Biomedical subjects
Publications and source records attributed to T J David.
Two sibs who both had anencephaly and diaphragmatic hernia are reported. The type of diaphragmatic defect seen in anencephaly may differ from the defect seen in other babies. It is important to perform a necropsy in anencephaly.
Three cases of herpes zoster occurring in infancy are reported. In each case the mother had chickenpox in pregnancy.
Ten cases of absence of the d triradius are reported from a heterogeneous collection of dermatoglyphs from 3610 subjects. There was one case in 1000 normal' controls. There were three cases in a group of 800 subjects with congenital heart disease. There were two cases with the 49, XXXXY constitution, a previously noted association. A pair of probably monozygous twins were discordant for absence of the d triradius. The condition was left-sided in six cases, right-sided in one case, and affected both sides in three cases.
Finger and palm print patterns (dermatoglyphs) are formed in very early pregnancy, at about the same time the limbs are developing, and their formation probably depends upon the surface contours of the palms and soles during morphogenesis. Dermatoglyphs are useful in skeletal dysplasias for the detection and study of syndactyly and symphalangism, for dating the onset and the dysplasias, for demonstrating and dating asymmetry, and sometimes for providing specific diagnostic features.
Scalp hair patterns have been examined in 1901 healthy subjects and 1789 severely subnormal patients. Patients with Down's syndrome had a highly significant excess of midline occipital whorls and a deficit of right-sided occipital whorls. Five out of 44 patients with microcephaly had a distinct 'up-sweep' of the frontal hair, a much lower proportion than found previously. Patients with unspecified mental subnormality had a highly significant deficit of multiple occipital whorls. Cutis verticis gyrata was noted incidentally in 15 subnormal patients, 13 of whom were males. Observation of hair patterns in individual patients with mental subnormality is of theoretical interest but is unlikely to be of great practical value.
A retrospective anatomical, family, and epidemiological study was made of 143 patients (81 female and 62 male) with diaphragmatic hernia who were born in the south-west of England between 1943 and 1974. Thirty-nine cases were stillborn. Seventy-five per cent of patients had a left-sided diaphragmatic defect, 22% had a right-sided defect, and 3% had a bilateral defect. Fifty per cent of the patients had other congenital malformations, most frequently of the nervous system. No maternal age or birth order effect was noted. Cases of diaphragmatic hernia without other malformations had in general a normal fetal growth rate. Eight per cent of the cases were illegitimate. There were two pairs of twins discordant for diaphragmatic hernia, one pair being dizygotic and the other monozygotic. In no case of diaphragmatic hernia was there a relative affected with a diaphragmatic hernia. The most common type of diaphragmatic defect was a posterolateral hernia (92%), followed in frequency by an eventration of the diaphragm (5%), the least common defect being a retrocostosternal hernia (2%). Diaphragmatic hernia appears to be aetiologically as well as anatomically heterogeneous. In this series there were two cases of trisomy 18, one case of trisomy 21, one case trisomic for a small part of chromosome 20, and two cases with the Pierre Robin syndrome. It seems likely that diaphragmatic hernia is a non-specific consequence of several teratological processes.
The necropsy reports of 294 cases of anencephaly and 50 cases of iniencephaly have been examined, and a tubulated list of associated malformations produced. Cases were divided by sex and the presence or absence of spina bifida. Forty-one per cent of the series had other malformations, and other malformations were more common in those cases with spina bifida than in those without. The most frequent single malformations were: hydronephrosis (8%), cleft palate (8%), diaphragmatic hernia (5%), exomphalos (5%), hare lip (4%), and horseshoe kidney (4%). It is suggested that the presence of other malformations in anencephaly or iniencephaly may imply some aetiological heterogeneity.
Explore the source record for details and available documents.
A retrospective anatomical and family study was made of 345 patients with oesophageal atresia who were born in the South West of England between 1942 and 1973. There were 186 males and 159 females. Twenty-one cases were stillborn. Eighty-five percent of the patients had a combination of oesophageal atresia with a tracheo-oesophageal fistula to the distal oesophageal segment, and 9 percent had atresia without a fistula. Fifty-five per cent of the patients had other congenital malformations and these tended to be multiple rather than single. Thirty-six per cent of singletons had unequivocal fetal growth retardation, and there is some evidence that nearly all cases have poor fetal growth. There appeared to be a maternal age effect, with an excess of mothers under 20 and over 35, and there was an unexplained excess of fathers employed in the Armed Forces. Ten per cent of the cases were illegitimate. There were 21 twins which is nearly three times the expected number; there were two pairs of twins concordant for oesophageal atresia, one being monozygotic and the other dizygotic. In one case there were two sibs with oesophageal atresia. Five out of 365 sibs had anencephaly. The blood group distributions of the patients and their mothers did not significantly differ from the expected distribution. Oesophageal atresia is aetiologically heterogenous. In this series there were at least five, and probably 10 cases of trisomy 18 and four cases of trisomy 21. Five mothers had overt diabetes, and there is some suggestion from other work that maternal diabetes or its treatment may be aetiologically important. Oesophageal atresia was part of a possibly recessively inherited malformation syndrome in two cases. A sibship with a case of rectal atresia, a case of Hirschprung's disease and a case of oesophageal atresia may represent the action of another recessive gene. It seems likely that oesophageal atresia is a rather non-specific consequence of several teratological processes.
Thirteen of 141 cases (9 percent) of overt, biopsy proven coeliac disease had a definitely affected relative. The pattern of inheritance in these families is compatible with an incompletely penetrant autosomal dominant gene. There was a female preponderance in the adults and the sporadic cases, but not in the children or the familial cases. The series included a pair of concordant and probably monozygotic twins. The authors believe that coeliac disease, as defined at present, is a heterogeneous condition.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Samples of soil collected from the Kennedy Space Center near the spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilzation techniques. The inactivation kinetics of the naturally occurring spores in soil were investigated by using dry heat and ionizing radiation, first separately and then simultaneously. Dry-heat inactivation kinetics of spores was determined at 105 and 125 C; radiation inactivation kinetics was determined for dose rates of 660 and 76 krads/h at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C, with a dose rate of 76 krads/h. Combined treatment was found to be highly synergistic, requiring greatly reduced radiation doses to accomplish sterilization of the population.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.