Report of Scientific and Standardization Subcommittee on Neonatal Hemostasis Diagnosis and Treatment of Neonatal Thrombosis.
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Administration, Oral↗
Biomedical subjects
B Schmidt
Publications and source records attributed to B Schmidt.
The internalization signal in the cytoplasmic tail of lysosomal acid phosphatase consists of the hexapeptide PGYRHV.
Lysosomal acid phosphatase (LAP) is rapidly internalized from the cell surface due to a tyrosine-containing internalization signal in its 19 amino acid cytoplasmic tail. Measuring the internalization of a series of LAP cytoplasmic tail truncation and substitution mutants revealed that the N-terminal 12 amino acids of the cytoplasmic tail are sufficient for rapid endocytosis and that the hexapeptide 411-PGYRHV-416 is the tyrosine-containing internalization signal. Truncation and substitution mutants of amino acid residues following Val416 can prevent internalization even though these residues do not belong to the internalization signal. It was shown recently that part of the LAP cytoplasmic tail peptide corresponding to 410-PPGY-413 forms a well-ordered beta turn structure in solution. Two-dimensional NMR spectroscopy of two modified LAP tail peptides, in which the single tyrosine was substituted either by phenylalanine or by alanine, revealed that the tendency to form a beta turn is reduced by 25% in the phenylalanine-containing peptide and by approximately 50% in the alanine-containing mutant peptide. Our results suggest, that in the short cytoplasmic tail of LAP tyrosine is required for stabilization of the right turn and that the aromatic ring system of the tyrosine residue is a contact point to the putative cytoplasmic receptor.
Acid Phosphatase↗
Purification and properties of a F420-nonreactive, membrane-bound hydrogenase from Methanosarcina strain Gö1.
The distribution of the F420-reactive and F420-nonreactive hydrogenases from the methylotrophic Methanosarcina strain Gö1 indicated a membrane association of the F420-nonreactive enzyme. The membrane-bound F420-nonreactive hydrogenase was purified 42-fold to electrophoretic homogeneity with a yield of 26.7%. The enzyme had a specific activity of 359 mumol H2 oxidized.min-1.mg protein-1. The purification procedure involved dispersion of the membrane fraction with the detergent Chaps followed by anion exchange, hydrophobic and hydroxylapatite chromatography. The aerobically prepared enzyme had to be reactivated anaerobically. Maximal activity was observed at 80 degrees C. The molecular mass as determined by native gel electrophoresis and gel filtration was 77,000 and 79,000, respectively. SDS gel electrophoresis revealed two polypeptides with molecular masses of 60,000 and 40,000 indicating a 1:1 stoichiometry. The purified enzyme contained 13.3 mol S2-, 15.1 mol Fe and 0.8 mol Ni/mol enzyme. Flavins were not detected. The amino acid sequence of the N-termini of the subunits showed a higher degree of homology to eubacterial uptake-hydrogenases than to F420-dependent hydrogenases from other methanogenic bacteria. The physiological function of the F420-nonreactive hydrogenase from Methanosarcina strain Göl is discussed.
Amino Acid Sequence↗
Inflammatory mediators in demyelinating disorders of the CNS and PNS.
Work in both experimental models and human disorders of the central and peripheral nervous system has delineated multiple effector mechanisms that operate to produce inflammatory demyelination. The role of various soluble inflammatory mediators generated and released by both blood-borne and resident cells in this process will be reviewed. Cytokines such as interleukin (IL)-1, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha are pivotal in orchestrating immune and inflammatory cell-cell interactions and represent potentially noxious molecules to the myelin sheath, Schwann cells, and/or oligodendrocytes. Arachidonic acid metabolites, synthesized by and liberated from astrocytes, microglial cells and macrophages, are intimately involved in the inflammatory process by enhancing vascular permeability, providing chemotactic signals and modulating inflammatory cell activities. Reactive oxygen species can damage myelin by lipid peroxidation and may be cytotoxic to myelin-producing cells. They are released from macrophages and microglial cells in response to inflammatory cytokines. Activation of complement yields a number of inflammatory mediators and results in the assembly of the membrane attack complex that inserts into the myelin sheath-creating pores. Activated complement may contribute both to functional disturbance of neural impulse propagation, and to full-blown demyelination. Proteases, abundantly present at inflammatory foci, can degrade myelin. Vasoactive amines may play an important role in breaching of the blood-brain/blood-nerve barrier. The importance of nitric oxide metabolites in inflammatory demyelination merits investigation. A better understanding of the multiple effector mechanisms operating in inflammatory demyelination may help to devise more efficacious antigen non-specific therapy.
