Forrester Cockburn

Neurological Aspects of Perinatal Asphyxia

Neurological findings in the newborn period are presented from a series of 94 infants who were selected from 760 asphyxiated newborn infants on the basis of seven criteria—feeding difficulties, apnoeic and cyanotic attacks, apathy, convulsions, hypothermia, persistent vomiting and a high‐pitched cerebral cry. These criteria were prognostic for subsequent handicap.

Prevalence of maternal HIV infection in Scotland based on unlinked anonymous testing of newborn babies

Dried blood spot samples from newborn babies have been successfully tested for HIV-1 antibody by the particle agglutination method to assess the prevalence of infection in the mothers. In January, 1990, unlinked anonymous testing of Guthrie cards for HIV antibody was begun in Scotland. 99.6% of Scottish births were tested. 9 mothers spontaneously refused to allow testing of their babys blood. Samples were coded by district postcodes. Eluates of 65,773 dried blood spots were initially tested for HIV-1 antibody with the Fujirebio technique. Of the 31 positive samples 19 were confirmed to be positive by enzyme-linked radioimmunoassay and western blot (seroprevalence 0.29 per 1000). All these samples came from large metropolitan areas on the east coast. Prevalences were 2.5 per 1000 for Edinburgh city, 1.4 per 1000 for Dundee, and 0.7 per 1000 for Aberdeen. We identified as HIV-positive all babies known to be so in named testing programmes. HIV testing of Guthrie cards can be used to monitor HIV status in mothers who have just given birth. The use of district postcode data in sample identification will allow accurate targetting of prevention strategies and early detection of spread of infection by geographic area.

CLINICAL AND CHEMICAL CORRELATES IN CONVULSIONS OF THE NEWBORN

Abstract 142 consecutive infants with neonatal convulsions were examined neurologically and biochemically, and were re-examined at four months and one year of age. Certain neurological and behavioural signs were a more effective way of differentiating brain-damage-associated from metabolic convulsions than was blood biochemistry. The convulsions in 62 infants were considered to have resulted from brain damage and in 80 from primary metabolic disturbance. Convulsions due to brain damage tended to occur in the first three days of life or after the eighth day, and convulsions due to metabolic disturbance between the fifth and eighth days. Taking all convulsions, the outcome was worse when a convulsion occurred in the first three days or after the eighth day. Certain clinical features occurring in association with a convulsion carried an adverse prognosis, others indicated a benign prognosis. Hypocalcaemia and hyperphosphataemia were common in both brain-damage-associated and metabolic convulsions, and hypomagnesaemia was common in metabolic convulsions. Hypoglycaemia occurred in about a third of convulsions due to brain damage and in a sixth of metabolic convulsions. Hyponatraemia and hypernatraemia could also occur in both types of convulsion.

Age- and Dietary-Related Distributions of Hepatic Arachidonic and Docosahexaenoic Acid in Early Infancy

ABSTRACT: A dietary-related deficiency of docosahexaenoic acid [C22:6(n-3)] in infant cerebral cortex has been identified. Absence or very low rates of hepatic synthesis from the essential fatty acid precursor, α-linolenic acid [C18:3(n-3)], in early life may have been a contributory factor. We have analyzed liver total lipid fatty acid compositions in 27 term (37–42 wk gestation) and 4 preterm (30–33 wk gestation) infants who died within the first 6 mo of life from sudden infant death syndrome. The infants were fed exclusively either human or formula milks. Formula-fed infants were subdivided into two groups, one receiving SMA milk with an α-linolenic acid content at 1.5% of total fatty acids and the other a composite group fed milks with low α-linolenic acid concentrations (<0.1% to 0.4%). The hepatic content of arachidonic acid [C20:4(n-6)] and docosahexaenoic acid was generally lower in both formula-fed groups than in the human milk-fed group. The age-related distributions of docosahexaenoic acid showed that coincident minimum levels were present in both formula groups in the third month of life. This may indicate that the hepatic enzymes involved in the final stage (A4-desaturation) conversion of α-linolenic acid to docosahexaenoic acid could be inactive in the first months of life. Emphasis must be on provision of preformed dietary docosahexaenoic acid and possibly arachidonic acid as well as their essential fatty acid precursors, to both term and preterm infants for at least the first 16 wk of life.

A randomized trial of long-chain polyunsaturated fatty acid supplementation in infants with phenylketonuria

Forty‐two infants (20 males, 22 females) with classical phenylketonuria (PKU) entered a prospective, double‐blind, randomized study to investigate the effects on biochemical and physiological outcomes of a phenylalanine‐free infant formula containing a fat blend supplemented with the long‐chain polyunsaturated fatty acids (LC‐PUFA), docosahexaenoic acid (DHA, C22:6n‐3), and arachidonic acid (AA, C20:4n‐6). Between entry and 20 weeks (entry and 1y) of age, median DHA levels in erythrocyte membrane phospholipids decreased by 15% (22%) in the LC‐PUFA supplemented group (n=21) and by 61% (64%) in the control group (p<0.001; n=18). A dietary supply of LC‐PUFA in infants with PKU prevents the decline in DHA levels associated with a diet supplying minimal sources of LC‐PUFA. DHA status in turn, independent of diet, may influence the maturation of the visual system in infants with PKU.

