PubMed HealthSearch

Biomedical subjects

A Kerr

Publications and source records attributed to A Kerr.

At least 19 recordsLinked to original sources

Subclavian artery to innominate vein fistula after insertion of a hemodialysis catheter.

Insertion of hemodialysis catheters for temporary use is now preferentially performed by percutaneous infraclavicular subclavian vein catheterization. This method involves passage of a stiff dilator and a peel-away sheath over a guide wire, and is usually carried out without fluoroscopy. For the most part this has proved to be a valuable and safe approach. However, a small incidence of major complications occurs, which needs to be emphasized. Sixteen cases of arteriovenous fistulas between the subclavian artery or its branches and the subclavian vein have been reported so far in the literature. To date only one case of subclavian artery to innominate vein fistula has been reported. We report the second case with this complication and suggest possible preventive measures.

Adult

A diffusible compound can enhance conjugal transfer of the Ti plasmid in Agrobacterium tumefaciens.

Several octopine strains of Agrobacterium tumefaciens were tested for Ti plasmid (pTi) transfer after induction by 400 micrograms of octopine per ml for 24 h. The strains could be divided into two groups, transfer efficient (Trae) and transfer inefficient (Traie); the respective rates of transfer were 0.77 x 10(-2) to 1.14 x 10(-2) and 0.33 x 10(-6) to 9.8 x 10(-6) plasmid transconjugant per donor cell. Transfer efficiencies of Traie strains were greatly increased when the time of induction was 72 h. A diffusible conjugation factor (CF) that can enhance conjugal transfer of pTi in A. tumefaciens was discovered when both Trae and Traie donor strains were induced in the same plate. The evidence indicates that CF is a key factor affecting transfer efficiency of pTi but is not sufficient by itself to induce transfer. Trac mutants can produce CF constitutively, and Trae strains can produce it after induction by low octopine concentrations. The transfer efficiency of Traie strains was greatly increased by adding CF to the induction medium. The thermosensitive strain B6S, which normally cannot conjugate at temperatures above 30 degrees C, could transfer pTi efficiently at 32 and 34 degrees C in the presence of CF. Production of CF is dependent on the presence of pTi but appears to be common for different opine strains; it was first detected in octopine strains, but nopaline strains also produced the same or a similar compound. CF is very biologically active, affecting donor but not recipient bacterial cells, but CF does not promote aggregation. Data suggest that CF might be an activator or derepressor in the conjugation system of A. tumefaciens. CF is a dialyzable small molecule and is resistant to DNase, RNase, protease, and heating to 100 degrees C for 10 min, but autoclaving (121 degrees C for 15 min) and alkaline treatment removed all activity.

Arginine

Non-attendance at a psychiatric day hospital new patient clinic.

People who do not attend for treatment present problems in the efficient running of any service. This is particularly the case with new patients referred to a psychiatric clinic where an hour may be set aside for the initial assessment. High non-attendance rates cause administrative problems and loss of valuable time. The referring doctor may be left with his patient unassessed, the patient may miss valuable treatment or advice, and an incorrect assessment of the true prevalence of some disorders may be made.

Hospitals, Psychiatric

Percutaneous catheter drainage for acute empyema. Improved cure rate using CAT scan, fluoroscopy, and pigtail drainage catheters.

Percutaneously inserted pigtail nephrostomy catheters were used to treat empyemas in 12 patients. Thoracic computed tomographic (CT) scan and fluoroscopy were used to localize precisely and place the catheters into loculated collections of fluid. Percutaneous catheter drainage (PCD) of empyema was successful in seven of seven patients (100%) in whom standard tube thoracostomy (STT) had initially failed and in three of five patients (60%) who had PCD as the initial drainage procedure. Overall, PCD was successful in treating empyema in ten of 12 patients (83%). The procedure was well tolerated and there were no complications. PCD is a safe and effective method for drainage of loculated empyemas as the initial procedure or after STT has failed.

Acute Disease

The pTiC58 tzs gene promotes high-efficiency root induction by agropine strain 1855 of Agrobacterium rhizogenes.

Root induction on flax (Linum usitatissimum L.) cotyledon explants by Agrobacterium rhizogenes strain 1855 is markedly increased by co-inoculation with disarmed A. tumefaciens strain LBA 4404 containing a plasmid carrying the tzs gene of pTiC58. Most of the roots (estimated to be more than 90%) were transformed. This effect is most likely due to the secretion of trans-zeatin by A. tumefaciens stimulating the division of plant cells making them more receptive to transformation by A. rhizogenes, although other explanations are possible. This observation supports the idea that the tzs gene, although not essential for transformation, may promote transformation. An obvious application for genetic engineering experiments involving transformation by A. rhizogenes, is to include a vir-induced tzs gene in the transformation system to help maximize transformation efficiency.

DNA, Bacterial

Characteristics of the nopaline catabolic plasmid in Agrobacterium strains K84 and K1026 used for biological control of crown gall disease.

