It has been shown that human diploid cells from various donor ages can be arrested in an essentially nonmitotic state by reducing the serum concentration of the incubation medium from 10 to 0.5 percent. Cells incubated at this serum level maintained the population distribution that was present when the cells reached confluency. The population, which has 90 percent of the cells in the G1 phase of the division cycle, was not static and exhibited a low level of mitotic activity with prolonged interdivision times.
South African Medical Journal = Suid-Afrikaanse Tydskrif Vir Geneeskunde
Of all the theories purporting to uncover the roots of childhood behaviour and its extension into adult behaviour, the most cogent relates to the physical and psychological bonds of attachment between infant and mother. It is helpful to divide the human lifespan into three periods, each of which has alternating phases of attachment and detachment.
The Id family of helix-loop-helix transcription factors is upregulated in a variety of human malignancies and has been implicated in promoting tumorigenesis through effects on cell growth, differentiation, and tumor angiogenesis. While expression of Id proteins has been associated with tumorigenesis, the precise mechanistic relationship between Id expression and carcinogenesis has not been clearly delineated. We have previously shown that Id1 delays cellular senescence in primary mammalian cells through inhibition of the cell cycle regulatory protein and familial melanoma gene, p16/INK4a.
The exceptional longevity of centenarians is due in part to inherited genetic factors, as deduced from data that show that first degree relatives of centenarians live longer and have reduced overall mortality. In recent years, a number of groups have performed genetic association studies on long-living individuals (LLI) and young controls to identify alleles that are either positively or negatively selected in the centenarian population as consequence of a demographic pressure. Many of the reported studies have shown genetic loci associated with longevity.
The cases of 23 patients whose condition was diagnosed as truncus arteriosus, type I or II, and who were seen at the Mayo Clinic during the decade preceding 1967, that is, before corrective operation became feasible, were reviewed. Ten were infants (through one year of age), and all ten have died. Eight ranged in age from more than one year through seven years of age, and all are living, except one, who diet 11 years after diagnosis. Five were older than seven years, and all had severe pulmonary vascular obstructive disease; three have died.
Mortality trends during the past 50 years in the population of a hospital group for the mentally handicapped are reported. There has been a marked change in the causes of death during this period. Whilst tuberculosis is no longer a major cause, other terminal respiratory tract infections are still prevalent. Deaths due to status epilepticus have decreased, with a concomitant increase in those due to carcinoma, myocardial infarction and cerebrovascular accident. Similarly, the mortality rate has altered significantly.
The pathogenetic links between diet and diseases such as hypertension and atherosclerosis remain the subject of much controversy. This article reviews the evidence about the relationship between diet and these two widespread adult conditions, proposes an approach for their early recognition, examines the rationale and safety of dietary changes, and formulates specific recommendations.
It is important to appreciate that the recent advances in nutritional management over the past two decades (19-22) have added to the longevity and the "joie de vivre" of children with chronic renal failure. The significant advances in vitamin D therapy and new treatment of complications in long-term maintenance dialysis have provided the pediatric nephrologist with new avenues of management.
Four classes of etiologic agents that cause human illness have been discovered. Sometimes members of two or more classes of agents cooperate to cause illness. Knowledge of etiology is necessary if a disease is to be eradicated. The leading causes of death in the United States have changed dramatically in the last century. Infection has been replaced by chronic illnesses of obscure etiology. Ischemic heart disease is the leading cause of death in middle age and is the major obstacle to becoming old.
Cystic fibrosis (CF) is an autosomal recessive disease characterized clinically by recurrent respiratory tract infections and malabsorption caused by pancreatic insufficiency. Typically diagnosed during infancy or childhood, CF impairs weight gain and growth, increases susceptibility to infection, and decreases longevity. Until recently, no guidelines for infant feedings were available. A consensus report prepared through the Cystic Fibrosis Foundation summarizes guidelines for the optimal nutrition management of patients with CF.