HYALINE-MEMBRANE DISEASE, ALKALINE BUFFER TREATMENT, AND CEREBRAL INTRAVENTRICULAR HÆMORRHAGE

Abstract In 55 preterm infants dying from hyaline-membrane disease (H.M.D.) in 1971-74, infants with associated cerebral intraventricular haemorrhage (H.M.D./I.V.H.) had been given more intravascular sodium-bicarbonate solution, but the same proportions of cases with H.M.D. and H.M.D./I.V.H. received bicarbonate at the time of birth. Much of the sodium-bicarbonate solution given to H.M.D./I.V.H. infants was injected in response to the clinical effects of I.V.H. Maximum serum-sodium concentrations correlated with sodium-bicarbonate dosage but not I.V.H. The incidence of I.V.H. in preterm infants in 1971-74 was unchanged from 1956-59 when alkaline buffer treatment was not used. These findings do not suggest that sodium-bicarbonate therapy plays a major part in the pathogenesis of I.V.H.

On the Rôle of Disseminated Intravascular Coagulation in the Pathology of Birth Asphyxia

A necropsy study of eight newborn infants who had developed consumption coagulopathy following severe asphyxia at birth revealed fibrin thrombi in five cases. These thrombi were not randomly distributed but were mainly found in veins and capillaries close to areas of tissue necrosis. Occlusive arterial thrombosis was not seen. Fibrin thrombi were found in the brain in only one infant, although severe anoxic‐ischaemic nerve‐cell change was present in the central nervous system in all cases. These observations suggest that fibrin thrombus formation and consumption coagulopathy in infants asphyxiated at birth are secondary to tissue damage in organs which are susceptible to ischaemia during circulatory disorders.

An audit of infants ‘unscreened’ by the neonatal screening system in Scotland during 1991

Abstract Introduction: The aim of this study was to assess the number of infants born in Scotland from whom a newborn screening specimen did not arrive at the screening laboratory. Methods: In a systematic 1 in 8 sample, records on 8379 babies registered as born during 1991, were supplied by the Office of the Registrar General (Scotland). These were matched with records from the neonatal screening laboratory database. For all unmatched records, local health board offices were phoned for evidence of a negative result. Results: Specimens from 8324 of these babies were received and tested by the screening laboratory. Of the remaining 55 babies, 34 had died within 24 h of birth, five had returned home (three to England and Wales and two to outside the United Kingdom), four refused for parental objection (three were Jehovahs Witnesses), and 12 were unscreened. Thus, only 0.14% (12 of 8379 of registered infants (95% Confidence Interval 0.22, 0.06)) were unscreened by the Inborn Errors Screening Program in Scotland during 1991. Discussion: From this study, an estimated 96 infants were unscreened for newborn screening (95% Confidence Interval 39, 143) of 67032 infants registered as born in Scotland during 1991. At this rate, a case of congenital hypothyroidism or phenylketonuria would be missed only every 47 and 78 years, respectively, as a result of having been unscreened by the program. Improvement is expected from regular audit now underway. The rate of 0.14% for Scotland is much lower than the rate of 0.82% estimated for unscreened infants in the New York State Newborn Screening Program.

Direct gas chromatographic assay of urinary medium-chain fatty acylcarnitines by their thermal decomposition

We report a gas chromatographic assay for urinary medium-chain acylcarnitines which employs their property of thermal lability, and by circumventing the need for specialised mass spectroscopy is suitable for routine laboratory use. The method produces readily interpreted, uncomplicated chromatograms and has proved to be both sufficiently sensitive and specific to enable detection of octanoylcarnitine in a symptomatic individual with medium-chain CoA dehydrogenase deficiency and in two asymptomatic siblings following administration of a carnitine load.

Artificial ultraviolet whole-body radiation does not modify serum lipoprotein, plasma fibrinogen, plasminogen or antithrombin III concentrations in post-myocardial infarction patients.

The relationship of ischaemic heart disease (IHD) to seasonal and latitude variation has prompted speculation that exposure to the ultraviolet component of solar radiation may reduce IHD risk. This hypothesis was partially tested by exposing 14 post-myocardial infarction patients to a 6 week course of artificial whole-body ultraviolet radiation (UVR). Serum lipoprotein and plasma coagulation factor concentrations were measured before and after the course of UVR. Results were compared with similar measurements from a placebo-controlled group of 13 post-myocardial patients. Despite a more than two-fold rise in mean serum 25-OHD, serum lipoprotein and plasma fibrinogen, antithrombin III and plasminogen concentrations did not change significantly in the UVR group. Significant but minor change in prothrombin time and thrombin time in the placebo group appear unlikely to be of biological significance. Seasonal and latitude variation in these IHD risk factors appear unrelated to corresponding variation in solar UVR exposure.