Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Famine”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed1994

The leucine-responsive regulatory protein, a global regulator of metabolism in Escherichia coli.

The leucine-responsive regulatory protein (Lrp) regulates the expression of more than 40 genes and proteins in Escherichia coli. Among the operons that are positively regulated by Lrp are operons involved in amino acid biosynthesis (ilvIH, serA)), in the biosynthesis of pili (pap, fan, fim), and in the assimilation of ammonia (glnA, gltBD). Negatively regulated operons include operons involved in amino acid catabolism (sdaA, tdh) and peptide transport (opp) and the operon coding for Lrp itself (lrp). Detailed studies of a few members of the regulon have shown that Lrp can act directly to activate or repress transcription of target operons. A substantial fraction of operons regulated by Lrp are also regulated by leucine, and the effect of leucine on expression of these operons requires a functional Lrp protein. The patterns of regulation are surprising and interesting: in some cases activation or repression mediated by Lrp is antagonized by leucine, in other cases Lrp-mediated activation or repression is potentiated by leucine, and in still other cases leucine has no effect on Lrp-mediated regulation. Current research is just beginning to elucidate the detailed mechanisms by which Lrp can mediate such a broad spectrum of regulatory effects. Our view of the role of Lrp in metabolism may change as more members of the regulon are identified and their regulation characterized, but at this point Lrp seems to be important in regulating nitrogen metabolism and one-carbon metabolism, permitting adaptations to feast and to famine.

Amino Acid Sequence↗
PubMed1986

Age specific xerophthalmia rates among displaced Ethiopians.

The recent famine in Ethiopia has resulted in the dislocation of millions of people. Many of these individuals have moved to refugee camps in Sudan or to feeding centres within Ethiopia. A total of 1325 children up to the age of 15 years were examined by an ophthalmologist in January 1985 at several sites in these two countries. The rates of Bitot's spots were three times greater in those between the ages of 7 and 10 compared with those under 7. Rates of corneal xerosis were comparable for each group. Previously, xerophthalmia was considered predominantly to affect children aged under 6. These data document the presence of the disease in older children and raise questions regarding future modifications in the prevention and treatment of xerophthalmia.

Adolescent↗
PubMed1987

Comparison of weight:height ratio and arm circumference in assessment of acute malnutrition.

Doctors working in famine relief commonly use the weight:height ratio and the circumference of the mid-upper arm to assess the nutritional state of children under 5. Threshold values indicating moderate and severe malnutrition are usually taken as 80% and 70%, respectively, of the expected weight:height ratio and arm circumferences of 13.5 cm and 12.5 cm, respectively. A study of 1260 children aged 1-5 showed that the thresholds of these two variables yielded significantly different proportions of children with malnutrition, the proportion being much larger when arm circumference was used as the criterion. Adjusting the thresholds would result in closer correspondence between the two variables.

Anthropometry↗
PubMed2000

Infant feeding and adult glucose tolerance, lipid profile, blood pressure, and obesity.

BACKGROUND: It is generally accepted that breast feeding has a beneficial effect on the health of infants and young children. Recently, a few studies have shown that the method of infant feeding is also associated with cardiovascular disease and its risk factors in adult life. AIMS: To examine the association between the method of infant feeding in the first weeks after birth and glucose tolerance, plasma lipid profile, blood pressure, and body mass in adults aged 48-53 years. METHODS: Subjects born at term between 1 November 1943 and 28 February 1947 in the Wilhelmina Gasthuis in Amsterdam around the time of a severe period of famine (late November 1944 to early May 1945). For 625 subjects, information was available about infant feeding at the time of discharge from hospital (on average 10.4 days after birth), and at least one blood sample after an overnight fast. RESULTS: Subjects who were bottle fed had a higher mean 120 minute plasma glucose concentration after a standard oral glucose tolerance test than those who were exclusively breast fed. They also had a higher plasma low density lipoprotein (LDL) cholesterol concentration, a lower high density lipoprotein (HDL) cholesterol concentration, and a higher LDL/HDL ratio. Systolic blood pressure and body mass index were not affected by the method of infant feeding. CONCLUSIONS: Exclusive breast feeding seems to have a protective effect against some risk factors for cardiovascular disease in later life.

Adolescent↗
PubMedDate not supplied

Information economics and the Internet.

