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PubMed1990

Surface and internal galactosyl receptors are heterooligomers and retain this structure after ligand internalization or receptor modulation.

We have developed a specific chemical affinity reagent for the hepatic galactosyl receptor (GalR) by derivatizing asialoorosomucoid (ASOR) with the homobifunctional N-hydroxysuccinimide (NHS) ester cross-linker disuccinimidyl suberate [Herzig, M. C. S., & Weigel, P. H. (1989) Biochemistry 28, 600]. NHS-ASOR cross-links with 30-50% efficiency to the three GalR subunits, designated rat hepatic lectins (RHL) 1, 2, and 3. Here, we examined the subunit structure of both surface and internal receptors of two functionally distinct GalR subpopulations, designated state 1 or state 2 GalR. Freshly isolated cells, referred to as state 1 cells, kept at 4 degrees C express only active state 1 GalR on their surface. When these cells are equilibrated at 37 degrees C, they then express both state 1 GalR and state 2 GalR on their surface. These cells are referred to as state 1,2 cells. After incubation at 4 degrees C with NHS-125I-ASOR, surface or internal GalR of state 1 cells or of state 1,2 cells incorporated 125I-ASOR into all three RHL subunits. As analyzed by autoradiography of SDS-PAGE, radiolabeling was identical for all conditions and was in a ratio of 1:1:1 for RHL 1:2:3. Native GalR structure was also examined by first cross-linking nonradiolabeled NHS-ASOR at 4 degrees C to surface or internal receptors of state 1 or state 1,2 hepatocytes. These cells were then washed with EGTA, extracted with Triton X-100, immunoprecipitated with anti-orosomucoid antibody, and subjected to Western blot analysis. Antisera specific for RHL 1 or RHL 2/3 detected cross-linked complexes of Mr congruent to 85K or congruent to 90K-115K, respectively, as well as un-cross-linked native subunits. In all four cases, the ratio of free to cross-linked subunits was greater than or equal to 5:1 for RHL 1 and less than or equal to 0.5:1 for RHL 2/3. Internalized GalR had the same ratio of free to cross-linked subunits as noninternalized GalR. Depletion of ATP either before or after cross-linking GalR to NHS/ASOR also did not alter the ratio of free cross-linked RHL subunits. We conclude that the surface and internal GalR of the two functionally distinct GalR populations have the same heterooligomeric subunit composition and that this GalR structure persists following endocytosis or ATP depletion.

Affinity Labels↗
PubMed2001

An international collaborative study to establish a World Health Organization international standard for hepatitis B virus DNA nucleic acid amplification techniques.

BACKGROUND AND OBJECTIVES: Twenty-two laboratories from nine countries participated in an international collaborative study to establish a World Health Organization (WHO) international standard for hepatitis B virus (HBV) DNA nucleic acid amplification techniques (NAT). MATERIALS AND METHODS: Three samples, AA, BB (both of which were lyophilized) and CC (which was a liquid preparation), were analysed using several different NAT assays. The mean HBV DNA content of each sample was determined from the study. RESULTS: Despite the range of assays (commercial and in-house) used by participants, there was good agreement among the overall mean 'equivalents'/ml obtained by the different assays, except for one laboratory (laboratory 4). The variation in estimates of log10 'equivalents'/ml was 1.75-1.25 for the three samples if results from laboratory 4 were excluded. The mean log10 'equivalents'/ml for all laboratories were 6.42 for sample AA, 6.30 for sample BB and 5.03 for sample CC (exclusion of results from laboratory 4 made little difference). The difference in titres between the two lyophilized samples (AA and BB) was not statistically significant but the titre of the frozen sample (CC) was significantly lower. Material AA (code 97/746) was accepted as the first WHO international standard for HBV DNA NAT assays and assigned a potency of 10(6) international units (IU)/ml. CONCLUSIONS: The titres (genome equivalents/ml) of three HBV preparations were determined by several laboratories using different NAT assays. This study enabled the establishment of an international standard, 97/746, for HBV DNA NAT assays.

