Physician extenders are part of the team in the '90s.
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Costs and Cost Analysis↗
Biomedical subjects
J King
Publications and source records attributed to J King.
[In vitro digestibility of a milk substitute produced with uncooked flour].
Milk substitutes are used for the breakfast of the recipients of the National School Feeding Programme in Chile. The major ingredients of milk substitutes are milk, sugar and cereal flours. The technical specifications to produce this type of food state, beside their proportions, that the flours must be precooked. This requisite is controlled by determining the gelatinization degree which must be 92% as a minimum. At present, a cheaper new alternative of milk substitute fabricated with uncooked flours and containing an enzymatic preparation has been presented to the Programme. It is postulated that when reconstituted in water under the manufacturer's directions (85 degrees C, 5 min settling time) precooking of the flours is reached. The objective of this work was to evaluate the in vitro digestibility, the effect of the enzymatic preparation (molecular size of starch and dextrose equivalent) and the degree of gelatinization of this product (MSE) when reconstituted under different temperatures and settling times. The same milk substitute but without the enzyme preparation was used as Control. In vitro digestibility (VD) of MSE was 93.8 when reconstituted at 85 degrees C/5 min. settling time. VD decreased at lower temperatures (p > 0.05) to 85.5% (75 degrees C), 82.2% (50 degrees C), 33.0% (40 degrees C) and 41.4% (20 degrees C). VD showed a significant increase when settling time was raised to 30 minutes but only at reconstitution temperatures > 60 degrees C. It was observed the enzyme present in MSE shows a 92.1% of the total potential activity when MSE is reconstituted at 85 degrees C/5 min. The degree of gelatinization, DG, ranged between 42.6% (40 degrees C) and 93.8% (85 degrees C) for 5 min settling time. These values increased after 30 min settling time. VD and DG values for Control were similar to MSE for all the conditions evaluated. It is concluded that both MSE and Control have a good in vitro digestibility and degree of gelatinization when the manufacturer's directions are followed. These results suggest that under these reconstitution conditions precooking of the flours could not be necessary and that the incorporation of enzyme in the formulation has the role of improving some physico chemical characteristics such as the viscosity of the substitute once reconstituted.
Animals↗
Octreotide reduces the kinetic index, proliferating cell nuclear antigen-maximum proliferative index, in patients with colorectal cancer.
BACKGROUND: Somatostatin has been shown to inhibit in vitro and xenograft growth of human colon cancer. The kinetic index, proliferating cell nuclear antigen (PCNA), has previously been used to measure the effects of manipulation of growth of normal rectal epithelium. METHODS: Twenty-five patients with distal colorectal cancer were considered for entry in a presurgical study of Sandostatin (Sandoz, East Hanover, NJ) 1 mg every 8 hours. Biopsies were performed pretreatment, during treatment (14 days), and day of surgical resection (2 days off treatment). A control series of 16 patients underwent endoscopic and subsequent surgical biopsy. A kinetic index was created called PCNA-maximum proliferative index (PCNA-MPI), which was reproducible within one biopsy and between two separate biopsies. Multiple biopsies were taken from the growing edge of tumors, the most cellular and best-stained fields selected, and the highest 6 of 10 separate counted fields were used to produce PCNA-MPI. RESULTS: A significant decline in PCNA-MPI was observed in 6 of the 10 treated patients for whom all three biopsies were available, followed by a significant elevation on withdrawal of treatment. Changes in PCNA-MPI in the control group were less frequent and smaller. CONCLUSIONS: Sandostatin causes a reduction in PCNA-MPI in patients with human colorectal cancer.
Antineoplastic Agents, Hormonal↗
Stability of wild-type and temperature-sensitive protein subunits of the phage P22 capsid.
Temperature-sensitive folding (tsf) mutants of the phage P22 coat protein prevent newly synthesized polypeptide chains from reaching the conformation competent for capsid assembly in cells, and can be rescued by the GroEL chaperone (Gordon, C., Sather, S., Casjens, S., and King, J. (1994) J. Biol. Chem. 269, 27941-27951). Here we investigate the stabilities of wild-type and four tsf mutant unpolymerized subunits. Wild-type coat protein subunits denatured at 40 degrees C, with a calorimetric enthalpy of approximately 600 kJ/mol. Comparison with coat protein denaturation within the shell lattice (Tm = 87 degrees C, delta H approximately 1700 kJ/mol) (Galisteo, M.L., and King, J. (1993) Biophys. J. 65, 227-235) indicates that protein-protein interactions within the capsid provide enormous stabilization. The melting temperatures of the subunits carrying tsf substitutions were similar to wild-type. At low temperatures, the tsf mutants, but not the wild-type, formed non-covalent dimers, which were dissociated at temperatures above 30 degrees C. Spectroscopic and calorimetric studies indicated that the mutant proteins have reduced amounts of ordered structure at low temperature, as compared to the wild-type protein. Although complex, the in vitro phenotypes are consistent with the in vivo finding that the mutants are defective in folding, rather than subunit stability. These results suggest a role for incompletely folded subunits as precursors in viral capsid assembly, providing a mechanism of reaching multiple conformations in the polymerized form.
