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Biomedical subjects

R Costello

Publications and source records attributed to R Costello.

101 records · Page 6Linked to original sources
PubMed1969

Lasting biological effects of early environmental influences. V. Viability, growth, and longevity.

The effects of neonatal influences on the growth and longevity of mice were studied by using animals derived from a highly inbred germfree colony that had been reassociated with a microbial flora free of known pathogens. The size of the animals at weaning time could be conditioned predictably by manipulating the diet of their mothers during gestation and lactation or by shortening or lengthening the period of lactation. A deficient diet during gestation or during lactation decreased the metabolic efficiency of the adult animal, even if it was fed an optimum diet after weaning. The effect was greatest when malnutrition occurred during both pregnancy and lactation. In contrast, an optimum diet during gestation and lactation rendered the animal less susceptible to the depressing effects of nutritional deficiency during adult life. A marked and lasting growth depression could be reproducibly achieved by contaminating newborn mice orally with an unidentified enterovirus. But neonatal infection with enterobacteria or mycobacteria even though severe, did not significantly alter the growth rate. Regardless of its initial cause, the depression of the growth rate during the preweaning period persisted throughout the whole life span of the animals, even when they were placed under optimum sanitary and nutritional conditions after weaning. Agencies (nutritional or infectious) which brought about a depression of whole body weight also affected the absolute and relative sizes of the various organs, especially of the brain. By manipulating neonatal influences, it was possible to produce at will in a given colony of highly inbred mice a family of strikingly different growth curves. This could be done without causing the death of any animal or affecting longevity.

Animals↗
PubMed1968

Lasting biological effects of early environmental influences. I. Conditioning of adult size by prenatal and postnatal nutrition.

Newborn specific-pathogen-free mice (SPF) were separated from their mothers shortly after birth and immediately reallocated at random to foster mothers, each of which received eight young. Under these conditions, the growth rate and adult size of the young were profoundly and lastingly conditioned by some unidentified influence exerted by the foster mother. In SPF mice nursed by their own mothers, the diet of the latter during gestation and lactation, or during lactation alone, conditioned the weight of the young at weaning time, and throughout their whole life span. Lasting depression of growth has been achieved by minor alterations of the dam's diet, for example by lowering its content in magnesium, or in lysine and threonine. The growth-depressing effect so achieved persisted throughout the whole life-span of the young, even though they were given at weaning time and constantly thereafter unlimited amounts of an optimum diet. In contrast, the weight-depressing effect of a diet deficient in lysine and threonine administered to adult animals was completely and rapidly reversible when a complete diet was later substituted for the deficient one. Depression of growth resulting from nutritional experiences during gestation or lactation did not seem to affect adversely the health of the young, or to decrease their longevity. In fact, the results of two experiments in which the animals nursed by mothers on different diets, were kept undisturbed and on optimum diets throughout their whole life span, suggest that the smaller animals had a greater average life expectancy than the larger ones.

Animals↗
PubMed1965

The influence of endotoxin administration on the nutritional requirements of mice.

Albino mice lose weight within 24 hours following administration of bacterial endotoxin. The initial weight loss is proportional to the dose of endotoxin injected only when this dose is very small. The loss during the 1st day reaches a maximum with 10 to 30 microg of endotoxin; larger doses increase the duration of the overall effect. The rate at which mice regain weight after administration of endotoxin is markedly influenced by the composition of the diet. Recovery was rapid and complete within a few days when the animals were fed commercial pellets or a semisynthetic diet containing casein. In contrast, recovery was slow and incomplete when wheat gluten was used instead of casein in the diet. The deleterious effect of the gluten diet was less marked in older than in younger animals, probably because the latter have less exacting nutritional requirements. It was postulated that the failure of endotoxin-treated mice to regain weight when fed the gluten diet was due to the fact that this protein is low in certain amino acids. In fact, rapid and complete recovery from the weight loss uniformly occurred when the gluten diet was supplemented with proper amounts of lysine and threonine. The composition of the diet did not influence the extent of the initial loss of weight caused by endotoxin, nor did it prevent the animals from developing tolerance to this substance.

Aging↗
PubMedDate not supplied

CSF and serum concentrations of albumin and IgG in Alzheimer's disease.

