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PubMed2006

Determinants of real-world functional performance in schizophrenia subjects: correlations with cognition, functional capacity, and symptoms.

OBJECTIVE: Impairments in adaptive life skills are a major source of disability in patients with schizophrenia. The relationship between adaptive life skills in real-world settings and performance on neuropsychological tests may be complicated by other factors that interfere with deployment of skills. Assessment of the ability to perform life skills under optimal conditions (i.e., assessment of functional capacity) has been proposed as a means to clarify these relationships. METHOD: The authors examined cross-sectional data from a study of the course of neuropsychological and adaptive life skills of older (age 50-85) schizophrenia patients (N=78). Functional capacity was examined with a performance-based measure (UCSD Performance-Based Skills Assessment), and case managers rated real-world adaptive functions (i.e., interpersonal skills, work skills, and community activities). Neuropsychological performance was assessed with a comprehensive battery, while symptoms were assessed with patient self-report and clinical ratings. RESULTS: Confirmatory path analyses were used to evaluate the effects of neuropsychological performance, functional capacity, and symptoms on the various domains of real-world functioning. Neuropsychological performance predicted functional capacity, which predicted all three domains of real-world functioning. Depression predicted interpersonal and work skills, while negative symptoms affected interpersonal skills independently of other predictors. CONCLUSIONS: Real-world adaptive life skills are predicted by neuropsychological performance, symptoms, and functional capacity. Neuropsychological performance contributes little to the prediction of real-world performance after accounting for functional capacity. In some domains, negative and depressive symptoms influenced real-world performance while not relating to functional capacity or neuropsychological performance.

Activities of Daily Living↗

PubMed2006

Small-world brain networks.

Many complex networks have a small-world topology characterized by dense local clustering or cliquishness of connections between neighboring nodes yet a short path length between any (distant) pair of nodes due to the existence of relatively few long-range connections. This is an attractive model for the organization of brain anatomical and functional networks because a small-world topology can support both segregated/specialized and distributed/integrated information processing. Moreover, small-world networks are economical, tending to minimize wiring costs while supporting high dynamical complexity. The authors introduce some of the key mathematical concepts in graph theory required for small-world analysis and review how these methods have been applied to quantification of cortical connectivity matrices derived from anatomical tract-tracing studies in the macaque monkey and the cat. The evolution of small-world networks is discussed in terms of a selection pressure to deliver cost-effective information-processing systems. The authors illustrate how these techniques and concepts are increasingly being applied to the analysis of human brain functional networks derived from electroencephalography/magnetoencephalography and fMRI experiments. Finally, the authors consider the relevance of small-world models for understanding the emergence of complex behaviors and the resilience of brain systems to pathological attack by disease or aberrant development. They conclude that small-world models provide a powerful and versatile approach to understanding the structure and function of human brain systems.

Animals↗

PubMed2003

Purification and characterization of a novel intracellular 17 beta-estradiol binding protein in estrogen-resistant New World primate cells.

Compared to Old World primates, including man, New World primates display target-tissue resistance to gonadal steroid hormones. In female New World primates this resistant phenotype is characterized by elevated concentrations of plasma estradiol and progesterone. Here we describe the discovery of an intracellular estrogen binding protein (IEBP) that acts to concentrate 17 beta-estradiol (E2) in the cytoplasm of New World primate target cells. IEBP was purified by E2-affinity chromatography from postnuclear extracts of the B95-8 cells established from an E2-resistant New World primate. Compared with unpurified extract, affinity-purified IEBP demonstrated a 300-fold enrichment in specific E2 binding activity; half-maximal displacement of [3H]E2 from affinity-purified IEBP was observed with 0.1 nM E2. Affinity-purified extracts were subjected to SDS-PAGE with isolation of a dominant 27-28 kDa protein. N-terminal sequencing of tryptic peptides of the protein showed sequence homology with human heat shock protein-27 (hsp27). By immunoblot and E2 binding capacity, IEBP was 1] 2-3-fold greater in New World than in Old World primate tissues and cell lines, 2] heat-inducible and 3] up-regulated in vivo in the presence of the functioning female gonad. In conclusion, IEBP is a specific E2-interacting heat shock protein in the hsp-27 family that is relatively overexpressed in estrogen-resistant cells.

Amino Acid Sequence↗

PubMed2004

T-wave and heart rate variability changes to assess training in world-class athletes.

