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3.
J Fish Biol ; 82(6): 1773-88, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23731136

ABSTRACT

This study investigated the morphology of the recurrent facial taste neurons and their organization in the recurrent ganglion of the sea catfish Plotosus japonicus. The recurrent ganglion is independent of the anterior ganglion, which consists of trigeminal, facial and anterior lateral line neurons that send peripheral fibres to the head region. The recurrent taste neurons are round or oval and bipolar, with thick peripheral and thin central fibres, and completely wrapped by membranous layers of satellite cells. Two peripheral nerve branches coursing to the trunk or pectoral fin originate from the recurrent ganglion. The results presented here show that the trunk and pectoral-fin neurons are independently distributed to form various sizes of groups, and the groups are intermingled throughout the ganglion. No distinct topographical relationship of the two nerve branches occurs in the ganglion. Centrally, the trunk and pectoral-fin branches project somatotopically in the anterolateral and intermediate medial regions of the trunk tail lobule of the facial lobe, respectively.


Subject(s)
Catfishes/anatomy & histology , Facial Nerve/anatomy & histology , Ganglia, Sensory/anatomy & histology , Taste Buds/anatomy & histology , Animals , Cell Size , Facial Nerve/cytology , Ganglia, Sensory/cytology , Oceans and Seas , Taste , Taste Buds/cytology
4.
Transplant Proc ; 45(3): 1133-6, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23622645

ABSTRACT

BACKGROUND: Intestinal/multivisceral transplantation (IT/MVT) is the gold standard treatment for patients with intestinal failure and complications related to total parenteral nutrition, gastrointestinal inoperable indolent tumors, or diffuse portal trombosis. Currently, the reported 1-year patient survival rate is around 80%, similar to other solid organ abdominal transplantations. Unfortunately, the patient survival decreases after the first year with the 5-year rate not close to 70% yet. Acute cellular rejection is the main cause of graft loss. Its early diagnosis may make it possible to improve survival of retransplantations. OBJECTIVE: To analyze the reported results published in the last 5 years by leading transplant centers to evaluate IT/MVT retransplantation results. METHODS: We performed a literature review using PubMed focusing on multivisceral and intestinal retransplantation in articles published between 2006 and 2012. In relation to the first transplantation, we analyzed demographics, imunosuppression, rejection, infection as well as graft and patient survival rates. RESULTS: Two centers reported results on intestinal and multivisceral retransplantations. Mazariegos et al reported their experience with 15 intestinal retransplantations in 14 pediatric recipients. Four patients died from posttransplant lymphoperliferative disease, severe acute cellular rejection, fungal sepsis, or bleeding from a pseudoaneurysm at a mean time of 5.7 months post-transplantation. Total parenteral nutrition was weaned at a median time of 32 days. Abu-Elmaged et al reported 47 cases with a 5-year survival of 47% for all retransplant modalities. Retransplantation with liver-contained visceral allograft achieved a 5-year survival rate of 61% compared with 16% for liver-free visceral grafts. CONCLUSION: Despite those huge improvements, some transplanted patients develop severe acute cellular rejection, culminating in graft loss and retransplantation. Repots on multivisceral and intestinal retransplantation outcomes suggest that it is a viable procedure with appropriate patient survival after primary graft loss.


Subject(s)
Intestines/transplantation , Reoperation , Adolescent , Adult , Child , Child, Preschool , Humans , Infant , Young Adult
5.
Transplant Proc ; 44(8): 2503-4, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23026631

ABSTRACT

Endoscopic treatment of biliary tract complications after Roux-en-Y surgery is still a challenge. With balloon enteroscopy, we can reach previously inaccessible areas changing the management of biliopancreatic diseases in patients with surgically altered anatomy. We report a case of single-balloon enteroscopy plus endoscopic retrograde cholangiopancreatography for the treatment of a pinpoint stricture in a hepaticojejunal anastomosis after liver transplantation.


