Solitary rectal ulcer syndrome

BACKGROUND: Solitary rectal ulcer syndrome is a rare disorder characterized by erythema or ulceration of the rectal wall, associated with typical histological features, and disturbed defaecatory behaviour with the passage of blood and mucus. METHODS: This is a review based on a literature search using a computer database (Medline) and manual cross-referencing. RESULTS: The pathogenesis is likely to vary in different patients; it includes trauma from straining, direct digital trauma and possibly primary neuromuscular pathology. The histological findings of extension of the muscularis mucosa between crypts and muscularis propria disorganization on full-thickness specimens are characteristic. Biofeedback defaecation retraining, including habit training, can lead to symptom improvement and return to work in a majority of patients. Abdominal rectopexy offers long-term symptom improvement in approximately 50 per cent of patients. Rectal ulceration may persist after any treatment, even if symptoms improve. CONCLUSION: Behavioural therapy and carefully considered operations offer the best treatment results. Further work on psychological factors and neuromuscular and vascular pathology is required.     

Localization of corticotropin-releasing factor in primary and secondary lymphoid organs of the rat

Cells of the immune system produce a variety of neuropeptides or peptide hormones, either constitutively or upon induction, and possess specific neuropeptide receptors that display ligand-receptor interactions similar to those described in the central nervous system (CNS). These findings suggest that specific subsets of lymphoid cells can produce and respond to peptides previously thought to be principally neural mediators. Recently, corticotropin releasing factor (CRF) mRNA was detected in the rat thymus and spleen, although the cells that synthesize CRF were not identified. We examined the localization of CRF and its mRNA in the rat spleen, thymus, and mesenteric lymph nodes using immunocytochemistry (ICC) and in situ hybridization (ISH), respectively. Immunoreactive CRF was present in cells in the marginal zone and red pulp of the spleen, in connective tissue septa and the subcapsular region of the thymus, and in the medullary cords and sinuses of the mesenteric lymph nodes. Dual ICC/ISH for CRF and its mRNA, respectively, demonstrated CRF mRNA over CRF-immunoreactive cells, suggesting CRF synthesis. Double-label ICC for CRF and markers for specific immunocyte subsets suggest that CRF+ cells in the spleen and thymus are macrophages. CRF+ cells in primary and secondary lymphoid organs reside in compartments that are innervated by sympathetic nerves, and some cells appears to be contacted by noradrenergic sympathetic nerve fibers, suggesting that CRF release may be influenced by the sympathetic nervous system, as it is in the hypothalamo-pituitary-adrenal axis. The presence of CRF in organs of the immune system suggests that this neuropeptide may modulate immune functions after paracrine release.     

Comparative analysis of semiotic shifts, established by LCS of blood plasma from random samples of studied subjects from the zone of the Chernobyl accident, "Ural Radiation Trace", and collaborators from St. Petersburg Institute of Nuclear Physics of the Russian Academy of Sciences

The effects of an alternative chelation program in thalassemic patients with severe iron overload are investigated. The schedule of treatment, feasible at home, consists in the administration of deferoxamine intravenously (100 mg/kg/die 8 hours 10 days a month), followed by 50 mg/kg/die subcutaneously in the remaining 20 days of the month. The results in 34 patients who underwent this program over 8 months are reported. After intensive chelation therapy serum ferritin and transaminase levels were significantly lower, and daily urinary iron excretion values were significantly higher when compared to the levels observed before the treatment. After the period of study, echocardiography revealed an ejection fraction (EF) significantly higher in 15 out of 34 cardiopathic patients. In conclusion, the alternative chelation program is effective in reducing iron overload of thalassemic patients, protecting them also against cardiac disease.     

Hygienic assessment of indicators of the nutritional status of Monchegorsk school children

Diets, energy expenditures, physical and mental performance, anthropometric indices, ascorbic acid excretion, and morbidity rates were studied in 7-9-year-old schoolchildren of Monchegorsk, Murmansk Region. The alimentary features found served as the basis for developing sanitary recommendations to optimize diets and to promote children's health.     

The wzz (cld) protein in Escherichia coli: amino acid sequence variation determines O-antigen chain length specificity

The O antigen is a polymer with a repeated unit. The chain length in most Escherichia coli strains has a modal value of 10 to 18 O units, but other strains have higher or lower modal values. wzz (cld/rol) mutants have a random chain length distribution, showing that the modal distribution is determined by the Wzz protein. Cloned wzz genes from E. coli strains with short (7 to 16), intermediate (10 to 18), and long (16 to 25) modal chain lengths were transferred to a model system, and their effects on O111 antigen were studied. The O111 chain length closely resembled that of the parent strains. We present data based on the construction of chimeric wzz genes and site-directed mutagenesis of the wzz gene to show that the modal value of O-antigen chain length of E. coli O1, O2, O7, and O157 strains can be changed by specific amino acid substitutions in wzz. It is concluded that the O-antigen chain length heterogeneity in E. coli strains is the result of amino acid sequence variation of the Wzz protein.     

Reduction of acyloxyacyl hydrolase activity in circulating neutrophils from cows after parturition

Bovine neutrophils contain the enzyme acyloxyacyl hydrolase, which hydrolyzes the acyloxyacyl linkage of the two nonhydroxylated fatty acyl chains to two 3-hydroxy fatty acids in the highly conserved lipid A part of endotoxins with high specificity. This hydrolysis decreases the toxicity of lipid A, but the immunostimulatory capacity of endotoxins is largely maintained. In two trials, we studied the activity of acyloxyacyl hydrolase in neutrophils that had been isolated from the blood of 18 dairy cows around parturition. Between 10 and 26 d after parturition, the activity of acyloxyacyl hydrolase in neutrophils decreased approximately 20% below prepartum activity. At about 2 mo after parturition, acyloxyacyl hydrolase activity returned to prepartum values. Changes in acyloxyacyl hydrolase activity could not be attributed to changes in binding of lipopolysaccharides by the CD14 molecules on neutrophils or monocytes. We hypothesize that decreased acyloxyacyl hydrolase activity in neutrophils shortly after parturition is a factor that increases the susceptibility of dairy cows to coliform mastitis during early lactation.