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Biomedical subjects

I V Allen

Publications and source records attributed to I V Allen.

At least 37 records · Page 2Linked to original sources
PubMed1990

Use of immunocytochemistry and biotinylated in situ hybridisation for detecting measles virus in central nervous system tissue.

Optimised immunocytochemical (ICC) and in situ hybridisation (ISH) protocols for long term, formalin fixed, central nervous system tissue infected with measles virus were developed. The effectiveness of 10 proteases for the enzymatic unmasking of formalin fixed antigen and nucleic acid was investigated. Protease VIII gave maximal signal generation with optimal tissue preservation and no background staining for both techniques. The use of a microwave oven as an additional pre-hybridisation step for RNA-RNA in situ hybridisation produced a significant increase in the number of cells labelled for genomic RNA. The ability to show the presence of antigen and nucleic acid in long term, formalin fixed tissue facilitates the use of stored necropsy material available in pathology departments for ICC and ISH investigations.

Antigens, Viral↗
PubMed1989

Antibodies to simian virus 5 in patients with multiple sclerosis and other neurological disorders.

Antibodies to the paramyxovirus simian virus 5 were measured in cerebrospinal fluid samples using an enzyme-linked immunosorbent assay. Six of the 13 clinically definite MS patients had elevated levels of antibodies compared with other neurological disease and orthopaedic controls. None of the samples from MS patients classed as probable or possible had increased amounts of SV5 antibodies. Simian virus 5 antibodies and measles antibodies showed a weak correlation and it is suggested that the elevated levels of the former are a manifestation of the increased antiviral response found in some MS patients.

Adult↗
PubMed1989

Examination of eight cases of multiple sclerosis and 56 neurological and non-neurological controls for genomic sequences of measles virus, canine distemper virus, simian virus 5 and rubella virus.

In situ hybridization studies have been carried out on brain samples from eight cases of multiple sclerosis (MS) and 56 non-neurological and neurological controls, using single-stranded 35S-labelled RNA probes prepared against genomic RNA sequences of measles virus, canine distemper virus, rubella virus and simian virus 5. Foci of hybridization were found using probes against the measles virus nucleocapsid protein (N), phosphoprotein and fusion protein gene sequences in two of the MS cases, and also in one control, a case of disseminated cytomegalovirus infection with spinal cord necrosis. This result was confirmed using biotinylated probes prepared against the measles virus N genomic sequence. No hybridization was found in any of the MS or control cases using any of the other viral genome-specific probes.

Astrocytoma↗
PubMed1989

Growth hormone treatment in adults with growth hormone deficiency: effect on muscle fibre size and proportions.

The effect of a 6-month period of substitution therapy with recombinant human growth hormone (rhGH) on muscle fibre size and muscle fibre type proportions has been investigated in a group of 13 adults with growth hormone deficiency. All had a peak growth hormone (GH) response to insulin-induced hypoglycaemia of less than 7 mU/l. There was no statistically significant change in the lesser fibre diameter or fibre proportions of either type 1 or type 2 muscle fibres in the rhGH group, as compared with placebo.

Adult↗
PubMed1988

Screening of multiple sclerosis cerebrospinal fluid for autoantibodies.

An enzyme-linked immunoadsorbent assay, using nitrocellulose discs as solid phase and small sample volumes (50 microliter), was developed for the measurement of antibodies. This was used to screen CSF samples for autoantibodies against tissue components. Extracts from a selection of tissues from both "normal" and MS patients and from 3 glial cell lines were made in phosphate-buffered saline; in the case of neural and lymphoid samples the remaining particulate materials were subsequently solubilised with octylglucoside. The saline-soluble components were screened against CSF samples from MS patients (18), patients with other neurological disorders (10), and matched orthopaedic patients but no differences were found among the 3 groups. However, when the detergent-soluble components were screened a significant (at the P less than or equal to 0.01 level) elevation of reactivity towards brain was found in 6/16 MS patients and 2/12 patients with other neurological diseases when compared to their controls.

Adult↗
PubMed1983

Experimental penetrating head injury: some aspects of light microscopical and ultrastructural abnormalities.

