Cadmium, copper, iron, and zinc concentrations in kidneys of grey wolves, Canis lupus, from Alaska, Idaho, Montana (USA) and the Northwest Territories (Canada).

Cadmium, copper, iron, and zinc levels were measured in the kidneys of 115 grey wolves (Canis lupus) from Idaho, Montana and Alaska (United States), and from the Northwest Territories (Canada). No significant differences in the levels of iron or copper were observed between locations, but wolf kidneys from more northern locations had significantly higher cadmium levels (Alaska > Northwest Territories > Montana ≈ Idaho), and wolves from Alaska showed significantly higher zinc than other locations. Additionally, female wolves in Alaska had higher iron levels than males, and adult wolves in Montana had higher copper levels than subadults.

Microcephaly: genetic counselling and antenatal diagnosis after the birth of an affected child.

We describe the clinical and genetic details of a series of microcephalic patients who were referred to the Genetic Counselling Service for the West of Scotland. There were 29 isolated cases of microcephaly and 9 families with recurrent microcephaly. The sib recurrence risk was 19%, which reflects the high incidence of autosomal recessive microcephaly in this series. There was evidence for several varieties of recessive microcephaly. The most frequent, affecting 5 sib pairs, was associated with spastic quadriplegia, seizures, and profound mental handicap. In 15 families with one microcephalic child, prenatal diagnosis by serial ultrasound scans was undertaken in 21 subsequent pregnancies. Four recurrences of microcephaly were detected in the third trimester and one recurrence was missed because no scans were performed after 24 wk gestation when the ultrasound measurements indicated satisfactory head growth. The main reason for late diagnosis of affected fetuses was that head growth did not slow appreciably until the last trimester. The high recurrence risk in this prospective series emphasizes the contribution of autosomal recessive inheritance of microcephaly amongst patients of our Genetic Counselling Service.

Lethal neonatal chondrodysplasias in the West of Scotland 1970-1983 with a description of a thanatophoric, dysplasialike, autosomal recessive disorder, Glasgow variant.

Complete ascertainment of lethal neonatal short-limb chondrodysplasias was attempted in the West of Scotland for the period 1970-1983. Forty-three cases were identified, representing a minimum incidence of 1 in 8,900. The differential diagnosis included 11 well-delineated skeletal dysplasias, one case of warfarin embryopathy, and one apparently new condition with presumed autosomal recessive inheritance that has radiographic similarities to those of thanatophoric dysplasia (TD). In this series TD had an incidence of 1 in 42,221, which is consistent with new dominant mutation at a rate of 11.8 +/- 4.1 X 10(-6) mutations per gene per generation. Ultrasonic measurement of fetal long bone length was performed in eight subsequent pregnancies at risk. Five unaffected fetuses were predicted correctly and three affected fetuses were detected during the second trimester (one with rhizomelic chondrodysplasia punctata-second trimester prenatal diagnosis not previously reported; one with achondrogenesis type II; and one with the new lethal condition).

Ultrasound detection of neural tube defects in patients with elevated maternal serum alpha-fetoprotein.

We conducted this study to determine the accuracy of ultrasound in the prenatal diagnosis of neural tube defects in women with elevated maternal serum alpha-fetoprotein (MSAFP). Among 905 pregnancies, 49 neural tube defects were correctly diagnosed by ultrasound alone; one was not. Ultrasound scanning had 98% sensitivity and 100% specificity for the detection of neural tube defects. The predictive value of a positive ultrasound diagnosis was 100% and of a negative ultrasound 99.9% for neural tube defects. Forty-three other structural abnormalities were also detected in patients with elevated MSAFP, including 19 abdominal wall defects, seven chromosomal abnormalities, five urinary tract abnormalities, one cardiac abnormality, and 11 others. Two chromosomal abnormalities were not detected. We suggest that ultrasound can be used reliably to detect neural tube defects, thereby avoiding the risks of amniocentesis.

Forty years of obstetric ultrasound 1957-1997: from A-scope to three dimensions.

In this article, we record the history of obstetric ultrasound as it developed worldwide in the second half of the twentieth century. The technological advances during this period saw the evolution of equipment from the original adapted metal flaw detectors producing a simple A-scan to the modern, purpose built, real-time colour flow machines with three-dimensional capability (Fig. 1). Clinically, ultrasound began as a research tool, but the poor quality of the images led to the ridicule of many of the early investigators. However, because of their perseverance, ultrasound developed into an imaging modality providing immense diagnostic capabilities and facilitating with precision many invasive procedures, diagnostic and therapeutic, both of which have made significant contributions to patient care. In this history, we recall the people, the personalities, and the problems they encountered during the development of ultrasound and how these problems were resolved, so that ultrasound now is available for use in the care of pregnant women throughout the developed world.

