anastomosis at the most distal end of the duplication to the original bowel.     

MRI of the gastrointestinal tract

To test whether the effects of marital status on health differ between never married women and divorced and separated women, this study utilizes prospective panel data for a large national sample of non-institutionalized young women in the U.S. (the National Longitudinal Surveys of Young Women). The women were aged 24-34 at the beginning of two successive five-year follow-up intervals (1978-1983 and 1983-1988). The health effects of marital status were evaluated in regressions which assessed the relationships between initial marital status and subsequent health trends in each follow-up interval. In the first follow-up interval, never married women tended to have worse health trends than divorced and separated women for physical impairments and for overall health problems. However, there were no differences between never married women and divorced and separated women in health trends for psychosomatic symptoms in either follow-up interval or for any health measure in the second follow-up interval. Our analyses of cross-sectional data showed few significant differences in health between never married women and divorced and separated women. Taken together, the evidence from our study and previous studies suggests that differences between never married women and divorced and separated women may vary by age and/or cohort. Evidence for the 1970s and 1980s suggests that, among older women, divorced and separated women may have experienced more harmful health effects than never married women; however, among younger women, this difference may have been absent or possibly reversed.     

Growth factors and the gastrointestinal tract

This paper reviews areas of interest in gut mucosal growth factor physiology. Several epidermal growth factor (EGF)-like peptides (EGF, transforming growth factor [TGF]-alpha, heparin-binding EGF-like peptide, amphiregulin, and betacellulin) have been identified in the gut, EGF is produced by the salivary glands and is present in milk. It may act on the mucosa from the lumen as a surveillance peptide promoting mucosal repair. A stem-cell-derived "ulcer-associated cell lineage" develops adjacent to ulcers and produces EGF, which may play a role in ulcer healing. TGF-alpha is expressed by villus enterocytes and may have an important role in mucosal healing. The Trefoil peptides (pS2, spasmolytic polypeptide, intestinal trefoil factor) are protease resistant molecules secreted by mucin cells throughout the gut, with a role in mucosal healing. The TGF-beta family inhibit cell proliferation, and promote cell differentiation. TGF-beta has a gradient of expression along the crypt villus axis, with maximum production at the villus tip. It is suspected that it may prevent cell proliferation and support differentiation of villus enterocytes. Hepatocyte growth factor is a multifunctional growth factor expressed in many tissues, including the gastrointestinal tract. It has a role in organogenesis. Intestinal adaptation is highly dependent on enteral nutrition, and it is likely that growth factors are involved in adaptation. Little is known, however, about interactions between nutrients and growth factors. Milk contains a range of potentially important growth factors. Their biological significance is uncertain, and this is an area of active research.     

Systemic amyloidosis and the gastrointestinal tract

Systemic amyloidosis is caused by a variety of different diseases and frequently involves the gastrointestinal tract. Each type of amyloid affects the gastrointestinal tract differently. This article reviews the unique pathogenesis, pattern of gastrointestinal disposition, diagnosis, and treatment of the five systemic amyloidoses, and discusses the gastrointestinal diseases that cause systemic amyloidosis: inflammatory bowel disease and familial Mediterranean fever.     

Endoscopic ultrasonography in the gastrointestinal tract

Endoscopic ultrasonography is a combination of endoscopy and ultrasonography. This method facilitates an accurate evaluation of singular layers of the gut-walls and adjacent structures. Great gain is represented by the possibility to analyze submucosal tumors, to diagnose vascular anomalies and especially the staging of both gastrointestinal malignancies and tumors in the pancreato-biliary area. The method is also suitable for the monitoring of treatment of these malignancies (chemotherapy, radiotherapy and laser therapy) as well as for an early diagnosis of tumor recurrences. The paper enumerates the possibilities, limits, some differential-diagnostic problems, complications, as well as perspectives of this modern method.     

General and gastrointestinal tract surgery in France

Forty-three state-run medical schools admit 30000 students per year but only 3500 receive their diploma after 6 years of studies. After passing a special examination, 480 of 2000 residents choose surgery and train during twelve 6-month rotations. Surgical research is organized through government agencies, individual units, or volunteer groups. In 1992, of 8268114 procedures, appendectomy represented 4.15%; hernia, 4.09%; varicose veins, 3.61%; and cholecystectomy, 1.82%. Appendectomy has decreased from 306500 per year in 1980 (34% of all gastrointestinal surgical procedures) to 159900 (15%) in 1996, whereas cholecystectomy has increased from 64700 to 95300. Emergency gastrointestinal procedures represented 15% of all surgical procedures in 1996, doubling in the last 4 years (essentially for labor and endoscopic procedures). Ambulatory procedures have increased 12-fold since 1980, essentially (75%) in private practice. About 27% of 160000 appendectomies and 77% of 95300 cholecystectomies were performed laparoscopically in 1997. One person of 4 in France has or has had cancer, mainly due to tobacco abuse. In 1993, 32000 surgical procedures were performed for gastrointestinal cancer. Of 532000 deaths (1992), about 150000 were due to cancer, 10000 to alcohol-related disease, and 22000 to trauma. Transplantation in France increased from 3180 procedures in 1993 to 2807 in 1996, essentially lungs and heart and lungs. Between 60% and 100% of health expenditures are reimbursed by the government, the remaining being covered by private insurances. Approximately 60% of 4500 French surgeons are in private practice; 25% also have part-time hospital employment. Almost 40% of surgeons work full-time in hospitals.     