Subject(s)
Anastomosis, Roux-en-Y/adverse effects , Cholangiopancreatography, Endoscopic Retrograde/methods , Choledochostomy/adverse effects , Cholestasis, Extrahepatic/surgery , Common Bile Duct/surgery , Liver Transplantation/adverse effects , Adult , Cholangiopancreatography, Endoscopic Retrograde/instrumentation , Cholestasis, Extrahepatic/diagnosis , Cholestasis, Extrahepatic/etiology , Common Bile Duct/pathology , Constriction, Pathologic , Dilatation , Humans , Treatment Outcome
6.
Transplant Proc ; 44(8): 2505-6, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23026632

ABSTRACT

In pancreas and kidney transplantations, the donor duodenum and pancreas are frequently anastomosed to the jejunum to allow exocrine drainage by creation of a Roux-en-Y jejunal loop. In this situation, those organs are relatively inaccessible using standard endoscopes. We present a case of the use of single-balloon enteroscopy in the treatment of cronic pancreatitis in the donor pancreas.


Subject(s)
Anastomosis, Roux-en-Y/adverse effects , Cholangiopancreatography, Endoscopic Retrograde , Drainage/methods , Kidney Transplantation/adverse effects , Pancreas Transplantation/adverse effects , Pancreatitis, Chronic/surgery , Sphincterotomy, Endoscopic , Aged , Duodenum/surgery , Humans , Jejunum/surgery , Male , Pancreatitis, Chronic/diagnosis , Pancreatitis, Chronic/etiology , Recurrence , Treatment Outcome
7.
Br J Radiol ; 85(1014): 745-52, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21385915

ABSTRACT

OBJECTIVES: Our aim was to determine whether ablated liver parenchyma surrounding a tumour can be assessed by MRI with ferucarbotran administered prior to radiofrequency ablation (RFA) compared with enhanced CT. METHODS: 55 hepatocellular carcinomas (HCCs) in 42 patients and 5 metastatic liver cancers in 3 patients were treated by RFA after ferucarbotran administration. We then performed T(2)* weighted MRI after 1 week and enhanced CT after 1 month. T(2)* weighted MRI demonstrated the ablated parenchyma as a low-intensity rim around the high intensity of the ablated tumour in these cases. The assessment was allocated to one of three grades: margin (+), high-intensity area with continuous low-intensity rim; margin zero, high-intensity area with discontinuous low-intensity rim; and margin (-), high-intensity area extending beyond the low-intensity rim. RESULTS: Margin (+), margin zero and margin (-) were found in 17, 35 and 5 nodules, respectively. All 17 nodules with margin (+) and 13 of those with margin zero were assessed as having sufficient ablative margins on CT. The remaining 22 nodules with margin zero had insufficient margins on CT. The overall agreement between MRI and CT for the diagnosis of the ablative margin was moderate (κ = 0.507, p < 0.001). No local recurrence was found in 15 HCC nodules with margin (+), whereas local recurrence was found in 4 (11.8%) out of 34 HCC nodules with margin zero. CONCLUSION: Administration of ferucarbotran before RFA enables the ablative margin to be visualised as a low-intensity rim, and also enables the evaluation of the ablative margin to be made earlier and more easily than with enhanced CT.


Subject(s)
Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/surgery , Catheter Ablation , Contrast Media , Dextrans , Liver Neoplasms/diagnosis , Liver Neoplasms/surgery , Magnetic Resonance Imaging/methods , Magnetite Nanoparticles , Tomography, X-Ray Computed , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/pathology , Female , Humans , Liver Neoplasms/pathology , Male , Middle Aged , Prospective Studies
8.
Methods ; 55(4): 415-20, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22079407

