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Biomedical subjects

P C Dowling

Publications and source records attributed to P C Dowling.

At least 19 recordsLinked to original sources
PubMed1992

Intravenous gamma globulin in progressive MS.

In an attempt to prevent disease exacerbations, intravenous gamma globulin (500 mg to 2 g/kg) plus methylprednisolone was administered monthly to 14 patients with progressive multiple sclerosis, 11 of whom were steroid dependent. Seventeen exacerbations of disease activity were seen in 11 patients over a mean follow-up period of 7.8 months. Four exacerbations occurred in 3 patients within one month of receiving 1.6 to 2.0 g/kg of intravenous gamma globulin (IVGG). Most exacerbations occurred within 2 weeks of steroids being tapered; thus a steroid sparing effect of IVGG could not be demonstrated. We conclude that IVGG plus methylprednisolone can be given safely at monthly intervals for a prolonged period but in the dosage administered did not prevent exacerbations in 80% of patients with progressive multiple sclerosis.

Adult↗
PubMed1990

Spinal cord disease in children with HIV-1 infection: a combined molecular biological and neuropathological study.

An autopsy study was performed on spinal cords from 18 children who died with HIV-1 infection, using standard histopathologic techniques as well as in situ hybridization and immunocytochemistry for HIV-1. Of 16 spinal cords examined by histology, nine had inflammatory cell infiltrates and six had multinucleated cells; both types of lesion are associated with the presence of HIV-1 in central nervous system tissue. HIV-1 type lesions were often present in the spinal cord and brain from the same patient. Pallor of myelin in corticospinal tracts in the cord was present in half of the cases; this change correlated with diffuse myelin pallor in the corresponding brains, but not with the HIV-1 associated changes in the cords. In situ hybridization for HIV-1 nucleic acid sequences gave positive results in seven of 18 spinal cords, with hybridizing signal usually localized to inflammatory cell infiltrates and multinucleated cells. Positive in situ hybridization, on frozen sections, correlated with the presence of HIV-1 associated changes on paraffin sections from the same cases. Immunocytochemistry for p25 core protein of HIV-1, using a monoclonal antibody on frozen sections, was positive in multinucleated cells, macrophages, and microglia. In this series there were two cases of vacuolar myelopathy, one a 30-month-old boy who had concomitant measles virus in the spinal cord grey matter, and the other nine-year-old girl who had severe HIV-1 infection of the cord. Other than the single case of measles virus, there were no opportunistic infections in the cords in this series. HIV-1 frequently involves the spinal cord in children with AIDS, while opportunistic infections are rare. Vacuolar myelopathy occurs in children with HIV-1 infection, although its occurrence is much less frequent than in adults with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Measles vaccination does not prevent multiple sclerosis.

Twenty-seven young patients with multiple sclerosis (MS) were studied to determine if they had received prior measles vaccination. Fourteen patients whose immunization records were available had received measles vaccine in childhood. Eight other patients gave a history of receiving measles vaccine. These results suggest that infection by measles virus is probably not the sole cause of MS and that, unlike subacute sclerosing panencephalitis and postmeasles encephalitis, MS may not be preventable by measles vaccination given at an appropriate age.

Activities of Daily Living↗
PubMed1988

Measles virus L protein evidences elements of ancestral RNA polymerase.

We have determined the nucleotide sequence of the measles virus (MV) L gene using a cDNA library encompassing the entire MV genome (J. Crowley et al. (1987) Intervirology, 28, 65-77). The L gene is 6639 nucleotides in length, and contains a single long open reading frame that could code for a protein of 247,611 kDa. Both the L gene and in particular the predicted L protein of MV bear substantial homology to their counterparts in Sendai virus and Newcastle disease virus, suggesting that the multifunctional nature of paramyxovirus L proteins imposes strong evolutionary constraints. The predicted MV L protein also contains distinct elements of a postulated ancestral RNA polymerase.

Amino Acid Sequence↗
PubMed1988

Sequence variability and function of measles virus 3' and 5' ends and intercistronic regions.

Sequences critical for the activity of the measles virus (MV) RNA polymerase in transcription and replication were analyzed using a MV genomic cDNA library containing overlapping clones encompassing the entire MV genome. Clones corresponding to the 3' and 5' ends of the MV genome were identified and sequenced, and these sequences were confirmed by primer extension experiments. Neither (+) nor (-) strand leader RNAs were detected in MV-infected cell extracts, using high specific activity riboprobes made form these clones. Clones representing each of the MV gene boundaries were also sequenced, and variations including point mutations, insertions, and deletions were noted. Together with the sequence of the MV L gene region, this report completes the sequence determination of the MV genome.

