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Biomedical subjects

G Parsons

Publications and source records attributed to G Parsons.

At least 55 records · Page 3Linked to original sources
PubMed1984

Avian paramyxovirus type 1 infections of racing pigeons: 2 pathogenicity experiments in pigeons and chickens.

Pathogenicity index tests on 40 paramyxovirus type 1 viruses isolated from field cases of disease in racing pigeons produced a close grouping of the values obtained in intracerebral pathogenicity index ( ICPI ) tests in day-old chicks (mean 1.48, range 1.28 to 1.76) but a much greater variation in intravenous pathogenicity indices ( IVPI ) in six-week-old chickens (mean 0.38, range 0 to 1.81), although 25 out of 40 isolates had an IVPI in the range 0 to 0.3. Isolates with low IVPIs in chickens gave much higher values in intravenously infected adult pigeons. Virulence for chickens was increased by passage through chickens and, regardless of initial IVPI , indices of about 2 were recorded for isolates passaged three to four times. Passage through chickens also increased the virulence for pigeons in the one isolate tested. Pigeons inoculated with isolate 561/83 by intranasal route or by placing birds in contact with infected birds were shown to excrete virus and respond immunologically but no clinical signs were recorded. Isolate 561/83 was shown to readily infect chickens placed in contact with infected pigeons but no disease signs were seen. The clinical signs associated with field disease in racing pigeons could be reproduced in experimental pigeons by intravenous inoculation of virus. Similar clinical signs were seen in chickens infected by the intravenous route.

Animals↗
PubMed1984

Disposition of and clinical response to salicylates in patients with rheumatoid disease.

The disposition of salicylic acid (SA) and its metabolites and the clinical response to long-term aspirin treatment at varying doses were assessed in patients with rheumatoid disease. Steady-state kinetics of SA (total and unbound), salicyluric acid (SUA), gentisic acid (GA), and clinical status were estimated weekly in 10 patients with rheumatoid arthritis. Eight received a soluble aspirin form and two received an enteric-coated form. The starting dose of aspirin in each patient was 1.8 gm (soluble) or 1.95 gm (enteric-coated) daily. Weekly increments in dose were made until a satisfactory clinical outcome was achieved. The final aspirin dose range was 3.6 to 8.1 gm daily, which resulted in mean steady-state plasma SA concentrations (CpSA) from 56 to 375 mg/l. Since the mean total CpSA increased approximately proportionately over the dose range, there was little change in total SA clearance. By contrast, increasing aspirin dosage resulted in decreased clearance and disproportionate increases in unbound SA (CpuSA). The maximum velocity of conversion of SA to SUA (Vm) increased significantly, from 57.3 +/- 11.7 mg/hr at an aspirin dose of 1.8 gm/day to 71.4 +/- 19.4 mg/hr at the next highest dose (2.7 to 3.6 gm/day), with no further change with increasing dosage. Km ranged from 0.4 to 1.2 mg/l for CpuSA and from 5.5 to 17.2 for total CpSA. Renal clearance of SUA (ClSUA) ranged from 124 to 893 ml/min and correlated with creatinine clearance. ClGA ranged from 23 to 164 ml/min, and ClSA ranged from 0.1 to 17.1 ml/min; neither correlated with creatinine clearance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Comparison of the immunogenicity of Newcastle disease virus strains V4, Hitchner B1 and La Sota in chickens. 2. Tests in chickens with maternal antibody to the virus.

The immunogenicity of three Newcastle disease virus (NDV) strains--V4, Hitchner B1 and La Sota, was assessed in chickens that had varying levels of maternal antibody to the virus. Chickens were immunised at different ages by the eye drop and aerosol methods. The immune response of chickens to similar doses of the strains was affected by the presence of maternal antibody. Both the level of maternal antibody and the strain of virus used affected the result. Strain La Sota was least affected as it took higher levels of maternal antibody to depress response to it than were required to have a similar effect on Hitchner B1 and V4. Strain V4 was the strain most affected by circulating maternal antibody. The results demonstrated that strain V4 was less immunogenic than Hitchner B1 and La Sota when used in chickens with maternal antibody to NDV.

Animals↗
PubMed1984

Duration of excretion of virulent Newcastle disease virus following challenge of chickens with different titres of serum antibody to the virus.

Virulent Newcastle disease virus (NDV) was isolated from susceptible and immune chickens following intra-ocular challenge with the Essex '70 strain. Challenge virus was isolated from the trachea and cloaca of susceptible birds until they died 7 to 9 days after challenge. This virus was isolated from immunised chickens for up to 14 days after challenge. The duration of excretion was influenced by the prechallenge serum antibody titre to NDV. It persisted longest in chickens with titres of 2(3) to 2(7) and decreased in length and frequency from chickens with titres in the range 2(8) to 2(12). Chickens with pre-challenge titres of 2(3) to 2(5) developed 2- to 3- fold increases in post-challenge titres, whereas those with higher pre-challenge titres had smaller proportional increases in titre. Excretion of virulent virus from immunised birds should be considered in the development of Newcastle disease control programs.

Animals↗
PubMed1984

Comparison of the residual virulence of Newcastle disease vaccine strains V4, Hitchner B1 and La Sota.

