SUMMARY Reference ranges for albumin bound and a2-macroglobulin bound zinc concentrations have been determined in a study of sera obtained from 134 healthy adults. The concentrations of zinc bound to a2-macroglobulin were remarkably constant with a mean (+SD) of 2-4 + 0-6 ,umol/l; the variations in total serum zinc concentrations were almost entirely accounted for by variations in the zinc associated with albumin. There were no sex related differences in the transport of zinc in serum; neither was this sensitive to the use of oral contraceptives. These data provide a baseline for further investigations into the effects of zinc deficiency on the serum transport of the metal.There is increasing recognition that secondary zinc deficiency states may complicate a wide variety of clinical conditions.' Research in this field has been inhibited, however, by difficulties associated with the assessment of body zinc availability, which is commonly attempted using analyses for the total zinc in samples of plasma or serum. Only the most florid deficiencies of zinc can be reliably diagnosed by such means since equivocally reduced plasma zinc concentrations may be found in many circumstances in which no deficiency of the metal is suspected.2 On some occasions these findings are the result of a transfer of zinc from the plasma to intracellular sites; this commonly occurs acutely after operations or after other similarly stressful events.3 Even in more stable clinical circumstances difficulties may arise because almost all of the plasma zinc is bound to proteins, which are themselves subject to changes of concentration in response to factors unrelated to the availability of the metal.Because of these latter problems attempts have been made to characterise the distribution of zinc between its plasma protein ligands, both in health and disease. Unfortunately, the results of these studies have often been contradictory, not only with regard to the identities of the protein species which bind zinc in plasma, but also with regard to the distribution of zinc between them. The disparity of Accepted for publication 13 June 1984 these findings almost certainly results from analytical errors arising from three principal sources: incomplete protein separation, disruption of metalprotein interactions during the process of protein fractionation, and contamination with exogenous zinc.We have recently shown that the zinc contained in human serum is bound almost exclusively to only two proteins-albumin and a2-macroglobulin45-and we have developed a rapid and reliable micromethod for the determination of these two zincprotein species.4 The present study was undertaken to investigate the concentrations of albumin bound and a2-macroglobulin bound zinc in the sera of healthy human subjects to provide control data for use in subsequent studies of zinc deficiency states. Subjects and methods SUBJECTSWhole blood was obtained from 134 normal healthy volunteers: 86 men aged 18-62 years and 48 women aged 19-60 years. Eleven of the women who participate...

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The concentrations of Cu and Zn were determined in the plasma, granulocytes and mononuclear cells of 26 patients with diabetes mellitus and 26 age and sex-matched controls. In addition, Cu was measured in both washed and unwashed red blood cells, and Cu,Zn-superoxide dismutase (SOD) activity measured in washed red blood cells. Cu and Zn were determined by Zeeman-effect graphite furnace atomic absorption spectrometry following separation of plasma and red blood cells, and the white blood cell fractions (granulocytes and mononuclear cells) by density gradient centrifugation. There were no significant differences in any of the matching factors, or lipid profiles, between the groups. Plasma Zn was reduced by 17% in diabetics, compared with the controls (P = 0.0001). Neither the plasma nor the red blood cell Cu concentrations were significantly different. Of the white blood cell fractions, only mononuclear cell Cu was significantly different (30% lower in diabetics P = 0.0035, The red blood SOD activity was reduced in diabetics by over 12%, but this difference was non-significant (P = 0.0872). There was a significant negative correlation between washed red blood cell Cu and the duration of diabetes (r = -0.613, P = 0.0069). In conclusion, the copper and zinc status of these diabetic patients was reduced, providing further evidence of a role for these antioxidant trace elements in this disease.

Objectives: The objective was to assess the effectiveness of a small-bore catheter (8F) connected to a one-way Heimlich valve in the emergency department (ED)-based outpatient management of primary spontaneous pneumothorax (PSP). Methods:The authors conducted a structured chart audit in a retrospective case series of patients with PSP who were treated with a small-bore (8F) catheter and a Heimlich valve who were seen in the ED of a community hospital between April 2000 and March 2005. To be eligible, patients had to be available for a telephone interview. Main outcomes were success of treatment (sustained, complete lung reexpansion), admission, and surgical intervention rates. Secondary outcomes included number of chest x-rays (CXRs), number of visits to the ED, treatment duration, complications, and recurrence rates.Results: The authors identified 62 discrete episodes of PSP in 50 patients, with a mean (±standard deviation [SD]) age of 25.5 ± 10.5 years (range = 14-53 years). In 50 of 62 episodes (81%, 95% confidence interval [CI] = 70.8% to 90.5%), patients were discharged directly from the ED. Patients were admitted to the hospital at some point for treatment in 27 ⁄ 62 episodes (43.5%, 95% CI = 31.2% to 55.9%). Surgery was performed for acute treatment failure in 17 episodes. Ultimately, 19 patients, who accounted for 21 of 62 episodes (33.9%, 95% CI = 22.1% to 45.6%), had surgery at some point in the study. Mean (±SD) time to admission for those patients initially discharged from the ED was 2.9 (±2.01) days (95% CI = 1.9 to 3.8 days). There were no serious complications from treatment; the minor complication rate (misplacement or dislodging of the chest tube) was 22.6% (95% CI = 12.2% to 33.0%). No association was found between the size of pneumothorax and treatment failure.Conclusions: This study suggests that the initial management of PSP with a small-bore catheter and Heimlich valve can easily be performed by emergency physicians in the community hospital setting and appears safe. A larger study systematically comparing this approach with alternative therapies is needed.ACADEMIC EMERGENCY MEDICINE 2009; 16:513-518 ª