Reference intervals for red cell variables and platelet counts in infants at 2, 5 and 13 months of age: a cohort study.

AIMS: To derive reference values for red cell variables and platelet counts from a cohort of infants sampled at precise ages during the first 13 months of life. METHODS: Blood counts, reticulocyte counts and zinc protoporphyrin concentrations were obtained from healthy term infants of North European ancestry at 2, 5 and 13 months of age. RESULTS: Mean cell volume (MCV) and mean cell haemoglobin (MCH) values did not differ significantly between 5 and 13 months and MCH concentration was unaffected by age. Values of all other variables at any one age differed significantly from those at the other two. Haemoglobin, mean cell haemoglobin, zinc protoporphyrin and platelet values (95% ranges) at 2 (n=119), 5 (n=97) and 13 months (n=42) were, respectively, 91-125, 101-129 and 105-133 g/L; 28.6-33.1, 24.5-28.7 and 24.3-28.7 pg; 36-116, 25-91 and 27-57 micromol/mol haem; and 216-658, 241-591 and 209-455×10(9)/L. At 2 and 5 months, respectively, 26.9% and 10.8% of subjects had platelet counts >500×10(9)/L. Reticulocyte counts at 2 months and MCV and MCH values at 5 months were significantly higher in girls. In boys, red cell distribution width values were significantly higher at 5 months, and zinc protoporphyrin values at both 2 and 5 months. CONCLUSIONS: These findings indicate the value of obtaining reference data at precise ages during infancy and confirm and extend earlier reports indicating a gender difference in laboratory measures used to assess iron status in early infancy.

Variable levels of carry over on platelet counts < or = 20 x 10(9)/l with the Bayer Advia 120.

Accurate platelet counts are essential for the safe management of severe thrombocytopenia (platelet counts < or = 20 x 10(9)/l). The effect of carry over on platelet counting in severe thrombocytopenia was investigated by performing counts before and after saline rinses on three Bayer Advia 120 automated blood counters. Counts were performed in both primary and manual closed tube system modes on two instruments and in manual open tube mode on a third. A total of 194 samples with platelet counts < or = 20 x 10(9)/l were studied. First counts were significantly higher in all groups. The magnitude of the difference varied both by analyser and counting mode. Carry over was minimal with one analyser in primary mode and second counts were on average only 5.5% lower; on a second analyser in manual closed tube system mode second counts were on average 37.7% lower. A first count of > or = 10 x 10(9)/l fell to <10 x 10(9)/l on the second count in 35 of 145 samples (24.1%). In five such samples, all tested on one analyser, the second count was <50% of the value of the first count. Two of 49 (4.1%) first counts of <10 x 10(9)/l increased to > or = 10 x 10(9)/l on repeat. These results show a variable and often potentially clinically important carry-over effect on severely thrombocytopenic samples using the Advia 120.

Cardiac metastasis from carcinoid tumour: magnetic resonance imaging findings.

A case of myocardial metastasis from a gastrointestinal carcinoid is presented. The colon was the primary site. The patient did not manifest symptoms of carcinoid syndrome and had no echocardiographic or MRI evidence of carcinoid valvular heart disease.

Atrial myxoma demonstrated by cine gradient refocused echo magnetic resonance imaging.

A case of atrial myxoma presenting with syncope evaluated by echocardiography and MRI is described. Cine gradient-echo MRI demonstrated atrial myxoma as a very low signal intensity mass indicating the presence of haemosiderin.

Total and differential leucocyte counts in infants at 2, 5 and 13 months of age.

Reference ranges for the total and differential leucocyte counts were determined from venous blood collected at 2, 5 and 13 months of age from a cohort of 112 healthy children of north European ancestry. At 2, 5 and 13 months, the ranges for neutrophils were found to be 0.7-4.7, 1.1-5.6 and 1.0-7.6 x 109/l, and for lymphocytes 3.3-10.5, 3.4-11.3 and 3.5-10.4 x 109/l, respectively. The upper limits for monocytes at each age were 1.2, 1.2 and 0.91 x 109/l, and for eosinophils 0.84, 1.0 and 0.88 x 109/l, respectively. Mean counts for all cell types, except monocytes, increased between 2 and 5 months of age. There was little change in mean counts between 5 and 13 months. Statistically significant correlations existed between the numbers of each cell type at 2 months of age, and were still present at 13 months between monocytes and each of the granulocyte series and between basophils and all other cell types. By comparison with older data these findings indicate a lower reference limit for neutrophils at 2 months of age, and a narrower range for this cell type at both 2 and 5 months of age. Reference ranges for lymphocytes and eosinophils are wider than indicated by some previous studies.

Farmworker exposure to organophosphorus pesticide residues during apple thinning in central Washington State.

