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Biomedical subjects

P Morris

Publications and source records attributed to P Morris.

At least 91 records · Page 5Linked to original sources
PubMed1994

An eight year experience of conservative management for aortic graft sepsis.

This paper describes the results of conservative management of 15 patients with aortic graft infection. The median time to presentation was 4 months. Six of eight grafts that were sent for culture grew organisms, of which the commonest were streptococci and coagulase negative staphylococci. Four patients did not receive intensive antibiotic treatment and all died of sepsis. Eleven patients received intensive intravenous and oral antibiotic therapy and appropriate surgical management; two of these died, one of a stroke and the other of an unknown cause. Two of the nine surviving patients had no surgery and the remainder had procedures to drain pus and unblock occluded grafts, including minimal graft excision in four patients, although two of these subsequently required total graft excision. The follow-up period for six of these nine patients is more than 4 years. For most patients with aortic graft infection aggressive antibiotic treatment supplemented by minimalist surgery is preferable to primary radical surgery.

Administration, Oral↗
PubMed1994

Excitotoxic amino acids cause appearance of magnetic resonance spectroscopy-observable zinc in superfused cortical slices.

(1) The effects of glutamate and NMDA on the free intracellular calcium concentration ([Ca2+]i) have been followed in superfused cortical slices using the 19F-magnetic resonance indicator 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (5FBAPTA). (2) Glutamate (0.5 or 1 mM) caused a 75-100% increase in [Ca2+]i, and a new resonance was attributed to zinc-5FBAPTA, which was confirmed from its disappearance in the presence of a high-affinity chelator of heavy metals, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine. The appearance of zinc occurred with or just after the rise in [Ca2+]i and was independent of Mg2+. (3) NMDA, N-methyl-DL-aspartate, or N-methyl-L-aspartate (10-200 microM) caused a slower increase in [Ca2+]i, and zinc was observed in some but not all experiments. When present, zinc appeared later than the increase in [Ca2+]i. These changes were also independent of Mg2+. (4) Decreases in both phosphocreatine and ATP were observed in all of these studies. (5) The results are discussed in terms of the proposed role of zinc as a modulator of excitotoxicity. Observations of zinc after exposure to glutamate or more slowly to NMDA, but not after depolarisation or deprivation of glucose and O2 (where increases also occur in [Ca2+]i), suggest that the cellular damage caused by the latter insults (depolarisation and fuel deprivation as in ischaemia) involves mechanisms not solely attributable to release of excitotoxins.

Animals↗
PubMed1994

Anaesthesia and mucopolysaccharidoses. A review of airway problems in children.

The airway problems encountered during anaesthesia in all children with mucopolysaccharidoses presenting for a surgical procedure from 1988 to September 1991 are reviewed. Thirty-four patients underwent 89 anaesthetics for 110 procedures. The results reveal a high incidence of airway problems. The overall incidence of difficult intubation was 25% and failed intubation 8%. In those children with Hurler's syndrome, the difficult intubation incidence was 54% and failed intubation incidence 23%. Other potential anaesthetic problems such as cardiac anomalies and obstructive sleep apnoea are also reviewed.

Adolescent↗
PubMed1994

Isolation of a fibronectin-binding tryptic peptide from the antigen 85A protein of Mycobacterium bovis BCG.

Antigen 85A, a major secreted mycobacterial fibronectin-binding protein, was isolated from culture fluids of the Tice substrain BCG vaccine. Tryptic digestion of this protein and passage of the digest through a fibronectin affinity chromatographic column resulted in the identification of a polypeptide fragment of molecular weight < or = 6.5 kD, which had marked fibronectin-binding activity. The identity of a 62-residue polypeptide was deduced from the amino-terminal sequence, indicating that the primary structure may define the integrin-binding capability.

Amino Acid Sequence↗
PubMed1993

Rapid diagnosis of cytomegalovirus pneumonia in marrow transplant recipients by bronchoalveolar lavage using the polymerase chain reaction, virus culture, and the direct immunostaining of alveolar cells.

The objective was to compare the use of the polymerase chain reaction (PCR), virus culture, and immunostaining of alveolar cells used alone and in combination as diagnostic methods for the rapid diagnosis of cytomegalovirus (CMV) pneumonia in marrow transplant recipients. Seventy-five marrow transplant recipients with clinical and radiological evidence of pneumonitis were used as subjects. Bronchoalveolar lavage was performed on all patients to obtain material for conventional and/or rapid CMV culture, immunostaining of alveolar cells with monoclonal antibodies (MoAbs), and amplification of CMV-DNA by PCR. Assay results were then prospectively correlated with clinical outcome. Seven of the 75 patients (9.3%) had CMV pneumonitis and 6 patients (8%) had CMV infection without pneumonia. PCR is the most sensitive assay for the detection of CMV in bronchoalveolar lavage fluid. For the diagnosis of CMV pneumonitis, the sensitivity of alveolar cell immunostaining and PCR were both 100%. The sensitivity of virus culture was 85.7%. The positive predictive value for each test, used alone, for the identification of CMV pneumonitis was low. However, when the result of the PCR assay was assessed in combination with CMV immunostaining of alveolar cells, the sensitivity, specificity, positive, and negative predictive value of this strategy was 100%. The concomitant use of PCR and the rapid immunostaining of alveolar cells for CMV has facilitated the development of a sensitive and specific diagnostic algorithm for the detection and early treatment of CMV pneumonitis in transplant recipients.