Base Sequence↗
PubMed1988

Total lymphoid irradiation for multiple sclerosis.

Although chemical immunosuppression has been shown to benefit patients with chronic progressive multiple sclerosis (MS), it appears that chemotherapy has an appreciable oncogenic potential in patients with multiple sclerosis. Accordingly, we developed a modified total lymphoid irradiation (TLI) regimen designed to reduce toxicity and applied it to a randomized double blind trial of TLI or sham irradiation in MS. Standard TLI regimens were modified to reduce dose to 1,980 rad, lowering the superior mantle margin to midway between the thyroid cartilage and angle of the mandible (to avert xerostomia) and the lower margin of the mantle field to the inferior margin of L1 (to reduce gastrointestinal toxicity by dividing abdominal radiation between mantle and inverted Y), limiting spinal cord dose to 1,000 rad by custom-made spine blocks in the mantle and upper 2 cm of inverted Y fields, and also protecting the left kidney even if part of the spleen were shielded. Clinical efficacy was documented by the less frequent functional scale deterioration of 20 TLI treated patients with chronic progressive MS compared to to 20 sham-irradiated progressive MS patients after 12 months (16% versus 55%, p less than 0.03), 18 months (28% versus 63%, p less than 0.03), and 24 months (44% versus 74%, N.S.). Therapeutic benefit during 3 years follow-up was related to the reduction in lymphocyte count 3 months post-irradiation (p less than 0.02). Toxicity was generally mild and transient, with no instance of xerostomia, pericarditis, herpes zoster, or need to terminate treatment in TLI patients. However, menopause was induced in 2 patients and staphylococcal pneumonia in one. Our data suggest that this modified TLI regimen has clinical efficacy and sufficiently low toxicity to make it suitable for investigative immunosuppressive treatment of patients with progressive MS or other non-malignant conditions.

Adult↗
PubMed1988

Multiple sclerosis in the Shetland Islands: an update.

Annual incidence rates of multiple sclerosis (MS) in the Shetland Islands have been updated from 1938 to 1986. These reveal a significant decline in MS incidence beginning between 1951 and 1968. No significant change in prevalence, age-specific prevalence, duration of MS, or mean age of the MS population in Shetland has been found since the last survey in 1974, although a trend towards an older MS population was noted.

Adult↗
PubMed1988

T cell subsets and disease progression after total lymphoid irradiation in chronic progressive multiple sclerosis.

T lymphocyte subset percentages were determined in 16 total lymphoid irradiation (TLI) treated and 18 sham treated control patients with chronic progressive multiple sclerosis. During the first year after treatment, the ratio of T helper/inducer to T suppressor/cytotoxic cells (Th/Ts ratio) was significantly higher in sham treated multiple sclerosis patients who worsened clinically compared with TLI treated and sham treated multiple sclerosis patients who remained clinically stable. TLI caused a fall in the percentage of T helper cells in treated patients, while the percentage of T suppressor cells remained stable during the first year after treatment. In contrast, the percentage of T suppressor cells fell in sham treated multiple sclerosis patients who worsened clinically.

Follow-Up Studies↗
PubMed1988

Effect of total lymphoid irradiation on functional status in chronic multiple sclerosis: importance of lymphopenia early after treatment--the pros.

To determine whether immunosuppression by total lymphoid irradiation (TLI) slowed deterioration of chronic progressive multiple sclerosis (MS), functional impairment score and blood lymphocyte counts were compared at 6-month intervals through 4 years following treatment of MS patients by either TLI (n = 27) or sham irradiation (n = 21). At each interval, 20 to 30% fewer TLI-treated patients had deteriorated (p less than 0.05 at 6, 12, and 18 months), and the difference in mean functional impairment score between groups became progressively greater (p less than 0.01 at 42 and 48 months). Benefit accrued principally to the 17 TLI-treated patients with absolute blood lymphocyte counts less than 900/mm3 3 months after treatment, whose mean functional impairment score remained within 0.6 units of baseline (p = NS), whereas the ten TLI patients with higher post-treatment lymphocyte counts had progressive deterioration (p less than 0.05 to p less than 0.001 versus TLI-treated patients with lower lymphocyte counts at all intervals except 30 months) and had deteriorated by more than 5 functional scale units by 42 and 48 months. Side effects were minor and complications rare in TLI-treated patients, but one TLI-treated patient developed staphylococcal sepsis. Thus, TLI slows deterioration of chronic progressive MS, with what appears to be enduring benefit through 4 years compartmented to patients with greater induced lymphopenia. Modification of lymphoid irradiation regimens to increase the proportion of MS patients who achieve a favorable degree of lymphopenia and to avert functional hyposplenism may further improve the benefit/risk ratio.

