Genomic HLA-DQβ Polymorphism Associated with Insulin-Dependent Diabetes Mellitus

Twelve insulin-dependent diabetes mellitus (IDDM) patients and healthy controls, who all carried the serologically defined DR3 and DR4 antigens, were compared with respect to other HLA polymorphisms. No significant differences between patients and controls were found by typing for HLA-Dw determinants by homozygous cell typing, nor by studies of their genomic DR beta polymorphism using different restriction enzymes. In contrast, certain DR beta polymorphism using different restriction enzymes. In contrast, certain DR4-associated genomic DQ beta fragments had a significantly different distribution among the IDDM patients than among the controls. Furthermore, when the distribution of all DQ beta-specific fragments which demonstrated polymorphism in our material was taken into account, nine of the 12 DR3, 4 IDDM patients demonstrated a similar DQ beta polymorphism compared with only two out of the 12 DR3, 4 controls (P = 0.006; corrected P = 0.037). Cells from patients and controls who demonstrated this IDDM-associated DQ beta polymorphism stimulated each other significantly less in reciprocal MLC tests, compared with the responses seen when their cells were confronted with cells from the DR3, 4 individuals with other genomic DQ beta polymorphisms.     

Nitric oxide administration after the ventilator: evaluation of mixing conditions

Background: Because of the potential toxicity of nitric oxide (NO) and its oxidising product nitrogen dioxide (NO₂), any system for the delivery of inhaled NO must aim at stable and predictable levels of NO and as low concentrations as possible of NO₂.
Methods: In a laboratory set-up, we have evaluated mixing conditions in a system where NO is added after the ventilator with continuous flow. Mixing was studied by using carbon dioxide (CO₂) as a tracer gas since capnography has a short response time (360 ms) in comparison with measurements of NO with electrochemical fuel cells (response time of 18s). CO₂ (in volumes corresponding to an ideal mixture of 1,3 and 6%) was fed, after the ventilator, either into plain breathing tubing, into one or two soda lime absorbers, or into an empty and a soda lime-filled canister, at different ventilatory rates and different I: E ratios. Samples were drawn from the inspiratory limb close to the Y-piece. NO was added in the same way and in the same volume as the highest concentration of CO₂.
Results: CO₂ added to plain tubing resulted in peak levels up to five times the set levels, while addition to a mixing box with an empty and a soda lime-filled canister resulted in even mixing with gas concentrations close to the ideal. When NO was fed into plain tubing, low levels were measured at the Y-piece, indicating poor mixing. Gas supply to a mixing chamber resulted in even concentrations.
Conclusions: Even and predictable levels of NO can be obtained with continuous flow of NO to the inspiratory limb, after the ventilator, if a mixing chamber is used. To obtain adequate mixing, the volume of the mixing box should be greater than the tidal volume.     

LONGITUDINAL COMPARISON OF CARBOHYDRATE-DEFICIENT TRANSFERRIN AND GAMMA-GLUTAMYL TRANSFERASE: COMPLEMENTARY MARKERS OF EXCESSIVE ALCOHOL CONSUMPTION

