Activity tracker-based intervention to increase physical activity in patients with type 2 diabetes and healthy individuals: study protocol for a randomized controlled trial.

BACKGROUND: One relevant strategy to prevent the onset and progression of type 2 diabetes mellitus (T2DM) focuses on increasing physical activity. The use of activity trackers by patients could enable objective measurement of their regular physical activity in daily life and promote physical activity through the use of a tracker-based intervention. This trial aims to answer three research questions: (1) Is the use of activity trackers suitable for longitudinal assessment of physical activity in everyday life? (2) Does the use of a tracker-based intervention lead to sustainable improvements in the physical activity of healthy individuals and in people with T2DM? (3) Does the accompanying digital motivational intervention lead to sustainable improvements in physical activity for participants using the tracker-based device? METHODS: The planned study is a randomized controlled trial focused on 1642 participants with and without T2DM for 9 months with regard to their physical activity behavior. Subjects allocated to an intervention group will wear an activity tracker. Half of the subjects in the intervention group will also receive an additional digital motivational intervention. Subjects allocated to the control group will not receive any intervention. The primary outcome is the amount of moderate and vigorous physical activity in minutes and the number of steps per week measured continuously with the activity tracker and assessed by questionnaires at four time points. Secondary endpoints are medical parameters measured at the same four time points. The collected data will be analyzed using inferential statistics and explorative data-mining techniques. DISCUSSION: The trial uses an interdisciplinary approach with a team including sports psychologists, sports scientists, health scientists, health care professionals, physicians, and computer scientists. It also involves the processing and analysis of large amounts of data collected with activity trackers. These factors represent particular strengths as well as challenges in the study. TRIAL REGISTRATION: The trial is registered at the World Health Organization International Clinical Trials Registry Platform via the German Clinical Studies Trial Register (DRKS), DRKS00027064 . Registered on 11 November 2021.

A large proportion of people who inject drugs are susceptible to hepatitis B: Results from a bio-behavioural study in eight German cities.

BACKGROUND: People who inject drugs (PWID) are at high risk of hepatitis B virus (HBV) infection by sharing needles and drug use paraphernalia. In Germany, no routine surveillance of HBV prevalence and vaccination coverage among PWID exists. METHODS: Socio-demographic and behavioural data were collected between 2011 and 2014 through face-to-face interviews, during a bio-behavioural survey of PWID recruited in eight German cities. Dried blood spots (DBS) prepared with capillary blood were tested for HBV markers. Factors associated with past/current HBV infection and vaccination status were analysed by univariable and multivariable analysis using logistic regression. The validity of self-reported HBV infection and vaccination status was analysed by comparison to the laboratory results. RESULTS: Among 2077 participants, the prevalence of current HBV infection was 1.1%, of past HBV infection was 24%, and of vaccine-induced HBV antibodies was 32%. No detectable HBV antibodies were found in 43%. HBV infection status was significantly associated with study city, age, years of injecting, use of stimulants, migration status, and homelessness; HBV vaccination status was significantly associated with study city, age, and level of education. Correct infection status was reported by 71% and correct vaccination status by 45%. CONCLUSIONS: HBV seroprevalence among PWID was about five times higher than in the general population in Germany, confirming PWID as an important risk group. Targeted information campaigns on HBV and HBV prevention for PWID and professionals in contact with PWID need to be intensified. Routinely offered HBV vaccination during imprisonment and opioid substitution therapy would likely improve vaccination rates among PWID.

The effect of thrombocytopenia on experimental arteriosclerotic lesion formation in rabbits. Smooth muscle cell proliferation and re-endothelialization.

This study was designed to investigate the mechanisms involved in fibromusculoelastic lesion formation produced by selective de-endothelialization by the intra-arterial balloon catheter technique in thrombocytopenic rabbits. Thrombocytopenia was induced and maintained for up to 30 days by daily injections fo highly specific sheep anti-rabbit platelet sera (APS). Evidence for re-endothelialization was obtained by i.v. Evans blue dye 30 min before sacrifice. Rabbits received daily injections of APS, which reduced the mean platelet count to 5,600/cm3; control animals received identically treated normal sheep sera on the same schedule, and had mean daily platelet counts of 363,000/cm3. Evaluation of intimal thickness was assessed by counting cell layers in semithin sections. Intimal thickening in aortae from rabbits treated with APS was strikingly suppressed, in contrast to those from normal sheep sera-treated animals which showed a mean intimal thickness of 18 cell layers within 28 days often after de-endothelialization. Re-endothelialization was not affected by APS treatment. These results indicate that the proliferation of smooth muscle cells is dramatically inhibited by reduction of platelets.