DNA, Viral↗
PubMed1995

The value of plasma calibrants in correcting coagulometer effects on international normalized ratios. An international multicenter study.

A study of lyophilized plasma calibrants in correcting for coagulometer effects on International Normalized Ratios (INR) has been conducted in an international survey. Prothrombin times were performed with the calibrants on 2 "common" thromboplastins and in-house thromboplastins in 3 brands of coagulometer at 37 centers. The International Sensitivity Indices (ISI) of 95 local systems with the calibrants were derived. The "true" INR of 10 test plasmas from warfarin-treated patients were established centrally using thromboplastin International Reference Preparations (IRP). International Normalized Ratios of these plasmas for each center were calculated using both the manufacturers' stated and the local ISI. The mean deviation of the 95 systems from the "true" INR of the warfarin plasmas was +14.4% with the manufacturers' ISI, but reduced to +1.04% with the local ISI. Local ISI determination with the calibrants avoids many of the difficulties of conventional thromboplastin calibrations. Plasmas from patients on warfarin and parallel manual PT with thromboplastin IRP are not required.

Blood Coagulation Tests↗
PubMed1995

Picornavirus internal ribosome entry segments: comparison of translation efficiency and the requirements for optimal internal initiation of translation in vitro.

On the basis of primary sequence comparisons and secondary structure predictions, picornavirus internal ribosome entry segments (IRESes) have been divided into three groups (entero- and rhinoviruses; cardio- and and aphthoviruses; and hepatitis A virus). Here, we describe a detailed comparison of the ability of IRESes from each group to direct internal initiation of translation in vitro using a single dicistronic mRNA (the only variable being the IRES inserted into the dicistronic region). We studied the influence of various parameters on the capacity of six different picornaviral IRESes, and the non-picornaviral hepatitis C virus IRES, to direct internal initiation of translation: salt concentration, the addition of HeLa cell proteins to rabbit reticulocyte lysate translation reactions, the presence of foot-and-mouth disease virus Lb or human rhinovirus 2A proteinase. On the basis of the characteristics of IRES-driven translation in vitro, the picornaviral IRESes can be classified in a similar manner to when sequence homologies are considered. IRESes from each of the three groups responded differently to all of the parameters tested, indicating that while all of these elements can direct internal ribosome entry, the functional requirements for efficient IRES activity vary dramatically. In the individual optimal conditions for translation initiation, the best IRESes were those from the cardio- and aphthoviruses, followed by those from the enteroviruses, which exhibited up to 70% of the efficiency of the EMCV element in directing internal initiation of translation.

Base Sequence↗
PubMed2001

International classification criteria for antiphospholipid syndrome: synopsis of a post-conference workshop held at the Ninth International (Tours) aPL Symposium.

An international workshop on classification criteria for antiphospholipid syndrome (APS) was held on 16 September 2000 in Tours, France, following the Ninth International APS Symposium. The workshop addressed issues that were not resolved by the previous (1998) international workshop on the classification criteria. Participants at the workshop agreed that no changes should be made to the international (Sapporo) criteria at the present time. However, to improve the criteria, future efforts should be focused on the following: (1) further evaluation of the international (Sapporo) criteria for definite APS; (2) definition of other categories of APS such as 'probable' and 'possible' APS; (3) guidelines for the clinical diagnosis as distinct from classification of APS; (4) strategies to improve the compliance of laboratories worldwide, with recommended procedures for Lupus anticoagulant (LA) and anticardiolipin (aCL) assays; (5) development of monoclonal antibody standard reagents for aCL and LA assays; and (6) refinement and subsequent evaluation of antibeta2GPI assays for use in idenfitication of APS.

Antiphospholipid Syndrome↗
PubMed2000

The C-terminal tail of the rat lutropin/choriogonadotropin (CG) receptor independently modulates human (h)CG-induced internalization of the cell surface receptor and the lysosomal targeting of the internalized hCG-receptor complex.