The utility of carbohydrate-deficient transferrin (CDT) andgamma-glutamyl transferase (GGT) as biochemical markers of excessivealcohol consumption was studied in alcohol-dependent subjects.Serum samples were collected once weekly from 10 male out-patientsundergoing a 6-month alcohol treatment programme. Frequencyof relapse into drinking (defined as any intake of alcoholicbeverage) was assessed by self-reports during patient interviewsthree times per week and by daily determination of the 5-hydroxytryptophollevel in urine. A marked decrease in mean CDT and GGT valueswas observed during the initial month. Only one patient remainedtotally abstinent throughout the observation period, while fourhad sporadic relapses (2–5 days with alcohol consumption).Both CDT and GGT remained below the respective reference limitsin those patients. The other five patients drank more frequently(range 22–57 days) and increased their mean levels ofCDT and GGT after the initial decrease. As determined from thevalues at admission and during the course of the study, CDTappeared to be the most sensitive marker in six out of the 10patients. In one patient, both markers were affected in a parallelway, whereas two of those with frequent relapses responded toalcohol consumption with a marked increase in GGT, but withno or only a slight increase in CDT. One patient did not showany abnormal CDT or GGT values. In 54 female and 60 male serumsamples collected at random from patients during admission atan alcohol detoxification unit, 35% and 58% of the CDT valuesexceeded the reference limits for females and males, respectively.For GGT, 59% of the female and 67% of the male values were abovecut-off. Carbohydrate-deficient transferrin and GGT were notsignificantly correlated. Taken together, the present resultsindicate that measurement of both CDT and GGT will increasethe possibility of identifying excessive alcohol consumption.By following changes in CDT and GGT values during a period ofalcohol withdrawal, the most sensitive individual marker canbe determined. This in turn allows for improved detection ofrelapse into heavy drinking dunng long-term monitoring of out-patients.     

Effects of myofibrillar bundle diameter on the unloaded shortening velocity of skinned skeletal muscle fibres

Using both slack tests and force clamp experiments, the velocity of unloaded shortening (Vu; Vu(st), slack test; Vu(fc), force clamp) was determined for maximally Ca2+-activated myofibrillar bundles. These were obtained by mechanically splitting single muscle fibres of rat, rabbit, crab and lobster skeletal muscles. A comparison was made between the Vu of thick (mammalian: 45-70 mum mean diameter; crustacean: 90-175 mum) and thin (mammalian: 25-40 mum; crustacean: 35-85mum) preparations of the same muscle fibre. The bundle diameter had opposite effects on Vu in mammalian and crustacean muscle fibres. The Vu of thin mammalian bundles was about 0.6times that of the thick ones, whereas in crustacean preparations this ratio was about 1.5. The kinetics of stretch-induced delayed force increase of maximally Ca2+-activated fibres (stretch activation) appeared not to differ between the thick and thin bundles from any animal preparation. Control experiments showed that the observed diameter effects on Vu are not due to differences in the chemical environment of the myofilaments. One possible explanation is that the intrinsic physical factors of the myofibrils modify Vu differently during progressive shortening in mammalian and crustacean preparations. This revised version was published online in August 2006 with corrections to the Cover Date.     

The influence of HLA-matched sibling donor availability on treatment outcome for patients with AML: an analysis of the AML 8A study of the EORTC Leukaemia Cooperative Group and GIMEMA

To determine whether patients with a HLA-identical sibling donor have a better outcome than patients without a donor, an analysis on the basis of intention-to-treat principles was performed within the framework of the EORTC-GIMEMA randomized phase III AML 8A trial. Patients in complete remission (CR) received one intensive consolidation course. Patients with a histocompatible sibling donor were then allocated allogeneic bone marrow transplantation (alloBMT), the patients without a donor were randomized between autologous BMT (ABMT) and a second intensive consolidation (IC2). 831 patients <46 years old and alive >8 weeks from diagnosis were included. HLA typing was performed in 672 patients. AlloBMT was performed during CR1 in 180 (61%) out of 295 patients with a donor. Another 38 patients were allografted: five in resistant disease, 14 during relapse and 19 in CR2. ABMT was performed in 130 (34%) out of 377 patients without a donor in CR1, in six (2%) patients during relapse and in 38 (10%) patients during CR2. The disease-free survival (DFS) from CR for patients with a donor was significantly longer than for patients without a donor (46% v 33% at 6 years; P = 0.01, RR 0.78, 95% confidence interval 0.63–0.96). The overall survival from diagnosis for patients with a donor was longer, but not statistically significant, than for patients without a donor (48% v 40% at 6 years; logrank P = 0.24). When patients were stratified according to prognostic risk groups, the same trend in favour of patients with a donor was seen for survival duration and the DFS remained significantly longer for this group of patients.     

