Biomedical subjects
Publications and source records attributed to J Andres.
In 1989, the Spanish Association of Nephrological Nursing (Sociedad Espanola de Enfermeria Nefrologica--SEDEN) created a course directed to all graduates in nephrological nursing in Spain to answer a need for further training. This article details the objectives, methodology, and results of the Course for Accrediting Specialized Knowledge in Nephrological Nursing since it was created.
The nature and role of cell surface proteins that bind members of the TGF-beta family has been investigated. TGF-beta, activins, and BMPs each bind to receptors of 55 kDa (type I) and 70 kDa (type II). In the TGF-beta system, these receptors are implicated in the mediation of multiple responses. A member of the type II receptor family has been cloned that encodes four alternatively spliced versions of a transmembrane serine/threonin kinase receptor related to the recently cloned mouse activin receptor and C-elegans daf-1 gene. Inhibitors of serine/threonine kinase activity block transcriptional and growth inhibitory responses to TGF-beta. In addition to the signaling receptors, many cell types express the TGF-beta binding proteoglycan betaglycan. Betaglycan has been purified, molecularly cloned, and shown to bind TGF-beta via its core protein and basic fibroblast growth factor via its heparan sulfate chains. In addition to receptors I and II and betaglycan, some cells express a newly identified set of membrane proteins that specifically bind either TGF-beta 1 or TGF-beta 2. Three of the four isoform-restricted binding proteins are bound to the membrane via phospholipid anchors. Like betaglycan, these proteins might function to regulate the interaction between TGF-beta and their target cells.
There is a proven relation between cytomegalovirus (CMV) infection in seronegative immunocompromised patients and transfusion of random CMV unscreened cellular blood products (BP), where the leukocytes are thought to be the vector of transmission. We examined whether freezing, thawing, and washing, in attempt to reduce the quantity of leukocytes, also reduces the CMV-DNA-carrying cells of BP of CMV-seropositive donors and their infectivity for fibroblasts, using the polymerase chain reaction (PCR). The leukocyte contamination of the thawed-washed erythrocyte concentrates was < 1 x 10(8)/l and of the thawed-washed platelet concentrates, approximately 2.5 x 10(8)/l. All plasma samples and most samples of BPs of the CMV-seronegative controls were PCR-CMV-DNA-negative. The differences of the PCR results with the samples of CMV-seropositive donors before and after freezing were not significant. Thus we concluded that freezing-thawing-washing of cellular BP could not eliminate all CMV-DNA-bearing leukocytes. Plasma carries low risk for CMV infection, if at all.
Mitochondrial respiration parameters were studied in mitochondria isolated from normal, ischemic and post-ischemic rabbit hearts. Mitochondrial function was related to tissue content of high energy phosphates (HEP) and cardiac function in the isolated working rabbit heart preparation. It was found that after 10 and 20 mins of global normothermic ischemia followed by 20 mins of Langendorff reperfusion, mitochondrial function and HEP content of the myocardium were not significantly diminished. Myocardial creatine phosphate even showed a significant overshoot as compared to the pre-ischemic condition. When these hearts were allowed to perform work, recovery of cardiac function was incomplete while mitochondrial function and HEP content remained in the normal range. Prolonged ischemia (30 mins) resulted in a significant depression of mitochondrial function and myocardial ATP content during and after ischemia. Recovery of contractile function was severely depressed. These results show that impaired cardiac function after a mild ischemic insult (myocardial stunning) can be associated with near normal mitochondrial function and HEP contents.
Transforming growth factors-beta (TGFs-beta) are representative of a superfamily whose members were first identified as regulators of morphogenesis and differentiation, and subsequently found to be structurally related. Other members of the family include the activins and inhibins, BMPs, MIS, the DPP-C gene product and Vg-1. When assayed by affinity-labelling techniques, TGFs-beta bind to three distinct cell surface proteins which are present on most cells. These proteins are all of relatively low abundance but bind TGFs-beta with affinities consistent with the biological potency of the factors. The Type I and Type II binding proteins are glycoproteins with estimated molecular weights of 53 and 73 x 10(3) Mr, respectively. They both bind TGF-beta 1 significantly better than TGF-beta 2. The Type I receptor has been identified as the receptor which mediates many of the responses of TGFs-beta, based on somatic cell genetic studies of epithelial cell mutants unresponsive to TGFs-beta. Betaglycan is the third binding protein present on many, but not all, cell types and is a large proteoglycan (approximately 280 x 10(3) Mr) with 100-120 x 10(3) Mr core proteins. A soluble form of this molecule is present in conditioned media of many cell lines and may be derived from the cell surface-associated molecule by cleavage of a small membrane anchor. Betaglycan binds TGF-beta 1 and TGF-beta 2 with similar affinity and this binding is to the core proteins, not the glycosaminoglycan side chains. This molecule may have a function in the localization and delivery or the clearance of activated TGFs-beta.(ABSTRACT TRUNCATED AT 250 WORDS)
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A confidential self-exclusion (self-exclusion means that the donor doesn't want his blood to be used for transfusion purposes) questionnaire was given during 12 months to 19,108 periodical blood donors in the College of Medicine in Hannover. 237 donors stated that their blood was not to be used for transfusion purposes. 70% of them were males, 30% females. 53% of these self-exclusion donors were between 21 and 30 years old. Among these self-exclusion donor, all the HIV-antibody-test showed negative results. The blood units from these donors were destroyed. The financial loss was DM 48,000. From among donors who thrice wished self-exclusion, one third declared promiscuity as the motive for self-exclusion, one third did not understand the questionnaire and one third could not or did not want to explain the self-exclusion. The question about the efficiency of the confidential donor self-exclusion process may be answered positively compared to the results of Nusbacher's study, which evaluated five times as many blood donations.