The analysis of 21 progressive truncations of the C-terminal tail of the rat LH/CG receptor (rLHR) revealed the presence of a region delineated by residues 628-649 that, when removed, enhanced the degradation of the internalized human (h)CG. The analysis of these truncations also revealed the presence of a region delineated by residues 624-631 that, when removed, enhanced the rate of internalization of hCG. Since there is little overlap between these two regions, we conclude that the structural features of the rLHR that mediate internalization and degradation of the internalized hormone are different. Detailed analyses of cells expressing a truncation at Y637 (designated rLHR-t637) showed that the enhanced degradation of hCG observed in the these cells is due to an increase in the rate of transfer of the internalized hCG-rLHR complex from the endosomes to the lysosomes rather than to the enhanced dissociation of the hCG-rLHR complex in the lysosomes.

Amino Acid Sequence↗
PubMed1989

Connections found between each meridian (heart, stomach, triple burner, etc.) & organ representation area of corresponding internal organs in each side of the cerebral cortex; release of common neurotransmitters and hormones unique to each meridian and corresponding acupuncture point & internal organ after acupuncture, electrical stimulation, mechanical stimulation (including shiatsu), soft laser stimulation or QI Gong.

Using the "Bi-Digital O-Ring Test Imaging Technique", the author has been able to accurately localize meridians and acupuncture points that correspond to specific internal organs and has found that most general patterns of meridians and the number of acupuncture points on each of the meridians of specific internal organs of the 12 main internal organs described in the literature of ancient Chinese medicine, are more or less correct, with the exception of some variations and inaccuracies. Each meridian of specific internal organs was found to be connected to the organ representation area in the cerebral cortex of specific internal organs. The acupuncture point has an area and occupies 3-dimensional space. It has a circular or slightly oval boundary with diameter in the range of 3 mm to 2.7 cm, although 6-12 mm are the most common diameters in human adults, with the exception of the area outside the corners of the nailbeds of the fingers and toes. Using the "Bi-Digital O-Ring Test Molecular Identification Method", the author also found that within the boundary of most acupuncture points and meridian lines (including Heart, Stomach, and Triple Burner) were high concentrations of neurotransmitters and hormones, including Acetylcholine, Methionine-Enkephalin, Beta-Endorphin, ACTH, Secretin, Cholecystokinin, Norepinephrine, Serotonin, and GABA. On all these meridian lines, in addition to the above neurotransmitters and hormones, Dopamine, Dynorphin 1-13, Prostaglandin E1 (PGE1) and VIP were found, but the latter do not usually exist within the boundary of the acupuncture point with the exception of the center midline of the acupuncture point where the meridian line is situated. Serotonin, Norepinephrine, and Cholecystokinin appeared in either one of the above 2 patterns, depending on the individual. Usually, no significant amounts of these neurotransmitters and hormones were found at the surrounding area outside of meridian and acupuncture points. However, the essential amino acid L-Tryptophan (which is a precursor of Serotonin), was usually found outside of the boundary of the acupuncture point and the meridian but not within the boundary of the acupuncture point and the meridian. Wherever Serotonin appeared, L-Tryptophan disappeared significantly and when the Serotonin disappeared, L-Tryptophan reappeared. In addition to the above common neurotransmitters and hormones, the Heart meridian had additional Atrial Natriuretic Peptide in both the meridian and its acupuncture points. Similarly, the Stomach meridian had additional Gastrin in both the meridian and its acupuncture points. Likewise,the Triple Burner meridian had additional Testosterone (in the male) and Estrogen (especially Estriol and Estradiol in the female.

Acupuncture Points↗
PubMed1958

Third international standard for posterior pituitary; re-named third international standard for oxytocic, vasopressor and antidiuretic substances in 1956.

