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PubMed1982

Tenure in medical schools in the 1980s.

Tenure in American medical schools is a personnel policy which exists in relation to institutional policies and realities. It is related to the functions of academic institutions and their capacity for carrying out these functions, and it arises from the needs of an open society to sustain critical and innovative roles for its universities, the necessity for universities to support and protect their faculties, the optimization of their capability to react to new opportunities, and the demands of ever shifting social circumstances. The relation between society and its universities and the balance among the various roles of the universities have not been stable in the past and will not be so in the future. Tenure policies will continue to be modified. The leadership of institutions needs to be aware of the fact that the modifications will occur and of what might be termed the plasticity of tenure.

Faculty, Medical↗
PubMedDate not supplied

Developing national performance standards for local public health systems.

Since the beginning of the 1990s, public health has struggled to measure its performance and capacity to carry out the core functions of public health practice, while facing increasing challenges within the ever-changing landscape of healthcare delivery, bioterrorism response, emerging infections, and other threats to the public's health. The article describes the development of a set of national performance standards for measuring how effectively public health systems deliver the 10 Essential Public Health Services. The standards were developed through a practice-driven approach that incorporated comprehensive field testing and iterative revisions. The standards represent a national consensus framework for measuring important aspects of public health practice.

Efficiency, Organizational↗
PubMed2006

Maternal and paternal influences on length of pregnancy.

OBJECTIVE: Biological evidence suggests that both mother and fetus are involved in triggering a normal delivery. A tendency of a child to have a gestational age at birth similar to the father's could represent the effect of genes passed from the father to the fetus. Similar tendencies between mother and child could represent maternal genes passed to the fetus, as well as genes to the mother received from the grandmother that affect a woman's capacity to carry a pregnancy. METHODS: The Medical Birth Registry of Norway contains data on all births in Norway from 1967 onward. We identified 77,452 pairs of boys and girls born at term who later became parents and linked their birth data to the birth records for their first child. RESULTS: Gestational age of the child at birth increased on average 0.58 days for each additional week in the father's gestational age (95% confidence interval 0.48-0.67) and 1.22 days for each additional week in the mother's gestational age (1.21-1.32). Gestational age was, however, 0.65 days reduced for each additional kilogram in the father's birth weight, presumably due to more rapid growth of the fetus triggering delivery. CONCLUSION: Initiation of delivery has a fetal component that is heritable (passed from father and mother to child) and an additional maternal component that is also heritable. In addition, a more rapid rate of fetal growth appears to trigger delivery at earlier gestation. LEVEL OF EVIDENCE: II-2.

Adult↗
PubMed1973

Steps in the acquisition of photosynthetic competence by plastids of maize.

Coupling factor particles are associated with membranes of maize etioplasts (Lockshin et al., 1971. Biochim. Biophys. Acta 226: 366-382). In addition, several, but not all, of the polypeptides found in the photosynthetic lamellae of maize chloroplasts are present in etioplasts.During the photoregulated maturation of chloroplasts from etioplasts, the membranes of the organelle acquire the capacity to carry on acid to base phosphorylation. The acquisition of this ability is closely correlated with the development of osmotic responsiveness and the appearance of a 46,000 dalton polypeptide in the membranes.

Journal Article↗
PubMed1991

A Quantification of the Significance of Assimilatory Starch for Growth of Arabidopsis thaliana L. Heynh.

These studies use starch synthesis mutants to quantify the contribution of assimilatory starch to whole plant growth and form. Arabidopsis thaliana (L.) Heynh plants were used with null plastid phosphoglucomutase (T Caspar, SC Huber, CR Sommerville, [1986] Plant Physiol 79; 1-7) or 7% of wild-type ADP-glucose pyrophosphorylase (T-P Lin, T Caspar, CR Sommerville, J Preiss [1988] Plant Physiol 88; 1175-1179). The daily turnover of starch and the rate of biomass increase in the mutants and the wild type were investigated during growth in a 14 hour light/10 hour dark cycle in high irradiance (600 micromoles per square meter per second) and nitrogen (6 millimolar NH(4)NO(3)), in high irradiance and low nitrogen (0.1 millimolar NH(4)NO(3)) or in low irradiance (80 micromoles per square meter per second) and high nitrogen. There is some variability in the data, but the following conclusions can be drawn. Growth was slow in the absence of starch turnover. In high nitrogen conditions, about 1 mole of carbon per gram dry weight per day was incorporated additionally into structural biomass for every one mole of carbon turned over as starch per gram dry weight per day. In low nitrogen, the gain was much lower. This indicates that temporary storage of photosynthate is important for rapid growth in high nitrogen, but not in low nitrogen when carbohydrate is in excess. Starch-deficient plants showed the usual decrease of the shoot/root ratio in low nitrogen and increase of the ratio in low light. This shows that adjustment of plant form to nitrogen nutrition and irradiance is not mediated via regulation of photosynthate partitioning in the leaf. Starch deficient plants had lower shoot/root ratios than the wild type and the nitrogen concentration in their leaves was increased. It is discussed how interactions between carbohydrate allocation, respiration and growth at the organ and whole plant level generate these changes. We conclude that mutants with a decreased capacity to carry out a particular partial process provide a powerful tool to disect complex mutually interacting systems, and define and quantify causal interactions at the level of whole plant growth.

