An epidemiological and sociological study of unexpected death in infancy in nine areas of southern England. IV. Evaluation of scoring

This paper shows that a modified form of scoring would be useful in identifying infants at risk in these areas. It is predicted that a useful reduction in unexpected infant deaths would follow increasing the care given to high risk infants.

To evaluate such a programme and to update the scoring system, an ongoing survey of all cases of unexpected death would be required. Case conferences based on this information would also improve the level of care so that the overall effect of the whole package might be substantially larger than predicted from theory.

An epidemiological and sociological study of unexpected death in infancy in nine areas of southern England. I: Epidemiology

An epidemiological survey of unexpected deaths in infancy covering nine areas of southern England is reported. The areas include specially deprived inner city areas of London, inner and outer suburbs of London, rapidly developing and new towns and their surrounding country districts and a coastal resort. The report is based on 308 cases and 236 controls.

Theepidemiological patterns found in respect of time of death, age, sex and season are similar to those reported by previous studies. The characteristic ‘cot death’ age distribution cannot be explained by the inclusion of older infants whose respiratory passages are obstructed by bedding or infection. Possible explanations for a substantial outbreak in one area are considered. Well recognized differences between cases and controls in respect of age of parents, parity, prematurity, twinning, hospital admission and clinic attendance were found to persist and to be essentially similar in all areas despite there being significant differences between the populations. Sociological differences between cases and controls were largest in the most socially deprived areas, illustrated by an illegitimacy rate of 27 per cent in inner north London.

Bottle feeding was only significantly associated with unexpected death when the standard of the home was excellent. Where the homes were poor more cases than controls were breast fed.

The effects of crimping on the healing of prosthetic arterial grafts

The purpose of this study was to determine whether the crimping of arterial prostheses affected their healing. In ten dogs, 6 mm knitted Dacron grafts were implanted in the infrarenal aortas; 6 grafts were crimped, 4 uncrimped. Each was seeded with venous endothelium to produce a cellular lining. The grafts were removed a month after implantation and compared by light microscopy as to the (1) thickness of the inner lining, (2) completeness of endothelial healing, and (3) patterns of vasa vasorum. (1) and (3) were assessed using H & E sections and (2) by AgNO3 Häutchen preparations. The lining in uncrimped grafts was thinner and more uniform than in crimped grafts: 50.1 +/- 45.7 vs 263 +/- 183 mu, p < 0.001. While the completeness of healing was similar for both groups, 4 crimped grafts had unhealed areas in the centers of the crimps, corresponding to the thicker areas of the linings. In both kinds of grafts, vasa vasorum communicated with vascular channels parallel to the axis of flow and near the perigraft fat. In the uncrimped grafts, the smaller secondary vasa also were directed along the axis of flow, in contrast to crimped grafts in which they were circumferential to the graft and parallel to the crimps. In all instances vasa penetrated within 500 mu of the lumen. We conclude that crimping causes a change in the pattern of development of vasa vasorum in healing fabric grafts and a thicker inner lining associated with areas of delayed healing which may increase the risk of thrombosis.

High Pressure Liquid Chromatographic Determination of Sulfamethazine or Sulfathiazole and Colorimetric Determination of Sulfathiazole in Feeds: Collaborative Studies