In October 1955, stocks of the Second International Standard for Posterior Pituitary were running low and the Department of Biological Standards of the National Institute for Medical Research, London, was asked to proceed with the arrangements for an international collaborative assay of material for the Third Standard. A single 142-g batch of posterior-pituitary-lobe powder was obtained and distributed in ampoules, in approximately 30-mg quantities. Samples were sent to 19 laboratories in 10 countries. In all, 185 assays were carried out, 122 for oxytocic activity, 53 for vasopressor activity and 10 for antidiuretic activity.On the basis of the results, which were analysed statistically at the National Institute for Medical Research, it was agreed that the potency of the Third Standard (re-named International Standard for Oxytocic, Vasopressor and Antidiuretic Substances in 1956, in view of the recent synthesis of oxytocin and vasopressin) should be expressed as 2.0 International Units per milligram. The International Unit therefore remains unchanged as 0.5 mg of the dry powder.

Biological Assay↗
PubMed1986

The involvement of cellular ATP in receptor-mediated internalization of epidermal growth factor and hormone-induced internalization of beta-adrenergic receptors.

Beta-Adrenergic receptors and epidermal growth factor receptors are both expressed on the cell surface of human astrocytoma cells. Incubation with a catecholamine or epidermal growth factor results in rapid internalization of the respective receptor. The internalized receptors co-migrate in light fractions on sucrose gradients. Astrocytoma cells maintain a constant ATP concentration by either glycolytic or mitochondrial ATP production. When cells are incubated in a medium depleted of substrates for glycolysis and gluconeogenesis, addition of inhibitors of mitochondrial ATP synthesis causes a rapid reduction in cellular ATP content. An immediate return to control ATP levels occurs upon addition of an appropriate nutrient, such as glucose. Decreasing the cellular ATP content to less than 10% of control markedly inhibits internalization of beta-adrenergic receptors and epidermal growth factor. The inhibition of endocytosis is reversed as soon as the intracellular ATP content is restored. Previous work by others (Clarke, B.L., and Weigel, P.H. (1985) J. Biol. Chem. 260, 128-133) suggested that ATP is not required for internalization (per se) of asialoglycoprotein in hepatocytes but was required for recycling of the asialoglycoprotein receptor. In contrast, our results indicate that in astrocytoma cells the process of internalization of epidermal growth factor and beta-adrenergic receptors, per se, is highly ATP dependent.

Adenosine Triphosphate↗
PubMed1988

[Studies on internal pressure and oxygen tension of bone tumors and tumor conditions. II--Growth rate, internal pressure and oxygen tension in bone lesions].

Internal pressure and oxygen tension were measured in 24 patients with bone tumors and tumorous conditions. High internal pressure were observed in most of the rapidly growing lesions. The internal pressure of slowly growing and non-growing lesions were not significantly different from those of normal bone marrow. Oxygen tension was commonly higher in the rapidly growing lesions than in simultaneously obtained peripheral venous samples from the same patients. A high correlation was found between internal pressure and the growth rate of the bone lesions in this study. These data suggest that internal pressure and oxygen tension of the lesions reflect the degree of blood supply to the bone tumors and tumorous conditions.

Adolescent↗
PubMed1980

Studies on phage internal proteins. VI. Interaction of bacteriophage T4 internal proteins with T4 DNA in vivo and in vitro.

Internal proteins are basic proteins bound to the DNA of T4 coliphage. Centrifugation in sucrose gradients was employed to isolate DNA-internal proteins complexes formed in vitro. Polyacrylamide gel electrophoresis of radioactive internal proteins in the presence of sodium dodecyl sulfate followed by autoradiography of the gels was used to identify the DNA-bound proteins and to determine their respective abundance in these complexes as well as in the bacteriophage head. The internal proteins were found to bind to the phage DNA (in vitro experiments) at the same ratio as that of internal proteins associated with the viral DNA within the phage head (in vivo binding).

Centrifugation, Density Gradient↗
PubMed2002

Role of the international organisation for animal health (Office International des Epizooties: OIE) in the control of foot and mouth disease.