The purpose of this study was to characterize worker exposure to azinphos-methyl (Guthion) over an entire 4-6 week apple-thinning season. Twenty workers from three work sites in the Chelan-Douglas County region of Washington state were recruited for the study. Exposure potential was estimated by dislodgeable foliar residue measurements, and individual exposures were estimated by biological monitoring through urinary metabolites. Measureable azinphos-methyl residues were found on apple foliage at all sites throughout the six-week sampling period, indicating continuous exposure potential (median residue level of 0.5 microgram/cm2). Measurable levels of the urinary dialkylphosphate metabolite, DMTP, were found in virtually all urine samples (limit of detection = 0.04 microgram/mL). Mean DMTP concentrations differed significantly across sites (0.53, 0.29, and 0.90 microgram/mL for Sites 1-3, respectively; analysis of variance, p < .002), and intraindividual variability was much greater than interindividual differences. Group mean DMTP concentrations at each site fluctuated according to foliar residue levels. Measurable DMTP concentrations were found in 9% of reference workers, ranging from 0.04-0.18 microgram/mL. Cholinesterase activity levels monitored with a field test kit were not considered reliable due to temperature changes of the instrument.

Women's sense of well-being before and after hysterectomy.

OBJECTIVE: To describe women's perceived sense of well-being before and after hysterectomy by examining a broad array of outcomes experienced by women undergoing hysterectomies for benign conditions. DESIGN: Prospective, descriptive. SETTING: A regional tertiary care facility in central Texas. PARTICIPANTS: One hundred seventy-eight women presenting for hysterectomies for nononcologic reasons who completed all three periods of data collection. MAIN OUTCOME MEASURES: Subjects completed a questionnaire assessing information pertinent to their current gynecologic health and the SF-36 Health Survey before surgery and of 4 and 11 months after surgery. The women also completed the Zung Self-Rating Depression Scale preoperatively and at 4 months postoperatively. Additional demographic and medical information was extracted from the medical record. RESULTS: In the initial period after surgery, the patients experienced an improved health status. In addition, the women reported on improvement in their psychologic well-being, including less depression and improved sexual functioning. Relationships with others also improved after the surgery. CONCLUSIONS: Outcomes for these women undergoing hysterectomy for nononcologic reasons were generally positive. This information is vital for preoperative counseling by nurses of women contemplating or about to undergo this surgery.

Biological monitoring of organophosphorus pesticide exposure among children of agricultural workers in central Washington State.

Children up to 6 years of age who lived with pesticide applicators were monitored for increased risk of pesticide exposure: 48 pesticide applicator and 14 reference families were recruited from an agricultural region of Washington State in June 1995. A total of 160 spot urine samples were collected from 88 children, including repeated measures 3-7 days apart. Samples were assayed by gas chromatography flame photometric detector for dimethylphosphate metabolites. Dimethylthiophosphate (DMTP) was the dominant metabolite. DMTP levels were significantly higher in applicator children than in reference children (p = 0.015), with median concentrations of 0.021 and 0.005 microg/ml, respectively; maximum concentrations were 0.44 and 0.10 microg/ml, respectively. Percentages of detectable samples were 47% for applicator children and 27% for reference children. A marginally significant trend of increasing concentration was observed with decreasing age among applicator children (p = 0.060), and younger children within these families had significantly higher concentrations when compared to their older siblings (p = 0.040). Applicator children living less than 200 feet from an orchard were associated with higher frequency of detectable DMTP levels than nonproximal applicator children (p =0.036). These results indicate that applicator children experienced higher organophosphorus pesticide exposures than did reference children in the same community and that proximity to spraying is an important contributor to such exposures. Trends related to age suggest that child activity is an important variable for exposure. It is unlikely that any of the observed exposures posed a hazard of acute intoxication. This study points to the need for a more detailed understanding of pesticide exposure pathways for children of agricultural workers.

Quantitation of o-, m- and p-cresol and deuterated analogs in human urine by gas chromatography with electron capture detection.

A gas chromatographic method for the analysis of cresol metabolites of toluene and [2H8]toluene in urine was developed. Cresol glucuronides and sulfates in urine were hydrolyzed with beta-glucuronidase and arylsulfatase. Following extraction with tert.-butyl methyl ether and solvent exchange into benzene, the cresols were derivatized with heptafluorobutyric anhydride to form the heptafluorobutyrate esters. The derivatives were analyzed by gas chromatography with electron capture detection. Chromatographic resolution was achieved between all cresol isomers and their 2H7 analogs. Calibration ranged from 0.001 to 500 microg/ml. Recoveries were 55-97% and showed no trend with respect to analyte concentration. Within-day precision of analyses of benchmark urine samples had a coefficient of variation of less than 4%. The assay sensitivity was limited by chromatographic background but was sufficient for quantification of the unlabeled cresols in urine from men with only environmental exposure to toluene. Average levels in urine samples from 45 men were 0.023, 0.054 and 37 microg/ml for o-, m- and p-cresol, respectively.

Usefulness of red cell zinc protoporphyrin concentration in the investigation of microcytosis in children.

