Catalytic activity of anion-exchange resins modified with metal-porphine in oxidative reactions of phenols

Anion-exchange resins modified with metal-porphine (M-Pr) have been investigated to develop a solid catalyst in the oxidative reaction of phenols by O2 in air. Co-Pr, which is easily prepared and separable from the reaction mixture, has been proved to accelerate the oxidative reaction of phenols such as 3,5-di-tertbutyl-4-hydroxyanisole. The resulting main oxidative products were identified to be quinones by using the GC-MS method.

Osteonecrosis of the femoral head in spontaneously hypertensive rats. Relation to ossific nuclei during growth

We observed the distribution of the ossific nuclei and the occurrence of osteonecrosis in the femoral capital epiphysis of spontaneously hypertensive rats. In 270 femoral heads, the ossific nuclei were seen in the following sites of the epiphysis: Type 1, the lateral portion in 150 femoral heads; Type 2, the central portion in 5 heads; Type 3, both lateral and central portions in 12 heads; and Type 4, throughout the epiphysis in 62 heads. The number of femoral heads with osteonecrosis in Types 1-4 was 61, 0, 5, and 17, respectively.

Searching for amino acid sequence motifs among enzymes: the Enzyme-Reaction Database

Recently we have constructed a database--the Enzyme-Reaction Database--which links a chemical structure to amino acid sequences of enzymes that recognize the chemical structure as their ligand. The total number of enzymes registered in the database is 1103 with 6668 NBRF-PIR entry codes and 1756 chemical compounds. The chemical structures and chemical names for 842 compounds are registered in the Chemical-Structure Database on the MACCS system. For each enzyme, the sequences were divided into clusters, and multiply aligned in each cluster to extract a conserved sequence. A total of 158,781 five-residue-long fragments were constructed from 433 conserved sequences and compared among different clusters of different enzymes. One of these motifs shared by different enzymes was S-G-G-L-D. The motif was conserved in both argininosuccinate synthase (EC 6.3.4.5) and asparagine synthase (glutamine-hydrolysing) (EC 6.3.5.4). This result showed that the database was useful for the analysis of the relationship between chemical structures and amino acid sequence motifs.

Searching for common sequence patterns among distantly related proteins

We have developed a program Gap Allowing Pattern Explorer (GAPE) to extract amino acid sequence motifs conserved among distantly related proteins. The GAPE program is designed to allow gaps in the sequences. First, this program generates all possible amino acid patterns comprising up to five amino acids. Sequences containing the amino acid residues in the same order as a generated pattern are selected as subsequences, where the differences in the distances between two consecutive amino acids are ignored. Next, the motifs are extracted from the subsequences under conditions in which all four distances between the five amino acids are fixed. At this stage, motifs with gaps in their subsequence are also found by relaxing one of the four fixed distances. The statistical significance for a motif obtained is calculated based on the amino acid composition of the sequences under consideration. When the GAPE program was applied to 59 pyridoxal-phosphate-related sequences and 64 ATP (AMP-forming)-related sequences, motifs extracted with a low expectation of occurrence contained some of the amino acid residues chemically proved to be involved in the ligand recognition.

Palmoplantar pustulotic arthro-osteitis of the peripheral joints with no sternocostoclavicular lesions

A 45 year old woman presented with swelling and pain on joint movement of her knees, although joint movement was relatively well maintained. Five years previously the patient had been diagnosed as having pustulosis palmoplantaris by a dermatologist. Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) had no effect, but treatment with 5 mg/day prednisolone caused remission of both the joint pain and swelling and the pustulosis palmoplantaris. There were no sternocostoclavicular lesions at any time during treatment. Clinical findings in this patient were different from previous reports and she was diagnosed as having palmoplantar pustulotic arthro-osteitis affecting the peripheral joints.

Crystallization and preliminary X-ray studies of glutathione synthetase from Escherichia coli B

The glutathione synthetase from Escherichia coli B has been crystallized from 27% saturated ammonium sulfate solution (pH 5.5). The crystals are hexagonal, space group P6(2)22 or P6(4)22. The cell dimensions are a = b = 88.0 A, c = 164.2 A, and gamma = 120 degrees. The enzyme is a tetramer (Mr = 143,000) with 222 symmetry, and the asymmetric unit contains one subunit molecule (Mr = 35,600). The crystals diffract to at least 2.5 A resolution.

