The CO adduct of yeast cytochrome c oxidase. Mössbauer and photolysis studies

Mössbauer spectra of 57Fe-enriched NADH-reduced yeast cytochrome c oxidase reveal two quadrupole doublets of unequal intensity; one (approximately 33%) is typical of high-spin ferrous heme with histidine coordination and is assigned to heme a3, while the other (approximately 67%) is typical of low-spin heme with two nitrogeneous axial ligands as expected from heme a. The excess intensity (approximately 17%) of the low-spin doublet must therefore be assigned to heme a3 in a modified environment. The Mössbauer spectra of the same sample exposed to CO show that 50% of the heme iron forms a CO adduct, consistent with heme a3 being inhibited by CO. While low-spin hem a has the same Mössbauer parameters as in the reduced sample, its intensity has dropped to 35%. A distinctly new high-spin species (approximately 15%) is observed and assigned to heme a in a modified environment. The comparable size of the unexpected high-spin heme a fraction in the CO adduct and the low-spin heme a3 fraction in the reduced enzyme suggest that they arise from the same material. This material is likely to be the inactive fraction that has been found in all preparations of resting yeast cytochrome c oxidase (Siedow, J.N., Miller, S., and Palmer, G. (1981) J. Bioenerg. Biomembr. 14, 171-179). The kinetics of CO recombination following photolysis of the CO complex further confirms the coexistence of two distinct fractions associated with active and inactive protein. The majority (approximately 74%), presumably active protein, recombines exponentially from 160 to 270 K following an Arrhenius law. The large activation enthalpy, delta H approximately 35 kJ/mol, is comparable to that found in the beef heart enzyme, suggesting that the flashed-off CO is bound by the nearby CuB as in the mammalian system (Fiamingo, F.G., Altschuld, R.A., Moh, P.P., and Alben, J.O. (1982) J. Biol. Chem. 250, 1639-1650). In the minority, presumably inactive, fraction the CO recombination has fast nonexponential kinetics with a distribution of activation enthalpies peaking near delta Hp = 13 kJ/mol reminiscent of CO binding to myoglobin. In this inactive fraction CuB is apparently not accessible to the flashed-off CO.

Separation of Cucurbitacins by Overpressure Layer Chromatography from Hemsleya gigantha1

Mixtures of cucurbitacins were obtained from an ethanol extract of H. GIGANTHA tubers. Purification was achieved by using the over-pressure layer chromatographic (OPLC) technique to yield cucurbitacin-F, 23,24-dihydrocucurbitacin-F, cucurbitacin-F-25- O-acetate, and 23,24-dihydrocucurbitacin-F-25- O-acetate.

Purification and characterization of an incompletely glycosylated form of human chorionic gonadotropin from human placenta

A small form of hCG (SP-hCG) was purified from an acetone powder preparation of human first trimester placenta by repeated gel filtration and ion exchange chromatography on a Q-Sepharose or FPLC Mono Q column. The estimated mol wt (Mr) of the small hCG by gel filtration is 43K compared to 58K for authentic hCG. The pI of SP-hCG is 10.0, suggesting deficiency of sialic acids. SP-hCG dissociates into subunits when treated with 6 M guanidine-HCl or analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two beta-subunits of SP-hCG were found with estimated Mr of 23K and 20K. Both are distinctly smaller than authentic hCG beta. A single alpha-subunit was found, with an estimated Mr of 21 K. The immunoactivity (8,900-10,000 IU/mg) of highly purified SP-hCG was comparable to that of reference hCG (CR119) determined by a RIA method using anti-hCG antibodies. The hCG/LH receptor-binding activity of SP-hCG is equivalent to that of reference hCG (CR119). Its biological activity is lower than that of reference hCG (approximately 30% or more) assayed by the in vitro stimulation of rat Leydig cells to produce testosterone and cAMP. A high dose is required to attain the same level of stimulation as reference hCG. The amino acid composition of SP-hCG is similar to that of reference hCG, whereas its hexsamine content is significantly lower. Its glucosamine content is about half that in reference hCG, while it completely lacks galactosamine. These findings suggest that SP-hCG is deficient in O-linked oligosaccharide chain in the beta-subunit, and that the N-linked oligosaccharide chains of both subunits are shortened. SP-hCG is one of the principal forms of the hormone present in first trimester placenta and may be a key intermediate in the posttranslational biosynthesis of hCG. Although it lacks O-linked sugar chains and shortened N-linked sugar chains, it possesses substantial biological activity. To have full biological activity, the hCG molecule must contain the complete complement of sugar chains.

