Lowering of plasma cholesterol levels in free-living adolescent males; use of natural and synthetic polyunsaturated foods to provide balanced fat diets.

Two hundred and twenty-nine adolescent male pupils, attending two boarding schools, participated in a study, under free-living dietary conditions, designed to assess the effects on plasma lipids of altering only the type and not the amount of dietary fat. The students were monitored for 6 weeks on three different diets. During the first study period, dietary changes comprised substituting a polyunsaturated dried "filled" milk and products derived therefrom for conventional dairy products (diet A). The second dietary phase involved replacing all meat and dairy products with equivalent polyunsaturated ruminant fat products (diet B). The third period consisted of a control diet of conventional dairy and meat products. During both polyunsaturated diets a 14% reduction in plasma cholesterol was achieved compared with control levels. Low-density lipoprotein cholesterol was similarly suppressed. A greater decrease in plasma cholesterol of 19-21% was recorded in those pupils with initial cholesterol levels greater than 230 mg/dl. There was no significant difference in plasma triglycerides between diet A and the control diet whereas the triglyceride levels were 16.5% lower during diet B. The fall in plasma cholesterol coincided with an increase in plasma triglyceride linoleate from 8% to 19% of total triglyceride fatty acids. Dietary analysis of the pupils' diet indicated an increase in the ratio of polyunsaturates to saturates from 0.27 during the control period to 1.08 on the dried filled milk and 0.90 on the polyunsaturated ruminant fat products. A palatability survey showed that both the dried filled milk and the polyunsaturated ruminant fat products were as well accepted by the pupils as the conventional products. The results suggest that such products could, if introduced to the general population, play an important part in plasma cholesterol suppression in the hope that this would significantly reduce the incidence of coronary artery disease.

Hypercholesterolaemia in primary cancer of the liver.

Hepatic synthesis of cholesterol in higher animals is normally markedly suppressed by dietary cholesterol. This feedback regulation has been shown to be absent in all experimental hepatomas studied, and also in the only 2 humans with primary hepatocellular cancer (PHC) who have been investigated. Another patient who presented with hypercholesterolaemia is described in whom cholesterogenesis in the tumour was not suppressed by cholesterol feeding. In order to determine the frequency with which hypercholesterolaemia occurs in PHC, serum cholesterol levels were measured in 132 Black patients with this tumour. Raised levels were found in 14 of the patients (11%). In only 2 of these was hypercholesterolaemia associated with obstructive jaundice.

Hepatitis B (surface) antigen in mothers and their infants.

Hepatitis B (surface) antigen (HBSAg) was found in the serum of 8 out of 4 245 women attending the antenatal clinic of the Queen Victoria Maternity Hospital Seven (0, 16%) were asymptomatic carriers of the antigen, while the eigth suffered from polyarteritis nodosa. Seven of the 8 babies born to these mothers were followed-up over periods of up to 18 months, and 1 has become a chronic carrier of HBSAg. The antigen was not detected in the colostrum (breast milk) of the 6 positive mothers tested, but it was present in amniotic fluid, placenta and cord blood of some of the mother-infant couples. The possible routes of transmission of the hepatitis B virus from mother to baby are discussed in the light of these findings. No cases of acute virus B hepatitis occurred in the latter months of pregnancy nor in the puerperium, among 4 088 women delivered at the hospital during this period.

Metabolic bone disease in the elderly. Biochemical studies in three different racial groups living in South Africa.

In an attempt to detect biochemical evidence of metabolic bone disease in the aged, we measured plasma parathyroid hormone (PTH) concentrations, in addition to plasma calcium, phosphorus, alkaline phosphatase and creatinine levels, in elderly White, Black and Indian women. All three ethnic groups demonstrated raised mean PTH concentrations. The Black patients, however, showed the greatest mean PTH elevation and the lowest plasma calcium level. Increased PTH secretion in elderly females may reflect either an age-related decline in renal function or subclinical osteomalacia. Elderly Black women seem particularly susceptible to the latter disorder, probably because of dietary and environmental factors.

Portacaval shunt in four patients with homozygous hypercholesterolaemia.

Four patients with homozygous hyperbetalipoproteinaemia who had proved resistant to intensive medical therapy have undergone portacaval shunt. During 3 weeks of total parenteral alimentation before the operation, the serum-cholesterol decreased significantly in each of the four patients. During the fat-emulsion phase of hyperalimentation, one patient experienced a rise in cholesterol. Postoperatively, the size of xanthomas decreased in all cases; serum-cholesterol levels rose above those achieved during hyperalimentation, and this rise continued for as long as 3 months before a further reduction was recorded. In patients with angina, this improved considerably; and in most cases bruits decreased in itensity. The results at this stage do not, however, suggest portacaval shunt for all patients with homozygous hypercholesterolaemia.

Serum immunoglobulin levels in hepatitis-B antigen-positive and hepatitis-B antigen-negative acute hepatitis.

IgG, IgA and IgM levels were measured in the serum of 73 patients with hepatitis-B antigen-positive (virus-B) acute hepatitis and 48 patients with hepatitis-B antigen-negative (virus-A) hepatitis. The mean serum IgM level on admission was significantly higher in virus-A than in virus-B hepatitis (p less than 0,01), and remained so for 2-3 weeks. However, the overlap between the individual figures in the two forms of the disease was so great as to make the estimation of little diagnostic value. The mean serum IgG and IgA levels at the time of admission were not significantly different in the patients with and without hepatitis-B anti-genaemia.

Serum alpha-fetoprotein levels in acute viral hepatitis.

Serum alpha-fetoprotein levels were measured serially by radioimmunoassay in 32 patients with acute viral hepatitis. With one exception, the levels were increased during the course of the illness. Raised concentrations of the protein occurred almost equally in patients with and without the hepatitis-B antigen. In the majority of patients the rise was modest but in seven levels were reached at which alpha-fetoprotein could be detected by immunodiffusion. Very high levels were more likely to occur in children. In eight patients the concentration increased as the serum glutamic pyruvic transaminase (SGPT) level, used as an index of hepatocyte damage, was returning to normal, a pattern which favoured increased synthesis of the protein during hepatocellular regeneration. In the remainder, the alpha-fetoprotein level paralleled that of SGPT, suggesting rather an acutephase reaction to liver injury.