Bacteriophage P22↗
In vitro folding of phage P22 coat protein with amino acid substitutions that confer in vivo temperature sensitivity.
The coat protein that forms the icosahedral shell of phage P22 can be efficiently refolded in vitro [Teschke, C. M., & King, J. (1993) Biochemistry 32, 10839-10847]. Temperature-sensitive mutants of coat protein interfere with folding or assembly in vivo [Gordon, C. L., & King, J. (1993) J. Biol. Chem. 268, 9358-9368]. The folding of a set of phage P22 coat proteins carrying the temperature-sensitive for folding (tsf) substitutions W48Q, A108V, G232D, T294I, and F353L has been investigated in vitro. Denatured tsf polypeptides were able to fold into soluble species with high efficiency. The efficiency of folding of the wild-type (WT) and mutant polypeptides at different temperatures showed sharp transitions where aggregation predominated over folding. The refolding of the tsf mutant proteins did not show an obvious thermal defect in yield. The tsf polypeptides folded through the long-lived kinetic intermediate previously described for WT coat protein with similar relaxation times. The folding kinetics of the tsf polypeptides in bisANS, a hydrophobic fluorescent dye, were also similar to those of the WT protein. However, the folded tsf proteins showed decreased secondary structure compared to WT coat protein. Analysis of the folded state by native gel electrophoresis revealed that the tsf coat proteins folded into dimers and trimers, not monomers. The dimer and trimer species were incompetent for assembly. Once formed, dimers and trimers showed no propensity toward aggregation. The folding pathway of the mutant polypeptides must be quite similar to the WT pathway, but at some step inappropriate intersubunit interactions occur due to the amino acid substitutions, trapping the subunits from assembly.
Anilino Naphthalenesulfonates↗
An acetohydroxy acid synthase mutant reveals a single site involved in multiple herbicide resistance.
Acetohydroxy acid synthase (AHAS) is an essential enzyme for many organisms as it catalyzes the first step in the biosynthesis of the branched-chain amino acids valine, isoleucine, and leucine. The enzyme is under allosteric control by these amino acids. It is also inhibited by several classes of herbicides, such as the sulfonylureas, imidazolinones and triazolopyrimidines, that are believed to bind to a relic quinone-binding site. In this study, a mutant allele of AHAS3 responsible for sulfonylurea resistance in a Brassica napus cell line was isolated. Sequence analyses predicted a single amino acid change (557 Trp-->Leu) within a conserved region of AHAS. Expression in transgenic plants conferred strong resistance to the three classes of herbicides, revealing a single site essential for the binding of all the herbicide classes. The mutation did not appear to affect feedback inhibition by the branched-chain amino acids in plants.
Acetolactate Synthase↗
Multimeric intermediates in the pathway to the aggregated inclusion body state for P22 tailspike polypeptide chains.
The failure of newly synthesized polypeptide chains to reach the native conformation due to their accumulation as inclusion bodies is a serious problem in biotechnology. The critical intermediate at the junction between the productive folding and the inclusion body pathway has been previously identified for the P22 tailspike endorhamnosidase. We have been able to trap subsequent intermediates in the in vitro pathway to the aggregated inclusion body state. Nondenaturing gel electrophoresis identified a sequential series of multimeric intermediates in the aggregation pathway. These represent discrete species formed from noncovalent association of partially folded intermediates rather than aggregation of native-like trimeric species. Monomer, dimer, trimer, tetramer, pentamer, and hexamer states of the partially folded species were populated in the initial stages of the aggregation reaction. This methodology of isolating early multimers along the aggregation pathway was applicable to other proteins, such as the P22 coat protein and carbonic anhydrase II.