The author describes activities conducted by the International Organisation for Animal Health (OIE: Office International des Epizooties) to control foot and mouth disease (FMD) world-wide. These activities fall within the framework of the principal missions of the OIE. The first of these missions is the collection and dissemination of epidemiological information and of scientific knowledge on animal diseases, the socio-economic or disease implications of which can be particularly serious. The implementation of the measures required to control the disease and to protect countries threatened by FMD depends on the quality and rapidity of the transmission of this information. The co-ordination of studies, research and control programmes against FMD is equally important for the OIE. This work is based, in particular, on work conducted by the OlE foot and mouth disease and other epizootics Commission. OIE Member Countries not only have access to the most recent data on the diagnosis, surveillance and control of FMD but also have recourse to the official recognition procedure for disease-free status provided by this Commission. Finally, through the standardisation of health recommendations, diagnostic tests, manufacture protocols and the control of biological products, made available by the OIE International Animal Health Code Commission in regard to the former and by the OIE Standards Commission in regard to the latter, the OIE provides the reference for international trade in animals and animal products, and is recognised in this role by the World Trade Organization.

Animal Welfare↗
PubMed1999

The International Health Program: the fifteen-year experience with Yale University's Internal Medicine Residency Program.

The purpose of this study was to assess the impact of international health electives on physicians-in-training. A retrospective study was conducted using an anonymous, self-administered mailed survey to internal medicine residents who trained at Yale from 1982 to 1996 based on their experience with our International Health Program (IHP). The response rate was 61%, with 96 completed surveys in the participant group and 96 completed surveys in the nonparticipant group. Participants were more likely than nonparticipants to care for patients on public assistance (77 versus 49; P < 0.001) and immigrant patients (41 versus 23; P = 0.006). Among residents who changed their career plans, participants (22) were more likely than nonparticipants (14) to switch from subspecialty medicine to general medicine (P = 0.02). Participants were significantly more likely to have a positive view of health care delivery in developing countries. Compared with nonparticipants (64), IHP participants (74) believed that the physical examination is under-used by physicians from the United States as a diagnostic skill (P = 0.03). International health experiences appeared to have an important impact on the decisions and attitudes of residents.

Adult↗
PubMed1989

International migration, international relations and foreign policy.

Recent literature on migration, international relations, and foreign policy is reviewed in this article, stressing applications of global systems paradigms, studies of state entry and exit rules, and anatomies of domestic policy-setting processes on migration. After a concise assessment of the contemporary theory of global political economy, the paper argues for seeking mid-range generalizations on the international relations of migration. It also suggests that analysis begin with the policy-setting processes of the state. Especially through the use of comparative perspectives available from domestic policy making studies and from the field of international comparative public policy, this approach offers the opportunity to fix empirically the political roles of transnational social forces, which often present themselves as participants in domestic policy contests. Promising future directions in the study of state-to-state relations are also evaluated, with the anticipation that verifying regional or other intermediate patterns of world migration politics may contribute to more general theories of international political economy.

Demography↗
PubMed1963

THE INTERNATIONAL REFERENCE PREPARATION OF SMALLPOX VACCINE. AN INTERNATIONAL COLLABORATIVE ASSAY.

A purified, concentrated sheep vaccine, prepared from a vaccinia strain in use in the United Kingdom for more than 60 years, has been established as the International Reference Preparation of Smallpox Vaccine, intended to permit comparative assay with national reference vaccines.Before its establishment as the International Reference Preparation, the proposed international reference vaccine was tested in seven laboratories in as many countries together with four other distributed vaccines and one local vaccine in each country. All laboratories used the scarification test on rabbits; four used the pock count method; the intracutaneous test in rabbits, the plaque count in tissue culture and the LD(50) test in eggs, cultures and newborn mice were used by one to three of the participants.The proposed international reference preparation met all the requirements laid down by the WHO Study Group on Requirements for Smallpox Vaccine in six laboratories when the scarification test was used and in all laboratories when the pock count test was used.

Animals↗
PubMed2000

Hepatitis A immunoglobulin: an international collaborative study to establish the second international standard.

