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Biomedical subjects

R E Horton

Publications and source records attributed to R E Horton.

At least 19 recordsLinked to original sources
PubMed2005

Influence of age and carriage status on salivary IgA to Neisseria meningitidis.

Asymptomatic carriage of Neisseria meningitidis is common (5-35% of individuals) while the incidence of invasive meningococcal disease is fairly low (<1-5 per 100,000 per annum in Europe). Naturally acquired protective immunity may account for this difference. In this study, we investigated the relationship between anti-meningococcal salivary IgA and age and carriage. We showed that salivary IgA to a range of meningococcal antigens increased successively with age with some specificity for commonly circulating serosubtypes. In a group of 258 students 37 (14%) of whom were carriers of N. meningitidis serogroup B, higher levels of specific IgA were associated with carriage. Stratified analysis revealed a positive relationship between smoking and specific anti- N. meningitidis IgA independent of current carriage, weighted odds ratio (OR) 4.1 (95% CI 1.1-18) and OR 3.8 (95% CI 0.96-16) for reference strains B:1:P1.14 and B:4:P1.5,4 respectively. These data implicate IgA as a factor in host defence from meningococcal invasion, although the precise mechanisms remain uncertain.

Adolescent↗
PubMed2001

Escherichia coli CreBC is a global regulator of gene expression that responds to growth in minimal media.

We have identified nine genes, the expression of which are regulated by the CreBC two-component system: the first members of the cre regulon. They are divided into eight transcriptional units, each having a promoter-proximal TTCACnnnnnnTTCAC "cre-tag" motif. The cre regulon genes are: the ackA/pta operon, the products of which collectively catalyze the conversion of acetyl-CoA into acetate and ATP; talA, which encodes an enzyme involved in the mobilization of glyceraldehyde-3-phosphate into the pentose phosphate pathway; radC, which encodes a RecG-like DNA recombination/repair function; malE, which is the first gene in the malEFG maltose transporter operon; trgB, which encodes an ADP-ribose pyrophosphorylase; and three other genes, creD, yidS and yieI, the products of which have not been assigned a function. Expression of each of these cre regulon genes is induced via CreBC during growth in minimal media, with the exception of malE, which is more tightly repressed. The diverse functions encoded by the cre regulon suggest that CreBC is a global regulator that sits right at the heart of metabolic control in Escherichia coli.

Aeromonas↗
PubMed1983

From the National Institute of Allergy and Infectious Diseases. Summary of the National Institutes of Health workshop on group B streptococcal infection.

Group B streptococci remain a serious cause of morbidity and mortality in neonates. GBS vaccine or immunoglobulin administered iv may enhance neonatal GBS immunity. Likewise, intrapartum antibiotic therapy of colonized mothers appears to reduce vertical transmission of group B streptococci and to prevent both maternal and neonatal GBS disease. However, the safety and effectiveness of routine penicillin prophylaxis less than or equal to 1 hr after birth remain in question. For example, penicillin prophylaxis appears to be of little value in infants with low birth weights (less than 2,000 g) who become symptomatic shortly after birth; however, it may reduce the incidence of disease in larger, full-term infants who acquire the group B streptococci at delivery or in the few hours immediately thereafter. The potential harm of administering penicillin to all neonates must also be considered, since routine antibiotic therapy may alter the incidence of both neonatal infections due to penicillin-resistant pathogens and possible later penicillin allergy. Theoretically, a single injection of penicillin at birth may suppress GBS disease in some neonates but not effectively treat it, allowing the disease to progress prior to diagnosis and therapy. The decision to use penicillin routinely in neonates to prevent GBS disease must therefore be made with caution. Presently, this decision must be made on a situational basis, with institutions having a high incidence of early-onset GBS disease electing to use penicillin only if the potential benefits outweigh the risks.

Anti-Bacterial Agents↗
PubMed1982

A randomised controlled trial to compare local with general anaesthesia for short-stay inguinal hernia repair.

A series of 117 consecutive unselected patients with clinically reducible unilateral inguinal herniae were admitted for short-stay repair. Seven expressed a strong preference for one form of anaesthesia (6 general (GA)) local (LA) and 7 were unfit for GA; these were excluded from the trial. The remaining 103 patients were allocated at random to receive either LA or GA in order to compare the two methods of anaesthesia. The resulting groups (53 LA, 50 GA) were well matched for age and obesity. Perand postoperative symptoms were assessed with linear analogues self-assessment questionnaires. Statistically significant differences were demonstrated between the groups; those patients having LA were able to walk, eat, and pass urine earlier than those having GA, who experienced more nausea, vomiting, sore throat, and headache. The postoperative course and additional symptoms were otherwise similar. Forty-five LA patients experienced mild pain during the operation, but nevertheless 85% of the total group said they would consent to its use again. Ninety-three patients (90%) were discharged at 24 h. LA was applicable to all types of clinically reducible inguinal hernia and was an acceptable, safe, and satisfactory alternative to GA.