PURPOSE: A decrease of electrocardiographic T-wave voltage with increasing training loads has been reported in elite endurance athletes and ascribed to training-related adaptation in sympathetic activity to the ventricles. A switch from vagal to sympathetic predominance in sino-atrial node regulation on going from low to peak training load has been reported in world-class rowers. In this study on world-class endurance athletes, we tested the hypothesis that training-induced variations in T-wave amplitude at higher training loads are paralleled by changes in HR spectral profile. METHODS: We studied eight male rowers of the Italian national team in the season culminating with the Rowing World Championship. Athletes were evaluated at 50 and 100% of training load, approximately 20 d before the World Championship, and during the World Championship, when the intensity was markedly reduced. We assessed T-wave maximum amplitude in chest lead V6 and cardiac autonomic regulation by power spectral analysis of R-R interval variability. RESULTS: The increase in training load from 50 to 100% was accompanied by a significant decrease in high frequency and a significant increase in low-frequency R-R variability (in normalized units) with a concomitant significant decrease in T-wave amplitude (microV). Reduction in training load during the World Championship resulted in a return of spectral profile to the level observed at 50% training load and in a partial recovery of T-wave amplitude. HR did not change significantly. CONCLUSIONS: In high-performance world-class athletes, training load simultaneously affects both ventricular repolarization and HR variability patterns possibly through variations in cardiac sympathetic modulation to the ventricles and the sino-atrial node. Information on concomitant changes in ventricular repolarization and autonomic cardiac regulation might be employed to tailor training protocols of elite athletes.

Adult↗

PubMed2003

The global problems of child malnutrition and mortality in different world regions.

The study of child mortality occupies a special place in the field of demographic research, since it represents the negative component of population growth. Also, the world food problem has become a familiar topic since the end of the World War II. The idea that population growth will sometime in the future outrun food supplies and universal starvation occurs. This study deals with what happened in global and regional variations regarding the child malnutrition and mortality rates. The main objective of the study is to explain and to explore the effect of the social, demographic, economic and health factors on child malnutrition and mortality rates among different regions in the globe. The study includes ten regions of the whole world compared to other studies that covered only one or two regions. Data were collected from various sources. The sample involved 191 countries. These countries divided by regions of world as following. East Southern Africa, West Africa, East Asia and Pacific, South Asia, Eastern Europe and Central Asia, Europe, Middle East, North Africa, North America, and South America. The results of descriptive analysis show that the highest mean rate of child malnutrition was found in South Asia region (57 children per 100), while the smallest mean rate was found in Europe region (just 1 child per 100). In West Africa region, the average of child mortality rate per 1000, 172 children, was the highest among all regions in the world, while in Europe was found to be 14 children per 1000. The results of correlation coefficients reveal that there were positive associations between illiteracy rate, unemployment, poverty, fertility rate, family size, food consumption, maternal mortality rate, population per physician, and child malnutrition and mortality in the whole world regions. Some regions have strong significant associations, such as Sub-Saharan Africa, Asia, and Americas, and other were non-significant association, such as Europe, Middle East, and North Africa. The results suggest that there were negative associations between GNP, household income, protein consumption, and child malnutrition and mortality in all world regions except Europe and Central Asia regions.

Child↗

PubMed1998

Globality and constructions of world health.

Explorations of the social construction of health and illness reveal that popular and professional discourses on health and disease implicitly contain underlying images of how societies can or should be structured. Globality, which is a notion that refers to the consciousness of the world as a single place, suggests that these images of world structure are now salient. This article describes four current discourses of "work health" and discusses them in terms of their underlying ideal images of world order. The four images of the world are defined in terms of four elemental points of reference: individuals, societies, the system of societies, and humankind. These ideal images have either a gemeinschaft (community) or gesellschaft (society) orientation. An anthropology of globality can refine and extend our understandings of discourses of world health. Sensitivity to these discourses and their world-oriented ideological roots should help to demystify the notion of world health.

Anthropology↗

PubMed1988

Commercial drug compendium information: a First World/Third World comparison.

The purpose of this study was to determine what differences exist in the content of commercial drug compendium monographs available in First World and Third World countries. A content model representing First World information was developed from monographs contained in the Physicians' Desk Reference, ABPI Data Sheet Compendium, and the Rote Liste. The content of the three First World compendia was found to be variable, with the Physicians' Desk Reference consistently more comprehensive than either the ABPI or Rote Liste. This result suggests that there is a lack of agreement among industrialized countries regarding what amount of information is necessary or appropriate for inclusion in a commercial drug compendium. A sample of 58 monographs was selected from four Third World compendia and evaluated in terms of comprehensiveness and accuracy. These monographs represented five commonly prescribed drugs from the World Health Organization's Essential Drugs List. The monographs were found to be less comprehensive than any of the three monographs contained in the First World compendia. Approximately 5 percent of the information contained in the sampled monographs was determined to be inaccurate. The sampled monographs for drugs supplied by multi-national pharmaceutical firms were found to contain the same amount of information as those for drugs supplied by domestic firms.