A collaborative study was carried out to assess the suitability of a candidate replacement material for the International Standard for hepatitis A immunoglobulin, which was found to be reactive for HCV RNA, and to calibrate it in International Units. The candidate standard, coded 97/646, was derived from a bulk of 16% immunoglobulin supplied by the Central Laboratory of the Netherlands Red Cross, Amsterdam, and diluted 1 in 2 in H2O resulting in a final immunoglobulin concentration of 8%. Sixteen laboratories from 11 countries participated in the study and contributed data from 64 assays performed using six commercial assay kits and four in-house methods. All assays were analysed as parallel line bioassays comparing assay response with log concentration. The overall mean potency of the candidate replacement immunoglobulin standard, 97/646, relative to the International Standard for hepatitis A immunoglobulin, was 98.6 IU/ml. A freeze-dried serum preparation, 97/648, was also calibrated in this study and had a potency of 22.64 IU/ml. The Second International Standard for hepatitis A immunoglobulin, human, was established by the World Health Organisation Expert Committee on Biological Standardisation in 1998 with a potency of 49 IU per ampoule when reconstituted in 0.5 ml.

Biological Assay↗
PubMed2001

International collaborative study: evaluation of proposed International Reference Reagent of pertussis antiserum (mouse) 97/642.

A freeze dried preparation of mouse serum in vials coded 97/642 containing antibodies to five pertussis antigens [pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), fimbriae type 2 and 3 (Fim 2 and 3)] has been assessed for its suitability as an international reference reagent in an international collaborative study by thirteen laboratories in nine countries. This serum has been compared with U.S. Standard Pertussis Antiserum (mouse) Lot No. 1 (US Lot 1), which has been in use since 1995, for antibodies for each antigen. Calibration of the proposed International Reference Reagent of Pertussis Antiserum (pIRR) in terms of US Lot 1 gives results which are broadly consistent between laboratories for antibodies to each antigen, although the between-laboratory differences are larger than those seen for comparison of identical sera. Calibration of two positive control sera in terms of the pIRR gave similar between laboratory variability of estimates to that obtained when the same sera were calibrated in terms of US Lot 1. Overall continuity of estimates is maintained if units are assigned to the pIRR based on its calibration in terms of US Lot 1 in this study. Data presently available indicate that the pIRR is sufficiently stable to serve as a reference reagent. It was therefore recommended, with the agreement of all participants, that the preparation in vials coded 97/642 be established as the First International Reference Reagent for Pertussis Antiserum, mouse, with assigned unitages 16 units of anti-PT per vial, 143 units of anti-FHA per vial and 30 units of anti-PRN per vial based on its calibration in terms of US Lot 1. These unitages are also consistent with calibration of 97/642 in terms of the Japanese preparations JNIH-11 for anti-FHA and of JNIH-12 for anti-PT. Purified antigens for Fim 2 and Fim 3 are not readily available and an arbitrary value of 32 units per vial is suggested for anti-Fim 2 and 3 mixture. These recommendations were agreed by the Expert Committee on Biological Standardization of the World Health Organization.

Adhesins, Bacterial↗
PubMed1983

[Stenosis of the internal carotid artery with contralateral occlusion--primary vascular operation of externo-internal bypass?].

Among 2135 patients undergoing vascular surgery of the carotid artery, 144 revealed a stenosis of the internal carotid in combination with an occlusion on the contralateral side. Temporary inlying bypass shunts to support cerebral circulation during the endarterectomies were employed when technically feasible. The mortality among the in-patients amounted to 3.47%. Postoperative permanent neurologic deficits did not appear. During the follow-up period lasting between 1 month and 9 years 6.5% had further TIA's or strokes. Approximately 90% of the patients remained without neurologic symptoms. Neurosurgeons generally recommend a prophylactic external-internal bypass, prior to the removal of the stenosis of the internal carotid artery. According to our experience the primary objective should be the reconstruction of the stenosed artery, particularly since complications in primary external-internal bypassed occur in an average of 3-4%.

Arterial Occlusive Diseases↗