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Biomedical subjects

B M Jones

Publications and source records attributed to B M Jones.

At least 145 records · Page 8Linked to original sources

An implanted ultrasound Doppler probe for microvascular monitoring: an experimental study.

An experimental investigation is presented into the use of pulsed ultrasound Doppler flowmetry with a percutaneously implanted probe as a monitor of microvascular anastomotic patency. The method accurately indicated and distinguished between experimental arterial and venous occlusion in epigastric island flaps. In free flaps it had advantages over manipulative, intraoperative tests of anastomotic patency and was a reliable post-operative monitor of flap circulation in the experimental model. The technique appears to have great potential as a post-operative monitor for free flaps, including those without a visible surface.

Animals↗

T-cytotoxic/suppressor cell phenotypes in a group of asymptomatic homosexual men with and without exposure to HTLV-III/LAV.

The number of lymphocytes bearing the Leu 2+ or T8+ (suppressor/cytotoxic) phenotype is elevated in asymptomatic homosexual men. By two-color immunofluorescence using paired monoclonal antibodies (alpha-Leu 2 and alpha-Leu 15, alpha-Leu 2 and alpha-Leu 7, alpha-Leu 7 and alpha-Leu 11), we enumerated phenotypic subpopulations that are associated with cytotoxic, suppressor, or natural killer function. Both cytotoxic (Leu 2+15-) and suppressor (bright Leu 2+15+) cell populations are elevated in homosexual men. Homosexual men who have been exposed to human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) have higher numbers of Leu 2+15- and Leu 2+7- cells than homosexual men who have not been exposed. Phenotypic subpopulations (dim Leu 2+ Leu 15+ and Leu 7-11+) that are associated with the most potent natural killer activity (against K562 target cells) were not found to be elevated in homosexual men.

Antibodies, Monoclonal↗

Activity of pefloxacin and thirteen other antimicrobial agents in vitro against isolates from hospital and genitourinary infections.

The in-vitro activity of the quinolone derivative pefloxacin was compared with that of three other quinolones, five beta-lactam antibiotics and three aminoglycosides against 367 isolates from hospital patients and from out-patients with genitourinary infections. MIC90 of pefloxacin and norfloxacin for each strain was the same; that of ciprofloxacin was a little lower. All strains except Escherichia coli were resistant to nalidixic acid. Pefloxacin was highly active against Staphylococcus aureus (39 strains; MIC90 1.0 mg/l) and most strains of coagulase-negative staphylococci (56; 4 mg/l), Esch. coli (50; 0.25 mg/l), other enterobacteria (33; 1.0 mg/l) and Pseudomonas aeruginosa 6; 0.25 mg/l). With Bacteroides spp. (total 78; 64 mg/l), the fragilis group (23) and the fusobacteria (19) were resistant, but the melaninogenicus-oralis group (31; range 0.06- greater than 64 mg/l) and B. ureolyticus (22; 0.125- greater than 64 mg/l) gave variable results. Amongst genitourinary isolates, Neisseria gonorrhoeae (15) and Haemophilus ducreyi (34) were sensitive (less than 0.06 mg/l) but Gardnerella vaginalis (25) and Mobiluncus spp. (11) were resistant (32 mg/l). Pefloxacin was more active than ceftazidime, cefotaxime, ceftizoxime, latamoxef and piperacillin against S. aureus and coagulase-negative staphylococci and than gentamicin, tobramycin and amikacin against coagulase-negative staphylococci. No enterobacteria or pseudomonads were resistant to pefloxacin or other quinolones, whereas some were resistant to beta-lactams and aminoglycosides.

Anti-Bacterial Agents↗

Susceptibility of Haemophilus ducreyi to ampicillin and sulbactam in vitro.