Data Collection↗

PubMed1999

[Current status of cord blood banks in the world].

Since the first successful transplantation of placental/umbilical cord blood (PCB) in 1988 at St. Louis Hospital in Paris, the effort has been made to establish large scale cord blood banks for allogeneic transplantation around the world. Recent reports from New York Blood Center which stocks 9000 units and shipped 700 units to US and other countries indicates that PCB transplantation is as effective as bone marrow transplantation. There are many cord blood banks in the world now and the number of PCB units stocked in the world are increasing rapidly. The methods for collection and processing of PCB, and test items for screening for viral infections, etc. differ greatly among banks. Therefore, the quality of PCB units stocked worldwide has become an important issue and some major banks are trying to introduce GMP or ISO system for the quality assurance of PCB. In this chapter, we introduce the activities of major cord blood banks in the world. Guidelines or regulation for hematopoietic stem cell processing including PCB has been enacted in some countries though the situation of support from their governments differ. International registry for PCB transplantation have been developed by EUROCORD. The international network of cord blood banks, NETCORD, has been established recently with major banks in Europe, United States and Japan to ensure the rapid supply of safe and efficient PCB units to the patients throughout the world. Obtaining information of international activities of cord blood banks in the world and cooperation with them should bring the National Cord Blood Bank in Japan into concordance with a developing world standards.

Blood Banks↗

PubMed1999

Loving openness as a meta-world hypothesis: expanding our vision of mind and medicine.

In 1942, Stephen C. Pepper published a seminal book, World Hypothesis, that sought to explain how people create hypotheses about the world. Pepper proposed that there were four basic world hypotheses: (1) formistic (the hypothesis that nature exists as categories); (2) mechanistic (the hypothesis that nature obeys cause-effect relationships); (3) contextual (the hypothesis that processes in nature are relative and context dependent); and (4) organismic (the hypothesis that processes in nature reflect interactive relationships in systems). Most classical and modern theories of science and medicine implicitly adopt one or more of these foundational hypotheses. In 1997, Schwartz and Russek proposed that there were four additional world hypotheses: (5) implicit process (the hypothesis that nature consists of invisible forces and information, such as energy and consciousness); (6) circular causality (the hypothesis that nature consists of circulating interactions that inherently change over time); (7) creative unfolding (the hypothesis that processes in nature reflect flexible designs or plans that have adaptive function); and (8) integrative diversity (the hypothesis that phenomena in nature reflect complex integrations of diverse processes). Theories in postmodern and integrative science implicitly adopt hypotheses 5 through 8. However, underlying the creation of the eight world hypotheses is an implicit meta-world hypothesis which we term loving openness (the hypothesis that phenomena in nature reflect levels of openness and caring). This paper briefly explains the origin and implications of the loving openness meta-world hypothesis for understanding mind-body healing in medicine, the reordering of values in integrative medicine (with a primary focus on caring with humility), and the fostering of a new vision for twenty-first century frontier science, spirituality, and medicine.

Attitude↗

PubMed1982

Psychological factors in breast feeding versus bottle feeding in the Third World.

Some readers may be aware of the sociopolitical and moral issues associated with the theme of Brenda Meldrum's article (Bulletin, June 1982) about breast and bottle feeding in the 3rd world. For over a decade many groups (e.g. War on Want; World Development Movement) have been concerned that unnecessary bottle feeding has almost certainly resulted in considerable infant disease and mortality in the 3rd world. Morever, such groups have been well aware of the high psychological value of formula foods; and have attributed this mainly to the aggressive and fundamentally dishonest way in which food companies promote their breastmilk substitutes. In 1979, in response to the bad publicity resulting from the campaigning of 3rd world agencies, Nestle and others agreed to adopt a voluntary code of practice proposed by World Health Organization and UNICEF. However, commercial interests have prevailed--baby food sales in 3rd world account for 2 1/2% of 1 transnational group's turnover--and the malpractices have continued. In view of this we feel that it is appropriate to amend Brenda Meldrum's conclusion to: While transnational corporations continue to actively promote their baby food products in the 3rd world, there can be no reversal to the old, exclusive breastfeeding of traditional practice, and that infants that would otherwise have lived will continue to die. The boycott campaign is continuing and might we suggest that BPS members who organize conferences give some thought to the possibility of requesting that their caterers do not use products of these companies. A list of companies may be obtained from New Internationalist (February 1982) or from us.