A high pressure liquid chromatographic method for sulfamethazine or sulfathiazole in feeds was studied collaboratively. The sample is extracted in 50% methanol and filtered, and an aliquot is injected into a liquid chromatograph. The column is μBondapak C18, the eluting solvent is acetonitrile–water (20+80), and the detection wavelength is 280 nm. Nine collaborators analyzed 3 different synthetic samples and 2 commercial samples labeled to contain 0.011% sulfamethazine, plus procaine penicillin and chlortetracycline. Average recoveries for the synthetic samples were 102.2% at the 0.005% level, 100.2% at the 0.01% level, and 103.6% at the 0.02% level; per cent standard deviations were 12.7, 10.4, and 8.67, respectively. Average sulfamethazine content of the 2 commercial samples was 77.8 and 82.9% of label with per cent standard deviations of 8.56 and 9.16. The same 2 samples, analyzed according to the official colorimetric procedure by 6 analysts, had an average sulfamethazine content of 81.7 and 89.4% of label with per cent standard deviations of 3.69 and 6.66. Eight collaborators analyzed 3 different synthetic samples and 2 commercial samples labeled to contain 0.011% sulfathiazole, plus procaine penicillin and chlortetracycline. Average recoveries of the synthetic samples were 101.6% at the 0.005% level, 103.0% at the 0.01% level, and 100.4% at the 0.02% level; per cent standard deviations were 9.52, 7.00, and 6.54. Average sulfathiazole content found by 9 collaborators was 0.0103% or 93.4% of label for Sample 1 and 0.0100% or 91.1% of label for Sample 2, with per cent standard deviations of 14.1 and 12.2. Colorimetric assays for sulfathiazole were made according to method 42.172–42.174 for sulfamethazine. Two synthetic samples were analyzed by 7 collaborators. Average recovery was 97.6% at the 0.01% level and 99.8% at the 0.02% level with per cent standard deviations of 5.05 and 8.16. The same 2 commercial samples used for the HPLC study were analyzed by 9 collaborators. Average sulfathiazole found was 86.4 and 87.9% of label with per cent standard deviations of 7.41 and 6.15.

The effect of estrogen priming on induction of labor with prostaglandins

A double-blind, randomized study was designed to determine whether estrogen "priming" of the unripe cervix followed by prostaglandin induction of labor would have a synergistic effect on cervical ripening and improve the success rate of induction. One hundred near-term patients with Bishop scores less than or equal to 4 received an intramuscular injection of either 10 mg of estradiol valerate or a placebo 48 hours prior to induction of labor with oral prostaglandin E2. The serial changes in Bishop scores were very similar in both groups. The success rate of induction in the study group (69.8%) was not statistically different from that in the control group (61.9%). The duration of labor was 9.9 +/- 4.1 hours in the study group versus 9.1 +/- 3.7 hours in the control group (not significant). This study showed that 10 mg of estradiol valerate had no detectable effect on the unripe cervix near term and did not show a synergistic effect with prostaglandins during induction of labor.

Mutagenicity of dichloroacetate, an ingredient of some formulations of pangamic acid (trade-named "vitamin B15")

Dichloroacetate demonstrates low grade mutagenicity in the Ames Salmonella/mammaltan microsome mutagenicity test. This evidence of probable carcinogenicity must be considered in any proposed use of dichloroacetate or of preparations of pangamic acid (trade-named "vitamin B15") CONTAINING DICHLOROACETATE.

Identification of some infants at immediate risk of dying unexpectedly and justifying intensive study

Children who die unexpectedly in infancy often have symptoms of illness before death. Survey data are used to evaluate risks associated with symptoms. There is a 1 in 50 chance of unexpected infant death occurring in the next 9 days when two or more symptoms occur in infants defined to be at high risk by a discriminant score. The score is based on data collected on all infants at birth and by health visitors at 1 month. This system would identify 50% of cot deaths and provides a basis for prospective physiological studies.

Seeding arterial prostheses with vascular endothelium. The nature of the lining

Arterial prostheses seeded with autogenous vascular endothelium demonstrate a well-organized, cellular, inner lining. To determine the nature of the lining cells, six animals underwent replacement of the infrarenal aorta with Dacron prostheses. During the preparation of three such grafts, endothelium was scraped from the saphenous vein with a steel wool pledget, suspended in chilled Sack's solution, and mixed with blood used to preclot the graft. This suspension was omitted from the three control grafts. After six weeks, the grafts were removed, rinsed and examined. Fluorescent Factor VIII related antigen (F VIII-RA) strongly stained the lining cells. Silver nitrate Haütchen and electron microscopy preparations revealed a lining pattern characteristic of vascular endothelium. Endothelial cell-specific Weibel-Palade bodies were identified in the lining cell cytoplasm. Masson's trichrome staining revealed a relatively collagen-poor connective tissue within the seeded fabric. Transmission electron microscopy disclosed vascular smooth muscle cells between the seeded graft fabric and the lining cells. Vasa vasorum, arising from the outer capsule, penetrated the fabric to supply the inner capsules of the seeded grafts. It is concluded that the cells lining seeded canine arterial prostheses are true vascular endothelium supported by vascular smooth muscle cells, that the lining contains minimal connective tissue, and that vasa vasorum develop. Unseeded control grafts lacked these features.