Adult↗
PubMed1981

Long grafts in the treatment of critical ischaemia.

Forty-two woven 10-mm Dacron grafts were implanted from the common iliac artery to the distal popliteal artery in 38 patients with rest pain or gangrene. The long-term patency at 5 years was 50%, using life-table analysis. These results show that iliopopliteal Dacron grafts are effective in preventing major amputations of severely ischaemic limbs.

Blood Vessel Prosthesis↗
PubMed1979

Pulsed Doppler angiography in lower limb arterial ischemia.

A 30-channel pulsed Doppler vessel imaging system (MAVIS, GEC Medical, Middlesex, England), was used to obtain images and maximal Doppler velocity time waveforms in the diagnosis of stenosis of the origin of the profunda femoris artery (PFA) and in the detection of structural changes within Dacron arterial grafts. In PFA scans of 33 limbs in 22 patients (mean age, 52 years), PFA stenosis of more than 50% at operation was invariably associated with a damping factor of the maximal Doppler velocity-time waveform of greater than 1.5 (eight limbs). In 12 limbs with a normal PFA at operation, the damping factor was always less than 1.4, and in 13 limbs of normal patients without arterial disease, the damping factor was always less than 1.34. In studies of 10 mm arterial grafts, the internal diameter of 14 iliopopliteal grafts scanned just above the popliteal anastomosis was strikingly reduced as compared with the femoral anastomosis of 14 aortoiliofemoral grafts and seven axillobifemoral grafts. These preliminary results suggest that MAVIS studies can be used noninvasively to detect PFA stenosis and to identify luminal narrowing of iliopopliteal grafts.

Angiography↗
PubMed1977

Iliopopliteal Dacron graft in treatment of advanced ischaemia of the leg.

This is a preliminary report of 14 patients treated for advanced ischaemic disease by iliopopliteal Dacron graft. In all the patients either the saphenous vein was not available for use or the occlusion was too long to be bypassed by saphenous vein. In these circumstances no alternative treatment exists other than amputation. The operation is not difficult and preliminary results are very favourable.

Humans↗
PubMed1977

Localized thrombus complicating saphenous vein grafts.

Recurrence of symptoms after a long saphenous vein graft may be due to a variety of causes. When the graft pulse can still be felt the presence of a localized thrombus partially occluding the lumen must be considered. After arteriographic confirmation such a thrombus can be easily removed.

Female↗
PubMed1970

Pathogenicity of Clostridium perfringens for germ-free guinea pigs after oral ingestion.

Germ-free guinea pigs died with signs and lesions of acute enterotoxemia after oral ingestion of C. perfringens types B, C, D, and E. The signs and lesions observed resembled those seen in acute enterotoxemia of sheep and cattle and the naturally occurring disease seen in "ex-germ-free" guinea pigs. C. perfringens type A was found to be innocuous. Conventional guinea pigs did not become ill after ingestion of any of the five toxigenic types.

Animals↗
PubMed1969

Blood group isoantibody stimulation in man by feeding blood group-active bacteria.

It was investigated whether or not the human blood group isoantibodies A and B could be induced by immunogenic stimuli via natural routes with a kind of antigenic substance to which all humans are commonly exposed, or if the appearance of these antibodies is independent of antigenic stimuli as has long been believed. Escherichia coli O(86), which possess high human blood group B and faint A activity in vitro, were fed to healthy humans and those with intestinal disorders. 80% of the sick individuals of blood group O and A responded with a significant rise of anti-B antibodies which was frequently de novo in infants; significant increase of anti-A isoantibodies among blood group O individuals was less frequent. Over one-third of the healthy individuals also had a significant isoantibody increase. Intestinal lesions favor isoantibody stimulation by intestinal bacteria; this view was supported by the study of control infants. Persons of blood group A responded more frequently with anti-B and anti-E. coli O(86) antibody production than those of blood group O. Isoantibody increase was accompanied with antibody rise against E. coli O(86). Inhalation of E. coli O(86) or blood group AH(O)-specific hog mucin also evoked isoantibodies. The induced isoantibodies were specifically inhibited by small amounts of human blood group substances. E. coli O(86)-induced anti-blood group antibodies in germ-free chickens and preexisting blood group antibodies in ordinary chickens were neutralized by intravenous injection of E. coli O(86) lipopolysaccharide. This study demonstrates that human isoantibodies A and B are readily elicited via physiological routes, by blood group-active E. coli, provided the genetically determined apparatus of the host is responsive. Antibodies against a person's own blood group were not formed. Interpretation of these results permits some careful generalizations as to the origin of so-called natural antibodies.

ABO Blood-Group System↗