Treatment of short-bowel syndrome

Glutamine as an immunonutrient

Dietary supplementation with nutrients enhancing immune function is beneficial in patients with surgical and critical illness. Malnutrition and immune dysfunction are common features in hospitalized patients. Specific nutrients with immunological and pharmacological effects, when consumed in amounts above the daily requirement, are referred to as immune-enhancing nutrients or immunonutrients. Supplementation of immunonutrients is important especially for patients with immunodeficiency, virus or overwhelming infections accompanied by a state of malnutrition. Representative immunonutrients are arginine, omega-3 fatty acids, glutamine, nucleotides, beta-carotene, and/or branched-chain amino acids. Glutamine is the most abundant amino acid and performs multiple roles in human body. However, glutamine is depleted from muscle stores during severe metabolic stress including sepsis and major surgery. Therefore it is considered conditionally essential under these conditions. This review discusses the physiological role of glutamine, mode and dose for glutamine administration, as well as improvement of certain disease state after glutamine supplementation. Even though immunonutrition has not been widely assimilated by clinicians other than nutritionists, immunonutrients including glutamine may exert beneficial influence on diverse patient populations.

A light and scanning electron microscope study of the albino rat ileum after partial obstruction

PURPOSE

Induction of an obstruction could be resorted to as a definitive line of management in some cases of short bowel syndrome (SBS). The goal of this study has been to elucidate histological and morphometric alterations in the albino rat ileum after surgically induced partial obstruction.

METHODS AND MATERIALS

Thirty adult male albino rats (240-250 g) were used in this investigation. They were divided into two equal groups: control and experimental. Small pieces of the ileum of the control and experimental animals were processed for histological and scanning electron microscope study.

RESULTS

The ileum of the experimental animals proximal to the site of obstruction showed an apparent enlargement in the Peyer's patches and an increase in the thickness of both the mucosa and muscle layers. The villi showed significant elongation and thickening. Both widening and deepening of the crypts were detected. There was an apparent increase in the goblet cell number and lymphocytic infiltration in both the corium and submucosa. In scanning electron microscopic examination, the microvilli showed scattered areas of shortening and irregular orientation. The surface was more frequently interrupted by goblet cell orifices.

CONCLUSIONS

Partial ileal obstruction resulted in hypertrophy of the ileal wall with considerable structural alterations oral to the obstruction site. Thus, the procedure apparently increased the absorptive surface area together with reduction in the speed of intestinal transit. These effects could support taking this technique into consideration as one of the suggested lines of treatment of some cases of SBS to eliminate the patient's need for parenteral nutrition and all of its associated complications.

Expression of growth hormone and its receptor in chronic atrophic gastritis and its clinical significance

AIM: To investigate the growth hormone (GH) and growth hormone receptor (GHR) expression of and its clinical significance in patients with chronic atrophic gastritis (CAG).

METHODS: A total of 90 cases were enrolled in the study. Thirty were healthy controls, the other 60 patients were divided into two groups according to the endoscopical and histological diagnosis. Blood samples were drawn in the morning (menarche did not occur during the blood extraction in female patients), gastric mucosa was obtained by endoscopy. Serum GH and gastrice mucosal GHR levels were measured using radioimmunoassay (RIA) and En Vinsion technique.

RESULTS: The average GH level was 1.021 ± 0.132 µg/L in CAG patients, in controls it was 2.869 ± 0.512 µg/L. There was a significant difference between these two groups (P < 0.01). The positive rate of GHR in CAG patients was 10%, in controls the rate was 100%. There was a significant difference (P < 0.01). There was no significant change of GH level (3.176 ± 0.421 µg/L) in patients with gastric carcinoma compared with controls (P > 0.05).

CONCLUSION: The study shows that levels of GH and GHR expression are low in CAG patients. CAG pathogenesis has a correlation with mucosal nutrient deficiency, decreased levels of GH and GHR have an adverse effect on the repair and regeneration of CAG. There is no significant change of GH in gastric carcinorma patients, GH dose not play a role in the pathogenesis of gastric cancer.

