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C A Morris

Publications and source records attributed to C A Morris.

At least 127 records · Page 7Linked to original sources
PubMed1977

Serological characterization of group-A streptococci associated with skin sepsis in meat handlers.

A series of outbreaks of skin sepsis among meat handlers in England during 1974 and 1975 afforded an opportunity to study the group-A streptococci commonly isolated from the lesions. Few of these streptococci could be M typed with existing antisera. Intensive study of strains from two outbreaks of sepsis in one abattoir in Shropshire led to the recognition of three new provisional M types. The streptococci were first sorted according to T-typing pattern and ability to produce opacity factor. Opacity-factor producing strains with the same T pattern were then screened for inhibition of opacity production by the sera of convalescents from the same outbreak. Finally, M antisera were made in rabbits against representative cultures. Sera against the three new provisional types were used to re-examine streptococci from 20 other outbreaks or incidents of sporadic infection among meat handlers. This increased the proportion of typable strains from 3% to 55%. Two of the new provisional types (nos. 2015 and 1658; both T25/Imp 19, opacity-factor positive) were confined to the Shropshire outbreak, but the third (no. 2681; T14, opacity-factor negative) was found among strains from meat workers in eight other geographically distinct areas. In all, 31% of 131 distinct strains from meat workers, but less than 1% of 2816 strains from other British sources, belonged to provisional type 2681. Thus, in Britain, one M-type of group-A streptococcus appears at present to be almost exclusively associated with sepsis in meat workers.

Abattoirs↗
PubMed1977

Regulation of compensatory kidney hypertrophy by its own products.

1. The ligation of blood vessels of one kidney of adult rats resulted in the compensatory hypertrophy of the other kidney. In most animals the rate of hypertrophy was indistinguishable from that observed after unilateral nephrectomy, but in a few cases the onset was retarded when the renal artery alone had been ligated and the collateral circulation increased.2. When the blood vessels of one kidney of adult rats were ligated and the cortex was excised, the rate of compensatory renal hypertrophy was similar to that observed after unilateral nephrectomy.3. In animals operated for simultaneous partial hepatectomy and unilateral nephrectomy, there was no sign of compensatory renal hypertrophy while the liver was undergoing regeneration. Renal hypertrophy started after 7 days, when about 98% of the amount of liver removed had been regenerated.4. Neither aseptic autolysis of one kidney following suppression of its blood supply, nor unilateral nephrectomy affected the rate of liver regeneration after simultaneous partial hepatectomy.5. Total splenectomy did not affect the rate of compensatory renal hypertrophy following unilateral nephrectomy.6. The heterotopic graft of renal cortical, but not of medullary, cells inhibited compensatory renal hypertrophy in adult rats. The removal of the graft after 14 days was followed by the resumption of compensatory hypertrophy.7. The inhibiting action of fractions of renal cortical extracts fractionated on Sephadex G100 resin and DEAE-52 cellulose were assayed on the ;growth' of renal explants reared in vitro. The final material, though only partially purified, proved to have an inhibiting activity between 250 and 500 times greater than that of the initial extract.8. When injected into unilaterally nephrectomized rats, the partially purified extract from the renal cortex had an inhibiting effect on compensatory renal hypertrophy.9. Immunofluorescence technique showed that the partially purified cortical extract affected the proximal convoluted tubes specifically, irrespective of animal species.

Animals↗
PubMed1977

Compensatory renal hypertrophy in hypophysectomized rats.

1. After hypophysectomy, both body and kidney weights fall, but at different rates. The rate at which the kidney decreases in weight is faster than that of the whole body.2. Seven days after unilateral nephrectomy, the dry weight of the remaining kidney of hypophysectomized rats, with the exception of rats which had been hypophysectomized for 2 days only, was always heavier than the kidney of control hypophysectomized rats of similar body weight.3. The difference between the dry weight of kidneys of unilaterally nephrectomized hypophysectomized and control hypophysectomized rats increased from 15% in early hypophysectomized (9 days) to about 35% in late hypophysectomized animals (23 days).4. The implantation of renal cortical cells from 2 day hypophysectomized rats into unilaterally nephrectomized control litter-mates inhibited compensatory renal hypertrophy in the latter. When a similar operation was made using kidney cells from animals which had been hypophysectomized for 23 days, there was no significant inhibition of compensatory renal hypertrophy.5. The renal contents of adenosine-3',5'-monophosphate (cyclic AMP) and of guanosine-3',5'-monophosphate (cyclic GMP) in rats hypophysectomized for 2 days were of the same order as those in normal rats, but were markedly lower in rats hypophysectomized for 23 days.6. In contrast to what had been observed in normal rats, in hypophysectomized (2 or 23 days) rats, unilateral nephrectomy did not affect significantly the levels of cyclic nucleotides in the remaining kidney.7. Cross-circulating anephric normal rats with 2 day hypophysectomized animals resulted in an increase of cyclic GMP content in their kidneys. The cross-circulation between anephric normal rats and 23 days hypophysectomized rats had no effect on the level of renal cyclic GMP of the latter.8. When rats hypophysectomized for either 2 or 23 days and which had been nephrectomized were cross-circulated with normal rats, there were no changes in the content of cyclic GMP in the kidneys of the latter.