ABSTRACT

Studies on four membrane protein systems, which combine information derived from crystal structures and biophysical studies have emphasized, as a precursor to crystallization, demonstration of functional activity. These assays have relied on sensitive spectrophotometric, electrophysiological, and microbiological assays of activity to select purification procedures that lead to functional complexes and with greater likelihood to successful crystallization: (I), Hetero-oligomeric proteins involved in electron transport/proton translocation. (1) Crystal structures of the eight subunit hetero-oligomeric trans-membrane dimeric cytochrome b(6)f complex were obtained from cyanobacteria using a protocol that allowed an analysis of the structure and function of internal lipids at specific intra-membrane, intra-protein sites. Proteolysis and monomerization that inactivated the complex and prevented crystallization was minimized through the use of filamentous cyanobacterial strains that seem to have a different set of membrane-active proteases. (2) An NADPH-quinone oxido-reductase isolated from cyanobacteria contains an expanded set of 17 monotopic and polytopic hetero-subunits. (II) ß-Barrel outer membrane proteins (OMPs). High resolution structures of the vitamin B(12) binding protein, BtuB, solved in meso and in surfo, provide the best example of the differences in such structures that were anticipated in the first application of the lipid cubic phase to membrane proteins [1]. A structure of the complex of BtuB with the colicin E3 and E2 receptor binding domain established a "fishing pole" model for outer membrane receptor function in cellular import of nuclease colicins. (III) A modified faster purification procedure contributed to significantly improved resolution (1.83Å) of the universal porin, OmpF, the first membrane protein for which meaningful 3D crystals have been obtained [2]. A crystal structure of the N-terminal translocation domain of colicin E3 complexed to OmpF established the role of OmpF as an import channel for colicin nuclease cytotoxins. (IV) α-Synuclein, associated with the etiology of Parkinson's Disease, is an example of a protein, which is soluble and disordered in solution, but which can assume an ordered predominantly α-helical conformation upon binding to membranes. When subjected in its membrane-bound form to a trans-membrane electrical potential, α-synuclein can form voltage-gated ion channels. Summary of methods to assay functions/activities: (i) sensitive spectrophotometric assay to measure electron transfer activities; (ii) hydrophobic chromatography to deplete lipids, allowing reconstitution with specific lipids for studies on lipid-protein interactions; (iii) microbiological screen to assay high affinity binding of colicin receptor domains to Escherichia coli outer membrane receptors; (iv) electrophysiology/channel analysis (a) to select channel-occluding ligands for co-crystallization with ion channels of OmpF, and (b) to provide a unique description of voltage-gated ion channels of α-synuclein.


Subject(s)
Bacterial Outer Membrane Proteins/chemistry , Cytochrome b6f Complex/chemistry , Escherichia coli Proteins/chemistry , Membrane Transport Proteins/chemistry , NADPH Dehydrogenase/chemistry , Porins/chemistry , alpha-Synuclein/chemistry , Crystallization , Crystallography, X-Ray , Cyanobacteria/enzymology , Enzyme Assays , Escherichia coli/enzymology , Humans , Models, Molecular , NADPH Dehydrogenase/isolation & purification , Protein Structure, Secondary , Protein Structure, Tertiary , Protein Subunits/chemistry
9.
Photochem Photobiol ; 84(6): 1349-58, 2008.
Article in English | MEDLINE | ID: mdl-19067956