Studies on the mechanism of decreased NMR-measured free magnesium in stored erythrocytes.

31P-NMR spectra have been recorded on erythrocytes stored at 4 degrees C in various preservation media. Storage was always associated with an upfield shift of the inorganic phosphate (Pi) resonance and a pronounced upfield shift of the ATP beta resonance, indicating decreased intracellular pH (pHi) and decreased intracellular free magnesium ([Mg2+]i). The decreased [Mg2+]i occurred in preservation media not containing citrate and even in media supplemented with Mg2+. It could not be attributed to the changes in pHi, Na+, K+, lactate, Pi or 2,3-diphosphoglycerate, that occur with storage. The decrease in [Mg2+]i was largely reversed when stored cells were incubated for 1 h at 37 degrees C in fresh plasma. Stored cells were found to contain significant amounts of inorganic pyrophosphate, up to about 200 mumol per liter cell water. Being a tight binder of Mg2+, pyrophosphate could account for some of the observed decrease in [Mg2+]i. Additional mechanisms may involve precipitation of some other Mg2+ complex during cold storage or enhancement of Mg2+ binding to membrane components.

Analysis of the risk of transmitting bovine spongiform encephalopathy through bone grafts derived from bovine bone.

Bone substitutes of bovine origin are widely used for treatment of bone defects in dental and orthopedic surgery. Due to the occurrence of BSE and the new variant of Creutzfeldt Jakob Disease risks of transmitting diseases through the use of such materials need to be carefully evaluated. Risk analysis can either be based on theoretical assessments or experimental evidence. Here we present a comparative study on two bovine bone substitutes (Bio-Oss and Osteograf/N) which is based on theoretical values. Furthermore, for one of these materials, i.e. Bio-Oss, the prion inactivation capacity of one of the production steps was experimentally evaluated. Theoretical and experimental data indicate that the use of these materials does not carry a risk of transmitting BSE to patients.

Rapid removal of heparin from plasma by affinity filtration.

Coagulation test abnormalities caused by the presence of heparin are not uncommon and frequently result in additional laboratory investigation and unwarranted therapy. Methods to neutralize the effect of heparin include the addition of polyanions, enzymes, or resins to the clinical samples. These techniques are time consuming and cumbersome and produce inconsistent results. As an alternative, use of a positively charged porous filtration medium to remove heparin from the sample is described. The filtration procedure requires less than one minute and provides a consistent and total removal of heparin at plasma concentrations in excess of therapeutic levels. Chromogenic substrate analysis for residual heparin activity confirms total removal of the drug at levels greater than one unit/mL of plasma. In clinical trials, filtration normalized the activated partial thromboplastin time (APTT) of all patient specimens containing heparin (n = 41). Filtration did not shorten the coagulation assay times of patients receiving warfarin (n = 36) or of those with a variety of acquired coagulopathies (n = 14). The level of coagulation factors adsorbed to the filter medium compares favorably to that adsorbed by other commercially available heparin-binding resins. Routine use of the filter in the clinical laboratory allows for the rapid and definitive identification of heparin in specimens with prolonged coagulation times and provides clinically meaningful data.

Eliminating unnecessary urine microscopy. Results and performance characteristics of an algorithm based on chemical reagent strip testing.

The ability of a urinalysis reagent strip to predict the presence of formed elements in the sediment was evaluated. The sensitivity of individual biochemical analytes varies from 0.51 to 0.85; however, the combined sensitivity of positive reactions for either protein, nitrite, leukocyte esterase, and/or hemoglobin is 0.95. Leukocyte esterase activity becomes detectable at a concentration of 15 white blood cells per high-power field (WBCs/HPF). Proteinuria is nonspecifically related to pyuria and detects a minimum concentration of 6 WBCs/HPF, and the hemoglobin reaction detects 6 red blood cells/HPF. Most false negative reactions are associated with bacteriuria. A positive chemical reagent strip test can be safely and effectively used as a prerequisite for routine urine microscopic examination.

A new assay for quantifying human reticulocytes.