Mucosal microcirculation and angiogenesis in gastrointestinal tract

In this review, various aspects of gastrointestinal microcirculation were described. Endothelin-1, vasoconstrictor, is elevated in gastric mucosa, causes gastric ischemia and results in gastric ulceration in human and animals under physical stress. Vasodilators such as NO anticipate the alove actions of endothelin, and thereby protect mucosa from injury. Once ulcer is developed, angiogenesis plays a key role in its healing. Various growth factors, cyclooxygenases-1 and -2, and non-peptide angiogenic factors stimulate this phenomenon and participate in ulcer healing. However, acidic conditions, H. pylori and its product, ammonia, suppress angiogenesis in vitro and in vivo. These evidences may explain why ulcer heals so slowly in gastroduodenal mucosa.     

Neurogenic inflammation in the gastrointestinal tract of the rat

To estimate the risk of repeat low birthweight deliveries among women whose first child was very low birthweight (less than 1500 g), a retrospective cohort of women who had their first and second children in Washington state between 1984 and 1991 was studied. After adjustment for potential confounding factors, a woman whose first infant was very low birthweight experienced an 11.5-fold increased risk of delivering a low birthweight (less than 2500 g) second infant (relative risk 11.5, 95% confidence interval 5.4 to 24.4). Women with a very low birthweight first infant also had a significantly increased risk of repeat very low birthweight infant (p < 0.0001). Women with a previous very low birthweight delivery are at increased risk of repeat low and very low birthweight infants. This high-risk group may benefit from education regarding recurrence risk and modification of factors associated with low birthweight, as well as good prenatal care.     

Sutureless anastomosis in the surgery of the gastrointestinal tract

The idea of the sutureless anastomosis is not a new one, but only the introduction of the VALTRAC-BAR instrument made the wide clinical application possible. The authors have applied this instrument in the case of 32 patients in a two years period. It was used in intestinal procedures in 28, in gastric resection in 4 occasions, respectively. In one case spontaneously recovered stercoral fistula was observed. According to our experiences, the instrument can be used advantageously in preparing anastomoses in the gastrointestinal tract.     

The content of ascorbic acid in plasma and in 14 tissues of lambs of different ages during normal feeding and feeding restricted from time to time during the suckling period

In normally fed lambs (group 1) the content of ascorbic acid (AA) in the plasma on day 8, 18, 28, 38, 48, 60 and 100 after birth was the same as in lambs, that were fed on days 8 to 17 (group 2), 8 to 26 (group 3) and 8 to 35 (group 4) on the maintenance level. The restrictive feeding induced for a certain time a decrease in the glucose content of the plasma. In the lambs of group 2 and 3 there was no differences in the content of AA in 14 tissues compared to group 1. In the lambs of group 4 the body weight on the 35th day was only 54 and the mass of the hypophysis 60, of the lung 55.9, of the liver 51, of the heart 47.2, of the spleen 44.7 and of the kidney 38% of that of group 1; there was a tendency to a lower content of AA in most tissues. With increasing age the content of AA in the cerebrum, in the cerebellum, in the brain stem and in the testicles decreased; the highest content in the hypophysis was determined on day 180. The regulation of the synthesis of AA in the liver under normal and pathological conditions is discussed.     

Effects of piroxicam-beta-cyclodextrin on the gastrointestinal tract

Piroxicam-beta-cyclodextrin (PBC), a complex of piroxicam with beta-cyclodextrin, was developed with the aim of improving the hydrosolubility and bioavailability of piroxicam. The complex is more rapidly absorbed, with a consequent reduction in the time of contact of piroxicam with the gastric and duodenal mucosa. It is hoped that the shorter contact time might reduce the local toxicity of piroxicam, but it is also possible that transiently higher local concentrations of the drug might worsen the injury to the gastro-duodenal mucosa. Four studies have been conducted in healthy volunteers in order to investigate the effects of PBC on the gastro-intestinal tract. In 3 of these trials, all of similar design, PBC (containing 20 mg of piroxicam) was compared with piroxicam 20mg and placebo given once daily with assessment of faecal blood loss using the 51Cr-labelled red-cell technique, and endoscopic appearance of gastroduodenal mucosa before and after 28 consecutive days of treatment. One study showed a significant difference in respect of faecal blood loss towards the end of the 4-week study period favouring PBC over piroxicam, while the 2 others showed comparable but non-significant trends in favour of PBC. In a fourth study, 32 non-patient volunteers received either piroxicam 20mg once daily; PBC 20mg equivalence; indomethacin 50mg twice daily; or placebo. The treatment was given double blind for 14 days. Endoscopy was performed and gastric potential differences were measured by neutral observers before and at the end of treatment. There were no significant differences in the endoscopic scores between the active treatment groups. The gastric potential difference showed greater changes with indomethacin and piroxicam than with placebo and PBC.(ABSTRACT TRUNCATED AT 250 WORDS)