The MICs of ampicillin, ampicillin plus sulbactam in equal proportions, and a range of ampicillin concentrations with a constant 0.5 micrograms/ml concentration of sulbactam were determined for 66 strains of Haemophilus ducreyi by an agar dilution technique with standardized inocula prepared by ultrasonication. Fifty-five strains were susceptible to ampicillin alone (MIC range, 0.06 to 1 microgram/ml). The MICs for the 11 resistant strains were (micrograms per milliliter): range, 8 to greater than 16; MIC for 50% of the strains tested (MIC50), greater than 16; MIC90, greater than 16; 8 of them produced beta-lactamase. In the presence of an equal concentration of sulbactam, the MICs for ampicillin-resistant strains were lowered to (micrograms per milliliter): range, 0.125 to 2; MIC50, 0.25; MIC90, 1. In the presence of a fixed 0.5-micrograms/ml concentration of sulbactam, the MICs for the resistant strains were (micrograms per milliliter): range, 0.125 to 2; MIC50, 0.125; MIC90, 0.25. Sulbactam-ampicillin appears to be suitable for the treatment of H. ducreyi infections, especially those caused by ampicillin-resistant strains.

Ampicillin↗

Susceptibility of Haemophilus ducreyi to spectinomycin in vitro.

Using an agar dilution technique with standardised inocula prepared by ultrasonication, the minimum inhibitory concentrations (MICs) of spectinomycin were determined for 66 strains of Haemophilus ducreyi, eight of which were beta lactamase producers. All strains were sensitive to concentrations of spectinomycin, which were well within the therapeutic ranges attained with normal dosage. The MIC50 and MIC90 were 8 mg/l, (range 0.007-16 mg/l).

Cells, Cultured↗

The social and emotional impact of cardiac transplantation.

To date, there has been limited systematic research in the area of the emotional impact of cardiac transplantation. Since September 1984, a prospective study addressing this issue has been in progress at St. Vincent's Hospital, Sydney, Australia. Initial results suggest that anxiety, associated with declining health and adjustment to the prospect of transplantation, was the major issue at pre-transplantation. Follow-up at the time of their first hospital discharge after transplantation and again at 3 months showed improvement in all psychological measures and did not identify any psychological morbidity.

Journal Article↗

Assignment of human ferritin genes to chromosomes 11 and 19q13.3----19qter.

Extracts of hamster-human and mouse-human hybrids, some with translocations involving chromosome 19, have been assayed for both human spleen ferritin (rich in L subunits) and human heart ferritin (rich in H subunits). Hybrid lines retaining part of the long arm of chromosome 19 including the region 19q13.3----19qter produced human "L" type ferritin. This confirms the previous assignment of the "ferritin gene" to chromosome 19 (Caskey et al. 1983). However, lines retaining chromosome 11 were found to contain human "H" type ferritin suggesting that the gene for the "H" subunit is on this chromosome. The presence of chromosome 6 was not necessary for the expression of either "H" or "L" type human ferritin. It thus seems unlikely that the gene for idiopathic haemochromatosis is a ferritin gene.

Animals↗

Immune complexes in the acquired immunodeficiency syndrome (AIDS): relationship to disease manifestation, risk group, and immunologic defect.

Immune complex assays (and other immunologic tests) were performed on sera from 162 patients with the acquired immunodeficiency syndrome (AIDS) and 275 AIDS-related subjects. Immune complexes were detected in 89% of AIDS patients and 93% of homosexual men with lymphadenopathy. Immune complex levels in AIDS patients were not associated with a particular risk group or with types of opportunistic infection or malignancy; however, they correlated with other laboratory features of the immune defect (depression in T helper cells and T helper/suppressor-cell ratio, and IgG levels). Immune complexes were also detected in a lesser proportion of risk-group controls (homosexual men, hemophiliacs, Haitians). In risk-group controls, immune complex levels were associated with certain features reflecting sexual practice, blood product exposure, or infection, but these features did not account for the higher levels found in AIDS patients. In appropriate situations, immune complex assays may be of value as screening tests or, possibly, as prognostic indicators for AIDS or AIDS-related syndromes.