Advertising↗

PubMed1985

Plasma and hepatic apoE isoproteins of nonhuman primates. Differences in apoE among humans, apes, and New and Old World monkeys.

We have used two-dimensional polyacrylamide gel electrophoresis (PAGE) to study the plasma and hepatic apoE isoproteins of nonhuman primates and have compared them with their human counterparts. We have found that apoE obtained from fresh monkey or ape plasma, as well as nascent apoE synthesized by perfused monkey livers, is composed of several isoproteins that resemble the homozygous (beta) apoE phenotype observed in humans. The nonhuman primate plasma apoE pattern of 90 animals from nine different species consisted of a major isoprotein designated apoE3 and a few minor isoproteins. A group of acidic apoE isoproteins is eliminated after treatment with C. perfringens neuraminidase and has been designated sialo apoE (apoEs). Nonhuman primate liver apoE isoproteins comigrate with their plasma apoE isoprotein counterparts on two-dimensional PAGE, but hepatic apoE is enriched in sialo apoE isoproteins when compared to plasma apoE. The apparent molecular weight of asialo and sialo apoE obtained from Old World monkeys and apes is identical to the molecular weight of the corresponding human isoproteins (E3 = 38K, Es = 38.5-39.5K). However, the apparent molecular weight of apoE isoproteins obtained from New World monkeys is increased by approximately 0.5K (E3 = 38.5K, Es = 39.0-40.0K) as compared to the molecular weight of human and Old World monkey and ape isoproteins. The isoelectric points of apoE3 obtained from Old World monkeys, New World monkeys, chimpanzees, and gibbons are 5.74, 5.76, 5.95, and 5.89, respectively. The entire New or Old World monkey, chimpanzee, and gibbon apoE pattern is shifted by approximately -2.0, -0.5, and -1.0 charges, respectively, relative to the pattern of the corresponding human E3/3 phenotype. The molecular weight difference in apoE observed among New and Old World monkeys, as well as the molecular weight and/or charge differences observed among monkey, ape, and human apoE are consistent with structural changes in the apoE gene which have occurred following the divergence of the different species. The observation of only the homozygous apoE phenotypes in all animals studied suggests that the common apoE genetic polymorphism recently described in humans may not be present in nonhuman primates.

Animals↗

PubMed2003

Rural health around the world: challenges and solutions.

Despite the huge differences between developing and developed countries, access is the major issue in rural health around the world. Even in the countries where the majority of the population lives in rural areas, the resources are concentrated in the cities. All countries have difficulties with transport and communication, and they all face the challenge of shortages of doctors and other health professionals in rural and remote areas. Many rural people are caught in the poverty- ill health-low productivity downward spiral, particularly in developing countries. Since 1992, WONCA, the World Organization of Family Doctors, has developed a specific focus on rural health through the WONCA Working Party on Rural Practice. This Working Party has drawn national and international attention to major rural health issues through World Rural Health Conferences and WONCA Rural Policies. The World Health Organization (WHO) has broadened its focus beyond public health to partnership with family practice, initially through a landmark WHO-WONCA Invitational Conference in Canada. From this has developed the Memorandum of Agreement between WONCA and WHO which emphasizes the important role of family practitioners in primary health care and also includes the Rural Health Initiative. In April 2002, WHO and WONCA held a major WHO-WONCA Invitational Conference on Rural Health. This conference addressed the immense challenges for improving the health of people of rural and remote areas of the world and initiated a specific action plan: The Global Initiative on Rural Health. The "Health for All" vision for rural people is more likely to be achieved through joint concerted efforts of international and national bodies working together with doctors, nurses and other health workers in rural areas around the world.

Culture↗

PubMed2005

Internet-based search of randomised trials relevant to mental health originating in the Arab world.