Information economics offers insights into the dynamics of information across networked systems like the Internet. An information marketplace is different from other marketplaces because an information good is not actually consumed and can be reproduced and distributed at almost no cost. For information producers to remain profitable, they will need to minimize their exposure to competition. For example, information can be sold by charging site access rather than information access fees, or it can be bundled with other information or "versioned." For information consumers, a variation of Malthus' law predicts that the exponential growth in information will mean that specific information will become increasingly expensive to find, because search costs will grow but human attention will remain limited. Furthermore, the low cost of creating poor-quality information on the Web means that the low-quality information may eventually swamp high-quality resources. The use of reputable information portals on the Web, or smart search technologies, may help in the short run, but it is unclear whether an "information famine" is avoidable in the longer term.

Information Services↗
PubMed1993

The stationary phase of the bacterial life cycle.

In the natural environment bacteria seldom encounter conditions that permit periods of exponential growth. Rather, bacterial growth is characterized by long periods of nutritional deprivation punctuated by short periods that allow fast growth, a feature that is commonly referred to as the feast-or-famine lifestyle. In this chapter we review the recent advances made in our understanding of the molecular events that allow some gram-negative bacteria to survive prolonged periods of starvation. After an introductory description of the properties of starved gram-negative bacteria, the review presents three aspects of stationary phase: entry into stationary phase, responses during prolonged starvation, and reentry into the growth cycle.

Bacteria↗
PubMed1995

How Salmonella survive against the odds.

The enteric pathogen Salmonella typhimurium faces daunting odds during its voyages in the natural environment and through an infected host. It must manage stresses ranging from feast to famine, acid to base, and high to low osmolarity, among others, as well as counter various types of oxidative stress and a variety of antimicrobial peptides. The defenses used to survive these encounters can be specific or can provide cross protection to a variety of hostile conditions. Once inside a host, Salmonella spp. escape the extracellular environment and thus humoral immunity by invading professional and nonprofessional phagocytes in which a new set of challenges await. Some of these stresses are similar to those encountered in the natural environment (e.g. acid, starvation) but the bacterial response is complicated by the simultaneous occurrence of multiple stresses. S. typhimurium appears to sense various in vivo cues and responds by seducing the host signal-transduction pathways that are required to phagocytize the bacterial cell. The pathogen then calls upon components of its stress-response arsenal to survive the intracellular environment. These survival strategies enable the organism to persist in nature, where conditions are usually suboptimal, and equip the bacterium with pathogenic properties that, if successful, will provide it with a very rich and stress-free growth environment, a dead host.

Adaptation, Physiological↗
PubMed1996

Control of fertility by metabolic cues.

In female mammals, reproduction is extremely sensitive to the availability of oxidizable metabolic fuels. When food intake is limited or when an inordinate fraction of the available energy is diverted to other uses such as exercise or fattening, reproductive attempts are suspended in favor of processes necessary for individual survival. Both reproductive physiology and sexual behaviors are influenced by food availability. Nutritional effects on reproductive physiology are mediated by changes in the activity of gonadotropin-releasing hormone (GnRH) neurons in the forebrain, whereas the suppression of sexual behaviors appears to be due, at least in part, to decreases in estrogen receptor in the ventromedial hypothalamus. Work using pharmacological inhibitors of glucose and fatty acid oxidation indicates that reproductive physiology and behavior respond to short-term (minute-to-minute or hour-to-hour) changes in metabolic fuel oxidation, rather than to any aspect of body size or composition (e.g., body fat content or fat-to-lean ratio). These metabolic cues seem to be detected in the viscera (most likely in the liver) and in the caudal hindbrain (probably in the area postrema). This metabolic information is then transmitted to the GnRH-secreting or estradiol-binding effector neurons in the forebrain. There is no evidence to date for direct detection of metabolic cues by these forebrain effector neurons. This metabolic fuels hypothesis is consistent with a large body of evidence and seems to account for the infertility that is seen in a number of situations, including famine, eating disorders, excessive exercise, cold exposure, lactation, some types of obesity, and poorly controlled diabetes mellitus.

Animals↗
PubMed2005

Effect of intermittent fasting and refeeding on insulin action in healthy men.