Electrophoresis, Gel, Two-Dimensional↗
A double mutant allele, csr1-4, of Arabidopsis thaliana encodes an acetolactate synthase with altered kinetics.
A comparison is made of the kinetic characteristics of acetolactate synthase (EC 4.1.3.18) in extracts from Columbia wild type and four near-isogenic, herbicide-resistant mutants of Arabidopsis thaliana (L.) Heynh. The mutants used were the chlorsulfuron-resistant GH50 (csr1-1), the imazapyr-resistant GH90 (csr1-2), the triazolopyrimidine-resistant Tzp5 (csr1-3) and the multiherbicide-resistant, double mutant GM4.8 (csr1-4), derived from csr1-1 and csr1-2 by intragenic recombination (G. Mourad et al. 1994, Mol. Gen. Genet. 243, 178-184). Kmapp and Vmax values for the substrate pyruvate were unaffected by any of the mutations giving rise to herbicide resistance. Feedback inhibition by L-valine (L-Val), L-leucine (L-Leu) and L-isoleucine (L-Ile) of acetolactate synthase extracted from wild type and mutants fitted a mixed competitive pattern most closely. Ki values for L-Val, L-Leu and L-Ile inhibition were not significantly different from wild type in extracts from csr1-1, csr1-2, and csr1-3. Ki values were significantly higher than wild type by two- and five-fold, respectively, for csr1-4 with L-Val and L-Leu but not L-Ile. GM4.8 (csr1-4) plants were also highly resistant in their growth to added L-Val and L-Leu.(ABSTRACT TRUNCATED AT 250 WORDS)
Acetolactate Synthase↗
Epidemic methicillin-resistant Staphylococcus aureus: controlling the spread outside hospital.
Over a 21-month period an outbreak of methicillin-resistant Staphylococcus aureus infection occurred in east Northamptonshire. The outbreak was caused by a novel phage-type (EMRSA-16) and affected 400 patients. It was centred on three hospitals but spread was also detected in the community, particularly among clients of nursing and residential homes. Three hundred and fifty residents in 15 care homes were screened for MRSA. Cross-infection of MRSA was demonstrated in 14 patients in six different homes. A key aspect of the overall containment of the outbreak was the implementation of infection control measures in the community, together with treatment and screening of known positive patients following their discharge from hospital.
Community-Acquired Infections↗
Clinical path coordinator: pulling it all together.
Institutions across the country are using different approaches to restructuring health care delivery systems. At Lehigh Valley Hospital collaborative practice was instituted to ensure the achievement of patient outcomes within appropriate time frames and with efficient use of resources. The role of the clinical path coordinator emerged from the collaborative practice model developed to manage the care of the patient with an abdominal aortic aneurysm. The step-by-step process for selecting, orienting, and implementing the role of the coordinator is discussed. Since the implementation of the coordinator role, patient satisfaction has been positive, length of stay and cost have decreased, and quality of care has improved for these patients.
Aortic Aneurysm, Abdominal↗
HIV-regulated diphtheria toxin A chain gene confers long-term protection against HIV type 1 infection in the human promonocytic cell line U937.
Gene therapy approaches have recently been investigated for the treatment of acquired immunodeficiency syndrome (AIDS), both in preclinical and clinical studies, because more traditional antiviral agents have proven to be of limited effectiveness. We have previously shown that long-term protection against both laboratory and clinical isolates of human immunodeficiency virus type 1 (HIV-1) was conferred by HIV-regulated diphtheria toxin A (DT-A) chain in a human T cell line. Because the monocyte/macrophage cell is an important reservoir for HIV-1 in infected individuals, we sought here to determine whether HIV-regulated DT-A would also be effective in the promonocytic cell line U937. We report here that long-term protection, conferred by HIV-regulated DT-A, was observed in U937 cells, but that protection was dependent on the stock of HIV IIIB used for challenge. HIV production was measured by p24 assays, polymerase chain reaction (PCR) for HIV vif, gag, and reverse transcriptase (RT) sequences, and cocultivation with peripheral blood mononuclear cells (PBMCs). Complete protection was seen in DT-A-transduced cells with a stock of IIIB propagated on H9 cells and titered on peripheral blood mononuclear cells (PBMCs), while protection in these same cells with a second stock of IIIB, propagated and titered on H9 cells, was only partial and dose dependent.
CD4 Antigens↗
Incidence and pathogenicity of Arcanobacterium haemolyticum during a 2-year study in Ottawa.