Site-directed mutagenesis of glutathione synthetase from Escherichia coli B: mapping of the gamma-L-glutamyl-L-cysteine-binding site

Lys18, Arg86, Asn283, Ser286, Thr288 and Glu292 of glutathione synthetase from Escherichia coli B are presumed to be highly concerned with the substrate, gamma-L-glutamyl-L-cysteine (gamma-Glu-Cys), binding by X-ray crystallography and affinity labeling studies. Using site-directed mutagenesis, we investigated functional roles of those residues for gamma-Glu-Cys binding. The mutant enzymes of Arg86 and Asn283 altered their kinetic parameters, especially the Michaelis constants of gamma-Glu-Cys. In the case of Asn283, the residue is not likely to have an essential role in gamma-Glu-Cys binding but its side chain would extend to make a van der Waals contact with bound gamma-Glu-Cys. Chemical modification of a cysteine residue with 5,5'-dithiobis(2-nitrobenzoate) (DTNB) showed Arg86 would not only be much responsible for gamma-Glu-Cys binding but would also have a role in maintaining the structural integrity of the enzyme. The other mutant enzymes showed little defect in their kinetic parameters of gamma-Glu-Cys.

Serial determinations of serum enzymes following aorta-coronary bypass surgery and acute myocardial infarction

Serial determinations of serum creatine kinase (CK), cardio-specific isoenzyme of CK (CK-MB), glutamic oxaloacetic transaminase (GOT) and alpha-hydroxybutylate dehydrogenase (HBD) were made in 29 consecutive patients undergoing aorta-coronary (AC) bypass grafting, and the results were compared with those in 31 patients with acute myocardial infarction (AMI). Postoperatively, all patients had an uneventful postoperative course and there was no evidence of AMI. The time course of enzyme activity following surgery was characterized by 1) shortening of peak activity time of all enzymes except CK, 2) rapid disappearance of CK-MB, 3) prolonged normalization of GOT and HBD. Peak activities of CK, CK-MB, GOT and HBD in AC bypass patients were 801 +/- 77, 46 +/- 6, 100 +/- 9 and 718 +/- 32 IU (mean +/- SEM), respectively, which were equivalent to 46%, 12%, 22% and 47% of those in AMI. The degree of postoperative CK-MB elevation was influenced by the duration of the operation and the extracorporeal circulation, and the number of grafts bypassed. The peak CK-MB activity did not correlate with the CK peak. The ratio of CK-MB to CK was much smaller in AC bypass than in AMI (6.5 +/- 1.8 vs. 20.1 +/- 1.4%). It was concluded that serum enzyme elevations after AC bypass surgery largely reflected enzyme release from the skeletal muscle rather than the myocardium.

Nicked multifunctional loop of glutathione synthetase still protects the catalytic intermediate

A derivative of glutathione synthetase (GSHase) with the multifunctional loop cleaved (nicked GSHase) was compared to both a deletion mutant of the loop (loopless GSHase) and wild-type with the intact loop (wild-type GSHase). The loop had been shown to be in a closed state in order to protect a catalytic intermediate and accelerate the reaction. Data indicated that cleavage of the loop resulted in a drastic decrease in glutathione synthetic activity which was similar to the results for the loop deletion. Kinetic analyses indicated that the manipulations of the loop impaired the substrate affinity, especially for glycine, and also catalytic efficiency. The nicked loop did not accelerate the reaction as fast as the intact loop; however, the catalytic intermediate was protected from hydrolysis by the cleaved loop as effectively as by the intact loop. These results suggest that the fragmental loop assumed the closed state. High concentrations of ATP showed some inhibitory effects on wild-type GSHase, while both nicked and loopless GSHase were not inhibited, indicating that the fragments of the nicked loop functioned independently. In conclusion, it is postulated that the two fragments of the nicked loop independently assumed the closed state to protect the catalytic intermediate and have lost the ability to accelerate glutathione synthesis.

ATP-dependent inactivation of Escherichia coli gamma-glutamylcysteine synthetase by L-glutamic acid gamma-monohydroxamate

Incubation of Escherichia coli gamma-glutamylcysteine synthetase with L-glutamic acid gamma-monohydroxamate and ATP caused slow but irreversible inhibition of the enzyme, and more than 90% activity was lost in three days. The enzyme was not inactivated when ATP was absent or L-aspartic acid beta-monohydroxamate was substituted for L-glutamic acid gamma-monohydroxamate, suggesting that the inactivation process reflected a mechanism-based reaction of L-glutamic acid gamma-monohydroxamate and ATP.

Displacement of the quadrigeminal plate in tumors of the fourth ventricle: MR appearance

Magnetic resonance studies of 12 fourth ventricle tumors were reviewed. The relationship between the tumor and surrounding structures, such as the corpus medullare, the superior medullary velum, and the quadrigeminal plate, was assessed on midsagittal inversion recovery images. Two of the 12 tumors displaced the superior medullary velum superiorly. Seven of the 12 tumors displaced the corpus medullare posteriorly. The superior medullary velum was not recognized in 10 cases and the corpus medullare in 5. Ten of 12 quadrigeminal plates were displaced superoposteriorly due to focal enlargement of the cerebral aqueduct secondary to large intraventricular tumors. In the remaining two cases the tumor was not large enough to enlarge the cerebral aqueduct. The larger the tumor was, the more frequent was the displacement of the quadrigeminal plate. On T2-weighted images, CSF flow-void sign was seen around the tumor in 5 of 12 cases. We consider superoposterior displacement of the quadrigeminal plate to be a relatively constant and reliable sign accompanying fourth ventricle tumors.