Insulin resistance is currently a major health problem. This may be because of a marked decrease in daily physical activity during recent decades combined with constant food abundance. This lifestyle collides with our genome, which was most likely selected in the late Paleolithic era (50,000-10,000 BC) by criteria that favored survival in an environment characterized by fluctuations between periods of feast and famine. The theory of thrifty genes states that these fluctuations are required for optimal metabolic function. We mimicked the fluctuations in eight healthy young men [25.0 +/- 0.1 yr (mean +/- SE); body mass index: 25.7 +/- 0.4 kg/m(2)] by subjecting them to intermittent fasting every second day for 20 h for 15 days. Euglycemic hyperinsulinemic (40 mU.min(-1).m(-2)) clamps were performed before and after the intervention period. Subjects maintained body weight (86.4 +/- 2.3 kg; coefficient of variation: 0.8 +/- 0.1%). Plasma free fatty acid and beta-hydroxybutyrate concentrations were 347 +/- 18 and 0.06 +/- 0.02 mM, respectively, after overnight fast but increased (P < 0.05) to 423 +/- 86 and 0.10 +/- 0.04 mM after 20-h fasting, confirming that the subjects were fasting. Insulin-mediated whole body glucose uptake rates increased from 6.3 +/- 0.6 to 7.3 +/- 0.3 mg.kg(-1).min(-1) (P = 0.03), and insulin-induced inhibition of adipose tissue lipolysis was more prominent after than before the intervention (P = 0.05). After the 20-h fasting periods, plasma adiponectin was increased compared with the basal levels before and after the intervention (5,922 +/- 991 vs. 3,860 +/- 784 ng/ml, P = 0.02). This experiment is the first in humans to show that intermittent fasting increases insulin-mediated glucose uptake rates, and the findings are compatible with the thrifty gene concept.

Adult↗
PubMed2002

Balkan nephropathy: a disorder of renal embryogenesis?

There is evidence to suggest that a renal embryogenesis disorder, with an associated deficit of nephrons, may be the cause of nephropathy later in the lives of patients with Balkan endemic nephropathy (BEN). This evidence includes the renal dysplasia or hypoplasia observed in BEN patients, the high incidence of renal pelvic and renal artery aberrations, primitive glomeruli and obstructed tubules on kidney biopsy, and an adult Fanconi-type syndrome of generalized proximal tubular dysfunction with hyperchloremic acidosis, potassium wasting, preserved urinary acidification, tubular proteinuria, aminoaciduria, uricosuria, hypomagnesemia, sodium wasting and normotension, as well as evidence from epidemiological data. The disease has affected no more than 2 generations, most of whom were in their 50s during 1965-1970, when maximal numbers of patients were seen. We are now observing a decreasing prevalence of BEN in Bulgaria and, even though this may have resulted from some prophylactic measures, the disease disappears much as it had appeared, as an epidemic. We speculate that some environmental factor may have had an impact on embryogenesis and resulted in nephropathy in patients with BEN. This could have been famine during the devastating Balkan wars in the beginning of 20th century, but may also have been an infectious or environmental factor, limited to the affected areas around the Danube river, which acted only during a limited period of time.

Adult↗
PubMed2006

Regulation of fat storage via suppressed thermogenesis: a thrifty phenotype that predisposes individuals with catch-up growth to insulin resistance and obesity.

Catch-up growth during infancy and childhood is increasingly recognized as a major risk factor for later development of insulin-related complications and chronic diseases, namely abdominal obesity, type 2 diabetes and cardiovascular disease. As catch-up growth per se is characterized by insulin resistance, hyperinsulinaemia and an accelerated rate of fat storage (i.e., catch-up fat) even in the absence of hyperphagia, the possibility arises that suppressed thermogenesis in certain organs/tissues - for the purpose of enhancing the efficiency of catch-up fat - also plays a role in the pathophysiological consequences of catch-up growth. Here, the evidence for the existence of an adipose-specific control of thermogenesis, the suppression of which contributes to catch-up fat, is reviewed. Recent findings suggest that such suppression of thermogenesis is accompanied by hyperinsulinaemia, insulin resistance in skeletal muscle and insulin hyperresponsiveness in adipose tissue, all of which precede the appearance of excess body fat, central fat distribution and elevations in intramyocellular triglyceride or circulating lipid concentrations. These findings underscore a role for suppressed thermogenesis per se as an early event in the pathophysiology of catch-up growth. It is proposed that, in its evolutionary adaptive role to spare glucose for the rapid rebuilding of an adequate fat reserve (for optimal survival capacity during intermittent famine), suppressed thermogenesis in skeletal muscle constitutes a thrifty phenotype that confers to the phase of catch-up growth its high sensitivity to the development of insulin resistance and hyperinsulinaemia. In the context of the complex interactions between earlier reprogramming and a modern lifestyle characterized by nutritional abundance and low physical activity, this thrifty 'catch-up fat phenotype' is a central event that predisposes individuals with catch-up growth to abdominal obesity, type 2 diabetes and cardiovascular disease.