Animals↗
PubMed1976

Comparison of antibody responses and reactivity of "Alice" and WRL 105 strain live influenza vaccines.

Groups of 45 adult volunteers were vaccinated intranasally with a single dose of either "Alice" or WRL 105 strain live influenza vaccines. Seroconversion rates against A/Scotland/840/74 were significantly greater following administration of WRL 105 but seroconversion rates against A/England/42/72, A/Port Chalmers/1/73, A/Finland/4/74, A/Victoria/3/75, and A/England/864/75 did not differ significantly between the two vaccines. Poor antibody responses were elicited by both "Alice" and WRL 105 strains against A/Victoria/3/75 and A/England/864/75. No severe reactions followed the administration of either vaccine.

Administration, Intranasal↗
PubMed1976

The response to oral poliovaccine in persons aged 16-18 years.

Serum neutralizing antibodies to polioviruses were titrated in serum samples from 182 police cadets aged 16-18 years before and, in 168 of the cadets, 6 weeks after vaccination with a single dose of oral polio vaccine (OPV). Faecal excretion of poliovirus was also followed. Vaccination histories were obtained and confirmed whenever possible. Pre-vaccination antibody could not be detected against type 1 in 9-3% cadets, against type 2 in 2-7% and against type 3 in 7-7%. Absence of antibody to at least one virus type was found in 14-3% of the cadets. In 93 cadets in whom vaccination histories could be confirmed 40 had received only inactivated polio vaccine (IPV) previously; of these 23% lacked antibody to at least one virus type, and they had less intestinal immunity to a challenge dose of OPV than those previously given OPV. Only two of the cadets known to have had OPV were non-immune - both had received a single dose following full courses of IPV. However, cadets who had received OPV had their last dose of vaccine more recently (average 4-6 years) than those who had received only IPV (all 12 years or more). The serum antibody response to a single booster dose of OPV, and the faecal excretion of each type of virus after vaccination, showed an inverse relation to the corresponding pre-vaccination antibody concentration. A single dose of OPV did not reliably boost the immunity of those who possessed adequate immunity, and a failure to respond was also observed in a proportion of the cadets with no detectable antibody, mostly in the case of type 3 antibody and particularly if antibody to types 1 or 2 virus was also absent. No evidence was obtained that intestinal immunity could be expected in the absence of detectable circulating antibody. The reasons for the absence of a serological response to OPV in some subjects are discussed and consideration is given to the practical significance of the findings. It is suggested that reinforcement of polio immunity at school-leaving is important, particularly at the present time when many of those aged 16-18 years will have been vaccinated only with IPV. A single dose of OPV is not ideal for this purpose, not only because a small proportion of persons are liable to be left unprotected, but also because failure to produce a reliable boost in persons with adequate immunity at the time of vaccination gives rise to the possibility that they may become susceptible later in adult life.

Adolescent↗
PubMed1976

Natural challenge of subjects vaccinated with WRL 105 strain live influenza vaccine in a residential community.

In the spring of 1975 an outbreak of influenza associated with influenza virus A/Scotland/840/74 virus occurred in a residential college where the previous autumn some students had been immunised with a single intranasal dose of Recombinant WRL 105 (H3N2) (A/Okuda/57xA/Finland/4/74) strain live attenuated infleunza virus vaccine. During the outbreak none of seven students who had been vaccinated suffered from influenza but an influenzal illness did occur in four of eleven who had received placebo nose drops only. Fourfold or greater increases in hemagglutinating inhibiting antibodies between sera collected three weeks after vaccination and those collected three months later following the influenza epidemic were found in one of seven vaccinated and in nine of eleven placebo treated subjects and also in one student who had received neither vaccine nor placebo; a difference in serological response which is statistically significant (p less than 0.01). Thus recombinant WRL 105 live attenuated vaccine was found to have conferred substantial protection against a current wild strain of influenza A virus without causing any appreciable untoward reactions.