The “Multi Clip” Method in Unruptured Complex Middle Cerebral Artery Aneurysms - A Case Series

This study aims to analyze the feasibility, indications and applicability of the "Multi Clip" method for accurate and complete clipping in patients with unruptured complex middle cerebral artery aneurysms. In this series, we achieved precise clipping in all cases without any intraoperative complications. On the basis of our work, we classified the necessity for multi-clipping into 3 categories: 1) precise clipping, 2) perforator preservation, and 3) reconstruction. The outcome in all patients was excellent. In conclusion, the "Multi Clip" method is a safe and an efficient procedure in cases of difficult unruptured middle cerebral artery aneurysms, where optimal neck closure cannot be obtained by single clipping.

Interleukin-1beta alters the oxygen delivery-oxygen consumption relationship in rabbits by increasing the slope of the supply-independent line

When systemic oxygen delivery (DO2) is reduced, oxygen consumption (VO2) is maintained until a critical level is reached (DO2crit). Sepsis is thought to shift DO2crit to the right and lengthen the supply-dependent portion. We tested the effect of interleukin (IL)-1beta, which is one of the key cytokines related to sepsis, on the DO2-VO2 relationship. Fifteen rabbits were subjected to stepwise cardiac tamponade to reduce DO2 to 10% by inflating a handmade balloon placed into the pericardial sac. Seven rabbits were given 10 microg/kg of IL-1beta intravenously (IL-1beta group) prior to the graded cardiac tamponade. The remainder received saline alone (control group). The DO2-VO2 relationship was analyzed by the dual-line method. IL-1beta significantly decreased mean arterial pressure (65 +/- 11 mmHg from baseline 85 +/- 7 mmHg) without altering cardiac output. The IL-1beta group showed significantly steeper supply-independent line slopes than did the control group (0.19 +/- 0.02 vs. 0.11 +/- 0.02, respectively), which resulted in a DO2crit shift to the left (IL-1beta group, 8.7 +/- 1.7 ml/kg x min vs. control, 11.7 +/- 0.7 ml/kg x min). The IL-1beta group also showed greater PO2 and plasma lactate levels in the portal vein than did the control group. These results indicate that IL-1beta impairs systemic oxygen uptake even before VO2 becomes supply-dependent, presumably due to maldistribution of the blood flow including the splanchnic circulation.

SPECT imaging in a case of primary respiratory tract amyloidosis

SPECT findings in a very rare case of primary amyloidosis localized in the laryngotracheobronchial area are reported. SPECT using Tc-99m PYP revealed widespread uptake in the larynx and the entire tracheobronchial tree up to the subsegmental divisions; the areas corresponded to diffuse thickening and calcification of the walls on CT. SPECT using Ga-67 citrate also showed marked uptake in the same area, consistent with the findings shown by SPECT using Tc-99m PYP.

Characterization of a catalytic antibody for stereoselective ester hydrolysis--a catalytic residue and mode of product inhibition

A catalytic antibody which catalyzes stereoselective ester hydrolysis was characterized, and the role of a catalytic Arg residue is discussed in terms of product inhibition. A monoclonal antibody 1C7 generated against the phosphonate 1 was highly stereoselective for (R)-isomer in hydrolyzing racemic ester 2. However, the reaction was almost stoichiometric due to strong inhibition by the product acid 3. One Arg residue in the antibody combining site was essential to the catalysis, and the same Arg was expected to play a dominant role in product inhibition by charge interaction with the negatively charged product acid. Indeed, the antibody experienced much less product inhibition with the hydrolysis of a carbonate ester 7, which yields a neutral alcohol 8 devoid of a negative charge, and exhibited at least 100 turnovers without any loss of activity. In addition, high stereoselectivity for (R)-isomer was still retained. The amino acid sequence and computer modeling of the variable domain of 1C7 suggested that Arg97 in the complementarity-determining region (CDR) of heavy chain was the putative catalytic residue.

