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Biomedical subjects

B R Jones

Publications and source records attributed to B R Jones.

At least 37 records · Page 2Linked to original sources

Acute follicular conjunctivitis and keratoconjunctivitis due to herpes simplex virus in London.

During the 18 months January 1975 to June 1976, 25 cases of acute herpetic follicular conjunctivitis and keratoconjunctivitis resembling adenovirus ocular infection presented in the External Eye Disease Clinic, Moorfields Eye Hospital, City Road, London. Herpes simplex virus was isolated in HEp2 cells in 22 patients, and the remaining 3 patients were identified by a minimum 4-fold rise in the level of antiherpes simplex virus antibody in their blood. No adenovirus was isolated from these patients, but complement fixation test for adenovirus was positive in 1 patient with cultural test positive for herpes simplex virus. Most patients were between 20 and 35 years old and the ratio of males to females was 12 to 13. At the initial visit the clinical features of disease were moderate to severe conjunctival papillary and follicular reasons with epithelial and subepithelial punctate keratitis but little systemic disease. In the absence of typical herpetic lesions of face, lids, or cornea the disease resembled adenovirus types 8 or 19 keratoconjunctivitis. Of these 25 patients 5 subsequently developed typical herpetic lesions of lids or cornea. In the remaining 20 cases the correct diagnosis could be made only by cultural or serological tests. Virological diagnosis provides a rational basis for antiherpetic chemotherapy, which appears to shorten the course of infection.

Adolescent

The Arden grating test of visual function: a preliminary study of its practicability and application in a rural community in north-west Iran.

In a preliminary study involving 75 normal and 10 abnormal eyes the Arden grating acuity test was assessed under difficult conditions of rural field work. It was found to be adequately sensitive and specific for screening out individuals with visual impairment due to refractive errors or ocular disease, and to distinguish between these. Inexperienced paramedical personnel could carry out the test satisfactorily with no difficulty and with a minimum of training. In spite of the unusually distracting conditions under which the test was carried out 95% of the subjects tested performed satisfactorily. The results of this preliminary study suggest that the Arden grating test is a valuable tool for screening large populations in rural areas of developing countries.

Adolescent

Effects of various concentrations of diethylcarbamazine citrate applied as eye drops in ocular onchocerciasis, and the possibilities of improved therapy from continuous non-pulsed delivery.

Diethylcarbamazine was given as eye drops in varying concentrations in a half-log dilution series from 1.0 to 0.0001% to patients with ocular onchocerciasis. Migration of microfilariae into the cornea, followed by their straightening and disintegration, was observed with delivery rates as low as 0.1 microgram/hour. Dose-related adverse inflammatory reactions, including the development of globular limbal infiltrates with itching and redness, were seen with delivery rates as low as 0.6 microgram/hour, but substantial inflammatory reactions, including severe vasculitis, were seen only with delivery rates of or above 1.0 microgram/hour. This suggests that it should be possible to achieve beneficial clearing of the microfilarial load, without adverse reactions, by continuous non-pulsed delivery of the drug. Technology exists for such delivery, either directly into the eye or systemically by a transdermal system that could give 3 to 7 days' treatment from each application. The observations reported suggest that after preliminary clearing of the microfilarial load by carefully controlled delivery of DEC it may be possible to maintain therapy by less strictly controlled delivery in DEC-medicated salt, or to use treatment with suramin, without incurring substantial adverse reactions, such as a deterioration in vision in cases in which the optic nerve is already compromised. Continuous non-pulsed DEC delivery systems could have a place in the management of onchocercal sclerosing keratitis. The unique opportunities for using the ocular model to define the requirements for beneficial non-damaging therapy with DEC should be explored in further field trials.

Adult

Evaluation of microfilaricidal effects in the cornea from topically applied drugs in ocular onchocerciasis: Trials with levamisole and mebendazole.

Increasing concentrations of levamisole and of mebendazole were applied to 1 eye in groups of 4 patients with ocular onchocerciasis in northern Cameroon. No effect resulted from up to 3.0% mebendazole suspensions, but 3.0% levamisole solutions rapidly caused entry of microfilariae, straightening out and subsequent opacification of previously curled-up living microfilariae, the rapid formation of typical limbal globular infiltrates, and the subsequent formation of fluffy opacities around the microfilariae. These changes are typical of all other drugs so far studied that have a microfilaricidal action on O. volvulus--diethlycarbamizine citrate (DEC), suramin, and metrifonate. The efficacy of 3.0% levamisole approximated to that of 0.03% DEC. This is in keeping with published observations on the filaricidal activity of these 2 compounds. It is suggested that this system of drug testing should be considered for systematic use in the search for more effective and safer drugs for onchocerciasis.

Cornea

Rapid serological test for diagnosis of chlamydial ocular infections.