BACKGROUND: The internet is becoming a widely used source of accessing medical research through various on-line databases. This instant access to information is of benefit to busy clinicians and service users around the world. The population of the Arab World is comparable to that of the United States, yet it is widely believed to have a greatly contrasting output of randomised controlled trials related to mental health. This study was designed to investigate the existence of such research in the Arab World and also to investigate the availability of this research on-line. METHODS: Survey of findings from three internet-based potential sources of randomised trials originating from the Arab world and relevant to mental health care. RESULTS: A manual search of an Arabic online current contents service identified 3 studies, MEDLINE, EMBASE, and PsycINFO searches identified only 1 study, and a manual search of a specifically indexed, study-based mental health database, PsiTri, revealed 27 trials. CONCLUSION: There genuinely seem to be few trials from the Arab world and accessing these on-line was problematic. Replication of some studies that guide psychiatric/psychological practice in the Arab world would seem prudent.

Arab World↗

PubMed2006

Changes in Scottish suicide rates during the Second World War.

BACKGROUND: It is believed that total reported suicide rates tend to decrease during wartime. However, analysis of suicide rates during recent conflicts suggests a more complex picture, with increases in some age groups and changes in method choice. As few age and gender specific analyses of more distant conflicts have been conducted, it is not clear if these findings reflect a change in the epidemiology of suicide in wartime. Therefore, we examined suicide rates in Scotland before, during and after the Second World War to see if similar features were present. METHODS: Data on deaths in Scotland recorded as suicide during the period 1931-1952, and population estimates for each of these years, were obtained from the General Register Office for Scotland. Using computer spreadsheets, suicide rates by gender, age and method were calculated. Forward stepwise logistic regression was used to assess the effect of gender, war and year on suicide rates using SAS V8.2. RESULTS: The all-age suicide rate among both men and women declined during the period studied. However, when this long-term decline is taken into account, the likelihood of suicide during the Second World War was higher than during both the pre-War and post-War periods. Suicide rates among men aged 15-24 years rose during the Second World War, peaking at 148 per million (41 deaths) during 1942 before declining to 39 per million (10 deaths) by 1945, while the rate among men aged 25-34 years reached 199 per million (43 deaths) during 1943 before falling to 66 per million (23 deaths) by 1946. This was accompanied by an increase in male suicides attributable to firearms and explosives during the War years which decreased following its conclusion. CONCLUSION: All age male and female suicide rates decreased in Scotland during World War II. However, once the general background decrease in suicide rates over the whole period is accounted for, the likelihood of suicide among the entire Scottish population during the Second World War was elevated. The overall decrease in suicide rates concealed large increases in younger male age groups during the War years, and an increase in male suicides recorded as due to the use of firearms. We conclude that the effects of war on younger people, reported in recent conflicts in Central Europe, were also seen in Scotland during the Second World War. The results support the findings of studies of recent conflicts which have found a heterogeneous picture with respect to age specific suicide rates during wartime.

Adolescent↗

PubMed1990

Comparison of muscle weight and force ratios in New and Old World monkeys.

Thin mandibles and small incisors found in New World monkeys as compared with Old World monkeys suggest that there may be differences in craniofacial loading patterns between these two groups, particularly in levels of mandibular corpus twisting (Hylander, 1975, 1979a; Eaglen, 1984; Bouvier, 1986a,b). This study examined the hypothesis that changes in the relative force contributions of the masticatory muscles were responsible for lowering torsion on the mandibular corpus in New World monkeys. Muscle weight and physiological cross-sections were compared using data from the literature (Schumacher, 1960: Turnbull, 1970; Cachel, 1979) as well as new data on adult male Cebus apella and Macaca mulatta. Both age and sex had an effect on muscle ratios. Mixed samples such as those used by Schumacher and Turnbull probably are not appropriate for drawing conclusions concerning species or group differences in muscle ratios. In addition, biomechanical conclusions based on muscle weight ratios alone to estimate muscle force may be misleading because fiber length inversely affects the amount of force a muscle can exert. A comparison of ratios based on physiological cross-section as an estimator of muscle force in New and Old World monkeys does not support the hypothesis that alterations in force contribution by individual masticatory muscles are responsible for minimizing mandibular corpus twisting in New World monkeys. Therefore, if twisting has been minimized in New World monkeys as suggested by their thin corpora, other changes in the craniofacial musculoskeletal complex, such as different muscle recruitment or pinnation patterns, may be responsible.

Animals↗

PubMed1992

Systematics and body size: implications for feeding adaptations in New World monkeys.