In January 1988, sales of new three-wheel all-terrain vehicles (ATVs) were banned in the United States because of the high incidence of injury associated with their use, especially by children. Four-wheel ATVs remain on the market. A retrospective review of all ATV injuries seen in a level I pediatric trauma center was conducted to compare the nature and severity of injuries in three-wheel vehicles with those associated with four-wheelers. A total of 36 ATV injuries were seen from April 1986 to August 1988. All patients were less than 16 years of age; 72% were less than or equal to 12 years of age. Of the patients, 56% were boys; 44% were girls. Although 56% of incidents involved three-wheelers, a larger number of more serious injuries, defined as the presence of indicators of injury severity (eg, death, Injury Severity Score greater than or equal to 10, intensive care unit admission, or need for surgery), involved four-wheel vehicles. A total of 15 injuries occurred in 1987; 12 injuries, including the first death involving an ATV at the pediatric trauma center, occurred in the 7 months since the sales ban. Immature judgment and/or motor skills were the most common factors contributing to injury. Existing information regarding injuries involving three-wheel ATVs is supported by our data, according to which it is suggested that four-wheel vehicles may be dangerous in the hands of immature or unskilled operators less than 16 years of age. Injury prevention efforts should be directed at prohibiting any ATV use by persons less than 16 years of age.
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We describe two brothers with small size at birth, early-onset insulin-dependent diabetes, and pancreatic exocrine insufficiency. In contrast to the findings in pancreatic aplasia, their serum C-peptide and glucagon levels were measurable. These findings, in concert with their clinical courses, are consistent with the diagnosis of congenital pancreatic hypoplasia.
In polytransfused patients the diagnostics of the iron overload belongs to the strategic programme of the treatment. It is particularly referred to the value of the desferal test. In the therapy of the transfusion haemosiderosis desferrioxamine is the remedy of choice. Its at present most favourable form of application is the subcutaneous infusion by means of the infusion group. A success of the treatment is only to be guaranteed, when the therapy is consequently performed over years under balancing the iron supply and excretion.
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In MOPP-resistant patients with Hodgkin-lymphoma stage III B and IV the well known ABVD-protocol was compared with the DBVCy-protocol (daunorubicin, bleomycin, vincristine, cytostasan) in a randomized prospective trial. 73 patients were evaluable, 35 received ABVD, 38 DBVCy. 4 out of 35 (11%) in the ABVD-group and 9 out of 38(24%) in the DBVCy-group reached complete remission. The median duration of the remission for DBVCy was 4,5 months, for ABVD 3,4 months (no significance). Median survivals (61 months in DBVCy and 37 months in ABVD) did not show significant differences; but the DBVCy-scheme seems to be better tolerabel. With the given evaluation can not be proved a difference between the two groups, but it is not likely, that one of the regimen is very much better or very much worse as the other.
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Aroclor 1254 and fireMaster BP-6, two commercial polychlorinated biphenyl (PCB) and polybrominated biphenyl (PBB) preparations, exhibit comparable biologic and toxic effects. In the present study the commercial PBB was more active than Aroclor 1254 in causing thymic atrophy in male Wistar rats. However, a direct comparison of the relative effects of bromine vs chlorine substituents is not possible with the commercial PBB and PCB mixtures due to their complex congeneric composition. This study reports the synthesis and biologic and toxic effects of a series of laterally substituted 3,3',4,4'-tetrahalobiphenyls which contain the following variable molecular Cl/Br ratios; Br4, Br3Cl, Br2Cl2 (two isomers), BrCl3, and Cl4. 3,3',4,4'-Tetrabromobiphenyl and 3,4,4'-tribromo-3'-chlorobiphenyl (150 mumol/kg)-pretreated animals significantly inhibited the growth rate of and caused thymic atrophy in immature male Wistar rats whereas those isostereomers with reduced Br (and increased Cl) content were either less active or inactive. Pretreatment of male Wistar rats with 10 mumol/kg of the 3,3',4,4'-tetrahalobiphenyls and determination of their effects as inducers of the hepatic microsomal drug-metabolizing enzymes also illustrated the effects of the relative Cl/Br ratios on induction potencies. Both 3,3',4,4'-tetrabromo- and 3,4,4'-tribromo-3'-chlorobiphenyl maximally induced the cytochrome P-448-dependent monooxygenases, benzo[a]pyrene and 4-chlorobiphenyl hydroxylase; the order of potency of the other isostereomers was 4,4'-dibromo-3,3'-dichloro- congruent to 3,4-dibromo-3',4'-dichlorobiphenyl greater than 4-bromo-3,3',4'-trichloro- greater than 3,3',4,4'-tetrachlorobiphenyl. With few exceptions this order of potency was observed for the induction of benzo[a]pyrene hydroxylase and ethoxyresorufin O-deethylase in rat hepatoma cells in culture and for their relative binding affinities to the rat cytosolic receptor protein. The data clearly demonstrate that the biologic activities of this group of isosteric halogenated biphenyls are enhanced with increasing bromine substitution and also support the hypothesis that the activities of this class of chemicals are mediated through the receptor.
Congestive cardiomyopathy and final stage of a liver cirrhosis due to massive overload of iron are often the cause of death in polytransfused patients with aplastic anaemia. With increasing frequency of transfusion the problem of overload of iron becomes more actual. The toxicity of abundant iron is based on various mechanisms of action, which are compiled with the help of literature. Our experiences hitherto made with the intravenous long-term infusion of desferrioxamine are reported. This regimen of therapy is not to be practiced in the long run.