Journal Article↗
PubMed1997

Antigen-presenting properties of gingival fibroblasts in chronic adult periodontitis.

Chronic periodontitis is characterized by dense infiltrations of T lymphocytes in the connective tissue, which consists mainly of gingival fibroblasts. It is becoming increasingly clear that T lymphocytes and gingival fibroblasts are capable of influencing each other. For example, the T cell cytokine interferon-gamma (IFN-gamma) is able to induce MHC class II molecules on the surface of several cell types, including gingival fibroblasts. Histological sections of chronically inflamed gingival tissue showed a great number of CD4+ and CD8+ T cells that produced IFN-gamma, and in addition showed abundant expression of MHC class II molecules on gingival fibroblasts. Therefore, we investigated whether these gingival fibroblasts acquire the capacity to carry out MHC class II-restricted functions such as antigen presentation to local T cells. In this study, we show that IFN-gamma-treated gingival fibroblasts were able to function as antigen-presenting cells (APC) for superantigen-mediated T cell proliferation. However, these fibroblasts failed to present whole-cell antigens of periodontitis-associated bacteria. Moreover, gingival fibroblasts inhibited the presentation of the whole-cell antigens of these bacteria by professional APC. This inhibition could be overcome by the addition of IL-2. These results suggest that gingival fibroblasts play an important role in the local specific immune response in chronic inflammatory periodontal lesions by regulating the response of infiltrating T cells.

Adult↗
PubMed1993

Are there different water requirements in different steps of a catalytic cycle? Hydration effects at the E1 and E2 conformers of sarcoplasmic reticulum Ca(2+)-ATPase studied in organic solvents with low amounts of water.

The Ca(2+)-ATPase from sarcoplasmic reticulum was transferred in an active form to a low-water system composed of toluene, phospholipids, and Triton X-100 (TPT). The Ca(2+)-ATPase activity in the TPT system with 4.0% water (by vol. was about 50% of the activity observed in all-aqueous mixtures. Phosphate formation was linear with time up to 20% of ATP hydrolysis and, as expected from an enzyme-catalysed reaction, activity was linear with protein concentration. No ATPase activity was detected in the presence of 3 mM EGTA, indicating that the enzyme retained its Ca2+ dependence in the TPT system. A hyperbolic response to ATP concentration was observed with a Km of 0.15 mM. There was no detectable ATPase activity at water concentrations below 1.5% (by vol.). With 2.0% water, activity became detectable and increased as the water content was progressively raised to 7.0% (by vol.). Higher amounts of water produced unstable emulsions. Enzyme phosphorylation by ATP and dephosphorylation took place in the TPT system. The velocities of both enzyme phosphorylation and dephosphorylation increased with increments in the water content. The enzyme could also be phosphorylated in the TPT system by inorganic phosphate. However, in comparison to ATP, phosphorylation by phosphate took place with significantly lower amounts of water. It is suggested that at low amounts of water, the enzyme is in a relatively rigid conformation and, as the water content is increased, the ATPase acquires more flexibility and, hence, the capacity to carry out catalysis at higher rates. Nevertheless, the release of conformational constraints of the catalytic site of the E2 conformer takes place at water concentrations much lower than those needed for the expression of catalytic activity by the E1 conformer.

Adenosine Triphosphate↗
PubMed1997

Expression of CYP3A in the human liver--evidence that the shift between CYP3A7 and CYP3A4 occurs immediately after birth.

