Growth of dendrites in the optic tectum of the chick embryo following destruction of the eye primordium.

The consequences of depriving the optic tectum of axons from the contralateral eye have been studied in Golgi-impregnated brains from a staged series of chick embryos. Following enucleation at 2–5 days of age, measurements of dendritic length and the numbers of branches at all orders for three cell types were performed with an automated three-dimensional tracking system at various survival times. Dendritic lengths and the number of middle order branches of neurons from control animals, aged 12–14 days (stages 38–40), are greater than those from non-innervated embryos of the same ages. However, by Day 18 (stage 44), no significant differences in length or branching are seen between neurons from control and experimental embryos. Observations of these neurons revealed qualitative differences between experimental and control embryos. Growth cones, varicosities and filopodia, indicators of dendritic differentiation, are more commonly associated with neurons from control Day 12 and 14 embryos, than operated embryos of the same stages. However, at Days 16 and 18 these growth characteristics are more usually seen on neurons from deafferented embryos than from controls.The deleterious effects observed in experimental animals between Days 12 and 14 are presumably caused by the absence of optic fibers. The eventual growth during late embryogenesis, of the cells deprived of optic input, may reflect a trophic influence not acting in the earlier period.     

Initiation and pattern of angiogenesis in wound healing in the rat

The object of this study was to examine the initiation and pattern of capillary growth associated with wound healing. Collagen sponges were implanted subcutaneously in the hind limbs of adult male rats to stimulate the formation of granulation tissue. Blood vessels of the hind limbs of euthanized rats were perfused with Mercox (an acrylic monomer) via the abdominal aorta at selected periods of time following sponge implantation. When the perfusate was completely cured, the sponge and parajacent tissues were excised and subsequently macerated by alternating immersion in 40% KOH and distilled water. Cast replicas of the vascular lumina were coated with gold and imaged by scanning electron microscopy. At 6 hr, punctate depressions at the periphery of the replicas of vein and venule lumina were noted. The depressions represented sites of leukocyte margination. By 24 hr, the depressions increased numerically, indicating a great increase in the sites of leukocyte margination. The number of these depressions decreased by 48 hr. Concomitantly, the depressions representing endothelial cell nuclei became more pronounced, indicating nuclear hypertrophy of these cells. In addition, capillary bud formation was initiated. At 72 hr, capillary buds were quite apparent and arose solely from venules. Between 7 and 14 days, replicas of capillary lumina were longer and formed an elaborate network, presumably by end-to-end, side-to-side, and end-to-side anastomoses. The network was formed circumferential to the sponge and then capillary sprouts entered the sponge's interstitial spaces.     

Demonstration of T Lymphocytes in Cerebrospinal Fluid

Cerebrospinal fluid (CSF) was allowed to drop straight into Hanks's balanced salt solution. After centrifugation the pellet was resuspended and mixed with sheep erythrocytes. The mixture was further handled as in the E-rosette test with peripheral blood lymphocytes. CSF from 20 individuals were investigated, and rosette-forming cells (RFC) were found in all. Six patients with normal fluid had between 46% and 83% RFC. Four patients with multiple sclerosis had increased numbers of RFC (94%-96%). Low numbers of RFC were found in one patient with cerebellar ataxia and in one of two patients with acute viral meningitis. With this technique RFC can be counted even in normal CSF with a 3-ml sample.     

Mucins and carcinoid tumours

Mucin was demonstrated in 11 of 16 carcinoid tumours of usual histological appearances. The mucin was characterized histochemically and shown to be similar to that which is produced in the gastrointestinal as well as the respiratory tract. This relative ubiquity of mucin in carinoid tumours has not hitherto been appreciated and more obviously "mixed" tumours have been regarded as rareties. The importance of these findings with respect to the neural crest theory of origin of enterochromaffin cells is discussed.     

Breast cancer prediction and the Wolfe classification of mammograms

Mammographic parenchymal patterns have been proposed as a method of determining women at high risk of developing breast cancer. Wolfe's original report of relative risks as high as 37:1 for "dysplastic" breasts (DY) as compared with adipose breasts (N1), with intermediate values of P1 and P2, were not uniformly confirmed by others. (Relative risks are used here as the equivalent of odds ratios.) A case-control study of 706 breast cancers, each with two matching controls, drawn from 40,000 participants in four Breast Cancer Detection Demonstration Project clinics, was conducted to assess the role of the Wolfe classification of breast parenchymal patterns as a breast-cancer risk factor together with a set of well-established risk factors for breast cancer. Relative risks of 3.1 for DY to N1, 3.5 for P2 to N1, and 2.0 for P1 to N1 were determined. These are comparable to or greater than other known risk factors found in the same population. The Wolfe classification of parenchymal patterns strengthens the basis for clinical judgment, but should not be used exclusively to determine intervention in an individual patient's care.     

High density lipoprotein cholesterol is not a major risk factor for ischaemic heart disease in British men

The concentration of high density lipoprotein cholesterol (HDL cholesterol) in serum was measured at initial examination in a large prospective study of men aged 40-59 drawn from general practices in 24 British towns. After an average follow up of 4.2 years 193 cases of major ischaemic heart disease had been registered in 7415 men in whom both HDL cholesterol and total cholesterol values had been measured. The mean HDL cholesterol concentration was lower in the men with ischaemic heart disease ("cases") compared with other men, but the difference became small and non-significant after adjustment for age, body mass index, blood pressure, cigarette smoking, and concentration of non-HDL cholesterol. The higher mean concentration of non-HDL cholesterol in "cases" remained highly significant after adjustment for other factors. Men in the highest fifth of non-HDL cholesterol values had over three times the risk of major ischaemic heart disease compared with men in the lowest fifth. Multivariate analysis showed that non-HDL cholesterol was a more powerful predictor of risk than the HDL to total cholesterol ratio. These British findings were compared with six other prospective studies. All the larger studies showed similar results, suggesting that HDL cholesterol is not a major risk factor in the aetiology of ischaemic heart disease.     

Disgusting disruptions: Capturing the everyday experience and burden of managing gastrointestinal infections in the home

Gastrointestinal (GI) infections exert a significant public health burden in the United Kingdom and the numbers of episodes are increasing. Younger children are considered particularly vulnerable to infection, and can experience 2–3 GI infections episodes per year, with consequences being more severe for more disadvantaged children, who are much more likely to be admitted to hospital. Few qualitative studies have explored the lived experience of GI infection in the community in the UK. The aim of the study reported here was to contribute to addressing this evidence gap, by examining the consequences of GI infection for ‘normal’ family life. Eighteen mothers with young children who had recently experienced a gastrointestinal infection were recruited from two socioeconomically contrasting neighbourhoods in North West of England. The findings demonstrated that GI infections were particularly disruptive: experienced as disgusting, laborious and stressful and significantly impacted normal family routines. Women felt burdened by the heavy physical and emotional demands of caring for a GI infection, resulting in feelings of isolation and insufficient support in their caring role from male partners. Tensions also arose from interactions with external community organisations, particularly in complying with their regulations on infection which often undermined caregivers knowledge and expertise of what was best for their children. This study challenges assumptions that managing GI infections in the home is unproblematic and experienced by caregivers as a ‘minor ailment.’ Infection control measures need to incorporate insights gleaned from the day-to-day realities of caring for sick children in the community.