The clinical response of 7-day-old chickens to Newcastle disease vaccine strains V4, B1 and La Sota administered by the aerosol method was used to study the residual virulence of the strains. Parameters used to assess the severity of the clinical response were the number of sneezes recorded and the weight gain of chickens in the 10 day test period. The demeanour of the chickens was also observed. Strain V4 was less pathogenic for chickens than strain B1 which was less virulent than strain La Sota. Statistically significant differences were recorded in weight gain and the number of sneezes detected in each group. An unexpected mild respiratory disease recorded in chickens dosed with strain V4 may have been associated with administration of virus as a fine particle aerosol.

Animals↗
PubMed1983

Freedom of coccidial oocysts from Newcastle disease virus.

Oocysts were recovered from chickens experimentally infected with the Mukteswar strain of Newcastle disease virus and Eimeria acervulina or E tenella. Oocysts sterilised by sodium hypochlorite solution were washed, ruptured and inoculated into embryonating eggs which were examined after five days by the haemagglutination test for virus. All these tests were negative. Virus, initially detected with oocysts separated from faeces, was no longer present after sporulation in 2 per cent potassium bichromate. The B1 strain of virus survived for up to 30 hours in 2 per cent sodium hydroxide and 2 per cent potassium bichromate but was quickly destroyed by sodium hypochlorite (specific gravity 1.075).

Animals↗
PubMed1982

Identification of paramyxoviruses isolated from birds dying in quarantine in Great Britain during 1980 to 1981.

During 1980 to 1981 a total of 61 paramyxoviruses were isolated from imported captive birds dying during the quarantine period required under the Importation of Captive Birds Order 1976. These viruses were identified as avian paramyxovirus serotype PMV-1, 13 isolates (eight Newcastle disease viruses of high virulence, five of low virulence); PMV-2, 38 isolates; PMV-3, nine isolates and one isolate provisionally typed as PMV-7.

Animals↗
PubMed1980

Effect of acute lung injury on angiotensin converting enzyme in serum, lung lavage, and effusate.

The administration of an acute pulmonary edemagenic dose (ip) of thiourea to rats results in an elevation of angiotensin converting enzyme (ACE) in serum, lung lavage, and pleural effusion. The increased serum ACE corresponds to a reduction in lung ACE, but it is transient, lasting between 1 and 2 h. ACE remains elevated in lung lavage and pleural effusion for at least 4 h after the administration of thiourea.

Acute Disease↗
PubMed1980

Effect of paraquat on serum angiotensin converting enzyme.

Intraperitoneal administration of paraquat to mice produced a linear dose-response increase (20 to 50 mg/kg of body weight) in serum angiotensin converting enzyme (ACE). The peak increase (31%) in ACE occurred after 50 mg/kg of paraquat and began at approximately 4 h. ACE was still significantly elevated 8 h after the administration of paraquat, but it began to return to normal 24 h later. Although serum ACE increased during the first 5 h after the administration of paraquat, lung ACE decreased. The enzyme that we measured in mouse serum was inhibited 100% by 10(-7) M of SQ 20881, a known ACE inhibitor.

Animals↗
PubMed1980

Experimental infection of turkeys with egg drop syndrome 1976 virus and studies on the application of the haemagglutination inhibition test.

Evidence that turkeys can be infected with virus 127 by the combined intranasal and oral route and that the haemagglutination inhibition (HI) test can be used to demonstrate past infection is presented. Experimental infection of turkeys (six weeks old and six months old) with virus 127 did not result in any clinical signs. However, a rapid HI response was detectable one week later and detectable titres were found 28 weeks after infection. No antibody was detected in 392 sera examined from commercial turkey flocks.

Animals↗
PubMed1979

Resistance of chickens to challenge with the virulent Herts 33 strain of Newcastle disease virus induced by prior infection with serologically distinct avian paramyxoviruses.

Results indicate that some degree of protection from challenge by Newcastle disease virus (NDV)/Herts 33 was conferred on chickens by prior infection with PMV/turkey/Wisconsin/68, PMV/turkey/Ontario/6661/68, PMV/Netherlands/449/75 and PMV/parakeet/England/39/78 viruses, all of which are serologically related but distinguishable from NDV. Except for one bird which survived challenge three weeks after infection with Robin/Hiddensee/19/75, no protection was seen in chickens infected with other unrelated avian paramyxoviruses. In contrast to infection with NDV-B1, birds protected by infection with avian paramyxoviruses showed large increases in NDV haemagglutination inhibition (HI) titres after challenge. In these birds considerable increases in the homologous HI titres were also seen after challenge.

Animals↗
PubMed1979

Characterisation of influenza viruses isolated from turkeys in Great Britain during 1963--1977.

Seven influenza viruses isolated from turkeys in Great Britain since 1963 were typed by haemagglutination inhibition and neuraminidase inhibition tests as: A/turkey/England/63 (Hav 1 Nav 3), A/turkey/England/66 (Hav 6 N2), A/turkey/England/69 (Hav 7 N2), A/turkey/Scotland/70 (Hav ? Neq 1), A/turkey/England/N28/73 (Hav 5 N2), A/turkey/England/110/77 (Hav 6 N2), A/turkey/England/647/77 /Hav 1 Neq 1). A/turkey/Scotland/70 failed to show a haemagglutinin relationship with any of the representative strains and may possess a hitherto unreported haemagglutinin subtype. Intravenous pathogenicity tests in six-week-old birds showed only A/turkey/England/63 to have high virulence for turkeys and chickens. A/turkey/England/69 produced some signs of disease in chickens and, to a lesser extent, turkeys but all other isolates were avirulent.

Animals↗