CYP3A isoforms are responsible for the biotransformation of a wide variety of exogenous chemicals and endogenous steroids in human tissues. Two members of the CYP3A subfamily display developmentally regulated expression in the liver; CYP3A7 is expressed in the fetal liver, whereas CYP3A4 is the major cyrochrome P-450 isoform present in the adult liver. To gain insight into the descriptive ontogenesis of CYP3A isoforms during the neonatal period, we have developed several approaches to explore a neonatal liver bank. Although CYP3A4 and CYP3A7 are structurally closely related, they differ in their capacity to carry out monooxygenase reactions. We have cloned CYP3A4 and CYP3A7 and established stable transfectants in Ad293 cells to investigate their substrate specificities. The 16alpha hydroxylation of dehydroepiandrosterone is catalyzed by both proteins, but CYP3A7 has a higher affinity and maximal velocity than CYP3A4. Conversely, the conversion of testosterone into its 6beta derivative is essentially supported by CYP3A4. We used these two probes to determine the ontogenic evolution at the protein level; CYP3A7 was very active in the fetal liver and its activity was maximal during the first week following birth before to progressively decline and reached a very low level in adult livers. Conversely, the activity of CYP3A4 was extremely weak in the fetus and began to raise after birth to reach 30-40% of the adult activity after one month. CYP3A4 RNA accumulation displays a similar pattern of evolution; when probed with an oligonucleotide, its concentration increased rapidly after birth to reach a plateau as soon as the first week of age. These data supports the assumption that CYP3A4 expression is transcriptionally activated during the first week after birth and is accompanied by a simultaneous decrease of CYP3A7 expression, in such a way that the overall CYP3A protein content and the level of pentoxyresorufin dealkylase catalyzed by the two proteins remain nearly constant.

Adult↗
PubMedDate not supplied

Veterinary use of antimicrobials and emergence of resistance in zoonotic and sentinel bacteria in the EU.

Antimicrobials are essential for treatment of sick animals, but even if used correctly, may eventually lead to antimicrobial resistance. While this represents a potential hazard to humans, the great majority of resistant human pathogens, especially the more important ones, are unrelated to animal sources. A survey of informed medical opinion suggested that of the human antimicrobial resistance problem, <4% was seen as potentially linked to animal sources. This proportion related largely to zoonotic bacteria which by definition have the capacity to carry resistance between species, although the evidence for resulting harm remains limited. A recent study compared resistance among chicken, pig and cattle isolates of Salmonella spp., Campylobacter spp. and Escherichia coli from a series of EU countries. When tested against antimicrobial agents, this survey showed variation of resistance between countries, between hosts and between organisms. Such variation may give insight into preferred methods of antimicrobial administration or disease control, but it is clear that the epidemiology of antimicrobial resistance induction and dissemination in animals remains complex and is yet to be fully understood.

Animals↗
PubMed1980

Population pressure and land use change: from tree crops to sawah in Northwestern Kalimantan, Indonesia.

The author describes the role of population pressure in the current transition from tree crops to wet rice cultivation (sawah) in Northwestern Kalimantan, Indonesia. He contends that this change is occurring "because the senescent trees no longer produce enough commodities to exchange for rice to feed an enlarged population." The historical background is described, policies of the Indonesian government are discussed, and data are presented on the rate of population growth

Agriculture↗
PubMed1988

The Indonesian transmigration program in historical perspective.

"The purpose of this paper is to look at what has been achieved by the transmigration program [in Indonesia], to examine the major problems that have arisen and to consider the present constraints which now cast some doubt upon the future of the program." A historical overview of government policies from 1905 to 1988 is provided, and problems of land supply, land use, and lack of funds are discussed. Data are from the 1961 and 1980 Indonesian censuses. (SUMMARY IN FRE AND SPA)

Agriculture↗
PubMed1988

Childhood mortality in relation to nutritional status and water supply--a prospective study from rural Malawi.

In connection with the introduction of an improved method of water supply in rural Malawi, the nutritional status, morbidity, and mortality among 1,178 children under five were studied during three rainy and three dry seasons. Data were collected at fortnightly home interviews. Nutritional assessment was made twice a year. One hundred and thirty-seven of the children died during the study period, and the probability of dying before the age of five was estimated to 270 per 1,000 children. The mortality risk was related to weight for height (p less than 0.001) and height for age (p less than 0.01) as well as to upper arm circumference (p less than 0.001) and triceps skinfold (p less than 0.05). Mortality among children living in households using the new, piped-water supply tended to be lower than mortality for those using traditional water sources, although the difference was not statistically significant (relative risk 0.4, 95% confidence interval 0.1-1.3).

Child Nutritional Physiological Phenomena↗