Unusual structures of Sporothrix schenckii

A series of environmental and clinical isolates of Sporothrix schenckii being studied in our laboratories under standard conditions of temperature, humidity and media, displayed, in some of the isolates, large dematiaceous hyphae. The large hyphae could be seen to produce the fine hyphae associated with S. schenckii on which typical microconidia developed. Typical microconidia also developed occasionally on the large hyphae, and strands of the unusually large hyphae also were seen to form arthroconidia. Some strains formed large, thin-walled cells on thin and/or thick hyphae resembling the 'balloon cells' seen in mature colonies of Trichophyton tonsurans. All strains which have demonstrated these various and unusual structures histopathologically produced typical sporotrichosis in laboratory animals. When reisolated from these animals, the cultures again exhibited the unusual structures, as well as those typical of S. schenckii.

Localization of the gene encoding human factor V to chromosome 1q21-25

The gene encoding human coagulation Factor V (FV), one of the cofactors in the blood clotting process, has been mapped to chromosome 1 by both Southern hybridization to DNA from human-hamster somatic cell hybrids and in situ hybridization. The whole plasmid pUC3A containing a 1.5-kb cDNA sequence for FV was 32P-labeled for Southern analysis and 3H-labeled for in situ hybridization to metaphase chromosomes. The results localized the FV gene to the region of 1q21-25.

Further in vitro studies with oxiconazole nitrate

Oxiconazole nitrate was compared in vitro with ketoconazole and econazole nitrate in tests with 96 dermatophytes, 18 isolates of Malassezia furfur, and seven isolates of Exophiala werneckii. An agar dilution procedure was used employing either Kimmig's agar or Sabouraud's dextrose agar supplemented with Olive oil and Tween 80. Econazole was the more active compound in tests with Microsporum species (41 isolates) and most isolates of Trichophyton species (45 isolates). Oxiconazole was the more active compound in tests with T. tonsurans and T. rubrum. However, differences between results for oxiconazole and econazole and the dermatophytes were only marginal. Ketoconazole was the most active compound in tests with M. furfur; some cross resistance on the part of several isolates of M. furfur between oxiconazole and econazole was noted. All three compounds were active against E. werneckii with MIC90 values of either 0.25 or 0.5 microgram/ml. Epidermophyton floccosum was the most susceptible of all organisms tested with all MIC values for all three drugs being less than or equal to 0.063 microgram/ml, the lowest concentration tested.

Seizures following myelography with iopamidol

Iopamidol, a water-soluble contrast medium, has been rarely associated with seizures. We describe 3 patients (from a series of 785) who had generalized tonic-clonic seizures after iopamidol myelography. Two of the patients underwent lumbar and one cervical myelography. There was a history of seizures in 2 patients, and the dose of iopamidol used in the patients who convulsed was high, ranging from 3,000 to 4,500 mg iodine. Despite the reported low incidence of complications with iopamidol, seizures may occur, especially in patients with previous seizures and also in those receiving higher doses of iopamidol.

[Electron microscopy of 300 tumors in the nervous system]

The results of 300 nervous system tumors observed by electron microscopy are reported. Of them, 12% depended on electron microscopy for diagnosis; 14% was further classified and typed by electron microscopy; 59% could be diagnosed by either electron or light microscopy but the former played an important role in confirming the diagnosis by light microscopy; 10% still could not be diagnosed even by electron microscopy; 5% failed in diagnosis due to faulty technique. The results indicate that the electron microscope is a useful tool in diagnosis of the nervous system tumor, particularly, in those whose diagnosis is difficult by light microscopy and in classification and typing of the tumor. In this paper, the pathognomonic ultrastructural features are described.

Failed arthrodesis of the spine for severe spondylolisthesis. Salvage by interbody arthrodesis

Four patients who had had grade-III or grade-IV symptomatic spondylolisthesis and a failed posterior or posterolateral arthrodesis were treated with transperitoneal anterior lumbosacral interbody arthrodesis and fixation with a fibular graft; the procedure was sometimes followed by posterolateral arthrodesis of the spine. The patients were examined ten to twenty-two years after the salvage operation. At follow-up, all had a solid fusion of the fifth lumbar to the first sacral vertebra. No neurological deficits had worsened and no iatrogenic neurological deficits had developed. The slip angle had improved by an average of 23.2 degrees (range, 12 to 35 degrees).