Acquired Immunodeficiency Syndrome↗

Surgical approaches to block dissection of the inguinal lymph nodes.

Block dissection of the inguinal lymph nodes is associated with a high incidence of complications, the most frequent of which are related to wound healing. To determine the optimal surgical approach, a review of our experience over the last 10 years was undertaken. Fifty inguinal lymph node dissections are presented. The patients were divided into four groups according to the surgical incision used. The duration of hospital stay and incidence of complications were compared. We conclude that the optimal surgical approach is an elliptical incision removing a 4 cm width of skin over the inguinal nodes. Incisions that did not sacrifice at least a 4 cm width of skin had an inordinately high complication rate and a prolonged hospital stay. Approaches to wound closure, the management of bulky disease and primary lesions in continuity with the groin, and the use of adjunctive measures to reduce morbidity are discussed.

Adult↗

An experimental investigation into the use of implanted thermocouples and differential thermometry as monitors for microvascular anastomoses.

It has been suggested that direct monitoring of arterial temperature using implanted thermocouples, may have value as a clinical postoperative monitor for vascularized free tissue transfers, including those with no visible surfaces. This study evaluated the technique in experimental animals, using simple, inexpensive equipment. Mean arterial differential temperature changes, with ipsilateral (n = 20) and contralateral (n = 21) references, of 0.6 degrees C and 0.5 degrees C respectively, reliably indicated occlusion of the superficial femoral artery in situ. In epigastric island flaps, arterial occlusion (n = 24) produced mean arterial temperature changes of 0.5 degrees C, but changes after venous occlusion were not significantly greater than unoccluded base line fluctuation. Venous differential temperature did not change significantly after either arterial or venous occlusion. In six epigastric free flaps, success or failure could not be distinguished, as the wide variation in measurements in the four successful flaps overlapped the recordings in the two which failed. It was shown that the nearer to the body core, the less the temperature difference between arterial wall and periarterial tissue. Occlusion of deeply sited arteries produced little or no change in arterial temperature. In view of these findings and because of the invasive nature of the technique, the authors did not pursue it clinically.

Anastomosis, Surgical↗

In-vitro and in-vivo activity of metronidazole against Gardnerella vaginalis, Bacteroides spp. and Mobiluncus spp. in bacterial vaginosis.

An open, randomized, culture-controlled clinical study was designed to compare the efficacy of a single 2 g dose of metronidazole (Elyzol) with standard 7-day therapy in the treatment of bacterial vaginosis (BV). Forty-one of 47 (87%) patients given the single dose and 30 of 33 (91%) given the 7-day treatment were found to be cured seven days after treatment. At final assessment, 24 of 34 (71%) patients given the single dose and 22 of 28 (79%) given the 7-day treatment remained cured. The two regimes were equally efficaceous in eradicating Gardnerella vaginalis, Bacteroides spp. and Mobiluncus spp. (anaerobic curved rods) from vaginal specimens from patients with BV. The in-vitro activity of metronidazole and its hydroxy metabolite was determined for 11 strains of Gard. vaginalis, 17 strains of Bacteroides spp. and 14 strains of Mobiluncus spp. which had been isolated from patients prior to treatment. The MIC of metronidazole against Gard. vaginalis varied between 2 and greater than or equal to 128 mg/l (median MIC 32 mg/l), but the hydroxy metabolite showed a markedly increased activity against eight of the strains tested (median MIC 4 mg/l). The MIC of metronidazole against the Mobiluncus spp. varied between 0.5 and greater than or equal to 128 mg/l (median MIC 16 mg/l) and the hydroxy metabolite showed little increased activity (median MIC also 16 mg/l). The Bacteroides organisms were highly susceptible to metronidazole and to the hydroxy metabolite, each having a median MIC of 1 mg/l.

Bacteria, Anaerobic↗