The authors describe a new method for quantitative reticulocyte analysis. The assay uses a conventional clinical blood cell analyzer to size a patient's red blood cell neocyte population, which relates to the reticulocyte fraction in a linear fashion. Blood is layered atop Stractan (arabino-galactan polysaccharide) and centrifuged for 30 minutes at 1,500 X g. This density medium fractionation process enriches the Stractan layer with neocytes by up to 20-fold as determined by G6PD enzyme analysis. The mean corpuscular volume (MCV) of the red blood cells partitioning in the Stractan layer and the starting whole blood is then measured. The ratio of the two MCV measurements is then related to the reticulocyte percentage by a standard curve. In 93 patients, the derived MCV ratio was linearly correlated with manual reticulocyte counts (r = 0.96/slope = 0.99). Agreement of results obtained for single samples was within 0.2%. The assay's within-run and between-run precision is excellent (coefficient of variation less than 1%). The assay provides data on the percentage of reticulocytes in whole blood with an accuracy and precision that is at least 20 times greater than conventional microscopic technics.

Volumetric erythrocyte macrocytosis induced by hydroxyurea.

An atypical form of macrocytosis termed volumetric macrocytosis is described. In contrast to the macrocyte associated with megaloblastic anemia and the pseudomacrocyte caused by viscoelastic defects, the volumetric macrocyte is characterized by an increased mean corpuscular volume and a normal cell diameter. The volumetric macrocyte proves to be thicker than the normocytic red blood cell. This large erythrocyte is overhydrated and contains an increased quantity of hemoglobin. The cell has many characteristics in common with the red blood cells of neonates. Volumetric macrocytosis accompanies sustained hydroxyurea therapy and may represent a drug-induced dyserythropoiesis.

Paradoxic effect of multiple mild coagulation factor deficiencies on the prothrombin time and activated partial thromboplastin time.

Single coagulation factor deficiencies predictably prolong the prothrombin time (PT) and activated partial thromboplastin time (APTT) at levels below 35% of normal activity. Acquired coagulopathies generally are characterized by multiple coagulation factor deficiencies. The effect was studied of such combined deficiencies on the PT/APTT using plasma from patients congenitally deficient in specific factors and pooled normal plasma. The PT begins to lengthen when individual factor levels fall below 25%. The APTT becomes prolonged when the levels of Factor V fall below 45%; the levels of Factors II and XI fall below 40%; and the levels of Factors I, V, VII, VIII, IX, and XII fall below 25% of normal. When plasma samples containing 50% activity of a single factor and 100% of all other factors were prepared by mixing the congenitally deficient plasma samples with the normal pool, the resulting mixtures had normal PT and APTT values. However, when two of these 50% factor-deficient plasmas were combined so that the mixture contained 75% activity of two coagulation factors and 100% of all other factors, the resulting PT and APTT were prolonged over the clotting times of either 50% factor-deficient plasma. Similar findings were obtained in patients with mild factor reductions caused by warfarin treatment. These data indicate that prolongations of the PT and APTT in disorders of coagulation affecting multiple factors represent less of a reduction in factor levels than is generally appreciated. This may explain the poor clinical correlation between abnormalities in these test results and clinical bleeding in acquired disorders of hemostasis.

Practical methods to improve transfusion safety by using novel blood unit and patient identification systems.

Human error is a leading cause of transfusion-associated death. Many of these events are associated with a failure to comply with established unit-recipient identification protocols. Although several dedicated systems designed to minimize this problem are currently available, none of them have been sufficiently challenged by the various conditions that exist in diverse clinical settings. However, data available for computer-based recognition procedures and for a disposable blood bag combination lock, which precludes access to the blood before it is properly identified, are encouraging.

The unwarranted use of replicate analysis in routine coagulation studies.

The need to assure the validity of semiautomated coagulation procedures by performing replicate determinations is assessed. Prothrombin times (PT) and activated partial thromboplastin times (aPTT) were run as duplicate assays using two different photo-optical detection systems. Sixty specimens with a broad range of PT and aPTT results were studied as aliquots of 80, 100, and 140 microL of plasma. A total of 1,440 studies were performed. No statistically significant differences were found among the data for complementary groups of assays. It is concluded that replicate analyses do not enhance the precision nor the accuracy of these coagulation studies. These factors are more controlled adequately by quality assurance procedures, including frequent calibration checks, the use of internal standards, and multilevel commercial controls.

The clinical utility of the leukocyte differential in emergency medicine.