ABSTRACT

The structure and function of the cytochrome b6f complex is considered in the context of recent crystal structures of the complex as an eight subunit, 220 kDa symmetric dimeric complex obtained from the thermophilic cyanobacterium, Mastigocladus laminosus, and the green alga, Chlamydomonas reinhardtii. A major problem confronted in crystallization of the cyanobacterial complex, proteolysis of three of the subunits, is discussed along with initial efforts to identify the protease. The evolution of these cytochrome complexes is illustrated by conservation of the hydrophobic heme-binding transmembrane domain of the cyt b polypeptide between b6f and bc1 complexes, and the rubredoxin-like membrane proximal domain of the Rieske [2Fe-2S] protein. Pathways of coupled electron and proton transfer are discussed in the framework of a modified Q cycle, in which the heme c(n), not found in the bc1 complex, but electronically tightly coupled to the heme b(n) of the b6f complex, is included. Crystal structures of the cyanobacterial complex with the quinone analogue inhibitors, NQNO or tridecyl-stigmatellin, show the latter to be ligands of heme c(n), implicating heme c(n) as an n-side plastoquinone reductase. Existing questions include (a) the details of the shuttle of: (i) the [2Fe-2S] protein between the membrane-bound PQH2 electron/H+ donor and the cytochrome f acceptor to complete the p-side electron transfer circuit; (ii) PQ/PQH2 between n- and p-sides of the complex across the intermonomer quinone exchange cavity, through the narrow portal connecting the cavity with the p-side [2Fe-2S] niche; (b) the role of the n-side of the b6f complex and heme c(n) in regulation of the relative rates of noncyclic and cyclic electron transfer. The likely presence of cyclic electron transport in the b6f complex, and of heme c(n) in the firmicute bc complex suggests the concept that hemes b(n)-c(n) define a branch point in bc complexes that can support electron transport pathways that differ in detail from the Q cycle supported by the bc1 complex.


Subject(s)
Cytochrome b6f Complex/chemistry , Cytochrome b6f Complex/metabolism , Animals , Cytochrome b6f Complex/genetics , Electron Transport , Genome/genetics , Lipid Metabolism , Protein Conformation , Protein Multimerization
10.
J Mol Biol ; 370(1): 39-52, 2007 Jun 29.
Article in English | MEDLINE | ID: mdl-17498743

ABSTRACT

A native structure of the cytochrome b(6)f complex with improved resolution was obtained from crystals of the complex grown in the presence of divalent cadmium. Two Cd(2+) binding sites with different occupancy were determined: (i) a higher affinity site, Cd1, which bridges His143 of cytochrome f and the acidic residue, Glu75, of cyt b(6); in addition, Cd1 is coordinated by 1-2 H(2)O or 1-2 Cl(-); (ii) a second site, Cd2, of lower affinity for which three identified ligands are Asp58 (subunit IV), Glu3 (PetG subunit) and Glu4 (PetM subunit). Binding sites of quinone analogue inhibitors were sought to map the pathway of transfer of the lipophilic quinone across the b(6)f complex and to define the function of the novel heme c(n). Two sites were found for the chromone ring of the tridecyl-stigmatellin (TDS) quinone analogue inhibitor, one near the p-side [2Fe-2S] cluster. A second TDS site was found on the n-side of the complex facing the quinone exchange cavity as an axial ligand of heme c(n). A similar binding site proximal to heme c(n) was found for the n-side inhibitor, NQNO. Binding of these inhibitors required their addition to the complex before lipid used to facilitate crystallization. The similar binding of NQNO and TDS as axial ligands to heme c(n) implies that this heme utilizes plastoquinone as a natural ligand, thus defining an electron transfer complex consisting of hemes b(n), c(n), and PQ, and the pathway of n-side reduction of the PQ pool. The NQNO binding site explains several effects associated with its inhibitory action: the negative shift in heme c(n) midpoint potential, the increased amplitude of light-induced heme b(n) reduction, and an altered EPR spectrum attributed to interaction between hemes c(n) and b(n). A decreased extent of heme c(n) reduction by reduced ferredoxin in the presence of NQNO allows observation of the heme c(n) Soret band in a chemical difference spectrum.


