PubMed Health⌕ Search

Biomedical subjects

J Holguin

Publications and source records attributed to J Holguin.

10 recordsLinked to original sources
PubMed1994

Serious paracetamol poisoning and the results of liver transplantation.

Paracetamol poisoning is the most common cause of fulminant liver failure in the United Kingdom. An accurate assessment of prognosis at the time of referral will allow the appropriate application of liver transplantation in this setting. The outcome of 92 patients consecutively admitted to a specialist liver unit with severe poisoning has been examined. In patients who did not have a transplant, a fatal outcome was seen for 26/82 (32%), and was associated with late presentation, coma grade, prothrombin time prolongation, metabolic acidosis, and renal dysfunction. Cerebral oedema, and sepsis were responsible for most deaths. Prognostic criteria defined at King's College Hospital seemed to predict the outcome of patients who did not have a transplant managed on the Birmingham liver unit. Seventeen patients were listed for transplantation, 10 had liver transplantation, and seven of 10 survived. Seven were listed but not transplanted, and one of seven survived. Psychological rehabilitation of patients who had a transplant has not proved difficult. These results suggest a role for liver transplantation in the management of selected patients with paracetamol poisoning.

Acetaminophen↗
PubMed1979

Nucleoside deoxyribosyltransferase-II from Lactobacillus helveticus Substrate specificity studied. Pyrimidine bases as acceptors.

The nucleoside deoxyribosyltransferase (nucleoside:purine (pyrimidine) deoxyribosyltransferase, EC 2.4.2.6) fraction catalyzing specifically the transfer of the deoxyribosyl moiety from a purine (or a pyrimidine) to a pyrimidine (or a purine) exhibits a broad specificity for the acceptor base. With a pyrimidine base as the acceptor a -OH or -SH group adjacent to the N-1 atom is essential. A substituent on position 6 hinders the reaction. On positions 4 and 5 various substituent were found to influence the reaction rate and some of them give non-competent substrates. A few anomalous cases are also discussed in relation with the role of N-3. Deoxyribonucleosides can also be obtained with non-pyrimidine rings.

Catalysis↗
PubMed1979

Mutations affecting pigmentation in man: I. Neuroectodermal melanolysosomal disease.

We describe a syndrome identified in three consanguineous families who had two and probably four common ancestors five generations ago. The syndrome is characterized by profound dysfunction of the central nervous system, silver-leaden colored hair, abnormal melanosomes and melanocytes, and abnormal inclusion bodies in fibroblasts, bone marrow histiocytes and lymphocytes which appear to represent abnormal lysosomal bodies. Because of the biochemical relationships between melanin-melanosomes and neuromelanin, we think that all the manifestations of the condition are related to and represent pleiotropic effects of a newly identified gene in man in its homozygous state. Biochemical reactions of the cells of these patients indicate presence of tyrosinase in the melanosomes.and show that the substance accumulated in cultured fibroblasts and in the bone marrow histiocytes is a PAS and Oil-red-O positive material but is Oil-red-O negative after extraction; it has the typical reactions of melanin withe the Masson and Fontana stain, but cannot be considered typical melanin, since without stain it is colorless. The ultrastructural studies showed round granules with variable matrix, similar in fibroblast and bone marrow, and with variable intensity of reaction to osmium. This mutation principally affects the neuroectoderm, but also the mesoderm.

Child, Preschool↗
PubMed1975

Trans-N-deoxyribosylase: purification by affinity chromatography and characterization.

trans-N-Deoxyribosylase (EC 2.4.2.6) is usually considered as a single protein catalyzing indifferently the transfer of the deoxyribosyl moiety to and from a purine or a pyrimidine base. Affinity chromatography of an extract from Lactobacillus helveticus with two types of ligands allowed the separation and purification of two distinct trans-N-deoxyribosylases. One catalyzes specifically the deoxyribosyl transfer to and from purine bases exclusively: trans-N-deoxyribosylase-I, the other catalyzes the transfer to and from pyrimidine and purine bases: trans-N-deoxyribosylase-II. A Tris inhibition study showed a markedly different susceptibility of the two enzymes. Preliminary results indicate that the purine-specific enzyme is a polymeric enzyme of molecular weight 86 000 (+/- 4000).

Chromatography, Affinity↗
PubMed1975

Trans-N-deoxyribosylase: substrate specificity studies. Purine bases as acceptors.

A series of purine bases and analogues were tested as substrates for trans-N-deoxyribosylase (EC 2.4.2.6). It was observed that the pyrimidine ring and its substituents on positions 1, 2 and 6, are of minor importance. On the other hand only a few modifications are tolerated on the imidazole moiety, as follows. 1. A tautomeric proton must be present on the imidazole ring. The "usual" shift is between position 9 and 7. 2. The position of the tautomeric proton governs the site of substitution. 3. For steric reasons no substituent is allowed on position 8.

Deoxyribonucleosides↗
PubMed1967

Migraine.

Explore the source record for details and available documents.

Adolescent↗