Wild-type Agrobacterium radiobacter strain 84 and its Tra- derivative K1026, used for biological control of crown gall disease, each contain the plasmid pAtK84b. It confers incompatibility to tumor-inducing (Ti) plasmids of pathogenic A. tumefaciens, thus preventing transfer of Ti plasmids into K84 and K1026, and the consequent development of pathogens resistant to the specific antibiotic, agrocin 84 produced by K84 and K1026. pAtK84b also resembles one group of Ti plasmids in its capacity for directing nopaline catabolism. A study of the DNA homology among pAtK84b, pTiC58, and pTiAch5 was carried out. pAtK84b was transferred by conjugation to a plasmidless recipient and, after isolation, was hybridized with Ti plasmid DNA. Areas of DNA homology were located on published maps of pTiC58 and pTiAch5, a restriction enzyme map of pAtK84b was constructed, and areas of homology with DNA of known genetic function were located on the map. Strong and extensive (over 50%) homology was found between pAtK84b and pTiC58 (nopaline catabolic, Noc), but much less between pAtK84b and pTiAch5 (octopine catabolic). There was no detectable homology between pAtK84b and the oncogenic T-DNA and virulence (Vir) regions of either Ti plasmid. The size of pAtK84b was 173 kb and the orientation of regions of identified gene function (Noc, incompatability/origin of replication, and conjugal transfer) on pTiC58 was matched by the locations of homologous areas on pAtK84b. It is concluded that pAtK84b may be a deletion product of a pTiC58-type plasmid which has been disarmed in the oncogenic T-DNA and Vir regions.

Arginine

Correlation of electroencephalogram, respiration and movement in the Rett syndrome.

Day time video records of 14 girls with the Rett syndrome (RS) (6-17, mean 7 years) were analysed to correlate episodic abnormalities in respiration, movement and electroencephalograms (EEG). Records were compared with those of 12 healthy girls (6-18, median 14 years) who hyperventilated voluntarily. Three RS girls (6-7 years) had minimal respiratory dysrhythmia and showed no correlation between EEG respiration and movement. The other 11 RS girls (6-17 years) had severe awake respiratory dysrhythmia; 10 showing hyperventilation (with hypocapnia) which alternated with active expiratory apnoeic pauses and one with the latter only. All had periods of awake regular breathing with normal respiratory gases. In these girls EEG showed non-epileptic generalised slow activity some of which was paroxysmal. In the six youngest (6-10 years) of these 11 RS girls, non-epileptic paroxysms of EEG slow activity at 1 1/2-4 Hz occurred and were associated with periods of normal breathing and normal pCO2 levels whether girls were alert, drowsy or asleep, but were uncommon during episodes of hyperventilation (and hypocapnia). In four of these girls the EEG paroxysms occupied less than or equal to 1-3% of the time during periods of respiratory dysrhythmia (81 minutes) and 8-100% of the time during alert periods with normal breathing (29 minutes), p less than or equal to 0.001 for this difference. Short bursts of EEG slowing occasionally followed prolonged apnoeic pauses. In two cases brief partial complex seizures occurred. In five of these girls stereotypic movements exacerbated during episodes of respiratory dysrhythmia and reduced during normal breathing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Domestic violence. Treat it seriously.

Domestic violence is costly to the community, not only in terms of medical, police and social security budgets but also in terms of the disruption caused to families and the effect on children raised in violent households. Doctors have a major role in solving the problem of domestic violence.

Australia

Motivation in deliberate self-harm.

Fifty adult patients presenting with deliberate self-harm at the Royal Victoria Hospital were given a choice of nine reasons for their actions. Most chose more than one reason and all but two of the 24 who said that they wished to die chose at least one other motive. There were no trends with respect to sex, past history, or method of deliberate self-harm. These results illustrate the complexity of this condition and show the importance of investigating motives beyond simply the intent to die.

Adult

Transplantation of monoclonal antibody-purged autologous bone marrow for treatment of poor risk common acute lymphoblastic leukemia.

Two murine monoclonal antibodies, FMC-8 and WM-21, reactive with the human leucocyte differentiation antigens CD-9 (p-24) and CD-10 (CALLA), respectively, have been used for purging leukemic cells from remission bone marrow. Nine patients with the common variant of acute lymphoblastic leukemia (c-ALL) in second or subsequent remission underwent bone marrow harvesting. Bone marrow mononuclear cells underwent lytic incubation in vitro with antibodies FMC-8 and WM-21, and rabbit serum as a source of complement, and were then cryopreserved. A mean of 0.90 +/- 0.50 x 10(8) nucleated cells per kilogram of recipient body weight remained after treatment, with 0.38 +/- 0.24 x 10(8) nucleated cells and 8.3 +/- 10.3 x 10(4) CFUGM per kg being recovered on thawing. Seven patients subsequently received marrow-ablative treatment with high dose cyclophosphamide (120 mg/kg) and fractionated total body irradiation (12 Gy), followed by infusion of antibody-purged autologous bone marrow. Three deaths due to sepsis occurred within the first 35 days, compounded in one patient by poor marrow engraftment. All other patients engrafted promptly, and four remain in continuous complete remission at 2, 6, 9, and 28 months after transplantation. The procedure carries a substantial risk of early toxicity, but offers a significant chance of prolonged unmaintained remission to selected patients with poor prognosis acute lymphoblastic leukemia.