Trichinella sp. in wolves from interior Alaska.

Tongue samples were collected from 148 wolf (Canis lupus) carcasses during 1993 and 1994 near Fairbanks (Alaska, USA). A standard peptic digestion procedure was used to detect Trichinella sp. larvae. Larvae were found in 54 of 148 (36%) samples. There was no significant difference in sex-specific prevalence. Prevalence was significantly related to age. There was no relationship between the number of larvae/g of host tissue and the age or sex of the host. Trichinella spp. infection may cause illness in individual wolves. However, there was no indication the parasite had any impact on the population.

Serologic survey for Toxoplasma gondii in lynx from interior Alaska.

Two hundred fifty-five lynx (Felis lynx) carcasses were collected from trappers in Interior Alaska (USA). Serosanguinous fluids were collected from the chest cavity of each carcass. These fluids were tested for evidence of exposure to Toxoplasma gondii by means of a modified agglutination test using formalin fixed tachyzoites and mercaptoethanol. Thirty-nine of the samples had titers greater than or equal to the threshold (> or = 25). Antibody prevalence differed between areas, and was directly related to age of the host.

Serologic survey for canine coronavirus in wolves from Alaska.

Wolves (Canis lupus) were captured in three areas of Interior Alaska (USA). Four hundred twenty-five sera were tested for evidence of exposure to canine coronavirus by means of an indirect fluorescent antibody procedure. Serum antibody prevalence averaged 70% (167/240) during the spring collection period and 25% (46/185) during the autumn collection period. Prevalence was 0% (0/42) in the autumn pup cohort (age 4-5 mo), and 60% (58/97) in the spring pup cohort (age 9-10 mo). Prevalence was lowest in the Eastern Interior study area. A statistical model indicates that prevalence increased slightly each year in all three study areas. These results indicate that transmission occurs primarily during the winter months, antibody decay is quite rapid, and reexposure during the summer is rare.

Value of antenatal diagnosis of abnormalities of the urinary tract.

OBJECTIVE: To assess the value of antenatal diagnosis of abnormalities of the urinary tract on ultrasonography. DESIGN: Retrospective study. SETTING: Two obstetric units in Glasgow. SUBJECTS: 62 Fetuses in which renal abnormalities were diagnosed on antenatal ultrasonography. INTERVENTIONS: Six fetuses had their bladders aspirated to determine renal function. Fifteen pregnancies were terminated on the basis of the findings on antenatal ultrasonography, and if possible necropsy was performed on the fetuses. In babies who were born alive the final diagnosis was made by postnatal ultrasonography, intravenous urography, radionuclide scanning, cystography, and, in those who died in the early neonatal period, necropsy. Neonates who were referred with a known obstructed kidney had nephrostomy or pyeloplasty. END POINT: Assessment of the value of antenatal diagnosis of renal abnormalities on ultrasonography for babies who had no clinical evidence of disease postnatally. MAIN RESULTS: Eighteen fetuses did not survive birth; the antenatal diagnosis was accurate in all 18. Of the 44 babies born alive, five had normal urinary tracts, in two of whom antenatal ultrasonography had probably indicated a false positive diagnosis. Fourteen babies died during the early neonatal period. Twenty five babies with renal abnormalities were followed up; the antenatal diagnosis was inaccurate for 10 of them, the commonest misdiagnosis being hydronephrosis for multicystic kidney and vice versa, and there was one false positive diagnosis. The initial clinical findings in 14 babies would have led to the early detection of a urological abnormality. In the 30 babies with no clinical evidence of disease the antenatal diagnosis was of definite value in eight, probable value in 15, and marginal value in seven. Overall, an accurate antenatal diagnosis was made in 46 of the 62 cases (74%); in 12 cases renal disease was detected but its specific nature was not determined; and in four cases the diagnosis was misleading. CONCLUSIONS: The overall value of antenatal diagnosis is that it indicates early termination of fetuses with fatal renal disease, prepares parents and medical staff for the likelihood of serious neonatal problems, and shows abnormalities of the urinary tract that may not be detected postnatally.

Diagnostic ultrasonography.

The use of diagnostic ultrasound has contributed to the evaluation of the fetal condition in two ways--the detection of fetal abnormality and the assessment of fetal growth and development. Routine early pregnancy scanning enables most major structural anomalies to be detected and provides accurate gestational dating. Maternal serum alphafetoprotein screening complements ultrasound in identifying abnormalities, and may also be an indicator of a growth problem in later pregnancy. In high-risk pregnancies, or when growth retardation or acceleration is suspected, abnormalities should always be considered and investigations should include karyotyping. Fetal growth may be assessed by multiple parameters, including measurement of fetal head, trunk, limbs, and amniotic fluid volume, in addition to grading of the placenta. Fetal responses to stimulation can be visualized and quantified. No single parameter may be used alone to predict fetal outcome, but by using this multiple-parameter approach, contributing to a biophysical profile of the fetus, the outcome of pregnancy may be predicted with greater accuracy.