The relationship between body size and feeding ecology is well established for primates. It is argued that the evolutionary history of modern New World monkeys and, in particular, the path to attainment of current body size is significant in understanding the similarities and differences between dietary strategies and other ecological parameters of similar-sized monkeys. Current interpretations of New World monkey evolutionary relationships are reviewed. Based on a synthesis of available body weights and the assumption that the earliest New World monkeys weighed close to 1 kg, similar to modern Aotus and Callicebus, predicted patterns of body size change in each lineage are given. Restrictions on directions of body size change in primates are discussed, and it is shown that "Stanley's Rule" offers a good explanation for differing body size ranges in New and Old World anthropoids. Predicted ecological correlates to body size drawn from the mammalian literature are offered and tested using data on New World monkeys, which show some concurrence and several interesting departures from predicted patterns. Sexual dimorphism in body weight of New World monkey species is reviewed, based on the new summary of body weight data given.

Adaptation, Physiological↗

PubMed1986

Studies on the evolution of multiple somatosensory representations in primates: the organization of anterior parietal cortex in the New World Callitrichid, Saguinus.

Because members of the New World family, Callithricidae, are generally regarded as the most primitive of monkeys, we studied the organization of somatosensory cortex in the tamarin (Saguinus) in hopes of better understanding differences in the organization of anterior parietal cortex in primates and how these differences relate to phylogeny. In most prosimian primates only one complete representation of cutaneous receptors has been found in the region of primary cortex, S-I, while in all Old and New World monkeys studied to date, two cutaneous representations exist in distinct architectonic fields, areas 3b and 1. In detailed microelectrode mapping studies in anesthetized tamarins, only one complete representation responsive to low-threshold cutaneous stimulation was evident in the S-I region. This topographic representation was in a parietal koniocortical field that architectonically resembles area 3b of other monkeys, and the general somatotopic organization of the field was similar to that of area 3b of other monkeys. Cortex rostral to the single representation was generally unresponsive to somatosensory stimuli, or required more intense stimulation for neural activation. Cortex caudal to the representation, in the region of area 1 of other monkeys, was generally either unresponsive or responded to only high-threshold stimulation, although some recording sites were activated by low-threshold tactile stimulation. The present evidence, together with that from previous studies, suggests that the single, complete body surface representation in Saguinus is homologous to the S-I representation found in some prosimians (Galago, Perodicticus) and the area 3b cutaneous representation found in New World Cebidae (Aotus, Saimiri, and Cebus) and Old World Macaca. Cortex rostral to S-I in Saguinus has the appearance of areas 3a and 4 of other primates. The cortex caudal to S-I in Saguinus, while resembling area 1 in some ways, does not have all of the features of area 1 of other monkeys. In particular, the field was not easily activated by low-threshold cutaneous stimuli, as area 1 is in other monkeys, and therefore a second cutaneous representation of all body parts was not demonstrated. Thus, cortex in the expected location of area 1 of Saguinus was not as responsive as area 1 of other monkeys, and it somewhat resembled the high-threshold fringe zones found caudal to S-I in anesthetized prosimians and some nonprimates. The results raise the possibility that the area 1 cutaneous representation that is characteristic of other New World monkeys and Old World monkeys evolved from a less responsive precursor along the caudal border of S-I in early monkeys.

Animals↗

PubMed1993

Identification of a competitive binding component in vitamin D-resistant New World primate cells with a low affinity but high capacity for 1,25-dihydroxyvitamin D3.

Monkeys in a number of different New World primate genera express a form of compensated target organ resistance to steroid hormones, including 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Characterization of these phenotypes has previously relied upon the study of the 1,25-(OH)2D3-receptor (VDR) interaction in cultured dermal fibroblasts from affected primates. In this report, we show that three of these prototypic phenotypes can be faithfully reproduced in previously established cultured cell lines: B95-8, EBV-transformed B lymphoblasts from the marmoset (Callithrix jacchus), a New World primate with recognized vitamin D resistance; OMK, renal tubular epithelial cells from the owl monkey (Aotus trivergatus), a New World primate with an Old World primate-like VDR phenotype; and MLA144, transformed B lymphoblasts from a gibbon (Hylobates), an Old World primate that expresses the wild-type VDR phenotype. The rank order of specific nuclear uptake and binding of [3H]1,25-(OH)2D3 to the VDR was OMK > or = MLA144 >> B95-8. Despite a 7- to 9-fold difference in cellular VDR content according to ligand binding analyses, there was no discernible difference in the internalization constant Kin for specific cellular uptake of [3H]1,25-(OH)2D3 (0.12-0.26 nM) or in the quantity of VDR detected by immunoblot analysis. We now speculate that the discrepancy in VDR quantitation by binding and immunoblot analysis in the B95-8 New World primate cell line results from the presence of an intracellular, vitamin D metabolite binding moiety in this cell line that competes with the VDR for metabolite binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