Theodore H. Ingalls

Experimental production of congenital anomalies; timing and degree of anoxia as factors causing fetal deaths and congenital anomalies in the mouse.

THE purpose of this communication is to sketch the status of acquired congenital anomalies of the mouse against a background of experimental embryology; to report progress in the induction of such ...

Preventive medicine and epidemiology.

Weanling diarrhea i.e. diarrhea that comes on when infants are transferred from a wholly breast-fed to a mixed breast bottle and supplementary food diet is no longer a major health problem in the advanced nations. It remains a major cause of infant morbidity and mortality in developing countries. Incidence statistics for the U.S. and for various regions of the world are cited. The infectious agents contributing to the etiology of the disease are described. In addition to infectious agents foods and medicines can trigger the disease. Evidence from field studies in the Punjab region of India is cited to show that the diarrheas and dysenteries common in early childhood are associated with weaning. They occur at the time of weaning because: 1) the introduction of foods other than breast milk increases the possibility of exposure to potential pathogens; 2) weaning is associated with a period of nutritional deficiency which can make the child more susceptible to infection; and 3) the diarrheas resultant from contaminated food in themselves lower the childs resistance to infections. Therefore it is seen that weanling diarrhea must be considered in both nutritional and infectional terms.

Incidence of Anencephalus, Spina Bifida, and Hydrocephalus Related to Birth Rank and Maternal Age

Association of characteristics of the offspring with birth order or with maternal age is provisional evidence of the operation of environmental influences in causation; in addition, such data may provide clues for the elucidation of the more specific environments involved. The weight of previously published evidence relating congenital malformations of the central nervous system to birth rank and maternal age suggests that both variables influence the occurrence of these anomalies. Penrose (1946), using a modification of the GreenwoodYule method, found an increasing frequency of a group of central nervous malformations (anencephalus, spina bifida, and hydrocephalus) with advancing maternal age. After correction for the effect of maternal age, occurrence was somewhat excessive in the first birth rank and at birth ranks 7 and over. Malpas (1937) analysed the distribution of anencephaly (44 cases among 13,964 deliveries) according to maternal age, and found the defect to occur about ten times more frequently in the age group 46-50 than in the age group 16-20. Book and Rayner (1950) surveyed the protocols of 67 cases of anencephaly without finding any significant relation of the defect to advancing age or birth rank. Schwidde (1952) and Polman (1950) have also reported negative findings. Buchi (1950) identified 2,922 malformed infants among some 160,000 births

Conjoined Twins in Zebra Fish

Eight cases of conjoined twins have been observed to occur among more than 5,000 embryonating zebra fish eggs that had been submitted to elevated water temperature several hours after fertilization. A naturally occurring epidemic of conjoined twins in salmon roe is described, and the principles which may underly the formation of conjoined twins in selected vertebrates and mammals are discussed. It is thought that environmental rather than genetic causes are usually at work in their production.

Chromosomal aneuploidies and polyploidies in embryos of diabetic mice.

Female mice were given a single intravenous injection of alloxan (60 or 80 mg/kg body weight) and caged with normal males when the blood glucose levels rose significantly. The morning when a vaginal plug was found was designated as day 0.5 of pregnancy. Blastocysts were recovered after sacrifice of mothers on day 3.5 of gestation. Cytogenetic examinations of these embryos were made after air-drying of eggs, and the findings were compared with those observed in embryos taken from control groups. A marked decrease in the number of viable embryos recovered from diabetic pregnant mice was observed. Chromosomal analysis revealed a high incidence of polyploidy and aneuploidy in eggs from the diabetic group as compared with those from controls.

Studies on the urinary excretion and blood concentration of ascorbic acid in infantile scurvy

Summary The excretion of ascorbic acid in the urine and its concentration in the plasma have been studied in seven cases of proved scurvy. Absolute depletion of ascorbic acid in the urine and very low values in the plasma were found. Vitamin replenishment was accomplished quickly or over a long period of time, depending primarily on the dose of ascorbic acid employed. In three groups of infants comprising well babies, babies picked at random from the ward, and patients with scurvy, concentrations of ascorbic acid in the plasma were demonstrated generally characteristic of optimal, suboptimal, and deficient intake of vitamin C. The limitations of the method and significance of results are discussed.

Intranasally administered rubella vaccine.

Abstract The RA27/3 strain of rubella virus, which is an effective attenuated strain when given subcutaneously, is also immunogenic when given intranasally. Given in a dose of 1000 plaque-forming units (P.F.U.) in the form of nose drops, the virus produced antibodies in 93% of subjects (mainly children); a dose of 100 P.F.U. immunised 50% of subjects. Clinical reaction was absent except for occasional lymphadenopathy. Nasopharyngeal virus excretion was sporadic, and there was no spread to contacts. Antibody responses to intranasal vaccination were equivalent to those obtained after subcutaneous inoculation.

Hypoxia as a chromosomal mutagen. Triploidy and tetraploidy in the hamster embryo.

Female hamsters breathing hypoxic atmospheres equivalent to 30,000 to 35,000 feat of altitude tor over three hours at three or 21 hours postcoitus were divided into two main groups for chromosomal examination at preimplantation and at organo-genetic stages of development Controls provided a basis for comparison. At preimplantation stages 4 of 166 embryos were found with triploidy and 14 with tetraploidy whereas only one with tetraploidy was found among 133 controls. At organogenetic six mosaics of diploid-tetraploid cells were founds three with 20% to 50% mixtures and three with 5% to 10% mosaicism. Higher concentrations of mosaic cells derived from mothers stressed on the first day of pregnancy; the lower proportions came from mothers treated later. Two triploid fetuses were found in the test group. No polyploid embryos were observed among controls.

Hypoxia at Normal Atmospheric Pressure As a Cause of Congenital Malformations in Mice.

Summary Pregnant mice kept for 2 hours during the 10th day of gestation in a gas chamber containing 6% oxygen in nitrogen at normal atmospheric pressure produced progeny having malformed ribs and vertebrae.

Chromosome Mutations and pH Disturbances

Chromosomal anomalies, namely hypodiploidies, hyperdiploidies, and endoreduplications, developed in nearly 25% of metaphase plates of replicating human lymphocytes exposed in vitro to either acid (6.5 to 6.9) or alkaline (8.4 to 8.8) pH equilibriums. The G group was most susceptible to aneuploid formation. Mammalian mutations may develop as the result of a pH disturbance during cleavage of the fertilized zygote.