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Biomedical subjects

R Montgomery

Publications and source records attributed to R Montgomery.

At least 37 records · Page 2Linked to original sources
PubMed1997

Laparoscopic assisted live donor nephrectomy--a comparison with the open approach.

Live donor renal transplantation provides significant advantages when compared with cadaveric donor renal transplantation in terms of improved patient and graft survival, a lower incidence of delayed function, and a shorter waiting time. Yet despite these advantages, live donors continue to be an under utilized source of kidneys for transplantation. Disincentives to live donation include the length of hospitalization, postoperative pain, cosmetic concerns, and the prolonged convalescence associated with the donor operation. In many instances minimally invasive video-assisted techniques have proven more efficacious than standard open procedures in terms of patient discomfort, length of hospital stay, cost, and length of time until the patient can return to full activity. Laparoscopic live donor nephrectomies are being performed at our institution in an attempt to make live donation more attractive to the potential donor. The purpose of this study was to retrospectively review the results of laparoscopic live donor nephrectomy (LapNx) and to compare them with those obtained using the standard open approach (OpenNx). Ten consecutive LapNx were performed from February 1995 through April 1996. The control group consisted of the 20 consecutive OpenNx performed at the same institution from January 1991 through January 1995 immediately before the initiation of the LapNx program. Live donors were considered candidates for LapNx if they possessed at least one kidney with normal renal anatomy with single renal vessels and a single ureter. LapNx was safely performed in all cases. No patients required open conversion or blood transfusions. The allograft warm ischemic time for the laparoscopic cases was 4.2+/-1.3 min. All kidneys harvested laparoscopically produced urine on the table immediately upon revascularization. Presently nine of the ten recipients have functioning allografts. At three months posttransplant the calculated recipient creatinine clearances were 67.0+/-11.5 ml/min and 64.8+/-21.4 ml/min for the LapNx and OpenNx groups, respectively (P=NS). The LapNx donors had a significantly decreased estimated blood loss, shorter time until resumption of oral intake, decreased postoperative pain (in terms of decreased analgesic requirements), shorter hospitalization, and a shorter interval until the resumption of full activities (P<0.05 for all). In addition, the LapNx group donors returned to work sooner than the OpenNx group (3.9+/-1.6 wk vs. 6.4+/-3.1 wk, respectively) (P=0.024). Four individuals agreed to donate a kidney only after learning of the availability of the laparoscopic approach. We conclude that laparoscopic live donor nephrectomy is technically feasible. In addition, it may offer significant advantages over the standard open approach in terms of patient comfort and convenience. These advantages may make live donor renal transplantation more attractive to prospective donors. The potential decrease in hospitalization and convalescence may also prove to be financially advantageous. We believe that further careful study of this procedure is warranted.

Adult↗
PubMed1997

Predictive assessment of vocal efficiency (PAVE). A method for voice therapy outcome measurement.

A prospective study was carried out to examine the degree to which a standard voice assessment could discriminate between the potential benefits of two different voice therapy programmes for individual patients. The study encompassed 200 dysphonia subjects who were referred for voice therapy and had completed treatment within a prescribed two-year period. A standard assessment procedure was carried out on first attendance for each patient and guidelines were used to assign patients to different treatment programmes on the basis of the assessment results. The assessment discriminated well between patients requiring voice therapy to change physiological parameters of voice usage and patients able to self adjust voice usage, and provided an objective means of measuring outcomes.

Humans↗
PubMed1997

The N-glycosylation sites of soybean seed coat peroxidase.

Tryptic digestion of apo-soybean peroxidase (apo-SBP), with and without acetamidation, chromatographic separation of the tryptic fragments and MALDI-TOF analysis of the major components, both before and after digestion with glycopeptidase A, demonstrated the presence of six carbohydrate groups on five peptides. Five of the glycopeptides can be mapped with confidence to the peptides containing Asn16, Asn90, Asn104, Asn169, and Asn174. The sixth N-glycosylation site is not known and does not appear to be Asn145. It may be present on the N-terminus of SBP, which has not been sequenced.

Amino Acid Sequence↗
PubMed1996

The structure of stewartan, a capsular polysaccharide produced by Erwinia stewartii strain DC283.