Effects of growth hormone on intestinal adaptation of rat with short bowel syndrome

AIM: To evaluate the effects of growth hormone (GH) on the residual small intestine of rats with short bowel syndrome (SBS), including adaptive hyperplasia and absorption of glucose and amino acids.

METHODS: Forty Sprague-Dawley (SD) male rats with more than 85% small intestine resected were equally divided into five groups randomly: H-GH group (high dose at 7.5 IU/kg per day), M-GH group (moderate dose at 3.75 IU/kg per day), L-GH group (low dose at 1.88 IU/kg per day), SBS group and sham operation group. From the second to the 15th day after operation, all the GH-managed groups were treated by sc injection twice a day, while SBS group and sham group were managed with same volume normal saline for injection. All samples were gained by laparotomy under anesthesia at the 16th day after operation.

RESULTS: Weight loss of rats in H-GH group (36±4.4 g), which was the least among the four groups except sham group, was significantly less than that in SBS group (94±10.0 g) (P < 0.05). But preoperative body weight of rats in the four groups except sham group was not retrieved. Among all groups there was no significant difference in the length of jejunum and ileum, as well as no significant difference in the morphological variables of colon. Mucosal height of jejunum and ileum was greater in H-GH group and M-GH group (997±65.9 m, 752±79.3 m and 974±67.6 m, 788±75.1 m respectively) than those in SBS group (776±61.0 m, 664±64.0 m) (P < 0.05). Similarly, intestinal wall width of jejunum and ileum was also thicker in H-GH group and M-GH group (1142±65.4 m, 884±91.2 m and 1 145±78.7 m, 895±95.6 m respectively) than those in SBS group (848±194.7 m, 776±57.5 m) (P < 0.05). But mucosal height and intestinal wall width of jejunum and ileum in H-GH group were not significantly greater than those in M-GH group. Blood insulinlike growth factor 1 (IGF-1) concentration and PCNA index of liver did not differ among the five groups. No significant differences of blood glucose and amino acids concentrations were detected after nutritional administration among the five groups.

CONCLUSION: Treatment of SBS with GH only slows body weight decrease rather than promotes body weight gain by the support of enteral nutrition. GH enhances adaptive mucosal hyperplasia after massive resection of small intestine, while its enhanced effect does not parallel its dose increase. Because of GH resistance resulted from the SBS-induced malnutrition,elevation of blood IGF-1 is impaired and absorpton of glucose and amino acids is not enhanced.

Irreversible intestinal failure

Intestinal failure (IF) can be defined as the reduction of functional gut mass below the minimal amount necessary for digestion and absorption adequate to satisfy the nutrient and fluid requirements for maintenance in adults or growth in children. In developed countries, IF mainly includes individuals with the congenital or early onset of conditions requiring protracted or indefinite parenteral nutrition (PN). Short bowel syndrome was the first commonly recognized cause of protracted IF. The normal physiologic process of intestinal adaptation after extensive resection usually allows for recovery of sufficient intestinal function within weeks to months. During this time, patients can be sustained on parenteral nutrition. Only a few children have permanent intestinal insufficiency and life-long dependency on PN. Non-transplant surgery including small bowel tapering and lengthening may allow weaning from PN in some cases. Hormonal therapy with recombinant human growth hormone has produced poor results while therapy with glucagon-like peptide-2 holds promise. Congenital diseases of enterocyte development such as microvillus inclusion disease or intestinal epithelial dysplasia cause permanent IF for which no curative medical treatment is currently available. Severe and extensive motility disorders such as total or subtotal intestinal aganglionosis (long segment Hirschsprung disease) or chronic intestinal pseudo-obstruction syndrome may also cause permanent IF. PN and home-PN remain are the mainstays of therapy regardless of the cause of IF. Some patients develop complications while receiving long-term PN for IF especially catheter related complications (thrombosis, sepsis) and liver disease. These patients may be candidates for intestinal transplantation. This review discusses the causes of irreversible IF and emphasizes the specific medico-surgical strategies for prevention and treatment of these conditions at several stages of IF.