Adipose Tissue↗
PubMed1991

Experimental studies on changes of neuroendocrine functions during starvation and refeeding.

Starvation resulting from famine and malnutrition remains an international concern. Malnutrition also influences the course and outcome of many diseases and when underestimated develops into a cycle of continuing dehabilitation. Thus, studies which contribute to the prevention, amelioration, or rehabilitation of the detrimental effect of starvation are warranted. Although investigations on endocrine changes related to starvation can be traced back to the early 1920s, there has been little work on the hypothalamic-pituitary axis until recently. The traditional line of thought tended to oversimplify the relationship between endocrine gland hypofunction and starvation by concluding that this hypofunction resulted from the inability of hormone production due to cellular damage and/or lack of raw materials and energy. Modern neuroendocrinology has established that neuroendocrine integration plays a major role in the body's homeostasis. The neuroendocrine system is the initial response to stress so that it is reasonable to assume that this system also plays a key role in the pathophysiological changes during starvation. This article presents a brief review of our research on: changes of anterior pituitary hormone secretions during starvation and refeeding; changes of hypothalamic neurotransmitters during starvation; and effects of modulation of central neurotransmitters on anterior pituitary hormone secretion of starved animals.

Adrenocorticotropic Hormone↗
PubMed1989

Effects of suckling and the postsuckling fast on weights of the body and internal organs of harp and hooded seal pups.

The weights of harp seal pups quadruple during 13 days of suckling while hooded seal pups double in weight in a lactation period of just 4 days. Pups of both species then fast for a month or longer. As a first measure of tissue responses to this 'feast and famine' pattern, we weighted the body, sculp (blubber and attached skin), core (carcass including viscera) and major internal organs of seal pups at birth, at the end of suckling, and at the end of the fast. When expressed as a percentage of body weight, the weights of the internal organs of newborn harp and hooded seals were within the range reported for newborn land mammals. During suckling, harp and hooded seals gained 2.3 and 6.5 kg/day body weight, respectively, but a large part (64-73%) of this gain was blubber and skin rather than core. Even though pups were ingesting great quantities of fat, their digestive organs (stomach, small and large intestines, pancreas) were neither particularly large at birth nor did these organs gain in weight or length unusually rapidly. Most organs increased in weight in proportion to the increase in core weight, but the liver and spleen increased proportionately more than the core, and the stomach, heart and kidneys increased proportionately less. At the end of suckling, sculp accounted for more than half of the body weight in both species. The subsequent 4-week fast resulted in weight loss from both the sculp and core, and the liver and spleen decreased in weight by about 70%. The net effect of sequential suckling and fasting was particularly striking in the hooded seal pup, which has a lighter core, heart, liver and spleen at 1 month postpartum than at birth. These data illustrate a remarkable cycle of nutrient deposition and depletion which is undoubtedly central to the survival of young seals in the harsh pack-ice environment.

Animals↗
PubMed2005

Hypertension in sub-Saharan African populations.