Adult↗
PubMed1987

Steroid therapy in multiple sclerosis. Point of view.

A number of studies have demonstrated that high-dose corticosteroid treatment improves the rate of recovery from acute exacerbations of multiple sclerosis. The beneficial effect is more rapidly and consistently produced by high-dose corticosteroid administration than with adrenocorticotropic hormone. The most rapid improvement in clinical condition and cerebrospinal fluid parameters of patients has been observed with short courses of very high-dose intravenous therapy. This form of treatment would be most advantageous for patients with severe and rapidly progressive exacerbations. Ultimately, the duration of treatment will depend on the patient's response to treatment, tolerance of corticosteroid withdrawal, and the occurrence of significant complications of therapy. However, in our experience, a three- to four-month slowly tapered course of oral therapy is often needed, and is usually well tolerated, with few serious side effects when given once daily in the morning.

Acute Disease↗
PubMed1987

Total lymphoid irradiation in multiple sclerosis: blood lymphocytes and clinical course.

We have found a significant relationship between blood lymphocyte count and prognosis in 45 patients receiving either total lymphoid irradiation or sham irradiation for chronic progressive multiple sclerosis. Patients with sustained lymphocyte counts less than 900 mm-3 for prolonged periods after treatment showed less rapid progression over the ensuing 3 years than did patients with multiple sclerosis who had lymphocyte counts above this level (p less than 0.01). Our results suggest that a simple laboratory test, the absolute blood lymphocyte count, may serve as a valuable barometer for monitoring the amount of immunosuppressive therapy needed to prevent progression in patients with multiple sclerosis, and possibly other autoimmune diseases.

Adult↗
PubMed1986

Effect of total lymphoid irradiation in chronic progressive multiple sclerosis.

Total lymphoid irradiation (TLI; 1980 cGy) or sham irradiation was given to 40 patients with chronic progressive multiple sclerosis (MS) in a prospective, randomised, double-blind study. During mean follow-up of 21 months, MS patients treated with TLI had less functional decline than sham-irradiated MS patients (p less than 0.01). A significant relation was noted between absolute blood lymphocyte counts in the first year after TLI and subsequent course, patients with higher lymphocyte counts generally having a worse prognosis (p less than 0.01). TLI was well tolerated and associated with only mild short-term, and to date, long-term side-effects.

Adult↗
PubMed1986

Measles virus nucleic acid sequences in human brain.

We constructed a measles virus genomic recombinant DNA library, and used clones coding for portions of the viral P, M and H proteins to probe for measles virus nucleic acid sequences in post-mortem multiple sclerosis, SSPE and control brains. By dot blot hybridization, the probes detected measles virus nucleic acid sequences in as little as 3 nanograms of total RNA extracted from measles virus-infected cells and also in highly diluted RNA extracted from SSPE brain, but did not detect measles virus sequences in RNA extracted from 11 multiple sclerosis or 8 control brains, even at a 1 000-fold higher concentration of RNA. By in situ hybridization, these probes detected measles virus nucleic acid sequences in virtually every cell and the surrounding neuropile of SSPE brain, but again did not detect such sequences in multiple sclerosis or control brains. Our findings using these highly specific probes confirm that measles virus is found in SSPE brains and indicate that measles virus genome is unlikely to be present in multiple sclerosis or normal brains.

Base Sequence↗
PubMed1986

Transcriptional map of the measles virus genome.

We have constructed a recombinant DNA library of the measles virus genome and identified gene-specific clones containing sequences coding for portions of each of the six viral structural proteins, as well as clones coding for intercistronic sequences. By Northern blotting, we could order the clones according to the pattern of individual gene-specific and readthrough mRNAs. Clones corresponding to the N, P/C and M genes were identified by correlation of the mRNAs with their in vitro translation products; clones corresponding to the H, F and L genes were identified by indirect evidence. The results indicated that the gene order in measles virus is that of a typical paramyxovirus (3'-N,P/C,M,F,H,L-5'), but that the M and F transcripts each contain 1.5 times the coding capacity needed for synthesis of these proteins in vivo.

Cloning, Molecular↗
PubMed1986

Potential role of paramyxoviruses in multiple sclerosis.

At the present time, the cause of multiple sclerosis (MS) remains unknown, although it seem likely that one or more infectious agents triggers the disease, perhaps through an autoimmune mechanism. In this article, evidence linking the paramyxoviruses, canine distemper, and measles to MS is reviewed.

Animals↗