Stewartan is a capsular polysaccharide produced by Erwinia stewartii, the causative agent of Stewart's wilt of maize. The structure of stewartan is shown, by a combination of methylation analysis, Li/ethylenediamine degradation, 1D and 2D NMR spectroscopy, partial acid hydrolysis and isolation of oligosaccharides, Smith degradation, MALDI-TOFMS analysis and exoglycosidase digestion, to have the following repeating unit: [sequence: see text]

Bacterial Capsules↗
PubMed1996

Do cyanobacteria swim using traveling surface waves?

Bacteria that swim without the benefit of flagella might do so by generating longitudinal or transverse surface waves. For example, swimming speeds of order 25 microns/s are expected for a spherical cell propagating longitudinal waves of 0.2 micron length, 0.02 micron amplitude, and 160 microns/s speed. This problem was solved earlier by mathematicians who were interested in the locomotion of ciliates and who considered the undulations of the envelope swept out by ciliary tips. A new solution is given for spheres propagating sinusoidal waveforms rather than Legendre polynomials. The earlier work is reviewed and possible experimental tests are suggested.

Cyanobacteria↗
PubMed1996

The glycans of horseradish peroxidase.

Horseradish peroxidase (E.C. 1.11.1.7) isozyme c (HRPc) is a glycoprotein found to contain 21.8% carbohydrate with the average composition: 2 mol GlcNAc, 2.6 mol Man, and 0.8 mol each of Fuc and Xyl. The oligosaccharides of HRPc were investigated by a combination of High pH Anion-Exchange Chromatography with Pulsed Amperometric Detection, methylation analysis and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. The structure of the major oligosaccharide released by digestion with glycopeptidase A, accounting for between 75 and 80% of the total, was confirmed to be [sequence: see text]. Most of the remaining oligosaccharides were found to belong to the (Xyl)xManm(Fuc)fGlcNAc2 (m = 2, 4, 5, 6; f = 0 or 1; x = 0 or 1) family. Less than 5% of the oligosaccharides were of the ManmGlcNAc2 (m = 4 to 7) type. Methylation analysis of holo- and apo-HRPc and its tryptic glycopeptides support the structures proposed for the oligosaccharides. Furthermore, methylation analysis of the tryptic glycopeptides provides evidence for the heterogeneity of the oligosaccharides occurring at each of the N-linked sites.

Carbohydrate Conformation↗
PubMed1996

Comparison of extracellular polysaccharides of Erwinia chrysanthemi spp.

Two extracellular polysaccharides from strains of Erwinia chrysanhemi Ech 1 and 9, phytopathogens of potatoes, have been isolated and purified. Both have similar compositions and other properties to that produced by strain SR 260, a phytopathogen of corn. These polysaccharides are composed of L-rhamnose, D-mannose, D-glucose, D-glucuronic acid in the ratio 3:1:1:1. Initial structural aspects of these polysaccharides are reflected in the 600 MHz 1H NMR spectra and the products of partial acid hydrolysis, which are presented for comparison.

Carbohydrate Sequence↗
PubMed1996

The glycans of soybean peroxidase.

Soybean hull peroxidase (SBP, E.C. 1.11.1.7), an anionic glycoprotein, was found to contain 18.2% carbohydrate with the average composition: 2 mol GlcNAc, 3.3 mol Man, 0.9 mol Fuc, and 0.7 mol Xyl. The oligosaccharides of SBP, after release with glycopeptidase A, were investigated by a combination of high pH anion exchange chromatography with pulsed amperometric detection, methylation analysis and matrix assisted laser desorption/ionization-time-of-flight mass spectrometry. The structure of the major oligosaccharide, accounting for 60 to 65% of the total, is Man alpha 1-->6(Man beta 1-->3)(Xyl beta 1-->2)Man beta 1-->4GlcNAc beta 1-->4(Fuc alpha 1-->3)GlcNAc. A further 20 to 25% of the released oligosaccharides belong to the (Xyl)xManm(Fuc)fGlcNAc2 (m = 2, 4, 5, 6; f = 0 or 1, x = 0 or 1) family. The rest of the oligosaccharides were of the high-mannose type. Investigation of the six tryptic fractions containing carbohydrate revealed considerable heterogeneity in the N-linked oligosaccharides present in each fraction. The major glycan (4, Table III) was present in each fraction. Two of the fractions contained the major part of the high-mannose type glycans, ManmGlcNAc2 (m = 5-9), the major species being Man7GlcNAc2. The other four fractions contained mainly members of the (Xyl)xManm(Fuc)fGlcNAc2 (m = 2, 4, 5, 6; f = 0 or 1; x = 0 or 1) family. Methylation analysis of the holo- and apo-SBP provide support for the structures proposed for the oligosaccharides as well as for the heterogeneity of the glycopeptide fractions.