Cerebrospinal fluid (CSF) and serum concentrations of albumin and immunoglobulin G (IgG) were measured in 31 patients with presumptive Alzheimer's disease (AD) and in 14 healthy control subjects. The albumin and IgG quotients, and IgG index were calculated to evaluate the permeability of the blood-brain barrier and the intrathecal production of immunoglobulins. X-ray computerized tomography (CT) of the head was performed to investigate the relation between cerebral atrophy and CSF protein concentrations. The albumin and IgG quotients, and the IgG index did not differ significantly between the AD and control groups. Cerebral atrophy, as measured by CSF volume, was not related to CSF protein concentrations in either group. The results do not support the hypothesized roles of blood-brain barrier disruption or of immunologically-mediated injury of the central nervous system in the pathogenesis of AD.

Aged↗
PubMedDate not supplied

Developing an Intensive Care Continuum: incorporating rehabilitation services in critical care.

The Intensive Care Continuum program offers hospitals an alternative that effectively uses critical care beds while delivering optimum quality care to those patients requiring extended acute care. This program provides an intensive level of care while integrating rehabilitation therapies into the patient's plan of care. Specific strategies for developing an Intensive Care Continuum are offered in this article.

Continuity of Patient Care↗
PubMedDate not supplied

The use of electronic mail in biomedical communication.

OBJECTIVES: To determine whether there are statistically significant differences in the content of electronic mail (e-mail) and conventional mail sent to authors of papers published in medical journals. DESIGN: Prospective study by postal questionnaire. Over two one-month periods, corresponding authors of papers published in medical journals were asked to record details of the correspondence prompted by their publications. MEASUREMENTS: Conventional and e-mail correspondence received. Reprint requests. Content of correspondence. Quality of correspondence. RESULTS: Eighty-two of 96 authors replied. Fifty received e-mail (mean, 5.7+/-8.8 e-mails per author) and 72 received conventional mail (15.5+/-32.8 letters per author) (p < 0.05). Seventy percent of e-mails and only 53% of correspondence sent by conventional mail (p < 0.05) referred to the content of the paper. CONCLUSIONS: Publication in general medical journals stimulates more conventional than electronic mail. However, the content of e-mail may be of greater scientific relevance. Electronic mail can be encouraged without fear of diminishing the quality of the communications received.

Authorship↗
PubMedDate not supplied

Sexual harassment: what every security manager needs to know.

Security directors are responsible for protecting against sexual harassment and ultimately may be civilly liable for any violations, says the author. His goals here are to highlight an often-overlooked topic, provide the reader with a basic understanding of sexual harassment, give a background of its growth since 1991, help security managers identify and prevent sexual harassment, and provide resources for further investigation.

Female↗
PubMedDate not supplied

Differential immuno-suppressive effects of metabolic inhibitors on T-lymphocyte activation.

An important challenge in the field of auto-immune diseases, bone marrow and organ transplantation is the control of T-lymphocyte activation. To gain more insight into the in vitro correlation of immunosuppression, we investigated the effects of cyclosporin A (CSA) and two other metabolic inhibitors on cytokine secretion and T-cell proliferation. Secretion of TNF-alpha and GM-CSF was much more resistant to metabolic inhibitors than proliferation or synthesis of IL-1 alpha or IL-2. Moreover, our data suggested that the regulation of IL-1 alpha production in T-cells was CSA and protein kinase C (PKC)-dependent, as opposed to monocytes regulation. The receptivity to the epithelial cell-derived cytokine IL-7, associated either with antigen-dependent or independent triggering, was almost similarly inhibited by cyclosporin A, forskolin or PKC inhibitor, in sharp contrast to IL-2 receptivity. In this latter case, CD28+ IL-2 stimulation was more sensitive to both forskolin and PKC inhibition than that of CD2 or CD3+ IL-2. With regard to CSA effects, limiting dilution analysis provided evidence for some heterogeneity at the clonal level. This strongly suggested that T-cell functional monitoring at the population level does not truly reflect the actual immunosuppression. Additional experiments are required to evaluate the sensitivity to metabolic inhibitors of T-lymphocyte activation via the natural ligands of CD2 and CD28.

Antigens, CD↗
PubMedDate not supplied

Interleukin-7, a major T-lymphocyte cytokine.

IL-7 is a single-chain 25 kDa protein first identified in bone marrow cultures through its pre-B cell growth factor properties, then also described as a potent T-lymphocyte growth factor. This review relates to the molecular and functional aspects of interleukin-7 (IL-7) and its receptor (IL-7R). We focused on the role of IL-7 in T-cell activation, cytotoxicity generation, leukemic cell growth and immunotherapy.

Amino Acid Sequence↗