Anti-thyroid drugs decrease mucosal damage in a rat model of experimental colitis

Background : Methimazole, an anti-thyroid drug, was recently found to be useful in the treatment of systemic lupus erythematosus and other autoimmune diseases. Moreover, decreased thyroid hormone production is associated with a variety of immunological manifestations, such as reduced activation of CD4⁺ cells, increased CD8⁺ cell activity and reduced soluble IL-2 receptors. In the present study we examined the effects of methimazole and propylthiouracil on a rat model of experimental colitis.
Methods : Colitis was induced by intracolonic administration of 30 mg trinitrobenzene sulphonic acid (TNB). Two weeks prior to induction of colitis, rats were treated by either methimaziole (0.04%) or propylthiouracil (0.01%) in drinking water after a week of free access to water. Rats were sacrificed 48 h or 7 days after induction of colitis. The colon was isolated, rinsed with ice-cold water and weighed. Damage was assessed both macroscopically and microscopically and myeloperoxidase (MPO) activity determined.
Results : All treated rats were hypothyroid as manifested by a significant elevation of thyroid stimulating hormone (TSH), by comparison with the control groups (mean -1.82±0.40 versus 0.11±0.02 mmol/L, respectively). The inflammatory response elicited by TNB resulted in severe mucosal damage 48 h after damage induction, which persisted for 7 days. Pre-treatment with either methimazole 0.04% or propylthiouracil 0.01% significantly decreased mucosal damage macroscopically (lesion area, lesion score and segmental weight) microscopically and also significantly decreased MPO level at both time points ( P <0.01).
Conclusions : Methimazole and propylthiouracil significantly reduce mucosal damage and colonic weight in a rat model of colitis. The mode by which they do so remains to be studied.     

Unsuspected Source of Vitamin K in Patients Treated with Anticoagulants: A Case Report

The administration of warfarin requires careful attention. Theconcurrent intake of drugs can either enhance or compete withits anticoagulant effect. Less frequently encountered are theeffects from vitamin K added to food, intake of foods with naturallyoccurring high levels of vitamin K and diets deficient in vitaminK. We report a case in which loss of anticoagulant control wascaused by a dietary supplement taken during a weight reducingdiet by a patient who was receiving warfarin following a pulmonaryembolus. A review of the literature reveals several similarcases. Amounts of vitamin K in food supplements and in foodswith large amounts of naturally occurring vitamin K are tabulatedalong with suggestions for surveillance of patients taking anticoagulants.     

Elevated growth hormone levels in patients with non-alcoholic chronic liver disease

High serum concentrations of growth hormone (GH) were found in five patients with chronic liver diseases, including auto-immune chronic active hepatitis (two cases), Budd-Chiari syndrome, primary biliary cirrhosis and hepatitis B virus associated cirrhosis. Mean levels of GH were 27.8 units (normal up to 5). In three patients elevated prolactin levels were also found (mean 37.3 units for two females, normal up to 20), and 36 units in one male (normal up to 9). No other endocrine disorders were found. Although the association of raised GH levels in patients with alcoholic cirrhosis is well known, its occurrence in patients with non-alcoholic chronic liver disease is not fully established. We describe the effect of the disease course, and steroid treatment on GH levels in one patient with auto-immune chronic active hepatitis, and propose possible mechanisms for this elevation.     

Intravascular Extraction of Problematic or Infected Permanent Pacemaker Leads: 1994–1996

Of the 400,000-500,000 permanent pacemaker leads implanted worldwide each year, around 10% may eventually fail or become infected, becoming potential candidates for removal. Intravascular techniques for removing problematic or infected leads evolved over a 5-year period (1989-1993). This article analyzes results from January 1994 through April 1996, a period during which techniques were fairly stable. Extraction of 3,540 leads from 2,338 patients was attempted at 226 centers. Indications were: infection (27%), nonfunctional or incompatible leads (25%), Accufix or Encore leads (46%), or other causes (2%). Patients were 64+/-17 years of age (range 5-96); 59% were men, 41% women. Leads were implanted 47+/-41 months (maximum 26 years), in the atrium (53%), ventricle (46%), or SVC (1%). Extraction was attempted via the implant vein using locking stylets and dilator sheaths, and/or transfemorally using snares, retrieval baskets, and sheaths. Complete removal was achieved for 93% of leads, partial for 5%, and 2% were not removed. Risk of incomplete or failed extraction increased with implant duration (P<0.0001), less experienced physicians (P<0.0001), ventricular leads (P<0.005), noninfected patients (P<0.0005), and younger patients (P<0.0001). Major complications were reported for 1.4% of patients (<1% at centers with >300 cases), minor for 1.7%. Risk of complications increased with number of leads removed (P<0.005) and with less experienced physicians (P<0.005); risk of major complications was higher for women (P<0.01). Given physician experience, appropriate precautions, and appropriate patient selection, contemporary lead removal techniques allow success with low complication rates.     

Low-dose immune tolerance induction for paediatric haemophilia patients with factor VIII inhibitors

Summary.  The development of an inhibitor against factor VIII (FVIII) is a serious complication in children with haemophilia A. Immune tolerance induction (ITI) therapy is generally considered to be the best approach to eradicate the inhibitor. In this paper, the low-dose (≤50 IU kg⁻¹ twice or three times weekly with plasma-derived factor concentrates) ITI regimen used in Turkey is discussed. This regimen was given to 21 haemophilia A patients with high titer inhibitors. The median age at the beginning of ITI was 9 years and exposure days were 25. The median pre-ITI historical peak inhibitor titer, and inhibitor titer when ITI started were 80 BU (range 6.0–517), 19.2 BU (range 3.6–515), respectively. Complete immune tolerance was defined as the time at which at least two negative inhibitor assays was obtained with no anamnestic response. Our two cases were not reached in follow-up period. Immune tolerance could be achieved in 5 of 19 (26.3%) patients within a median time of 6 months. Partial tolerance was obtained in 7 patients while treatment failed in spite of significant decreased inhibitor levels in the other patients. A relapse developed in one immune-tolerized patient, one year later. The level of inhibitor titer at the beginning of ITI (≤10 BU), the pre-ITI historical peak inhibitor titer (<50 BU), and the time between the first diagnosis inhibitor to starting ITI (<12 months) were main factors in the success (complete or partial tolerance) of ITI. In conclusion, the outcome of low-dose ITI protocol was not satisfactory in this retrospective study.     

Thiolysis of the 3-nitro-2-pyridinesulfenyl (Npys) protecting group An approach towards a general deprotection scheme in peptide synthesis

The hydroxylic side-chain functional groups of serine, threonine, hydroxproline and tyrosine, the α and ε-amino moieties of lysine and the thiol group of cysteine were masked by the 3-nitro-2-pyridinesulfenyl (Npys) protecting group. Deprotection was mildly affected by thiolysis with either 2-mercaptopyridine and 2-mercaptomethyl imidazole (O- and N-Npys) or with 3-mercaptoacetic acid and 2-mercaptoethanol (S-Npys). Thiolysis was monitored spectrophotometrically and was completed in a rather short time. Incorporation of the Npys group into a whole and single thiolyzable deprotection scheme is suggested.