Amidohydrolases↗
PubMed1996

Laparoscopic live donor nephrectomy: the initial 3 cases.

PURPOSE: Successful laparoscopic live donor nephrectomy in 3 patients is described. MATERIALS AND METHODS: The procedures were performed completely laparoscopically and the kidneys were extracted via 8 cm. infraumbilical incisions. RESULTS: In all 3 cases warm ischemic time was less than 5 minutes, and the renal vessels and ureter of the harvested kidneys were of adequate length for routine transplantation. Donors required minimal postoperative parenteral analgesia and were discharged home 1 to 3 days after the procedure. All harvested kidneys were successfully transplanted, and functioned well initially and at hospital discharge. CONCLUSIONS: Laparoscopic live donor nephrectomy may be an alternative surgical modality to conventional open nephrectomy. Advantages include less postoperative pain, shorter hospital stay and convalescence, and a more desirable cosmetic result. Additionally, these advantages may encourage more individuals to consider live donation, resulting in an increase in organ supply.

Adult↗
PubMed1994

Separation and analysis of 4'-epimeric UDP-sugars, nucleotides, and sugar phosphates by anion-exchange high-performance liquid chromatography with conductimetric detection.

An anion-exchange HPLC method coupled with conductimetric detection was developed for the analysis of UDP-sugars, nucleotides, and sugar phosphates, each in a single chromatographic run. The analysis was applicable to concentrations over 50 pmol. The utility of this technique was demonstrated by the measurement of UDP-sugar 4'-epimerase activity of cell-free extracts from wild-type and mutant Neisseria meningitidis serogroup B strains. Additionally, the method has been applied to the analysis of the intermediates of glycolysis in human erythrocytes.

Chromatography, High Pressure Liquid↗
PubMed1994

Extracellular polysaccharide of Erwinia chrysanthemi Ech6.

Many strains of Erwinia chrysanthemi, which are Gram-negative bacterial phytopathogens, produce copious amounts of extracellular polysaccharides. The extracellular polysaccharide from E. chrysanthemi pv. zeae strain SR 260, a phytopathogen of corn, is a branched-chain glucomannorhamnan of proven structure (Gray et al., Carbohydr. Res. 1993, 245, 271-287). The extracellular polysaccharide from E. chrysanthemi Ech6 is different, containing no rhamnose or mannose. It is composed of L-fucose, D-galactose, D-glucose and D-glucuronic acid in the ratio 2:2:1:1. The structure of the polysaccharide is as follows: [sequence: see text]

Carbohydrate Conformation↗
PubMed1994

Merger offers IS managers flexibility & less stressful integrating, downsizing, & outsourcing. Interview by Bill Childs.

A merger between two multi-million dollar IS firms in July 1993 created a company with $315 million in sales and a sharp focus on healthcare. National Healthtech Corp., parent firm of MRI, brought the focus to the deal. And Dallas-based Affiliated Computer Services, a data services provider to financial, commercial and healthcare organizations, brought telecommunications and outsourcing expertise. Bill Childs, editor-in-chief, recently spoke with the two firms' principals--Richard A. Montgomery, CEO of National Healthtech Corp., and Steve Carpenter, senior VP of ACS and COO of NHC. Excerpts from their conversation follow.

Contract Services↗
PubMed1993

Structure of an extracellular polysaccharide produced by Erwinia chrysanthemi.

Erwinia chrysanthemi pv zeae strain SR260, a phytopathogen of corn, produced from lactose an acidic extracellular polysaccharide which was purified and found to consist of L-rhamnose, D-mannose, D-glucose, and D-glucuronic acid in the ratio of 3:1:1:1. A combination of chemical (carboxyl-group reduction, methylation analysis, periodate oxidation, Smith degradation, and lithium-ethylenediamine degradation) and physical (1 and 2D NMR spectroscopy) methods revealed that the polysaccharide is composed of a hexasaccharide repeating unit 1: [formula: see text]

Carbohydrate Conformation↗