Administration, Intranasal↗
PubMed1975

Recombinant WRL 105 strain live attenuated influenza vaccine. Immunogenicity, reactivity, and transmissibility.

The immunogenicity, reactivity, and transmissibility of recombinant WRL 105 (H3N2) (A/Okuda/57XA/Finland/4/74) strain live attenuated influenza virus vaccine were studied in adult male volunteers in a residential community in rural England. Thirteen volunteers received a single dose of 10(7.0) E.I.D.50 recombinant WRL 105 vaccine administered as nose drops, and twelve volunteers received placebo. Nine (82%) of eleven volunteers with initial antibody titres of less than or equal to 1/96 showed a significant antibody response to vaccination, but there was no evidence of transmission of vaccine virus to those who received placebo. The incidence and nature of reactions were similar in those who received vaccine and placebo. The vaccine was shown to confer protection against natural infection with a strain exhibition antigenic characteristics equivalent to those of A/Scotland/840/74.

Administration, Intranasal↗
PubMed1975

Purification and properties of a soluble nicotinamide adenine dinucleotide-linked isocitrate dehydrogenase from Crithidia fasciculata.

A soluble NAD+-linked isocitrate dehydrogenase has been isolated from Crithidia fasciculata. The enzyme was purified 128-fold, almost to homogeneity, and was highly specific for NAD+ as the coenzyme. There is also a cytoplasmic NADP+-linked and a mitochondrial isocitrate dehydrogenase in the organism. Studies of the physical and kinetic properties of the soluble NAD+-isocitrate dehydrogenase from this organism showed that it resembled microbial NADP+-isocitrate dehydrogenases in general, all of which are cytoplasmic enzymes. The enzyme appeared not to be related to other NAD+-isocitrate dehydrogenases, which are found in the mitochondria of eukaryotic cells. The molecular weight of the soluble NAD+-isocitrate dehydrogenase was 105,000 which is within the range of the values for microbial NADP+-isocitrate dehydrogenases. Similar to the NADP+-isocitrate dehydrogenase in this organism, the enzyme was inhibited in a concerted manner by glyoxalate plus oxalacetate. Kinetic analysis revealed that Mn2+ was involved in the binding of isocitrate to the enzyme. Inhibition of the NAD+-linked isocitrate dehydrogenase by p-chloromercuribenzoate could be prevented by prior incubation of the enzyme with both Mn2+ and isocitrate; however, neither ion alone conferred protection. Free isocitrate, free Mn2+, and the Mn2+-isocitrate complex could all bind to the enzyme. Four different mechanisms with respect to the binding of isocitrate to the enzyme were tested. Of these, the formation of the active enzyme-Mn2+-isocitrate complex from (a) the random binding of Mn2+, isocitrate, and the Mn2+-isocitrate complex, or (b) the binding of Mn2+-isocitrate with free Mn2+ and isocitrate acting as dead-end competitors were both in agreement with these data.

Animals↗
PubMed1975

Epidemic viral enteritis in a long-stay children's ward.

Two outbreaks of acute gastroenteritis occurred in 1974 in a long-stay children's ward. Electron microscopy demonstrated rotaviruses in faeces from the affected children in the first outbreak, and adenoviruses in faeces from affected children and a nurse in the second outbreak. The illness in both outbreaks was very mild; but the diarrhoea associated with rotavirus infection usually lasted 5-8 days (in one patient it lasted for 28 days) and sometimes started with vomiting; whereas the adenovirus-associated diarrhoea lasted only 2-4 days and was not associated with vomiting. Neither the rotaviruses nor the adenoviruses could be established in tissue-culture.

Acute Disease↗
PubMed1975

Some observations on cooling in laboratory autoclaves.

Cooling times for various autoclave loads were recorded using thermocouples. Loads which may be encountered during normal laboratory working require between 17 and 174 minutes to cool to 100 degrees, C and up to 260 minutes to cool to 95 degrees C. Such long cooling times had an adverse effect on nutritive properties of bacteriological culture medium. Observations are made on some factors which influenced the cooling times, and the need for artificially assisted cooling is stressed. Recommendations are given for the safe operation of laboratory autoclaves.

Culture Media↗