Changes in Plasma Epinephrine Concentration and in Heart Rate During Head-Up Tilt Testing in Patients with Neurocardiogenic Syncope:

Sympathetic Activation in Neurocardiogenic Syncope. Introduction : Tilt table testing is widely used in the management of patients with neurocardiogenic syncope. However, the exact pathophysiologic mechanism of this disorder is still under debate. Likewise, therapy of these patients continues to represent a challenge in many cases. Therefore, the present study aimed to gain further insight into the pathophysiology of this syndrome and to examine easily accessible clinical parameters that can improve therapy selection.
Methods and Results : In 16 patients with neurocardiogenic syncope, changes in endogenous catecholamine concentrations were determined during repeated tilt table testing before and during treatment with metoprolol. Tachycardia preceded syncope in 8 of 10 responders compared to only 1 of 6 nonresponders (P < 0.05). In responders, the relative increase in epinephrine levels averaged 197%± 51% during drug-free tilting and 75%± 33% during repeated testing while on β-blocker therapy (P < 0.05). In nonresponders, there was a smaller relative increase in epinephrine averaging 137%± 35% at baseline tilt. During repeated tilt testing, a similar increase was observed in these patients with recurrent syncope (156%± 104%; P = NS compared to baseline).
Conclusion : In patients with neurocardiogenic syncope who show both an increase in epinephrine concentration during tilt test and sinus tachycardia prior to the onset of symptoms, β-blocker treatment is very effective. These findings confirm the major role of sympathetic activation as a trigger of syncope. Particularly, heart rate changes at the onset of syncope may allow early identification of patients responding to antiadrenergic therapy.     

Evidence for a light chain restriction of glycoprotein Ib/IX and Ilb/IIIa reactive antibodies in chronic idiopathic thrombocytopenic purpura (ITP)

To address the assumption of clonally restricted antibodies in immune thrombocytopenias we studied sera from 19 patients with chronic ITP known to possess antibodies reactive with glycoprotein (GP) Ib/IX and/or GPIIb/IIIa. These sera were re-analysed using the standard monoclonal antibody immobilization of platelet antigens (MAIPA) assay and 16 patients exhibited IgG antibodies reactive with GPIIb/IIIa; seven patients showed also a reactivity with GPIb/IX. Employing a light-chain-specific MAIPA assay, 75% (12/16) of these sera displayed GPHb/ Ilia-specific antibodies that were light chain restricted; only 13% (2/16) of the GPIIb/IHa reactive sera showed a mixed kappa and lambda phenotype. A light-chain-restricted phenotype was also seen for the GPIb/IX reactive antibodies. To further substantiate these findings, the MAIPA assay was modified in order to avoid interference from human anti-mouse antibodies. A high frequency of light-chain restricted platelet antibodies was also found using the modified MAIPA technique. These results support the hypothesis of a clonal B-cell expansion in immune thrombocytopenias, producing antibodies with a restricted idiotype repertoire and reacting with a limited number of epitopes.     

Recent developments in clinimetric instruments

Summary.  Assessment of impairment and function is essential in order to monitor joint status and evaluate therapeutic interventions in patients with haemophilia. The improvements in the treatment of haemophilia have required the development of more sensitive tools to detect the more minor dysfunctions that may now be apparent. This paper outlines some of the recent developments in this field. The Haemophilia Joint Health Score (HJHS) provides a systematic and robust measure of joint impairment. The MRI Scoring System has been designed to provide a comprehensive scoring system combining both progressive and additive scales. The Functional Independence Score for Haemophilia (FISH) has been developed to assess performance of functional activities and can be used in conjunction with the Haemophilia Activities List (HAL) which provides a self report measure of function. It is recommended that both measures are evaluated as these tools measure different constructs. Further refinement and testing of the psychometric properties of all of these tools is in progress. More widespread use of these tools will enable the sharing of data across the world so promoting best practice and ultimately enhancing patient care.