Arcanobacterium haemolyticum has been described as a rare cause of systemic invasive disease and is occasionally isolated from throat swabs. We describe a 2-year study of the incidence and clinical features of A. haemolyticus infection in a pediatric and adolescent population. A total of 11,620 throat swabs were examined for A. haemolyticum with use of a locally developed selective medium. Controls (2,241) were healthy students who were recruited from a separate study. A. haemolyticum was isolated from 42 patients, with the maximum incidence in the 15 to 18-year-old age group; in this subset the incidence was 2.5%. There were no isolates of A. haemolyticum found in the healthy controls, and the difference in incidence between patients and controls in the 15 to 18-year-old age group was highly significant (P < .01). Approximately half of the patients infected with A. haemolyticum had a rash. In 5 patients, A. haemolyticum was associated with a positive monospot test. The organism was highly susceptible to erythromycin and less susceptible to penicillin. The evidence from this study suggests that A. haemolyticum may be a pathogen with maximum incidence in the 15 to 18-year-old age group.
Actinomycetaceae↗
Therapeutic regimens in acute experimental pancreatitis in rats: effects of a protease inhibitor, a beta-agonist, and antibiotics.
The osmolality of contrast injected retrograde into the rat pancreatic duct did not affect the severity of the pancreatitis (Urografin, 1,300 mOsm/kg, and Hexabrix, 580 mOsm/kg). The severity of the pancreatitis induced in rats was assessed by survival rate, histologic grading, wet lung ratio, and serum levels of amylase, lipase, and trypsin-like activity. Rats with pancreatitis induced by retrograde injected Urografin, lipopolysaccharide, taurocholic acid plus enterokinase were treated with either intravenous (i.v.) FUT-175 (Nafamstat Mesilate), FUT-175 administered by retrograde pancreatic injection, i.v. terbutaline, i.v. piperacillin sodium, piperacillin sodium by retrograde pancreatic duct injection, or a combination of FUT-175 plus terbutaline and piperacillin. Survival among the rats was increased and the incidence of pancreatic infection reduced in rats treated with i.v. piperacillin or with a combination of FUT-175 plus i.v. terbutaline, plus i.v. piperacillin compared to controls.
Acute Disease↗
Aspirin and prevention of preeclampsia. Position statement of the use of low-dose aspirin in pregnancy by the Australasian Society for the Study of Hypertension in Pregnancy.
1. A heterogeneous group of randomized trials have been conducted using low-dose aspirin to prevent preeclampsia. The results do not support widespread use of low-dose aspirin to prevent preeclampsia. 2. On the basis of existing literature, it is reasonable to use prophylactic low-dose aspirin from early pregnancy in the following groups: (i) Women with prior fetal loss after the first trimester, with placental insufficiency (ii) Women with severe fetal growth retardation in a preceding pregnancy either due to preeclampsia or unexplained (iii) Women with severe early-onset preeclampsia in a previous pregnancy necessitating delivery at or before 32 weeks' gestation. 3. On the basis of existing literature, it is recommended that aspirin not be used in the following groups: (i) Healthy nulliparous women (ii) Women with mild chronic hypertension (iii) Women with established preeclampsia. 4. The data are sufficient to support further trials in more homogeneous select subgroups of women considered at risk of developing preeclampsia.
Aspirin↗
Effect of granulocyte colony-stimulating factor on acute lung injury in the rat.
The effect of G-CSF pretreatment on experimental acute lung injury was studied in Sprague-Dawley rats receiving one of the following treatments: (1) G-CSF 50 micrograms/kg subcutaneously twice daily beginning 2 d prior to being killed; (2) ANTU 50 mg/kg intraperitoneally; (3) ANTU+G-CSF 50, 25, or 12.5 micrograms/kg; (4) HCl 0.6 ml of a 0.1 N solution intratracheally; (5) HCl+G-CSF 50 or 25 micrograms/kg; (6) control solutions. Lung injury was quantified by measurement of lung wet/dry weights, by histopathologic scoring, and by measurement of fluid flux during ex vivo perfusion. G-CSF pretreatment elevated the baseline blood neutrophil counts as much as 6-fold compared with Control, and it increased the numbers of lung neutrophils and caused a mild histologic lung injury, but it did not significantly alter wet/dry weight ratios or fluid flux. ANTU alone and HCl alone caused a moderate histologic lung injury, increased wet/dry weight ratio, and resulted in a small increase in flux. The combination injuries, ANTU+G-CSF and HCl+G-CSF, caused a more severe lung injury manifested by increased wet/dry weight ratios and increase in flux when compared with ANTU alone and HCl alone, respectively. We conclude that pretreatment with G-CSF potentiates ANTU- and HCl-induced lung injury in non-neutropenic rats. The potential for G-CSF to aggravate acute lung injury in patients remains speculative.