Animals↗
PubMed1993

Studies on metabolic regulation using NMR spectroscopy.

The effects of hypoxia and hypoglycaemia on cerebral metabolism and calcium have been studied using multinuclear magnetic resonance spectroscopy. 13C MRS showed that severe hypoxia did not cause any further increase in metabolic flux into lactate seen in mild hypoxia, but there was a further increase in 13C labelling of alanine and glycerol 3-phosphate. These results are discussed in terms of the ability of lactate dehydrogenase to maintain normal levels of NADH in mild hypoxia, but not in severe hypoxia. We conclude that glycerol 3-phosphate and alanine may provide novel means of monitoring severe hypoxia whereas lactate is a reliable indicator only of mild hypoxia. 19F- and 31P NMR spectroscopy showed that neither hypoxia nor hypoglycaemia alone caused any significant change in [Ca2+]i. Combined sequential insults (hypoxia, followed by hypoxia plus hypoglycaemia), or vice versa, produced a 100% increase in [Ca2+]i, whereas immediate exposure to the combined insult (hypoxia plus hypoglycaemia) resulted in a large 5-fold increase in [Ca2+]i, with severe irreversible effects on the energy state. These results are discussed in terms of metabolic adaptation to the single type of insult, which renders the tissue less vulnerable to the combined insult. The effects of this combined insult are far more severe than those caused by glutamate or NMDA, which throws doubt on the current excitoxic hypothesis of cell damage.

Animals↗
PubMed1993

Variations in therapeutic interventions for Cambodian and Chilean refugee survivors of torture and trauma: a pilot study.

The treatment of refugee survivors of torture and trauma has attracted increasing clinical attention. The present study surveyed therapists concerning the emphasis that was placed on disclosure of previous traumatic experiences in therapy with refugees from Chile and Cambodia. Significant differences were found between the two groups with trauma story discussion being judged by therapists to be more important to treatment outcome in Chilean patients. The problem of potential therapist bias limits definitive conclusions, however we suggest that differences in cultural preparedness for psychotherapy aimed at uncovering previous traumatic experiences may be the main reason for variations in styles of therapy offered to these distinctive ethnic groups. Other possible explanations are differences in diagnostic profiles and types of previous traumatic experiences.

Acculturation↗
PubMed1993

Biliary cystadenocarcinoma arising in a liver with fibropolycystic disease.

Intrahepatic cholangiocarcinoma associated with fibropolycystic disease of the liver and biliary cystadenocarcinoma are rare tumors that are considered distinct entities. We present a case of a malignant tumor with features of hepatic cystadenocarcinoma arising in a background of fibropolycystic disease.

Bile Duct Neoplasms↗
PubMed1992

Shielded gradient coils and radio frequency probes for high-resolution imaging of rat brains.

A shielded gradient system and radio frequency probes for a 4.7-T/30-cm horizontal bore magnet are described. The systems were designed principally to obtain images and localized spectra from rat brains. The gradients can operate in either a shielded or non-shielded mode. The rf probe, which combines both highest sensitivity and highest resolution, consists of a large modified saddle type transmitter and a small surface reception coil, actively decoupled using diodes. The system performance is demonstrated on phantoms and on a rat brain, where an image with in plane resolution of 80 microns and a slice thickness of 150 microns is obtained.

Animals↗
PubMed1992

The iduronate sulfatase gene: isolation of a 1.2-Mb YAC contig spanning the entire gene and identification of heterogeneous deletions in patients with Hunter syndrome.

A recently isolated cDNA clone from the iduronate sulfatase (IDS) gene has been used both to seed a contig of overlapping yeast artificial chromosomes (YACs) and to investigate the molecular defect in patients with Hunter syndrome (MPS II). Six YAC clones were found to span the IDS gene, and those and 14 other YACs were assembled into a 1.2-Mb contig around the gene in Xq27-q28. The physical map of the region identifies several putative CpG islands, suggesting the presence of other genes in the vicinity. DNA from a patient with a translocation breakpoint in the gene also permitted the orientation of the contig in the chromosome. Southern analysis of DNA from 25 unrelated Italian Hunter syndrome patients revealed 4 with deletions or rearrangements in the IDS gene.

Blotting, Southern↗