Pseudopseudohypoparathyroidism with spinal cord compression

We describe a patient with pseudopseudohypoparathyroidism who had an osseous tubercle on the anterolateral margin of the foramen magnum causing compression of the spinal cord. This patient had no evidence for any endocrinopathies and had no other spinal canal anomalies. We suggest that the morphologic phenotype found in patients with pseudopseudohypoparathyroidism, also known as Albright's hereditary osteodystrophy, has an associated risk for spinal cord compression due to congenital vertebral anomalies. The poor recovery of neurologic function following spinal decompression mandates prompt recognition and therapy of this condition in patients with Albright's hereditary osteodystrophy.

Localization of the processed gene for human ceruloplasmin to chromosome region 8q21.13----q23.1 by in situ hybridization

A processed gene for human ceruloplasmin has been localized to 8q21.13---q23.1 by in situ hybridization. This result confirms the assignment of this locus to chromosome 8 by Southern blot analysis using human x hamster somatic-cell hybrids and localizes the gene to the long arm of chromosome 8.

[Experimental chemotherapy of human gastric cancer cell lines in vitro and in nude mice]

Cytotoxic effects of allyl trisulfide (Alt, a synthetic chemical identical with one of the main active principles of garlic), 5 FU, MMC and DDP on SGC 7901 ( a moderately differentiated human gastric adenocarcinoma cell line) and MGC 803 (a poorly differentiated human gastric mucoadenocarcinoma cell line) had been reported before. In this paper, effects of repeated two doses of each drug and the combination of two drugs on these two cell lines were studied using relative clone-survival test. The inhibitory effects of Alt, MMC alone or combined on MGC tumor in nude mice were observed. No drug resistance was found when any one of the four agents at the same concentration were repeated twice separately at 60 hour interval in vitro. The cytotoxic effect of the repeated two doses was approximately equal to that of the single dose at double concentration. The in vitro test of combinations of two drugs showed that Alt plus MMC or 5 FU plus DDP had markedly synergistic effect on MGC cells; 5 FU plus DDP had markedly synergistic effect on SGC cells. The inhibition test on the growth of MGC tumor in nude mice indicated that the inhibition rates of Alt, MMC alone or combined were 58.3%, 86.3% and 84.3%. The systemic toxic effect of MMC alone was severe, whereas Alt alone or MMC plus Alt showed mild toxicity. For this reason, Alt plus MMC is recommended for clinical trials on poorly differentiated gastric cancer. In addition, for the comparison of in vitro test dose and clinical dose of each drug, the principle of clinical adult dose range (CADR) is proposed.

On the Efficiency of NC Tool Path Planning for Face Milling Operations

Face milling operations are important for producing flat machined surfaces. Existing methodologies to generate NC tool path for face milling are employed everyday by manufacturing industries without considering the impact of tool path selection. A systematic study has been conducted in order to identify those critical control parameters affecting length of cut in face milling operations. Basic polygons, from triangles to heptagons, were planned using both window frame and stair case milling procedures. For each polygon, each vertex was introduced as a possible starting point for a single run in the window frame milling. The cutting orientation was further examined for stair case milling by enumerating the tool sweep angle from 0 to 180 (and 180 to 0 as well) degrees from each vertex. The results are analyzed and important conclusions are drawn noting the efficiency of the cutting process.

Tissue-specific expression of the human alpha 1-antitrypsin gene is controlled by multiple cis-regulatory elements

Human alpha 1-antitrypsin (AAT) is expressed in the liver, and a 318 bp fragment immediately flanking the CAP site of the gene was found to be sufficient to drive the expression of a reporter gene (CAT) specifically in hepatoma cells. The enhancing activity however, was orientation-dependent. The DNA fragment was separated into a distal region and a proximal region. A "core enhancer" sequence GTGGTTTC is present within the distal region and is capable of activity enhancement in both orientations when complemented by the proximal region in the sense orientation. The results strongly suggest that there are multiple cis-acting elements in the human AAT gene that confer cell specificity for its expression. Nuclear proteins prepared from the hepatoma cells bound specifically to the proximal region in a band-shifting assay that was resistant to competition by the globin promoter DNA. Foot-printing analysis showed a protected domain within the proximal region that contains a nearly perfect palindromic sequence TGGTTAATATTCACCA, which may be important in the regulation of AAT expression in the liver.