Seeding endothelium onto canine arterial prostheses. The effects of graft design

To identify prosthetic characteristics that support the proliferation of an endothelial lining, 14 different graft designs were studied in dogs. The grafts were prepared by the use of a technique of endothelial seeding that we described previously. They were studied two and four weeks after their implantation. Weft-knit Dacron grafts (water porosity from 1,400 to 1,650 mL/min/sq cm) were the most successful. A velour index (velour stitch frequency times velour loop height) was computed. When the internal velour index (IVI) was greater than 60,000 loop-mu/sq cm, the percentage of clot-free surface was 17.2 +/- 14.5%, compared with 62.0 +/- 26.9% when the IVI less than 60,000 loop-mu/sq cm. Endothelium could be detected on 61.5% of the grafts when the IVI less than 60,00 loop-mu/sq cm, compared with 0% when the IVI greater than 60,000 loop-mu/sq cm. The cells that formed the outer capsule were better organized and more adherent to the graft when an external velour was present, but external velour did not affect the inner lining. We conclude that weft-knit Dacron grafts with water porosities from 1,400 to 1,650 mL/min/sq cm and with limited internal velour (IVI less than 60,000 loop-mu/sq cm) are suitable substrates for single-staged endothelial-cell seeding.

Multistage scoring system for identifying infants at risk of unexpected death

Obstetric and perinatal records have been assembled on 250 infant deaths and an equal number of live controls including 55 deaths associated with congenital anomalies. The information was used to construct a scoring system to identify high-risk infants at birth. Parents of 115 of the cases and their controls were also interviewed and all hospital, general practitioner, and health service records abstracted. Cases and controls were compared item by item in respect of all information available up to the age of one month and a scoring system constructed for use at one month. The 'at birth' and combined scoring systems are presented. The chance of death by age attained is presented for various risk groups. In a small prospective test, the multistage scoring system was nearly 50% more effective than the birth score alone.

Induction of morphological transformation in mouse C3H/10T1/2 clone 8 cells and chromosomal damage in hamster A(T1)C1-3 cells by cancer chemotherapeutic agents

Various cancer chemotherapeutic agents including alkylating agents, antimetabolites, and antibiotics or natural products were studied for their ability to produce morphological transformation in the C3H/10T1/2 clone 8 mouse cell line and chromosomal damage in the A(T1)C1-3 hamster cell line following a 24-hr exposure of each agent at different concentrations. Those drugs that were known to be carcinogenic in vivo also produced morphological transformation and chromosomal damage, whereas those agents that have not been shown to be carcinogenic in vivo produced neither transformation nor chromosomal lesions. The concentrations used for these studies were in general similar to those actually reached in the plasma of patients treated with these same drugs for malignant, as well as certain nonmalignant, conditions.

Mourning, mummification and living with the dead

Six cases are reported in which the bereaved kept the decreased's body for periods ranging from one week to ten years. Some relevant anthropological and psychoanalytical observations are discussed. This phenomenon does not appear to have been reported in the literature of Western psychiatry.

Malarial antibodies in tropical splenomegaly syndrome in Papua New Guinea

Levels of species and class-specific malarial antibody were studied in 249 New Guineans with tropical splenomegaly syndrome (TSS) and in 87 control subjects living in the same area. Titres of IgG and IgM antibody to Plasmodium falciparum, P. vivax and P. malariae were estimated by indirect immunofluorescence. Both Ig and IgM antibody levels were higher in subjects with TSS than in controls; IgM titres were highest in those with the greatest splenic enlargement. Responses to all three species were comparable. It is concluded that there is no evidence from this study to incriminate any one species of malaria parasite in the production of tropical splenomegaly syndrome.

In vitro correlates of transformation in C3H/10T1/2 clone 8 mouse cells

Various potential in vitro correlates of malignancy were studied in four chemically transformed C3H/10T1/2 Clone 8 mouse cell lines and were compared with controls cells. The degree of tumorigenicity was best predicted by the relative plating efficiencies of the morphologically transformed cells in soft agar. All transformed cells also showed an increase in extracellular fibrinolytic activity which may be an additional marker for transformation. Intracellular fibrinolytic activity and loss of 125I-labeled cell surface protein (M.W. 250,000) were not correlated with morphological transformation or tumorigenicity in these cells.