BACKGROUND: Hypertension in sub-Saharan Africa is a widespread problem of immense economic importance because of its high prevalence in urban areas, its frequent underdiagnosis, and the severity of its complications. METHODS AND RESULTS: We searched PubMed and relevant journals for words in the title of this article. Among the major problems in making headway toward better detection and treatment are the limited resources of many African countries. Relatively recent environmental changes seem to be adverse. Mass migration from rural to periurban and urban areas probably accounts, at least in part, for the high incidence of hypertension in urban black Africans. In the remaining semirural areas, inroads in lifestyle changes associated with "civilization" may explain the apparently rising prevalence of hypertension. Overall, significant segments of the African population are still afflicted by severe poverty, famine, and civil strife, making the overall prevalence of hypertension difficult to determine. Black South Africans have a stroke rate twice as high as that of whites. Two lifestyle changes that are feasible and should help to stem the epidemic of hypertension in Africa are a decreased salt intake and decreased obesity, especially in women. CONCLUSIONS: Overall, differences from whites in etiology and therapeutic responses in sub-Saharan African populations are graded and overlapping rather than absolute. Further studies are needed on black Africans, who may (or may not) be genetically and environmentally different from black Americans and from each other in different parts of this vast continent.

Africa South of the Sahara↗
PubMed1998

Diabetes epidemic in newly westernized populations: is it due to thrifty genes or to genetically unknown foods?

Until a few decades ago, certain 'new-world' populations that kept to traditional dietary habits were virtually free from diabetes; then, after they began eating some foods that are common in Europe, the disease reached epidemic proportions. Europeans, by contrast, have a low rate of diabetes. To account for this paradox, it has been suggested that those new-world populations have a thrifty genotype, which would have conferred a selective advantage during the frequent famines of the past, while today it would be detrimental because the recently adopted foods are constantly available. Here it is proposed that thrifty genes are unlikely to exist. Both the diabetes epidemics that occur in newly westernized populations and the low rate of diabetes in Europeans can be explained by the hypothesis that Europeans, through millenary natural selection, have become adapted, albeit incompletely, to some diabetogenic foods for which humankind is genetically unequipped.

Adaptation, Physiological↗
PubMed2003

A short history of randomized experiments in criminology. A meager feast.

This article discusses advantages of randomized experiments and key issues raised in the following articles. The main concern is the growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office, although other experiments are also discussed. It is concluded that feast and famine periods are influenced by key individuals. It is recommended that policy makers, practitioners, funders, the mass media, and the general public need better education in research quality so that they can tell the difference between good and poor evaluation studies. They might then demand better evaluations using randomized experiments.

Criminology↗
PubMed1989

The state of food production and nutrition in the developing countries.

The genesis of the problem of food production and nutrition of African, Asian and Central and South American countries can be traced back to the beginning of 'inter-continental trade' and the emergence of colonialism. Indigenous food patterns and social and economic orders that had evolved to befit the inhabitants and the environment were destroyed. A nutritional framework and an agricultural and economic policy designed to benefit the colonising nations were fostered. At present, millions of people in the developing countries suffer from endemic undernutrition and associated diseases. Famine is always present under the surface claiming families and individual hamlets and breaks through when the semblance of equilibrium between minimal food requirement for survival and supply is disturbed by natural or man-made disaster. Landlessness, an uneven distribution of wealth, overemphasis on cash-crop production, neglect of peasant agriculture in favour of unnecessary expenditure on military hardware and other misguided projects, and crop specialisation are some of the factors responsible for food shortage and undernutrition. Moreover, most of the staple foods of the developing countries are of low energy density and deficient in some essential nutrients. The cycle of undernutrition, hunger, disease and death can only be broken by instituting a well planned, peasant-orientated, integrated development programme based on self-reliance and self-sufficiency.

Developing Countries↗
PubMed1996

John Forbes and Daniel O'Connell: the meeting of a Scottish physician with an Irish nationalist in 1841.

Last year was the 150th anniversary of the failure of the potato crop in Ireland, which initiated the famine years of 1845-9. The consequences for agricultural communities dependent on this source of food for survival were disastrous in terms of mortality and emigration, although it was not the sole cause for the emergency of an Irish "diaspora". Within two years the Irish people suffered a further blow with the death of their parliamentary champion, O'Connell. Daniel O'Connell (1775-1847) was popularly known in Ireland as the "Liberator", as he promoted the cause of Catholic emancipation together with repeal of the Act of Union between Great Britain and Ireland of 1801. He was skilled as a barrister and politician, and remarkable in that he advocated non-violent means to achieve his aims. His family were fairly well-to-do landowners in County Kerry, in the south-west. In contrast, John Forbes came from a humbler background of tenant farmers in the north-east of Scotland. It may be of interest to outline the circumstances leading to his meeting with O'Connell in 1841.

History, 19th Century↗