Animals↗
Fetal cleft lip repair in rabbits: histology and role of hyaluronic acid.
This study examines the histologic and biochemical features of wound healing in a cleft lip model in the mid-third-trimester fetal rabbit. At days 1, 2, and 4 after the procedure, control, unrepaired, and repaired fetal heads were obtained, sectioned, and stained for histologic examination. The localization of hyaluronic acid in the wound was documented using a cartilage-derived hyaluronic acid-binding protein. In both repaired and unrepaired wounds, the fetal cleft healed without inflammatory cell infiltration or scar formation. Six months after birth, the repaired cleft showed complete regeneration of muscle across the wound and the collagen fibers were of normal density and orientation. Decreased hyaluronic acid deposition was observed in unrepaired clefts as compared with adjacent tissue; no such difference was detected in repaired clefts. Our findings support the hypothesis that a cleft lip repaired in utero heals without the scarring that accompanies postnatal repair. This may explain the lack of maxillary growth restriction after in utero cleft lip repair.
Animals↗
Enzymatic biosynthesis of cyclosporin A and analogues.
The final assembly of the undecapeptide chain of cyclosporin A and its cyclization is accomplished in Beauveria nivea by cyclosporin synthetase. This multienzyme is the largest integrated enzyme structure so far reported. Its size has been estimated at approximately 1,400 kDa by two different methods: 1), by 3% SDS-PAGE using the related multienzymes ACV synthetase and gramicidin S synthetase 2 as references (420 and 556 kDa, respectively); and 2), by CsCl density gradient centrifugation experiments using fluorescence-labeled cyclosporin synthetase. Besides cyclosporin A and a number of cyclosporins known from fermentation studies cyclosporin synthetase is capable of synthesizing some new cyclosporins which are so far unobtainable by fermentation. So, for example the synthesis of [N-methyl-(+)-2-amino-3-hydroxy-4,4-dimethyloctanoic acid1]CyA, dihydro-CyA, [L-norvaline2,5, N-methyl-L-norvaline11]CyA, [L-allo-isoleucine5, N-methyl-L-allo-isoleucine11]CyA, [D-2-aminobutyric acid8]CyA, [beta-chloro-D-alanine8]CyA and some related compounds could be established. By using a related but different enzyme from Cylindrotrichum Bonorden, the peptolide [L-threonine2, L-leucine5,10, D-2-hydroxyisovaleric acid8]CyA could be synthesized in vitro. We were able to synthesize these cyclosporins in sufficient quantities to examine their structure by FAB mass spectroscopy and explore their immunosuppressivity. It was found that all new cyclosporins so far synthesized in the in vitro system are immunosuppressive.
Amino Acid Sequence↗
Isolated bowel injury in blunt abdominal trauma in childhood.
From a total of 734 children with a blunt abdominal trauma admitted to the hospital in the past 15 years, 21 patients (3%) sustained an isolated injury of the bowel (8 duodenal, 9 jejunal and 4 colon ruptures). All patients were laparotomized without a postoperative mortality. Accompanying abdominal injuries were seen only in duodenal ruptures (pancreatitis and one choledochal and pancreatic ruptures). In 85% the blunt violence was caused by bicycle accidents due to the handle bar, in one case by a car accident and in 3 children by falls. Accurate diagnosis was only possible regarding the history, the mechanism of the accident and an exact repeated clinical examination. Despite further investigations of blood chemistry laboratory findings, ultrasound and x-ray, no further confirmation of the diagnosis could be achieved. Complications, occurring in 14% of our patients, were not related to the trauma itself, but caused by a delayed diagnosis and therapy.
