Collagenous colitis: Clinical and histological spectrum in ten patients

Collagenous colitis is characterized by the presence of a thick subepithelial collagen band in the colonic mucosa. The condition was diagnosed on rectal biopsy in 10 patients (one male, nine females) who presented with watery diarrhoea. Although rectal mucosal erythema was present in three and ulceration in two, the mucosa was of normal endoscopic appearance in five of the patients. There was marked variability in the thickness of the submucosal collagen band, both between and within individuals. Empirical drug therapy included sulphasalazine, glucocorticoids and antidiarrhoeals. All patients reported symptomatic improvement.     

Post–traumatic Alzheimer''s disease: preponderance of a single plaque type

The cause of Alzheimer's disease is unknown. Several factors have been proposed including head trauma. At present, the link between head injury and a subsequent neurodegenerative process is largely circumstantial, except in the case of dementia pugilistica (punch drunk syndrome) found in boxers. Recent studies have shown that the brains of boxers with this syndrome contain large numbers of 'diffuse' beta-protein immunoreactive plaques. We supposed that this plaque type might be associated with trauma induced Alzheimer-like degeneration. In order to test this hypothesis we have re-investigated a previously reported case of post-traumatic premature Alzheimer's disease. Immunocytochemistry using antibodies to amyloid beta-protein revealed large numbers of 'diffuse' non-Congophilic plaques with little or no neuritic component. A similar preponderance of this plaque type is present in the brains of boxers with dementia pugilistica. Our observations support the idea of a trauma induced Alzheimer-like degenerative process and indicate that such a condition is associated with a marked preponderance of 'diffuse' plaques.     

Structure-activity studies of hydrophobic amino acid replacements at positions 9, 11 and 16 of glucagon

We have designed and synthesized eight compounds 2-9 which incorporate neutral, hydrophobic amino acid residues in positions 9, 11 and 16 of the glucagon molecule: (2) [desHis¹,Va1⁹,11e^11,16] glucagon amide, (3) [desHis¹,Val^9,11,16]glucagon amide, (4) [desHis¹,Va1⁹,Leu^11,16]glucagon amide, (5) [desHis¹,Nle⁹,11e^11,16]glucagon amide, (6) [desHis¹,Nle⁹,Val^11,16]glucagon amide, (7) [desHis¹,Nle⁹,Leu^11,16]glucagon amide, (8) [desHis¹,Val⁹,Leu^11,16,Lys^17,18,Glu²¹]glucagon amide and (9) [desHis¹,Nle⁹,Leu^11,16,Lys^17,18,Glu²¹]glucagon amide. The effect of neutral, hydrophobic residues at positions 9, 11 and 16 led to good binding to the glucagon receptor. Compared to glucagon (IC₅₀= 1.5 nM), analogues 2-9 were found to have IC₅₀ values of 6.0, 6.0, 11.0, 9.0, 2.5, 2.8, 6.5 and 7.0 nM, respectively. When these compounds were tested for their ability to block adenylate cyclase (AC) activity, they were found to be antagonists having no stimulation of adenyl cyclase, with PA₂, values of 6.15, 6.20, 6.30, 7.25, 6.10, 7.30, 6.25 and 7.25, respectively. © Munksgaard 1997.     

How can we reduce disagreement among guidelines for venous thromboembolism prevention?

See also Struijk‐Mulder MC, Ettema HB, Verheyen CC, Büller HR. Comparing consensus guidelines on thromboprophylaxis in orthopedic surgery. This issue, pp 678–83.     

Histamine release from peripheral blood leucocytes in egg-allergic patients

Twelve egg-allergic patients were selected on the basis of a clinical history of egg allergy and a positive skin-prick test (SPT) to whole egg. A study was then carried out on the ability of the patients’ washed leucocytes to release histamine in the presence of whole egg, ovomucoid, ovalbumin and ovotransferrin. Histamine release (HR) from washed leucocytes was demonstrated in ten out of twelve patients, but only four out of ten released over 40% of their total histamine. Spontaneous HR ranged from 2·1–14·5% with a mean of 7·5%. There was good agreement between positive and negative HR, skin test and radioallergosorbent test (RAST) results. Concordance between the HR and skin test was found in 83%, HR and RAST in 71% and skin test and RAST in 78% of patients. However there was poor quantitative agreement between these three tests. When skin-prick tests and HR thresholds were compared, ovomucoid elicited the greatest skin test sensitivity in five out of six patients, whereas five of the same six were more sensitive to ovalbumin when judged by HR.     

Development of a microassay for histamine release

A microassay has been developed to measure histamine release from both washed human leucocytes and whole blood, in which blood samples can be diluted down to 1:20 without affecting their sensitivity to antigen. The sensitivity and reproducibility of the single isotope histamine radioenzymatic assay [REA] was compared to the conventional spectrofluorometric histamine assay. The limit of detection was 0.2 and 2.0 ng/ml, respectively, and the agreement between the two assays was good (r = 0.94). There was also a good qualitative agreement between skin-prick test and histamine release (92%). In order to see if this assay was suitable for small volumes of blood, we measured histamine release to antigen from both diluted whole blood taken by a thumb prick (as a model of the heel prick used in obtaining paediatric blood samples), and undiluted venous blood. There was complete agreement between a positive or negative histamine release response to antigen by diluted thumb prick and undiluted venous blood samples. Leucocyte sensitivity to antigen increased slightly upon dilution, but remained within a ten-fold antigen dilution. The micro-histamine release assay described here offers an opportunity to measure basophil sensitivity to allergens where the availability of the blood is limited (in young babies for example) as well as making possible multiple allergen testing.     

RESOLUTION OF ACROMEGALY AFTER REMOVAL OF A BRONCHIAL CARCINOID SHOWN TO SECRETE GROWTH HORMONE RELEASING FACTOR

A 29 year old woman with an enlarged pituitary fossa and classical acromegaly, possibly present for ten years, had biochemical and partial somatic resolution of the disorder after removal of a bronchial carcinoid tumour. In addition, galactorrhea stopped, menstruation returned after two years, and amenorrhea and elevated prolactin levels fell towards normal.
Immunocytochemistry showed numerous growth hormone releasing factor (GRF) staining cells in the tumour. The tumour cells, when cultured, produced a supernatant selectivity stimulating human pituitary somatotrophic cell cultures to produce growth hormone (GH). The bronchial carcinoid did not secrete detectable GH, but extracts of it, and preoperative serum contained GRF immunoreactivity which coeluted with synthetic human pancreatic GRF.     

Fiberenboscopic Removal of Long Foreign Bodies from the Stomach Using a Colon Stiffening Tube as a Protective Sheath

A colonoscopic stiffening tube was effectively used as a protective sheath in the esophagus during the endoscopic removal of a long ballpoint pen and a writing pencil from the stomach.