Animals↗
Binding of scaffolding subunits within the P22 procapsid lattice.
The capsid assembly pathways of the dsDNA bacteriophages, herpesviruses, and adenoviruses all proceed through a precursor shell lacking DNA. These procapsids contain scaffolding proteins required for assembly but absent from mature virions. The bacteriophage P22 procapsid contains approximately 300 molecules of the 33-kDa gene 8 scaffolding protein, in addition to the 420 molecules of gene 5 coat protein. During the process of DNA packaging and phage maturation, all 300 scaffolding molecules are released intact to participate in subsequent rounds of procapsid assembly. Low concentrations of guanidine hydrochloride (GuHCl) reproduce the release of scaffolding from procapsids in vitro, in the absence of DNA. The release was reversible; when the GuHCl was removed by dialysis, the scaffolding subunits reentered the extracted capsids to regenerate morphologically normal procapsids. The subunits presumably exited and reentered through the channels recently observed at the centers of the pentamers and hexamers (Prasad, B. V. V., Prevelige, P. E., Marietta, E., Chen, R. O., Thomas, D., King, J., and Chiu, W. (1993). J. Mol. Biol. 231 65-74). We have utilized this reaction to investigate the binding of scaffolding within normal procapsids and to other large structures of coat protein. Procapsids contained two classes of scaffolding subunits, which may represent binding of scaffolding to different specific positions within the T = 7 procapsid lattice. These sites became lost or inaccessible upon phage maturation.
Bacteriophage P22↗
Selective in vivo rescue by GroEL/ES of thermolabile folding intermediates to phage P22 structural proteins.
The in vivo conformational substrates of the GroE chaperonins have been difficult to identify, in part because of limited information on in vivo polypeptide chain folding pathways. Temperature-sensitive folding (tsf) mutants have been characterized for the coat protein and tailspike protein of phage P22. These mutations block intracellular folding at restrictive temperature by increasing the lability of folding intermediates without impairing the stability or function of the native state. Overexpression of GroEL/ES suppressed the defects of tsf mutants at 17 sites in the coat protein, by improving folding efficiency rather than assembly efficiency or protein stability. Immunoprecipitation experiments demonstrated that GroEL interacted transiently with newly synthesized wild-type coat protein and that this interaction was prolonged by the tsf mutations. Folding defects of the tailspike polypeptide chains were not suppressed. A fraction of the tsf mutant tailspike chains bound to GroEL but were inefficiently discharged. The results suggest that 1) thermolabile folding intermediates are natural substrates of GroEL/ES; 2) although GroEL may bind such intermediates for many proteins, the chaperoning function is limited to a subset of substrate proteins; and 3) a key reason for the heat-shock response may be to stabilize thermolabile folding intermediates at elevated temperatures.
Bacteriophage P22↗
Intracellular trapping of a cytoplasmic folding intermediate of the phage P22 tailspike using iodoacetamide.
Critical steps in polypeptide chain folding within the bacterial cytoplasm have been difficult to identify. Salmonella cells infected with temperature-sensitive folding mutants of the P22 tailspike protein at restrictive temperature accumulated a metastable folding intermediate with a half-life of 6 min at 39 degrees C. The native trimeric tailspike contains 24 buried cysteines (8/chain) but neither disulfide bonds nor active site cysteines. Eighteen of the 24 cysteines are involved in strong hydrogen bonds (Thomas, G. J., Jr., Becka, R., Sargent, D., Yu, M.-H., and King, J. (1990) Biochemistry 29, 4181-4187). Cyanide and iodoacetamide prevented the folding and association of the restrictive temperature folding intermediate to the native state after shift to permissive temperature. The cytoplasmic folding intermediate was covalently modified by iodoacetamide within infected cells. Chains which had reacted with iodoacetamide were unable to proceed through the folding pathway. Iodoacetamide also reacted with a folding intermediate during the refolding of purified tailspike chains in vitro, inhibiting further folding. No reaction occurred with native tailspike in vivo or in vitro. The target residues in the intermediates were in the carboxyl terminus of the chain and may be a unique set of cysteine residues that are activated during protein folding, but not in the native state.
Bacteriophage P22↗