Adolescent

Coexpression of p165 myeloid surface antigen and terminal deoxynucleotidyl transferase: a comparison of acute myeloid leukaemia and normal bone marrow cells.

A double immunofluorescence technique, using antibodies to terminal transferase (TdT) and a 165-kilodalton myeloid differentiation antigen (p165), has been used to investigate the phenomenon of TdT expression in cases of acute myeloid leukaemia (AML). Five cases of AML were shown to have significant (18-90%) numbers of leukaemic cells that concurrently expressed both TdT and p165 myeloid surface antigen. Examination of nonleukaemic bone marrow cells showed that the vast majority of normal TdT+ cells are p165 negative. However, in 5 of the 11 samples analyzed, rare cells staining for both p165 and TdT were found. These results suggest that some cases of TdT+ AML may arise from the clonal expansion of rare "biphenotypic" precursor cells existing in normal bone marrow.

Adult

Standardization of monoclonal antibodies for use in autologous bone marrow transplantation for common acute lymphoblastic leukemia.

Two monoclonal antibodies suitable for leukemia cell purging of remission bone marrow from patients with common acute lymphoblastic leukemia (common-ALL) are described. WM-21, reacting with the gp 100 common-ALL associated antigen (CALLA), and FMC-8, reactive with a p24 surface antigen, both bind to the majority of leukemic blast cells from cases of common ALL, and promote complement-mediated lysis of CALLA+ leukemias and cell lines. After initial dye exclusion studies to standardize antibody and rabbit complement concentrations and incubation times, an in vitro plating assay using CALLA+ p24+ cell lines was used to investigate the lytic ability of monoclonal antibody treatment. Incubation with WM-21, FMC-8, and complement produced up to 5 logs inhibition of growth in this system. Under similar conditions, no inhibition of in vitro growth of normal bone marrow myeloid progenitor cells was seen. These antibodies therefore appear to be useful therapeutic reagents for removing residual common ALL blast cells from bone marrow prior to autologous marrow transplantation.

Antibodies, Monoclonal

Characterizing "difficult" acute leukemias. A combined electron microscopic and immunological marker study.

The techniques of transmission electron microscopy (TEM), including ultrastructural myeloperoxidase cytochemistry (MPO), and immunological marker analysis, have been used to classify 58 "difficult" cases of acute leukemia where a precise diagnosis could not be made on the basis of conventional light microscopy and cytochemistry. TEM with MPO proved most valuable in characterizing 15 cases of acute myeloid leukemia and its variants, as well as defining complex cellular subpopulations in 11 cases of chronic myeloid leukemia in blast crisis. Immunological marker studies provided conclusive evidence of lymphoid differentiation in 18 cases of acute lymphoblastic leukemia and related disorders. In addition, the combined techniques were used to document 14 cases of terminal transferase-positive acute myeloid leukemia. This study demonstrates that these 2 techniques provide overlapping and complementary information for accurate diagnosis and classification of morphologically difficult hematological malignancies.

Adolescent

Antigenic phenotype of TdT-positive cells in human peripheral blood.

Double immunofluorescence studies for terminal deoxynucleotidyl transferase (TdT) and leucocyte surface membrane antigens have been used to characterize the small subpopulation of TdT-positive cells in human peripheral blood. The predominant antigens demonstrated were those coded for by the major histocompatibility complex, namely HLA-A,B and Ia-like antigens. A small proportion of TdT+ cells expressed antigens restricted to B lymphocytes and their precursors (BA-1+ CALLA+). In contrast, antigens associated with T-lymphocyte differentiation were not detected using a panel of T-cell-specific monoclonal antibodies. These results preclude the possibility that circulating TdT+ cells are immature cortical thymocytes that have "leaked" into the bloodstream. Although bone marrow-derived prothymocytes, which have not yet acquired T-cell lineage markers, may be included amongst this subset, the expression of B-cell related antigens by some TdT+ cells indicates the likely existence of lineage heterogeneity amongst this population of lymphoid cells. The relevance of these findings to the monitoring of human acute lymphoblastic leukaemia is discussed.

Adult

Immunological detection of covert leukaemic spread in mediastinal T-cell lymphoblastic lymphoma.

A double immunofluorescence assay for terminal transferase (TdT) and surface membrane T-cell differentiation markers, defined by monoclonal antibodies, was used to analyse peripheral blood and bone marrow from patients with mediastinal T-cell lymphoma with clinically localized disease. In 2 patients, at diagnosis and during two subsequent relapses, cells with abnormal immunological phenotype were detected in low numbers in the peripheral blood, which contained no morphologically abnormal cells on any occasion. Bone marrow was uninvolved by immunological criteria on 3 of 4 examinations. The findings suggest that morphologically undectable T-lymphoblasts escape from the site of disease origin in the thymus in patients with lymphoblastic lymphoma, leading to "seeding" of sites such as bone marrow and central nervous system. Furthermore, the techniques described appear to be potentially very useful for the monitoring of lymphoblastic lymphoma patients for early prediction of disease relapse.

Adolescent