Role of gastrointestinal hormones in the proliferation of normal and neoplastic tissues

Gastrointestinal (GI) hormones are chemical messengers that regulate the physiological functions of the intestine and pancreas, including secretion, motility, absorption, and digestion. In addition to these well-defined physiological effects, GI hormones can stimulate proliferation of the nonneoplastic intestinal mucosa and pancreas. Furthermore, in an analogous fashion to breast and prostate cancer, certain GI cancers possess receptors for GI hormones; growth can be altered by administration of these hormones or by blocking their respective receptors. The GI hormones that affect proliferation, either stimulatory or inhibitory, include gastrin, cholecystokinin, gastrin-releasing peptide, neurotensin, peptide YY, glucagon-like peptide-2, and somatostatin. The effects of these peptides on normal and neoplastic GI tissues will be described. Also, future perspectives and potential therapeutic implications will be discussed.

The anabolic effects of recombinant human growth hormone and glutamine on parenterally fed, short bowel rats

AIM: To evaluate the metabolic effects associated with administration of rhGH and/or Gln in parenterally fed, short-bowel rats.

METHODS: Forty SD rats subjected to 75% intestinal resection and maintained with parenteral nutrition were randomly divided into 4 groups as follows: -rhGH, -Gln; -rhGH, +Gln; +rhGH, -Gln; +rhGH, +Gln. Body weight and nitrogen balance were evaluated daily. After 6 d of PN, rats were killed, various organs were dissected and weighted, the carcasses were used for analysis of body composition. Serum GH and IGF-1 were determined by RIA method.

RESULTS: Weight loss in rats with rhGH (17.4 ± 12.8 g) and rhGH+Gln (23.8 ± 3.5 g) was significantly less than rats with PN alone (29.6 ± 6.9 g) and rats with Gln-supplemented PN (31.85 ± 12.8 g), P < 0.05. The accumulated NB in rats with rhGH (1252.9 ± 294.3 mg N/d) and rhGH+Gln (1261.7 ± 85.5 mg N/d) was significantly greater than those with PN alone (704.8 ± 379.0 mg N/d) and with Gln-supplemented PN (856.7 ± 284.4 mg N/d), P < 0.05. The absolute weight of gastrocnemius muscle in rats with rhGH (2683.9 ± 341.6 mg) and rhGH+Gln (2579.1 ± 359.5 mg) was greater than those with PN alone (2176.3 ± 167.1 mg) and with Gln-supplemented PN (2141.9 ± 353.6 mg). Although the absolute weight of remnant small intestine itself was not significantly different in 4 experimental groups, the weight/length of the segments was greater in rats with rhGH and/or Gln (48.7 ± 5.5, 52.7 ± 4.1 and 67.4 ± 5.3 respectively) than those with PN alone (47.8 ± 5.0), there were synergistic effects between rhGH and Gln in improvement of the weight/length of remnant small intestine, P < 0.05. Analyses of body carcass composition showed that a higher percentage of carcass weight as protein and a lower percentage of carcass weight as fat were occurred in rats with rhGH (20.8 ± 4.0, 6.0 ± 2.6) and rhGH+Gln (21.3 ± 2.4, 4.4 ± 1.5) than those with PN alone (16.4 ± 2.4, 9.2 ± 3.7) and with Gln-supplemented PN (17.8 ± 3.0, 6.3 ± 2.0), rhGH had significant effects on alteration of body composition, P < 0.05. Serum GH and IGF-1 concentration in rats with rhGH (5.221 ± 0.8 and 425.1 ± 19.2 ng/mL respectively) and rhGH+Gln (5.507 ± 1.0 and 461.1 ± 49.9 ng/mL respectively) were greater than those with PN alone (3.327 ± 1.7 and 325.8 ± 29.6 ng/mL respectively) and with Gln-supplemented PN (3.433 ± 0.1 and 347.7 ± 55.7 ng/mL respectively), P < 0.01.

CONCLUSION: rhGH significantly improves the anabolism in parenterally fed. Short bowel rats, anabolic effect with Gln is less dramatic, there is no synergistic effect between rhGH and Gln in improvement of whole body anabolism. IGF-1 plays an important part in growth-promoting effects of rhGH.