BRITISH MEDICAL JOURNAL 8 MARCH 1975 553 fetal breathing movements; but further control studies will have to be done to exclude the possibility of the degree of inhalation varying with the type of cigarette.Cigarette smoking in pregnancy is suspected of being detrimental to the fetus. Statistical surveys have shown that the babies are smaller at birth (Butler et al., 1972) and suggested an increase in prematurity and perinatal mortality. It is not easy to relate our observations on the acute effects of smoking two cigarettes to the long-term epidemiological reports. Nevertheless, physiological factors such as hypoxia and hypoglycaemia, which might be expected to have a detrimental effect on the fetus, also reduce the normal incidence of fetal breathing movements in animals and man (Boddy and Dawes, 1975; Boddy et al., 1975). Whether the similar effect of cigarette smoking is to be interpreted in the same way is as yet a matter for conjecture. The size of the transient change observed (see fig.) was less than the normal diurnal variation in the incidence of fetal breathing.We make this report because clinical physiologists and obstetricians in several countries are beginning to use fetal breathing movements as an index of health. These observations are best made some hours after the last cigarette has been smoked to exclude the acute effects of this variable.This work was carried out with the aid of a grant from the Medical Research Council. We thank Professors G. S. Dawes and Alec Turnbull for their help, the consulting staff of the department of obstetrics for access to their patients, the nursing staff, and the subjects. who volunteered for the study.

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1. Methods for the separation of membrane-bound and free ribosomes from rat brain (cortex) and skeletal muscle were described and the preparations characterized by chemical analysis and electron microscopy. The attachment of ribosomes to membranes is not an artifact of the separation procedure. 2. The rate of incorporation of l-[(14)C]leucine into protein in vitro by the membrane-bound and free ribosomes from these two predominantly non-protein-secreting tissues is compared with that by similar preparations from rat liver. With all three tissues the initial rate was higher for the membrane-bound preparations. 3. By using the technique of discharging nascent polypeptide chains by incubation with puromycin followed by treatment with sodium deoxycholate (Redman & Sabatini, 1966), a major difference was observed for the vectorial discharge of nascent protein synthesized both in vivo and in vitro on membrane-bound ribosomes from liver, on the one hand, and brain and muscle, on the other. Whereas a large part of nascent protein synthesized on membrane-bound liver ribosomes was discharged into the membranous vesicles (presumably destined for export from the cell), almost all nascent protein from membrane-bound ribosomes from brain and muscle was released directly into the supernatant. Incorporation of [(3)H]puromycin into peptidyl-[(3)H]puromycin confirmed these findings. There was thus no difference between membrane-bound and free ribosomes from brain on the one hand, and from free polyribosomes from liver on the other, as far as the vectorial release of newly synthesized protein was concerned. 4. Incubation with puromycin also showed that the nascent chains, pre-formed in vivo and in vitro, are not involved in the attachment of ribosomes to membranes of the endoplasmic reticulum. 5. The differences in vectorial discharge from membrane-bound ribosomes from liver as compared with brain and muscle are not due to the different types of messenger RNA in the different tissues. Polyphenylalanine synthesized on incubation with polyuridylic acid was handled in the same way as polypeptides synthesized with endogenous messenger. 6. It is concluded that there is a major difference in the attachment of ribosomes to the membranes of the endoplasmic reticulum of secretory and non-secretory tissues, which results in a tissue-specific difference in the vectorial discharge of nascent proteins.

The morphological changes in a patient with a generalized storage disease characterized by the intracellular deposition of neutral lipid are described. There is widespread accumulation of lipid in the cytoplasm of many cells and in occasional nuclei. Diagnosis may be facilitated by the recognition of clear vacuoles in the cytoplasm of granulocytes in blood films. In jejunal biopsies vacuolation of the epithelial cells may simulate the appearances of a-betalipoproteinaemia. The lipid inclusions consist largely of normal triglycerides and are free in the cytoplasm, unassociated with any organelle. The biochemical basis of the lesions is uncertain. Although there are lipoprotein abnormalities the primary defect appears to be intrinsic to the cell and may involve either a defective cytoplasmic lipase or an impaired uptake and utilization of fatty acids by mitochondria.