Subject(s)
Cytochrome b6f Complex/antagonists & inhibitors , Cytochrome b6f Complex/chemistry , Heme/analogs & derivatives , Protein Structure, Quaternary , Quinones/chemistry , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Binding Sites , Cadmium/metabolism , Crystallography, X-Ray , Cytochrome b6f Complex/metabolism , Heme/chemistry , Heme/metabolism , Hydroxyquinolines/chemistry , Hydroxyquinolines/metabolism , Ligands , Models, Molecular , Oxidation-Reduction , Polyenes/chemistry , Polyenes/metabolism , Protein Binding , Quinones/metabolism
11.
Int J Gynecol Cancer ; 17(1): 285-90, 2007.
Article in English | MEDLINE | ID: mdl-17291269

ABSTRACT

Leiomyomas of uterus are common disease in gynecology. It is important to differentiate leiomyoma from leiomyosarcoma at the decision of treatment methods, especially in the case of the conservative treatment for uterine leiomyoma. But the exact diagnosis of benign leiomyoma is often difficult due to the degeneration of myoma by imaging modalities including magnetic resonance imaging. Recently, whole-body positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) has been used for a diagnosis of malignant tumors. There is a growing body of evidence for the use of FDG in differentiating malignant from benign disease. But optimal utilization in gynecology remains unclear. Our case represents increased uptake of FDG in myomatous uterus, which is pathologically confirmed benign leiomyoma by the hysterectomy. Immunohistochemical analysis of glucose transporter-1 showed positive in endometrial tissue and negative in leiomyoma. Our case indicates that myomatous uterus in premenopausal women shows the potential pitfall of a positive result of FDG-PET.


Subject(s)
Fluorodeoxyglucose F18/pharmacokinetics , Leiomyoma/diagnostic imaging , Leiomyoma/metabolism , Uterine Neoplasms/diagnostic imaging , Uterine Neoplasms/metabolism , Female , Fluorine Radioisotopes , Humans , Middle Aged , Radionuclide Imaging , Radiopharmaceuticals/pharmacokinetics
12.
J Mol Biol ; 364(4): 716-34, 2006 Dec 08.
Article in English | MEDLINE | ID: mdl-17028020

ABSTRACT

Crystals of the apo form of the vitamin B12 and colicin receptor, BtuB, that diffract to 1.95 A have been grown by the membrane-based in meso technique. The structure of the protein differs in several details from that of its counterpart grown by the more traditional, detergent-based (in surfo) method. Some of these differences include (i) the five N-terminal residues are resolved in meso, (ii) residues 57-62 in the hatch domain and residues 574-581 in loop 21-22 are disordered in meso and are ordered in surfo, (iii) residues 278-287 in loop 7-8 are resolved in meso, (iv) residues 324-331 in loop 9-10, 396-411 in loop 13-14, 442-458 in loop 15-16 and 526-541 in loop 19-20 have large differences in position between the two crystal forms, as have residues 86-96 in the hatch domain, and (v) the conformation of residues 6 and 7 in the Ton box (considered critical to signal transduction and substrate transport) are entirely different in the two structures. Importantly, the in meso orientation of residues 6 and 7 is similar to that of the vitamin B12-charged state. These data suggest that the "substrate-induced" 180 degrees -rotation of residues 6 and 7 reported in the literature may not be a unique signalling event. The extent to which these findings agree with structural, dynamic and functional insights gleaned from site-directed spin labelling and electron paramagnetic resonance measurements is evaluated. Packing in in meso grown crystals is dense and layered, consistent with the current model for crystallogenesis of membrane proteins in lipidic mesophases. Layered packing has been used to locate the transmembrane hydrophobic surface of the protein. Generally, this is consistent with tryptophan, tyrosine, lipid and CalphaB-factor distributions in the protein, and with predictions based on transfer free energy calculations.


Subject(s)
Bacterial Outer Membrane Proteins/chemistry , Escherichia coli Proteins/chemistry , Membrane Transport Proteins/chemistry , Amino Acids , Crystallization/methods , Crystallography, X-Ray , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Protein Conformation
13.
Eur J Pharm Sci ; 29(3-4): 315-24, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16806858

ABSTRACT

The regulations with respect to biowaivers for immediate release (IR) solid oral dosage forms in the USA, the EU, Japan and from the World Health Organization (WHO) are summarized and compared. Two case studies are presented, one from our own files and one from the open literature, showing the similarities and the differences among the qualification requirements of the four systems. The regulatory experience gained up to now is reviewed and expected future trends are discussed.