Leukocyte differentials from 468 emergency room patients were assessed for clinical value by determining their associations with diagnosis, disposition, therapy, and prognosis. The test efficiency of an elevated band count as an indicator of infectious or inflammatory disease is 86%. However, all but 2 of the 99 patients in this disease category had additional indicators of inflammation, including elevated temperatures and/or white blood cell (WBC) counts. The band count lacks utility beyond this limited function. The remaining parameters of the differential count correlate poorly with all diagnostic subsets. The use of antibiotics correlates well with fever and WBC count (r = 0.95) and less well with the differential count, bands (r = 0.85), and granulocytes (r = 0.5). Elevations in the total WBC count and the band count are each associated with an increased likelihood of hospitalization. However, in the absence of leukocytosis, an elevated band count was instrumental in suggesting admission for only one patient. The patient's outcome correlates poorly with the total WBC and differential count. It is concluded that most leukocyte differentials performed for emergency room patients provide information that is no more clinically significant than that obtained from the medical history, physical examination, and absolute leukocyte count.

Clinical utility of serum tests for iron deficiency in hospitalized patients.

Serum iron and ferritin measurements lack the requisite sensitivity and/or specificity to accurately diagnose iron deficiency. To determine their utility in hospitalized patients, the authors compared the results of these tests with the presence of stainable iron in bone marrow aspirates of 301 patients. Forty (13.3%) had absent marrow iron. The serum diagnosis of iron deficiency was accepted on the basis of the following: iron less than 11 mumol/L, total iron-binding capacity (TIBC) greater than 45 mumol/L, transferrin saturation (%Sat) less than 0.20, and ferritin less than 13 micrograms/L for females and less than 25 micrograms/L for males. Using these criteria, iron deficiency was correctly diagnosed by serum iron in 41%, TIBC in 84%, %Sat in 50%, and ferritin in 90% of the patients. The serum ferritin is clearly the only useful serum test for diagnosing iron deficiency in hospitalized patients but is limited by a low sensitivity. The bone marrow examination is the most sensitive test for diagnosing iron deficiency in hospitalized patients.

Characterisation of a novel airway late phase model in the sensitized guinea pig which uses silica and Bordetella pertussis as adjuvant for sensitization.

The objective of the present investigation was to validate a novel model of allergic late phase reaction in the airways of conscious guinea pigs by monitoring airway function with CO2-forced respiration. In addition airway inflammation as one possible cause for the development of airway late phase reaction was characterized by a novel technique which consists of bronchoalveolar lavage via the orotracheal route. Guinea pigs were sensitized twice at 2-week intervals with ovalbumin in silica and Bordetella pertussis. Two weeks after the booster sensitization all guinea pigs showed an acute decrease of tidal volume under CO2-forced respiration 5-15 min after antigen challenge. In contrast 42 out of 68 (= 62%) screened guinea pigs exhibited airway late phase response between 4-10 h after aerosol antigen challenge. During a subsequent cross-over study methylprednisolone (twice at 16 and 1 h before ovalbumin) did not significantly interfere with the acute response. In contrast the airway late phase response as well the associated eosinophil influx into the bronchoalveolar lavage were attenuated by the steroid. In conclusion, the sensitization procedure in combination with the novel method for monitoring airway function allowed measurement of a reproducible airway late phase response in about 60% of sensitized guinea pigs. The sensitivity of exclusively the late phase response and eosinophil influx to treatment with a glucocorticoid not only correlates this model with clinical pharmacotherapy but also strengthens the inflammatory nature of this model.

False positive immunometric assays caused by anti-immunoglobulin antibodies: a case report.

A serological phenomenon causing aberrant results with monoclonal immunoenzymetric assays (IEMA's) is reported. Two different commercial IEMA kits detected low levels of choriogonadotropin (hCG) in the serum of a non-pregnant woman. These assays detected between 32 and 55 IU/l of serum hCG over a 3-wk period; however, an RIA for beta-subunit and two monoclonal immunoradiometric assays (IRMA's) detected no hCG (less than 5 IU/l). An IEMA measurement of creatine kinase MB isozyme was also elevated. Antisera to either human immunoglobulin or specifically to human IgM, added to the serum prior to assay, substantially decreased these IEMA reactions. Addition of either mouse serum or purified mouse IgG totally abolished them. It is concluded that these spurious reactions were most likely caused by an IgM antibody which binds to native and enzyme-labelled mouse IgG, but not to iodinated IgG.

The H*1 hematology analyzer. Its performance characteristics and value in the diagnosis of infectious disease.