The safety of diagnostic ultrasound.

Although there has been no conclusive evidence to suggest that ultrasound is dangerous in pregnancy, precautions would seem sensible. Doctors should minimize patient exposure time but a gesture by the machine manufacturers to incorporate the reduction of acoustic output into their design requirements would be admirable.

Prenatal diagnosis. Amniocentesis.

Is amniocentesis safe? Does it still have a place in prenatal diagnosis? These questions continue to be asked, but it remains the cornerstone of diagnosis while other methods are being evaluated.

Obstetric aspects of prenatal diagnostic methods.

The vast improvements in ultrasound technology have proved to be an important starting point for invasive investigative procedures in obstetrics. These methods not only allow a more precise diagnosis to be made but also offer considerable scope for in utero therapy.

Ferritin as an assessment of iron stores in normal pregnancy.

In Glasgow, the iron stores in healthy women and in normal pregnant women on prophylactic iron supplementation have been assessed by measurement of plasma ferritin. Ferritin concentration fell progressively to a low level in late pregnancy suggesting that the average iron store was inadequate to meet the demands of pregnancy and that dietary iron supplements were therefore required. There was no evidence that iron supplementation led to excessive iron stores.

Gastroschisis and exomphalos: precise diagnosis by midpregnancy ultrasound.

As part of a regional screening programme for neural-tube defects the cause of the raised alpha-fetoprotein levels was correctly identified in 13 pregnancies with a fetal abdominal wall defect by the 22nd week. Careful ultrasound study identified gastroschisis in seven fetuses and exomphalos in six: the presence or absence of a sac, the course of the umbilical vessels and the abdominal organs involved were the most important diagnostic criteria. Pregnancy continued into the third trimester in five cases complicated solely by gastroschisis and two babies have survived the neonatal period following surgical correction. It is suggested that precise identification by ultrasound of the type and severity of abdominal wall defect and also of the presence or absence of associated anomalies will enable the selection of some babies with gastroschisis or isolated exomphalos which have a good prognosis for survival without handicap.

Renal tubular function in normal pregnancy.

Maternal plasma and urine concentrations of beta2- microglobulin and gamma-glutamyl transpeptidase (EC:2.3.2.2) were measured serially in normal pregnancy. These parameters remained constant throughout and can therefore be used to evaluate tubular function in pregnancies complicated by renal disorders.

The relation between fetal abdominal circumference and birthweight: findings in 3512 pregnancies.

OBJECTIVES: To establish the relation between fetal abdominal circumference and birthweight in a large population of fetuses; to identify whether the error in estimating birthweight by abdominal circumference varied with the magnitude of abdominal circumference; and to establish whether adding femur length to abdominal circumference caused a clinically important reduction of error in predicting birthweight. DESIGN: A retrospective study. SETTING: The ultrasound department of a teaching maternity hospital offering a tertiary referral service. SAMPLE: From 3512 nondiabetic women with a normally formed singleton fetus, an abdominal circumference measurement of the infant was made within seven days of delivery; of these, 1213 had a femur length measurement performed at the same time. RESULTS: There was a linear relation between abdominal circumference and birthweight. There was a strong inverse correlation between the proportional error in predicting birthweight from the abdominal circumference and the magnitude of the abdominal circumference. Both the Campbell and Wilkin equation (abdominal circumference alone) and the Hadlock equation (abdominal circumference and femur length) were associated with systematic errors, especially with larger birthweight infants. The median absolute errors for the two equations were not significantly different overall (6.98% and 6.86% respectively), although the Hadlock equation was significantly more accurate in predicting birthweight in infants weighing greater than 4500 g. However, no threshold value of abdominal circumference or of estimated fetal weight using the Hadlock equation had a positive predictive value in estimating infants of > 4500 g of greater than 35%. CONCLUSIONS: Prediction of birthweight should be by abdominal circumference alone. Table 1 presents robust estimates of the error of predicting birthweight using fetal abdominal circumference.

Perinatal deaths: analysis by clinical cause to assess value of induction of labour.

Over the 10 years 1966-75 the rate of induction of labour in the Glasgow Royal Maternity Hospital has increased from 16-3% of all births. During the same period perinatal mortality fell from 33 to 22 per 1000, mainly because of significantly fewer deaths due to antepartum haemorrhage; trauma; maternal diseases; and unknown causes in mature babies. The reduction in the number of deaths of unknown causes in mature fetuses was achieved by preventing deaths occurring after 40 weeks and was recorded in all age and parity groups. The results suggested that increased use of induction of labour has contributed to the improved perinatal mortality rate.