The clinical usefulness of the measurement of red cell zinc protoporphyrin (ZPP), an indicator of iron-deficient erythropoiesis, was assessed in a group of UK children undergoing investigation for red cell microcytosis. Of 213 children studied, 136 had increased ZPP values. Of these, 86 also had reduced iron stores as indicated by serum ferritin concentration. The 50 children with increased ZPP and normal ferritin values could be divided into two main groups. One group comprised 28 children who had evidence of coexistent infection or inflammatory disease. The other included 21 children who had beta-thalassemia trait (n = 19) or disease (n = 2). Among the 77 children with normal ZPP values, 22 had reduced serum ferritin concentrations and 45 did not, nor did they have evidence of beta-thalassemia. Microcytosis in some of these children could have been due to alpha-thalassemia trait. Measurement of ZPP is a simple, quick, and relatively cheap method of confirming the presence of iron-deficient erythropoiesis even when inflammation makes serum ferritin measurements unreliable. It is not as sensitive as the ferritin assay to the early stages of iron deficiency, and its specificity is reduced by the occurrence of raised values in most children with beta-thalassemia trait. Where there is microcytosis, normal values, together with normal hemoglobin A2 and serum ferritin concentrations, are likely to indicate alpha-thalassemia trait.

Protection and radiography of heat affected teeth.

The authors propose a protocol for the stabilisation and protection of the fragile human skull (following very hot fires where there is breakdown of teeth and bone). Also discussed is a method for carrying out dental radiology on heat affected bone and teeth.

Effect of storage on blood count variables in small samples.

The effects on haematological variables of mail transport, and storage at room temperature and 4 degrees C over a period of 72 h, were observed on 186 'micro' samples of venous and skin puncture blood. White cell, red cell, haemoglobin, MCH and platelet values were sufficiently stable for clinical purposes, but haematocrit, MCV and MCHC values were unstable in samples stored at room temperature. These findings indicate that for the most important haematological variables stored or mailed 'micro' samples are neither more nor less reliable than larger volumes of venous blood, despite the potential for evaporation and over-anticoagulation with small samples.

Factor VIII inhibitor assay using skin puncture blood samples.

A method was developed for the measurement of factor VIII inhibitors by the Bethesda technique using small volumes of skin puncture blood. Human and porcine inhibitor concentrations on paired venous and skin puncture samples measured on 10 occasions were highly correlated, with no significant difference between them. Assays on four inhibitor negative haemophiliac patients were also negative by the skin puncture method. Sample dilution at the collection stage results in loss of sensitivity to inhibitor concentrations below 1 unit/ml, but the technique will be of value in monitoring higher concentrations when venous access is difficult and must be saved for parenteral treatment.

Percutaneous transluminal coronary angioplasty after non-Q-wave infarction.

Non-Q-wave infarction is associated with a significant incidence of infarction and death. We followed 52 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) within three months of non-Q-wave myocardial infarction. Thirty-eight patients had single-vessel disease, 12 had double-vessel disease, and two had triple-vessel disease. At follow-up at 28 +/- 8 months, all patients were alive. Three suffered a recurrent myocardial infarction during the follow-up period. Nine underwent repeat angioplasty. Four patients had bypass surgery for recurrent symptoms. Only 25% of the patients had angina at follow-up, and all but two were in an improved functional class. PTCA may be used safely in the management of patients after non-Q-wave infarction and results in a favorable long-term prognosis.

Identification of a novel dihydroxy metabolite of aflatoxin B1 produced in vitro and in vivo in rats and mice.

HPLC analysis of bile obtained from rats given aflatoxin B1 (AFB) demonstrates the presence of numerous polar metabolites. The glutathione conjugate derived from AFB 8,9-epoxide and the glucuronide conjugate of aflatoxin P1 (AFP) have previously been identified as the two major polar metabolites. The most polar peak present in bile from AFB-treated rats is converted to a less polar peak upon incubation with beta-glucuronidase, which has a parent ion m/e of 314 amu. Treatment of this aglycon with diazomethane produced a product which cochromatographs with aflatoxin M1 (AFM). From these data it is concluded that the most polar peak in bile from AFB-treated rats is the glucuronide conjugate of 4,9a-dihydroxyaflatoxin B1. This dihydroxy AFB metabolite was produced in vitro in mouse microsomal incubations, and time-course studies of its production suggest that it is largely formed by 9a-hydroxylation of AFP, although some may be formed by 4-O-demethylation of AFM. Direct incubation of AFP and AFM with mouse microsomes confirmed that this metabolite can be formed from both AFP and AFM. An HPLC method is described which is capable of base line resolution of this novel dihydroxyaflatoxin metabolite and eight other hydroxylated metabolites of AFB, as well as the glutathione conjugate of AFB 8,9-epoxide.

Venous and skin puncture blood counts compared.

Venous and skin puncture blood counts were compared in 80 paired samples from 33 children, aged 6 months to 14 years, and 10 adults. Significantly higher mean values for Hb, RBC, haematocrit and neutrophils were found in skin puncture blood in children whereas platelet values were slightly higher in venous blood. Similar results were found in adult samples. Only occasionally were differences likely to be of clinical importance. The excellent comparability of paired platelet counts, at variance to that found in some previous studies, indicates that skin puncture blood can be used for platelet estimation providing an appropriate counting method is used.