Subject(s)
Dosage Forms , Drug and Narcotic Control , Administration, Oral , Chemistry, Pharmaceutical , Solubility , United States , United States Food and Drug Administration , World Health Organization
14.
Am J Physiol Endocrinol Metab ; 288(3): E534-40, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15536204

ABSTRACT

D-mannose is an essential monosaccharide constituent of glycoproteins and glycolipids. However, it is unknown how plasma mannose is supplied. The aim of this study was to explore the source of plasma mannose. Oral administration of glucose resulted in a significant decrease of plasma mannose concentration after 20 min in fasted normal rats. However, in fasted type 2 diabetes model rats, plasma mannose concentrations that were higher compared with normal rats did not change after the administration of glucose. When insulin was administered intravenously to fed rats, it took longer for plasma mannose concentrations to decrease significantly in diabetic rats than in normal rats (20 and 5 min, respectively). Intravenous administration of epinephrine to fed normal rats increased the plasma mannose concentration, but this effect was negated by fasting or by administration of a glycogen phosphorylase inhibitor. Epinephrine increased mannose output from the perfused liver of fed rats, but this effect was negated in the presence of a glucose-6-phosphatase inhibitor. Epinephrine also increased the hepatic levels of hexose 6-phosphates, including mannose 6-phosphate. When either lactate alone or lactate plus alanine were administered as gluconeogenic substrates to fasted rats, the concentration of plasma mannose did not increase. When lactate was used to perfuse the liver of fasted rats, a decrease, rather than an increase, in mannose output was observed. These findings indicate that hepatic glycogen is a source of plasma mannose.


Subject(s)
Glycogen/metabolism , Liver/metabolism , Mannose/blood , Administration, Oral , Alanine/pharmacology , Animals , Arabinose , Blood Glucose/drug effects , Blood Glucose/metabolism , Chlorogenic Acid/pharmacology , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Disease Models, Animal , Epinephrine/pharmacology , Glucose/metabolism , Glucose/pharmacology , Glucose-6-Phosphatase/antagonists & inhibitors , Glycogen Phosphorylase/antagonists & inhibitors , Hexosephosphates/analysis , Hexosephosphates/metabolism , Imino Furanoses , Injections, Intravenous , Insulin/blood , Insulin/pharmacology , Lactic Acid/pharmacology , Liver/chemistry , Liver/drug effects , Male , Mannose/metabolism , Models, Biological , Rats , Rats, Inbred Strains , Rats, Wistar , Sugar Alcohols/pharmacology
15.
São Paulo; s.n; 2004. 17 p.
Non-conventional in Portuguese | Coleciona SUS, HSPM-Producao, Sec. Munic. Saúde SP, Sec. Munic. Saúde SP | ID: biblio-937528

ABSTRACT

A doença do xarope de bordo também conhecida como Maple Syrup Urine Disease (MSUD) ou Leucinose é um erro inato do metabolismo de aminoácidos de cadeia ramificada leucina, isoleucina e valina e de seus alfa-cetoácidos, devido a uma deficiência ou ausência de um complexo multienzimático mitocondrial alfa cetoácido desidrogenase. É uma doença hereditária autossômica recessiva, ainda não foi possível localizar o gene desta aminoácidopatia parecendo haver múltiplos lócus e subunidades.Esse cetoácidos se acumulam no sangue, tecidos e urina e parte deles se converte novamente em aminoácidos de cadeia ramificada: leucina, isoleucina e valina. O diagnóstico pode ser feito através de cromatografia de camada delgada no sangue e na urina. Esta doença apresenta-se com sete variantes clínicas, em cindo delas apresentando um recém-nascido normal que evolui, ao redor do 10º dia de vida rapidamente para dterioração do sistema nervoso, culminando freqüentemente para o coma e óbito


