The magnetic resonance appearances of the normal thymus in children.

The normal thymus in children is highly variable in size and shape. In some cases this has led to the misdiagnosis of mediastinal pathology and an unnecessary thoracotomy. Twenty-five children without suspicion of mediastinal pathology and five children with suspected mediastinal pathology were imaged using magnetic resonance imaging (MRI). MRI is recommended to distinguish between the normal and abnormal thymus in difficult cases where other imaging techniques are inconclusive.     

Effect of different questionnaire formats on reporting of occupational exposures

During an exposure monitoring study, 78 saw maintenance tradesmen were randomly assigned to be interviewed about their exposures using one of two questionnaire formats: open-ended and partly prompted questions about five categories of materials; and detailed prompting about 75 agents. The more open-ended questionnaire elicited fewer exposure responses overall, but more responses about agents not included on the detailed questionnaire. Composite materials and trade name products were more frequently cited as exposures than individual metals or compounds. Validity of responses was ascertained using air measurements (individual metals) or observations of the employees (composite materials). Sums of sensitivities and specificities were very low (near 1.0) for most of the metals for both types of questionnaire. For composite materials, validity improved substantially. Sensitivities with the partly prompted format (0.44–0.85) were always lower than with detailed prompting (0.80–1.00). Specificities were usually, but not always, higher with partial prompting (0.66–0.92) than with detailed prompting (0.18–0.86). Selection of questionnaire format for an epidemiologic study would depend on the likely prevalence of exposure in controls and the effects of trade-offs in sensitivity and specificity.     

Different subtypes of pseudohypoparathyroidism in the same family with an unusual psychiatric presentation of the index case.

A 13 year old Asian girl presenting with apparent hysterical paralysis and subsequent rapid cycling bipolar mood disorder was found to have biochemical evidence of pseudohypoparathyroidism type II. The mood disorder responded to treatment of the pseudohypoparathyroidism with a vitamin D analogue. Investigation of her parents and siblings showed phenotypes consistent with two distinct types of pseudohypoparathyroidism (type I and type II) in different family members.     

Pulmonary Function in Survivors of Wilms' Tumor

The respiratory status of 47 patients surviving childhood Wilms' tumor was studied. The group that had receivedflnnk irradiation (which impinges on the lower lung) (n - 17) had a sisnijGantly lower mean percent predicted for forced expiratory volume in one second, residual volume, and total lung capaci(v when compared to those who had received no irradiation (n - 23). Those patients who had received whole-lung irradiation (n - 3) had sisnijicantly lower transfn. foctor for carbon monoxide and gas transfer per unit lung volume whm compared to the nonirradiated group (n - 23). There was no sipiftiant dimue in the prevalence of respiratory symptoms between the three groups. Patients receiving any form of radiotherapy for Wilms' tumor may have abnormulities o f pulmonary function and should have pulmonary function tests performed as part o f their long-tmn follow-up.     

Effects of two synthetic parathyroid hormone-related protein fragments on maternofetal transfer of calcium and magnesium and release of cyclic AMP by the in-situ perfused rat placenta.

Two human parathyroid hormone-related protein (hPTHrP) fragments were tested for effects on maternofetal transfer of 45Ca and Mg across the in-situ perfused rat placenta at 21 days of gestation (term = 23 days). The fetal placental circulation was perfused with a Mg-free Krebs-Ringer solution and the unidirectional maternofetal clearance (Kmf) of 45Ca and Mg compared with that of 51Cr-EDTA, the latter being employed as a paracellular diffusional marker. Placental perfusion with hPTHrP(1-34) (100 ng/ml) or hPTHrP(75-86)amide (50 ng/ml) did not significantly alter the Kmf of 45Ca or that of Mg. In separate rats, however, hPTHrP(1-34) but not hPTHrP(75-86)amide stimulated marked placental cyclic AMP (cAMP) release, the peak response of 63 +/- 7 pmol/min occurring 10 min after the beginning of the peptide perfusion. A lower dose of hPTHrP(1-34) (4 ng/ml) produced a similar peak release of cAMP, as did [Nle8,21, Tyr34]-rPTH(1-34)amide (4 ng/ml) and the adenylate cyclase agonist forskolin (17 mumol/l). Forskolin also rapidly increased the Kmf of 45Ca but not that of Mg or 51Cr-EDTA. The present study indicates that hPTHrP does not acutely affect maternofetal transfer of Ca or Mg across the perfused rat placenta. The data also question the role played by cAMP in the stimulatory actions of forskolin on placental Ca transport.     

Histologic analysis of tissue response to bucrylate-pantopaque mixture

A toxicologic-pathologic study of isobutyl-2-cyanoacrylate (Bucrylate) was carried out first in dogs and then in humans whose arteriovenous malformations were infused with this embolic agent. The canine specimens obtained at 7, 18, 28, and 147 days after embolization showed the development of a mild histiocytic giant cell reaction, which evolved to end-state sclerotic arteritis. The response was confined to the vessels and did not involve contiguous parenchymal tissues. Ten human specimens, obtained from 1 hr to 7 years after treatment, showed a similar bland reaction with no evidence of suppuration or premalignant changes.     

Uptake and tissue distribution of mercury in some plant species collected from a contaminated area in India: Its ecological implications

A study was made of the pattern of distribution of mercury in the tissues of some plant species collected around a chlor-alkali factory in India. Different plants accumulated different levels of mercury in their tissues. Accumulation in leaves was the highest, followed by the stem and the root and, in some cases, the root and the stem. A significant correlation was noted between the mercury concentration of the soil and the plant tissues and between different tissues. Grazers (goats, sheep) also accumulated significant levels of mercury in their tissues.     

Social and reproductive characteristics of the first 100 couples treated by in vitro fertilisation programme at National Women's Hospital, Auckland

Reproductive and social histories of the first 100 patients attending the in vitro fertilisation (IVF) programme at National Women's Hospital, Auckland, have been studied. The average age at first treatment was 31.6 (SD 3.9) for women, and 34.2 (4.6) for men. The couples had been married 7.6 (3.3) years and had experienced 6.7 (3.2) years infertility. It was a second marriage for 16. The husbands had on average a higher social classing than the population (class: number [population]--1:16 (7%), 2:18 (14%), 3:42 (28%), 4:19 (29%), 5:4 (14%), 6:1 (8%); but this bias diminished in the next 159 couples. Nine couples withdrew before their quota of cycles, 7 from stress. Tubal disease was the cause of infertility in 93, but in 69 its origin was untraceable. In 22 it could be attributed to pelvic inflammatory disease (eight associated with IUCDs and 2 with sexually transmitted disease) and in two to sterilisation. Although 59 women had a history of having conceived, only 34 were parous, and only 11 had a child of the current union.