Surgical treatment of patients with unruptured intracranial aneurysms

We present our experience with elective microsurgical clipping of unruptured intracranial aneurysms (UIA) and analyze this management. A total of 150 patients with UIA were reviewed and data were collected with regard to age, sex, presence of symptoms, location and size of the aneurysms, surgical complications and postoperative 1 year outcomes. Aneurysm size was assessed either by three-dimensional CT angiography or digital subtraction angiogram. Glasgow Outcome Scale was used to assess clinical outcomes. One hundred and fifty patients with 165 aneurysms were treated in this series. The mean size of the UIA was 5.6mm. Eighty aneurysms (48.5%) were less than 5mm in size, and 73 (44.2%) were from 5 to 10mm. Ten (6.1%) of the aneurysms were large and two (1.2%) were giant. One hundred and forty-three were asymptomatic and seven were symptomatic before surgery. The outcome was good in 147 patients (98%), and only three patients (2%) had a treatment-related unfavorable outcome. Five patients experienced transient neurological deficits and one patient experienced permanent neurological deficits. Overall 98.7% of the treated aneurysms were satisfactorily obliterated. Wound complications were seen only in three patients. In conclusion, UIA pose a significant challenge for neurosurgeons, where a delicate balance between benefits and possible risks must be weighed. If the requisite expertise is available, they can be treated surgically with low morbidity and a good outcome at specialized neurovascular centers.

Crystallization and preliminary crystallographic study of tropinone reductase II from Datura stramonium

Tropinone reductase II is an NADPH-dependent oxidoreductase involved in a plant alkaloid metabolism. The enzyme from Datura stramonium has been crystallized using 2-methyl-2,4-pentanediol as a precipitant and a macro-seeding technique. The crystal belongs to space group P42212, with cell dimensions a = b = 62.8 and c = 128.4 A. A data set to 2.6 A resolution has been collected at a cryogenic temperature.

Cardiovascular response to exercise in pacemaker implanted patients with fixed heart rate

Cardiovascular response to supine exercise was studied in 11 patients with chronic ventricular pacing for complete atrioventricular block whose heart rate was fixed during exercise, and compared with 11 age- and sex-matched normal subjects. Oxygen uptake increased linearly with increasing work rate, and attained maximum values of 15.7 +/- 0.7 and 29.5 +/- 1.1 ml/min.kg, respectively. In both groups, cardiac output increased in association with oxygen uptake, although the maximum value in the patients was less than one half that in the controls (6.8 +/- 0.5 and 15.1 +/- 0.3 l/min). Stroke volume, however, could change in patients, as in the controls under similarly increased afterloads (maximum values were 96 +/- 7 and 93 +/- 3 ml/beat, respectively). During exercise, the systolic arterial pressure elevated to a similar extent in both groups (221 +/- 14 and 235 +/- 12 mmHg, respectively). The increase in stroke volume in the patients was achieved by complete systolic emptying and the Frank-Starling mechanism. It is considered that in patients with ventricular pacing, exercise can produce an increase in stroke volume when myocardial function is not impaired.

Similarity graphing and enzyme-reaction database: methods to detect sequence regions of importance for recognition of chemical structures

We developed a new method which searches sequence segments responsible for the recognition of a given chemical structure. These segments are detected as those locally conserved among a sequence to be analyzed (target sequence) and a set of sequences (reference sequences). Reference sequences are the sequences of functionally related proteins, ligands of which contain a common chemical substructure in their molecular structures. 'Similarity graphing' cuts target sequences into segments, aligns them with reference sequence pairwise, calculates the degree of similarity for each alignment, and shows graphically cumulative similarity values on target sequence. Any locally conserved regions, short or long in length and weak or strong in similarity, are detected at their optimal conditions by adjusting three parameters. The 'enzyme-reaction database' contains chemical structures and their related enzymes. When a chemical substructure is input into the database, sequences of the enzymes related to the input substructure are systematically searched from the NBRF sequence database and output as reference sequences. Examples of analysis using similarity graphing in combination with the enzyme-reaction database showed a great potentiality in the systematic analysis of the relationships between sequences and molecular recognitions for protein engineering.

Crystallization and preliminary crystallographic study of asparagine synthetase from Escherichia coli

Crystals of Escherichia coli asparagine synthetase have been obtained from 45% saturated ammonium sulfate solution at pH 7.5 by using its Cys-free (Cys51-->Ala, Cys315-->Ala) mutant. The crystals belong to space group P2(1), with cell dimensions a = 52.90(4), b = 126.2 (2), c = 52.8 (1) A and beta = 105.3(1) degrees. The self-rotation function specifies that there is one dimer in the asymmetric unit and the subunits are related by a non-crystallographic twofold axis. Complete data sets up to 2.7 A resolution have been collected on an R-AXIS IIc imaging-plate system.

Fibroma of tendon sheath with ulceration

We describe a 44-year-old man with fibroma of tendon sheath. The tumor originated in the foot and developed an ulcer during its course. It was totally excised, and the defect was reconstructed by full-thickness skin graft. The patient has been free of any recurrence during the follow-up period of one year. Fibroma of tendon sheath rarely occurs in the foot, and, to our best knowledge, this condition with ulceration is the first case reported.