Subject(s)
Humans , Infant, Newborn , Maple Syrup Urine Disease , Metabolism, Inborn Errors
16.
São Paulo; s.n; 2004. 17 p.
Non-conventional in Portuguese | Sec. Munic. Saúde SP, HSPM-Producao, Sec. Munic. Saúde SP, Sec. Munic. Saúde SP | ID: sms-2771

ABSTRACT

A doença do xarope de bordo também conhecida como Maple Syrup Urine Disease (MSUD) ou Leucinose é um erro inato do metabolismo de aminoácidos de cadeia ramificada leucina, isoleucina e valina e de seus alfa-cetoácidos, devido a uma deficiência ou ausência de um complexo multienzimático mitocondrial alfa cetoácido desidrogenase. É uma doença hereditária autossômica recessiva, ainda não foi possível localizar o gene desta aminoácidopatia parecendo haver múltiplos lócus e subunidades.Esse cetoácidos se acumulam no sangue, tecidos e urina e parte deles se converte novamente em aminoácidos de cadeia ramificada: leucina, isoleucina e valina. O diagnóstico pode ser feito através de cromatografia de camada delgada no sangue e na urina. Esta doença apresenta-se com sete variantes clínicas, em cindo delas apresentando um recém-nascido normal que evolui, ao redor do 10º dia de vida rapidamente para dterioração do sistema nervoso, culminando freqüentemente para o coma e óbito


Subject(s)
Humans , Infant, Newborn , Metabolism, Inborn Errors , Maple Syrup Urine Disease
17.
J Mol Biol ; 314(1): 103-12, 2001 Nov 16.
Article in English | MEDLINE | ID: mdl-11724536

ABSTRACT

The crystal structure of Nicotiana alata (ornamental tobacco) S(F11)-RNase, an S-allelic glycoprotein associated with gametophytic self-incompatibility, was determined by X-ray diffraction at 1.55 A resolution. The protein has a tertiary structure typical of members of the RNase T(2) family as it consists of a variant of the (alpha+beta) fold and has eight helices and seven strands. A heptasaccharide moiety is also present, and amino acid residues that serve as the catalytic acid and base can be assigned to His32 and His91, respectively. Two "hypervariable" regions, known as HVa and HVb, are the proposed sites of S-allele discrimination during the self-incompatibility reaction, and in the S(F11)-RNase these are well separated from the active site. HVa and HVb are composed of a long, positively charged loop followed by a part of an alpha-helix and short, negatively charged alpha-helix, respectively. The S(F11)-RNase structure shows both regions are readily accessible to the solvent and hence could participate in the process of self/non-self discrimination between the S-RNase and an unknown pollen S-gene product(s) upon pollination.


Subject(s)
Nicotiana/enzymology , Nicotiana/physiology , Ribonucleases/chemistry , Ribonucleases/metabolism , Amino Acid Sequence , Binding Sites , Carbohydrates/analysis , Crystallography, X-Ray , Disulfides/analysis , Endoribonucleases/chemistry , Glycosylation , Models, Molecular , Molecular Sequence Data , Protein Structure, Secondary , Protein Structure, Tertiary , Reproduction/physiology , Sequence Alignment , Static Electricity , Structure-Activity Relationship , Substrate Specificity , Water/chemistry , Water/metabolism
18.
Clin Orthop Relat Res ; (388): 147-56, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11451114