Abdominal Injuries↗
Thawing fresh frozen plasma in a microwave oven. A comparison with thawing in a 37 degrees C waterbath.
We show in this report that fresh frozen plasma (FFP) can be thawed faster using a specifically designed microwave oven (MWO) (WesLabs Plasma Defroster, Westmorland Laboratories, Inc., New Brunswick, Canada) than using 37 degrees C water bath (WB) and that the thawed product was equivalent to FFP thawed by WB. Paired plasma bags (200 mL/bag) from plasma pools were frozen, stored at -35 degrees C, and thawed in parallel, one bag in MWO, the other in WB. Mean thaw time (mean + SD) by MWO was 6.99 + 1.3 minutes; by WB the time was 17.6 + 1.7 minutes (n = 24; P less than 0.005). Rapid calorimetry of thawed plasma showed that MWO-thawed FFP temperature was 20.4 + 2.5 degrees C, whereas WB-thawed FFP was 15.4 + 3.3 degrees C (n = 24; P less than 0.005). Except for thrombin time (MWO = 20.1 seconds; WB = 19.8 seconds; n = 24; P = 0.023), no significant differences were observed in the 23 other coagulation parameters and plasma proteins studied. Faster thawing and freedom from risk of contamination may make MWO the method of choice for emergency thawing of FFP.
Blood Coagulation↗
Transient cellular expression of gamma-interferon in myelin-induced and T-cell line-mediated experimental autoimmune neuritis.
This study reports the cellular localization of gamma-interferon (gamma-IFN) in nerve roots during the course of experimental autoimmune neuritis induced either by active immunization (EAN) or adoptive transfer of P2-specific T-cells (AT-EAN). One micrometre thick cryosections of ventral roots of EAN and AT-EAN animals were labelled with the monoclonal antibodies DB-1 and DB-12 recognizing different epitopes of rat gamma-IFN. In EAN numerous gamma-IFN-positive cells were present before overt clinical signs and demyelination (days 11-13 after immunization). Concomitantly, raised gamma-IFN levels were measured in the serum of these animals. However, systemically increased gamma-IFN serum levels were not specific for a neuritogenic T-cell response. At subsequent stages when many axons were demyelinated (day 16 and later) gamma-IFN-positive cells had disappeared and gamma-IFN serum levels returned to normal value. gamma-Interferon positive cells could be identified as W3/13 positive T-cells and polymorphonuclear leukocytes. Additionally, a considerable number of ED1-positive macrophages showed gamma-IFN immunoreactivity. The majority of macrophages and all Schwann cells were gamma-IFN negative. Similar results were obtained in AT-EAN 4 d and 6 d following cell transfer. After nerve transection no gamma-IFN-positive cells were found in the distal stumps. The localization of gamma-IFN in nerve roots indicates an important role of this lymphokine in acute immune-mediated demyelination. gamma-Interferon most likely locally affects macrophage functions such as migration, major histocompatibility complex (MHC) class II antigen (Ia) expression, and production of cytotoxic molecules in nerves, and thereby contributes to myelin damage.
Animals↗
Identification and molecular characterization of the gene coding for acetaldehyde dehydrogenase II (acoD) of Alcaligenes eutrophus.
The N-terminal amino acid sequence of purified acetaldehyde dehydrogenase II (AcDH-II) from ethanol-grown cells of Alcaligenes eutrophus was determined. By using oligonucleotides deduced from this sequence the structural gene for AcDH-II, which was referred to as acoD, was localized on a 7.2-kbp EcoRI restriction fragment (fragment D), which has been cloned recently (C. Fründ, H. Priefert, A. Steinbüchel, and H. G. Schlegel, J. Bacteriol. 171:6539-6548, 1989). A 2.8-kbp PstI subfragment of D, which harbored acoD, was sequenced. It revealed an open reading frame of 1,518 bp, encoding a protein with a relative molecular weight of 54,819. The insertions of Tn5::mob of two transposon-induced mutants of A. eutrophus, which were impaired in the catabolism of acetoin, were mapped 483 or 1,359 bp downstream from the translational start codon of acoD. The structural gene was preceded by a putative Shine-Dalgarno sequence. The transcriptional start site 57 bp upstream of acoD was identified and was preceded by a sequence which exhibited a striking homology to the enterobacterial sigma 54-dependent promoter consensus sequence. This was in accordance with the observation that the expression of acoD and of other acetoin-catabolic genes depended on the presence of an intact rpoN-like gene. Alignments of the amino acid sequence deduced from acoD with the primary structures of aldehyde dehydrogenases from other sources revealed high degrees of homology, amounting to 46.5% identical amino acids.
