Determination of zinc in erythrocytes, granulocytes and serum by flame atomic absorption spectrophotometry

Zinc was determined in granulocytes, erythrocytes and serum by flame atomic absorption spectrophotometry. Using a Teflon sampling cup, the sample volume for a single granulocyte zinc determination was reduced to 100 microliter. Zinc in serum and erythrocytes was measured by aspirating the sample at a rate of 5 ml/min. The total volume of blood used was 23-28 ml. The intra-assay coefficient of variation of the method for granulocytes was 0.01 and of the method for serum and erythrocytes 0.018. The corresponding inter-assay coefficient of variation was 0.037 and 0.03, respectively. Recovery of zinc determined by the method of aspirating the small volume (100 microliter) was 103% and by the method of aspirating 5 ml/min 97%. The coefficient of correlation between the two methods was r = 0.9968.     

The Standardized Normal Ivy Bleeding Time and Its Prolongation by Aspirin

A standardized, reproducible Ivy bleeding time technic has been describedwhich permits one to obtain accurate bleeding time data in man. Thetechnic was used to standardize an aspirin tolerance test in which 60 normal males had a control bleeding time; were given, on a double blind basis,either placebo or 1 Gm. of aspirin, and had a second bleeding time 2 hourslater. The control values were: mean, 5 min.; mean ± 2 st. dev., 2 min.,30 sec. to 10 min. The values after placebo were: mean, 5 min., 30 sec.;mean ± 2 st. dev., 2 min., 30 sec. to 11 min. The values after aspirin were:mean, 9 min., 30 sec.; mean ± 2 st. dev., 4 min. to 21 min. The differencebetween the mean bleeding time after placebo and after aspirin was highlysignificant (p < 0.001). The distribution of the bleeding times after aspirinsuggested that normal subjects do not respond to aspirin as a single population. The degree of prolongation of the bleeding time and the large size ofthe drops of blood observed in some subjects suggested to us that smallamounts of aspirin may exert a significant effect upon hemostasis in normalindividuals.

Submitted on January 10, 1969 Accepted on April 23, 1969     

Increased Hemolysis after Intramuscular Iron Administration in Patients with Paroxysmal Nocturnal Hemoglobinuria: Report of Six Occurrences in Four Patients, and Speculations on a Possible Mechanism

Four patients with PNH were described who developed accelerated activityof their disease after the intramuscular administration of iron-dextran fortreatment of iron deficiency. This was considered to reflect a unique effect ofiron on PNH erythrocytes. It was postulated that this effect resulted from celldamage caused by iron catalyzed peroxidation of erythrocyte lipids, a reaction to which PNH erythrocytes could be unusually susceptible by virtue ofan increased content of unsaturated fatty acids or pro-oxidants or decreasedcontent of antioxidants.

Submitted on August 13, 1964 Accepted on November 11, 1964     

DFP Labeling of Platelets During Recovery from Thrombocytopenia

Rat platelets were labeled with tritiated diisopropylfluorophosphate(³H-DFP) during recovery from acute thrombocytopenia. The results indicated that there was significant labeling of megakaryocytes by ³H-DFPwhich, in the presence of an increased rate of platelet production, resulted inmaintenance of relatively constant values for platelet-bound radioactivity during the period of maximum platelet production and reactive thrombocytosis.Significant random loss of platelets was apparent, and, when a cohort ofyoung platelets was transfused to normal recipients, they were destroyed at anormal rate.

     

Manual strength testing in 14 upper limb muscles: a study of inter-rater reliability

BACKGROUND: Manual muscle testing has been termed a "lost art" and is often considered to be of minor value. The aim of this investigation was to study the inter-rater reliability of manual examination of the maximal voluntary strength in a sample of upper limb muscles. PATIENTS AND METHODS: The material consisted of a series of 41 consecutive patients (82 limbs) who had been referred to a clinic of occupational medicine for various reasons. Two examiners who were blinded as to patient-related information classified 14 muscles in terms of normal or reduced strength. In order to optimize the evaluation, the individual strength was assessed simultaneously on the right and left sides with the limbs in standardized positions that were specific for each muscle. Information on upper limb complaints (pain, weakness and/or numbness/tingling) collected by two other examiners resulted in 38 limbs being classified as symptomatic and 44 as asymptomatic. For each muscle the inter-rater reliability of the assessment of strength into normal or reduced was estimated by kappa-statistics. In addition, the odds ratio for the relation to symptoms of the definition in agreement of strength was calculated. RESULTS: The median kappa-value for strength in the muscles examined was 0.54 (0.25-0.72). With a median odds ratio of 4.0 (2.5-7.7), reduced strength was significantly associated with the presence of symptoms. INTERPRETATION: This study suggests that manual muscle testing in upper limb disorders has diagnostic potential.