ABSTRACT

The two transepicondylar axes (the clinical and surgical epicondylar axes), the posterior condylar axis, and the anteroposterior axis were constructed using computed tomography scans in 111 (66 patients) knees with symptomatic arthritis. The relationships between angles made by these reference axes and two angles indicating frontal knee alignment (the tibiofemoral valgus angle and the femoral valgus angle) were investigated. In Y of the knees, the surgical epicondylar axis could not be constructed because the sulcus of the medial epicondyle was not recognizable. The condylar twist angle was almost constant and averaged 6 degrees when the femoral valgus angle was 9 degrees or less, but increased gradually when the angle was greater than 9 degrees. The difference between the condylar twist angle and the posterior condylar angle was constantly 3 degrees. The anteroposterior axis was almost at right angles to the clinical epicondylar axis, and the relationship between these axes was constant, independent of the femoral valgus angle. With 3 degrees to 6 degrees external rotation relative to the posterior condylar axis, the femoral component could be set parallel to the transepicondylar axis in common varus or neutral knees. In cases with a larger femoral valgus angle, the anteroposterior axis would be a more reliable reference axis. Preoperative computed tomography scans are recommended for patients with knees with severe valgus deformity or severe hypertrophic osteoarthritis.


Subject(s)
Femur/physiopathology , Knee Joint/physiopathology , Osteoarthritis, Knee/physiopathology , Aged , Biomechanical Phenomena , Female , Femur/diagnostic imaging , Humans , Knee Joint/diagnostic imaging , Male , Middle Aged , Osteoarthritis, Knee/diagnostic imaging , Radiography , Rotation
19.
Biochim Biophys Acta ; 1512(2): 251-8, 2001 Jun 06.
Article in English | MEDLINE | ID: mdl-11406102

ABSTRACT

The effects of the carotenoids beta-carotene and astaxanthin on the peroxidation of liposomes induced by ADP and Fe(2+) were examined. Both compounds inhibited production of lipid peroxides, astaxanthin being about 2-fold more effective than beta-carotene. The difference in the modes of destruction of the conjugated polyene chain between beta-carotene and astaxanthin suggested that the conjugated polyene moiety and terminal ring moieties of the more potent astaxanthin trapped radicals in the membrane and both at the membrane surface and in the membrane, respectively, whereas only the conjugated polyene chain of beta-carotene was responsible for radical trapping near the membrane surface and in the interior of the membrane. The efficient antioxidant activity of astaxanthin is suggested to be due to the unique structure of the terminal ring moiety.


Subject(s)
Adenosine Diphosphate/chemistry , Antioxidants/chemistry , Cardiolipins/chemistry , Iron/chemistry , Lipid Peroxidation , Liposomes/chemistry , Phosphatidylcholines/chemistry , beta Carotene/analogs & derivatives , beta Carotene/chemistry , Ferrous Compounds/chemistry , Free Radicals/chemistry , Hydrogen Bonding , Kinetics , Models, Molecular , Molecular Conformation , Oxidation-Reduction , Surface Properties , Xanthophylls , Zeaxanthins
20.
Acta Crystallogr D Biol Crystallogr ; 57(Pt 7): 941-7, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11418761

ABSTRACT

The X-ray structure of bovine heart cytochrome c oxidase solved for orthorhombic crystals showed a dimeric structure stabilized by four subunit-subunit contacts, namely, subunit Vb-subunit Vb on the matrix side, subunit I-subunit VIa, subunit VIa-subunit I in the transmembrane region and subunit VIb-subunit VIb on the intermembrane side. The same intermonomer contacts as in the orthorhombic crystals were observed in both hexagonal and tetragonal crystals, the X-ray structures of which were determined by the molecular-replacement method. These results suggest that the dimeric structure also exists under physiological conditions. These contacts, especially the subunit IVa-subunit I contact, in which the N-terminal portion of subunit IVa is placed on the surface of subunit I near the dioxygen-reduction site, indicate that the function of the bovine heart enzyme is likely to be controlled by perturbation of the monomer-monomer association.


Subject(s)
Electron Transport Complex IV/chemistry , Myocardium/enzymology , Animals , Cattle , Dimerization , Models, Molecular , Protein Conformation
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