Acetoin↗
Thrombin/antithrombin III complex formation in the neonatal respiratory distress syndrome.
Intravascular and intra-alveolar thrombin generation may exacerbate the pulmonary hypertension and surfactant dysfunction that characterize the neonatal respiratory distress syndrome (RDS). Although low levels of the most important thrombin inhibitor, antithrombin III (AT III), have been reported in infants with RDS, direct evidence of increased intravascular thrombin generation has been lacking. Accordingly, the objective of this study was to determine whether thrombin generation is increased in severe neonatal RDS. Thirty-nine infants of 25 to 29 wk gestation with a clinical and radiologic diagnosis of RDS were enrolled in a prospective cohort study. Plasma levels of thrombin/antithrombin III complexes (TAT) and AT III activity, measured 36 to 72 h after birth, were related to RDS severity. Seventeen infants had severe RDS (mean airway pressure greater than 10 cm H2O or FlO2 greater than 0.8), and 22 had mild or moderate disease. Mean birthweight (1,017 versus 1,054 g) and mean gestational age (27.8 versus 27.4 wk) were similar in both groups. The median TAT level in infants with severe RDS was significantly higher than that in patients with mild or moderate disease (10.7 and 4.0 micrograms/L, respectively; p less than 0.001). In addition, the mean AT III activity in infants with severe RDS was significantly lower than that in less severely affected patients (0.31 and 0.46 U/ml, respectively; p less than 0.01). Considering the entire cohort, plasma TAT levels were inversely correlated with the arterial/alveolar oxygen tension ratio (r = -0.48, p = 0.0022) and the ventilator efficiency index (r = -0.51, p = 0.0011). The elevated TAT levels and reduced AT III activity in infants with severe RDS are consistent with increased thrombin generation and resulting AT III consumption. Therefore, to regulate thrombin activity, these infants may benefit from replacement therapy with AT III concentrate.
Antithrombin III↗
Thrombin inhibition is impaired in plasma of sick neonates.
The sick neonate may develop spontaneous or catheter-related thromboses, which must in part reflect poor regulation of the formation and activities of the coagulation enzyme, thrombin. We hypothesized that the balance between the generation and inhibition of thrombin may differ in sick neonates compared with healthy neonates. Fifty neonates with respiratory failure requiring mechanical ventilation and 40 healthy neonates were studied on d 1 of life. All neonates had normal coagulation screening tests and a platelet count greater than 150 x 10(9)/L. Plasma pools from neonates with similar gestational age (GA), birth weight, and health status were prepared. Eight plasma pools from 40 healthy neonates of GA 30-38 wk were compared with six plasma pools from 30 sick neonates of GA 30-38 wk. An additional four plasma pools prepared from 20 sick neonates of GA less than 30 wk were studied. Thrombin generation was measured by amidolysis of a chromogenic substrate, S2238, after defibrination, contact activation, and recalcification of the test plasmas. The contributions of antithrombin III, heparin cofactor II, and alpha 2-macroglobulin as inhibitors of 125I-thrombin were quantitated by SDS-PAGE followed by autoradiography and densitometry. Thrombin generation was similar for both healthy and sick neonates of GA 30-38 wk. However, the inhibition of thrombin was impaired in plasma from sick neonates of GA 30-38 wk compared with plasma from healthy neonates of GA 30-38 wk (4.37 +/- 0.22 versus 5.21 +/- 0.21 nmol; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Antithrombin III↗
High social risk screening mechanisms: patient characteristics as predictors of social work utilization in the VA.