The performance characteristics and the value of data provided by the H*1 Automated Blood Cell Analyzer in the diagnosis of infectious disease are assessed. Data produced by the machine are precise over a wide range of complete blood cell counts and differential white blood cell (WBC) parameters. It is capable of accurately quantifying WBCs greater than 4000/mm3 (4 X 10(9)/L); red blood cells (RBCs), greater than 2.5 X 10(6)/mm3 (2.5 X 10(12)/L); and platelets greater than 1 X 10(3)/mm3 (1 X 10(9)/L). There is good agreement between the neutrophils and lymphocytes quantified by the standard microscopic count and the automated system; however, cells that are generally present in low incidence, namely, monocytes, basophils, and eosinophils, are less well correlated. The microscopic band cell count provides the greatest test efficiency in the diagnosis of infection. None of the unique parameters generated by the H*1 differential analyzer proved to have neither a test efficiency nor a diagnostic index greater than that of the absolute WBC count in the diagnosis of infection. The "left shift" in the leukocyte differential count as detected by the H*1 relates poorly to the presence of band neutrophils in the specimen. It is concluded that the state-of-the-art automated leukocyte differential count can dramatically reduce workload, but offers no advantage over the traditional differential WBC count in the diagnosis of infectious disease. Its potential value in the diagnosis of other conditions, particularly hematologic diseases, and in the sequential monitoring of infections in individual patients were not addressed by the present study.

Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: a 5-year study on 15 patients.

The efficacy of Bio-Oss as a graft material for sinus floor elevation was studied in 15 patients. A total of 20 sinus augmentation procedures was performed, and 6 months later 57 implants were placed into the augmented sinuses. New bone formation was confirmed in biopsies of 3 patients (new bone: 21.08% +/- 7.25% after 6 mo, 27.55% +/- 4.88% after 12 mo; Bio-Oss: 39.17% +/- 4.36% after 6 mo, 27.01% +/- 11.64% after 12 mo). After a mean loading period of 4.0 +/- 0.5 years (range 3.2 to 4.8 y), 56 implants remained in place. This study confirms Bio-Oss's good osteoconductive properties.

Detection of undiagnosed coagulopathies using routine rapid heparin neutralization.

OBJECTIVE: To determine the most frequent clinical causes of a prolonged activated partial thromboplastin time (APTT) result, and to determine whether a new heparin-removal device (the Hepchek, Pall Biomedical, Glen Cove, NY 11542) is capable of efficiently detecting the causes of these values. DESIGN: A combination of chart review and laboratory testing comparing the criterion standard--the heparin chromogenic substrate assay--with the Hepchek. Laboratory investigations were blinded and controlled. SETTING: Inpatient, acute-care hospital. PATIENTS: A total of 1,000 hospital patients with a variety of hemostatic disorders. MAIN OUTCOME MEASURE: The extent to which the Hepchek accurately identified the etiology of a prolonged APTT result. RESULTS: The APTT was prolonged in 25.2% of samples. The presence of heparin in the sample was confirmed by chromogenic assay or by using the Hepchek heparin-removal filter. The presence of heparin was confirmed in 12.8% of all samples and in more than 50% of all abnormal samples. The cause of the abnormal APTT was often unappreciated by the clinician. Bayesian analysis of the Hepchek's ability to diagnose heparin correctly as the cause of the abnormal APTT showed a sensitivity of 100% and specificity of 99.9%. CONCLUSION: Use of the Hepchek in the routine clinical laboratory is an efficient and rapid method of detecting heparin as a cause of isolated prolonged APTT results, and should reduce demands for unwarranted coagulation analyses and inappropriate treatment with blood products.

Performance characteristics of state-of-the-art hematology analyzers.

Data were obtained from four state-of-the-art automated hematology analyzers and compared with those obtained from microscopic reference procedures. The instruments evaluated were the Technicon's H*1, Sysmex's NE-8000, Coulter's STKR, and Coulter's STKS. Accuracy was assessed by comparing machine-generated white blood cell and red blood cell profiles with those obtained manually by experienced laboratorians. Specimens used were actual clinical samples submitted for routine analysis. The precision of the instruments in counting and sizing blood cells was not significantly different at the clinical decision-making level and consistently exceeded that of the microscopic method. Significant shifts in the leukocyte population were detected with relatively similar sensitivity by all instruments. As expected, the oldest model's clinical efficiency was exceeded by that of the newer analyzers. None of the analyzers performed with an accuracy that permits the laboratory to completely eliminate a microscopic scan of a stained blood film obtained from a patient's initial specimen.