A high velocity model of penetrating head injury has been developed in the rhesus monkey and a lower velocity model in the baboon. It is apparent that pathological changes are widespread and develop early although the pathogenesis of the diffuse vascular changes is unknown. The present study involved the sampling of grey and white matter from 20 monkeys with high velocity injury, and 10 baboons with low velocity injury together with similar material from a number of normal control animals. 30 minutes after a high velocity injury swelling of perivascular astrocytes was present, sometimes associated with an increase in extracellular fluid. Animals with lower velocity injuries survived for some hours. Astrocytic swelling and perivascular oedema associated with cellular necrosis was frequently found in this group. The pathogenesis of these lesions is discussed.

Animals↗
PubMed1983

An ultrastructural study of experimental high velocity penetrating head injury.

Experimental high velocity missile brain injury in the rhesus monkey produces widespread swelling of perivascular astrocytes within 30 min of injury. Possible mechanisms for this lesion include a direct effect of force, chemical mediation secondary to the extravasation of blood, alterations in the permeability of the blood brain barrier and ischaemia. The implications of this findings for the function of the blood brain barrier, for neurotransmission and for neuronal survival are discussed.

Animals↗
PubMed1982

Experimental high-velocity missile head injury.

A standardized experimental high-velocity penetrating head-injury model has been produced in which pathological lesions were observed, not only in the wound track but at sites more remote from the track in the hypothalamus, brain stem and cerebellum. Diffuse subarachnoid haemorrhage was common and intraventricular haemorrhage was a constant feature. Other constant histological abnormalities were:L 1. Perivascular "ring' haemorrhages. 2. Perivascular haemorrhage with a surrounding zone of decreased staining intensity. 3. Perivascular increased staining intensity. 4. Areas of decreased staining intensity apparently dissociated from areas of haemorrhage. The pathogenesis of the perivascular lesions is discussed and preliminary studies suggest that these may be the site of early oedema. The implications of this experiment for military surgery and for ballistic protection of the head are discussed.

Animals↗
PubMed1981

The isolation of large and small plaque canine distemper viruses which differ in their neurovirulence for hamsters.

Large and small plaque-forming viruses were isolated from the Onderstepoort strain of canine distemper virus (CDV). Small plaque virus, which was released more slowly from infected cells than large plaque virus, readily established persistent infections in Vero cells, whereas large plaque virus required undilute passage to do so. All persistently infected cultures eventually released small plaque virus. No difference was found in the size of polypeptides induced by either plaque-purified viruses or virus released from persistent cultures. Both dilute and undilute passage, large plaque virus produced an acute neurological illness in weanling hamsters. whereas small plaque virus failed to produce any clinical signs of disease for 3 months after inoculation. After this period 50% of the animals infected with small plaque virus showed a general deterioration in their condition and lesions were observed in the brain which resembled those found in cases of large plaque virus infection. Serum-neutralizing antibody titres to CDV rapidly increased after infection with small plaque virus, whereas animals infected with large plaque virus had low or undetectable levels. All hamsters infected with small plaque virus and a small number which survived large plaque virus infection had elevated titres of antibody over a test period of 15 months.

Animals↗
PubMed1979

A histological, histochemical and biochemical study of the macroscopically normal white matter in multiple sclerosis.

In a combined histological, biochemical and histochemical study of the macroscopically normal white matter in multipe sclerosis 72% of samples were histologically abnormal. The significance of this fact in the interpretation of previous biochemical studies and in the design of future studies is discussed. The present study showed a significant elevation of the lysosomal enzyme beta-glucosaminidase in the microscopically normal white matter in MS as compared with controls. Studies on lysosomes separated from microscopically normal or mild to moderately gliosed white matter in multiple sclerosis showed an increase in lysosomal fragility. Histochemical study of the microscopically normal white matter in multiple sclerosis revealed an increase in the number of acid phosphate-containing cells as compared with normal and neurological control material. The significance of these findings is discussed and it is suggested that irrespective of the primary or secondary nature of these abnormalities, the white matter may be rendered more susceptible to the pathogenetic process in this disease.

Acetylglucosaminidase↗