To facilitate timely access to social services in hospitals, high social risk (HSR) screening mechanisms have been implemented throughout the country. The purpose of these mechanisms is to identify patients upon admission who are most likely to need service. Because these screening mechanisms often identify patients who do not need service, this study determined how well the patient characteristics used as screening factors actually predicted service utilization. A multivariate logistic regression model was developed using 1,659 discharges from two midwestern hospitals. The most powerful predictors of social service use were age, multi-system illness, not having a spouse, and psychiatric co-morbidity. Despite the significant contribution of each predictor, their combined ability to predict who receives service was modest.
Activities of Daily Living↗
Carrier detection of Duchenne and Becker muscular dystrophy using muscle dystrophin immunohistochemistry.
To ascertain whether dystrophin immunohistochemistry could improve DMD/BMD carrier detection, we analyzed 14 muscle biopsies from 13 DMD and one BMD probable and possible carriers. All women were also evaluated using conventional methods, including genetic analysis, clinical and neurological evaluation, serum CK levels, EMG, and muscle biopsy. In 6 cases, there was a mosaic of dystrophin-positive and dystrophin-deficient fibers that allowed to make the diagnosis of a carrier state. Comparing dystrophin immunohistochemistry to the traditional methods, it was noted that this method is less sensitive than serum CK measurements, but is more sensitive than EMG and muscle biopsy. The use of dystrophin immunohistochemistry in addition to CK, EMG and muscle biopsy. improved the accuracy of carrier detection. This method is also helpful to distinguish manifesting DMD carriers from patients with other neuromuscular diseases like limb-girdle muscular dystrophy and spinal muscular atrophy.
Adolescent↗
[Management of metatarsalgia using Helal's method for metatarsal osteotomy].
Authors report on the result of Helal's metatarsal osteotomies performed on 62 feet of 48 patients for metatarsalgia. In 85 per cent the result proved to be excellent, in 15 per cent there was no improvement. Analysing the causes of the postoperative complaints they call attention to the overload of the marginal arches and to the metatarsalgia developing on the non osteotomized neighbouring arch. These complaints appeared in 1/3 of their material and could be generally well influenced with conservative treatment.
Adolescent↗
Juvenile dermatomyositis and pregnancy: report and literature review.
Reports of dermatomyositis (DM) and polymyositis complicating pregnancy are rare. Only nineteen cases have been published. We describe the first case in which juvenile DM appeared during pregnancy. An emergency cesarean section had to be performed due to fetal distress at 37 weeks of gestation. Patient and infant are doing well after 8 months of followup.
Adolescent↗
[Sex in the hospital--a hot pavement].
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Education, Nursing↗
Adsorption profile of commercially available adsorbents: an in vitro evaluation.
Adsorbents from four commercially available devices, Protein A-Sepharose (Immunosorba Protein A-62,5; Excorim KB, Lund Sweden), Tryptophan-PVA (Immusorba TR-350; Asahi Medical Co., Tokyo, Japan), Phenylalanine-PVA (Immusorba PH-350; Asahi Medical Co., Tokyo, Japan), and Dextran sulfate (Liposorber LA-15; Kanegafuchi Chemical Co. Ltd, Osaka, Japan) were tested under optimal in vitro conditions to determine their adsorption capability for several plasma constituents which are usually the target of plasma therapy. The parameters of interest were: double stranded DNA-antibodies (anti-dsDNA), antiglomerular basement membrane antibodies (anti-GBM), anti-acetylcholin receptor antibodies (AChRAb), circulating immune complexes (CIC), rheumatoid factor (RF), IgA, IgG, IgM, IgE, C3c, C4, LDL-cholesterol, total cholesterol, erythropoietin (EPO) and beta 2-microglobulin (beta 2M). The IgG auto antibodies, CIC and RF can be removed by Protein A-Sepharose, Try-PVA and Phe-PVA. IgG is best adsorbed by Protein A-Sepharose, while IgE can be removed efficiently by Try-PVA. Dextran sulfate is without doubt the best adsorbent for LDL-cholesterol. All four adsorbents bind also complement components C3c and C4. No significant adsorption was found for EPO and beta 2M. The four devices exhibit a quite different adsorption profile which can be used as a guide for the optimal selection of an adsorption column in clinical apheresis.
Adsorption↗