A rapid serodiagnostic test for the diagnosis of paratrachoma (TRIC ophthalmia neonatorum, inclusion conjunctivitis, TRIC punctate keratoconjunctivitis, and trachoma of sexually transmitted origin) has been developed. The technique is based on using a modified micro-immunofluorescence test for detecting antichlamydial IgG and IgM in the blood and IgG and IgA in tears. The blood samples are collected on cellulose sponges after a finger prick, and tears are collected by introducing small sponges into the lower conjunctival fornix of the eye. The blood and tear samples collected in this way could be sent to the diagnostic laboratory by post without special arrangements for cold storage. In general the presence of antichlamydial IgG at a level of greater than or equal to 1/32 or IgM at a level of greater than or equal to 1/8 in blood and antichlamydial IgG or IgA at a level of greater than or equal to 1/8 in tears was closely associated with ocular paratrachoma. The combined results of the micro-IF test of blood and tears has yielded the highest rate of positivity (90%). In patients with acute untreated paratrachoma the sensitivity of this test was similar to that of irradiated McCoy cells. In patients with a milder infection receiving antibiotics the sensitivity of the serodiagnostic test was superior to that of the cultural test. The high sensitivity and specificity of this rapid, simple and inexpensive serodiagnostic test for the diagnosis of chlamydial ocular infections, coupled with simple and practical methods of collection and transport of blood and tear specimens, offer advantages over cultural tests for routine diagnosis and study of chlamydial ocular infections.

Antibodies, Bacterial

Antichlamydial antibody in tears and sera, and serotypes of Chlamydia trachomatis isolated from schoolchildren in Southern Tunisia.

A predominance of TRIC serotype A has been isolated from schoolchildren in a population in Southern Tunisia with severe hyperendemic trachoma. The serotyping results correspond precisely with the serological findings in patients' tears and sera. Geometric mean titres of serum or tear antibody in defined populations or areas can thus give a useful indication of the prevalent serotypes. Collection of tear fluids on sponges is a more practical method than collection by filter paper strips and gives higher levels of antibody. The presence of antibody to Chlamydia trachomatis in tears correlates well with the presence of infectious agent in the eye and with the intensity of conjunctival inflammatory disease. The measurement of antichlamydial tear antibody can thus provide a meaningful index of the prevalence and intensity of active trachoma in a population. The role these antibodies may play in resistance to re-infection is not yet clear.

Antibodies, Bacterial

Dynamic pulmonary compliance as a measurement of lung function in dogs.

Measurement of the dynamic pulmonary compliance was carried out on 27 normal dogs weighing 11-8 to 26-4 kg Variations in the results of repeated observations and difficulties in allowing for differences in lung size between dogs limited the usefulness of the measurement as a test of lung function. Pulmonary compliance was found to correlate better with trunk length than with bodyweight or chest circumference. The mean value for dynamic pulmonary compliance measured during inspiration in 27 normal dogs was 0-117 litre/cmH20 with a standard deviation of 0-046 litre/cmH2O. Measurements were made on six dogs with clinical respiratory disease.

Anesthesia, Intravenous

Conjunctival impression cytology.

A new technique is presented using impression of the conjunctiva with a plastic device to study the conjunctival response in various conjunctival disease states. When used with a rapid acting stain the impression technique proved to be accurate, reproducible, and nondestructive when compared to the standard spatula scraping of the conjunctiva using Giemsa stain.

Conjunctiva

Antiviral activity in the rabbit cornea of adenine arabinoside, Ara-A 5' monophosphate, and hypoxanthine arabinoside; and interactions with adenosine deaminase inhibitor.

The multiple microtrephination technique was used in the rabbit cornea to compare the activity against herpes simplex virus (hsv) of adenine arabinoside (ara-A), ara-A 5'monophosphate (ara-AMP) and hypoxanthine arabinoside (ara-Hx), and to determine the effect of addition of adenosine deaminase inhibitor (ADAI) to each. The greatest antiviral activity was shown by ara-AMP, and the least by ara-Hx. ADAI increased the activity of ara-A but had no effect on ara-AMP or ara-Hx.

Adenosine Deaminase Inhibitors

Epidemic keratoconjunctivitis and chronic papillary conjunctivitis in London due to adenovirus type 19.

Since July 1973 cases of keratoconjunctivitis resembling epidemic keratoconjunctivitis were observed in the External Eye Disease Clinic at Moorfields Eye Hospital; City Road, London. Adenovirus type 19 was isolated in human embryonic kidney cells from 21 patients. The majority were males between 20 and 40 years old. A small hospital outbreak involving six patients occurred. Clinical features of the disease, consisting of moderate to severe follicular conjunctivitis, major subepithelial punctate keratitis, sometimes with pseudomembrane and scarring, were closely similar to those of epidemic keratoconjunctivitis caused by adenovirus type 8. This similarity, as well as the ability of the agent to cause hospital outbreaks, indicates that adenovirus type 19 is a cause of epidemic keratoconjunctivitis. A case of bilateral chronic papillary conjunctivitis that persisted for 16 months following an acute onset was described. Adeno 19 was isolated from the eye of the patient after 12 months of recrudescent or recurrent illness. Chronic adenovirus infection lacking the usual clinical picture of an acute follicular reaction has not hitherto been described. Such cases are probably important because of the obvious danger of continuing the carriage and shedding of infective adeno 19 from one outbreak to another, by presenting subsequently in eye clinics, and providing an unrecognised source of infection to initiate further outbreaks of hospital transmission.

Adenoviridae