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J Knight

Publications and source records attributed to J Knight.

At least 19 recordsLinked to original sources
PubMed1992

Pholasin: a new chemiluminescent probe for the detection of chloramines derived from human phagocytes.

We have previously reported that normal human polymorphonuclear neutrophils (PMN) release taurine-chloramine, a long-lived oxidant, in response to stimulation by phorbol myristate acetate (PMA) or opsonized zymosan in the presence of exogenous taurine. We now describe a new, simple, and highly sensitive method for the detection of chloramines, including taurine-chloramine, using the chemiluminescent probe Pholasin, the luciferin of the mollusc Pholas dactylus. Taurine-chloramine (N-chlorotaurine) detection was assessed with both a colorimetric method (based on the oxidation of potassium iodide) and with the Pholasin-dependent chemiluminescence (CL) method. The taurine-chloramine concentration in PMN supernatants determined using the potassium iodide (KI) method correlated closely with Pholasin-dependent CL. This CL was also assessed in nonoxidative conditions. No taurine-chloramine was detected in supernatants of lymphocytes and PMN from patients with an oxidative burst defect (chronic granulomatous disease, CGD) with the KI method, but Pholasin-dependent CL was consistently observed. The use of methionine, a specific chloramine scavenger in our incubation conditions, allowed us to define a methionine-inhibitable fraction of Pholasin-dependent CL (i.e., chloramine-induced CL).

Child↗
PubMed1992

Can autoimmune mechanisms account for the genetic predisposition to schizophrenia?

Applications of molecular genetic techniques to schizophrenia have shown great initial promise but have then proved disappointing. In order to maximise chances of elucidating the genetic mechanism underlying schizophrenia, diverse strategies and diverse perspectives must be adopted. Most studies begin with the premise that, although schizophrenia may be a heterogeneous collection of diseases, some subtypes will be primarily single-gene disorders. We are concerned that this single-gene hypothesis may be incorrect. Schizophrenia research may benefit from application of knowledge from other disciplines and from other diseases which, in terms of epidemiology and apparent genetic mechanisms, bear some resemblance to schizophrenia.

Autoantibodies↗
PubMed1991

Ketoconazole-induced fulminant hepatitis necessitating liver transplantation.

The most serious side effect of ketoconazole is hepatitis, which has proved fatal in seven reported cases. We present a case of fulminant hepatic failure in a 45-year-old Oriental woman that probably would have been fatal except for a successful liver transplant. A review of the literature of fatalities associated with ketoconazole is presented.

Candidiasis↗
PubMed1990

Screening for prolonged incubation of HTLV-I infection in British and Jamaican relatives of British patients with tropical spastic paraparesis.

OBJECTIVE: To compare the prevalence of antibody to and proviral DNA of the retrovirus HTLV-I in relatives of 11 British patients with tropical spastic paraparesis who had migrated from Jamaica before they developed symptoms, and to examine factors possibly related to transmission of HTLV-I. DESIGN: Migrant, family study. Antibody state was determined by several methods and confirmed by western blotting; the polymerase chain reaction was used to detect proviral DNA. SETTING: Britain and Jamaica. SUBJECTS: All available first degree relatives: those born and still resident in Jamaica (group 1); those born in Jamaica who migrated to Britain (group 2); and index patients' children who were born and resident in Britain (group 3). All had been breast fed and none had had blood transfusions. RESULTS: Of the 66 living relatives, 60 were traced. Seroprevalence among those born in Jamaica (irrespective of current residence) was 22% (10/46; 95% confidence limits 9 to 34%) compared with zero among British born offspring (0/14) and was higher in group 2 at 33% (7/21; 12 to 55%) than in group 1 at 12% (3/25; 0 to 25%). (Patients in group 1 had the greatest mean age.) Proviral DNA was not detected in any subject negative for HTLV-I antibody, making prolonged viral incubation in those negative for the antibody unlikely. CONCLUSION: In this sample factors related to place of birth and early residence were more important in transmission of HTLV-I than maternal or age effects. In areas with a low to moderate prevalence policies of preventing mothers who are carriers of the virus from breast feeding would be premature.

Base Sequence↗
PubMed1978

Peer review.

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Australia↗
PubMed1978

Medical manpower.

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Australia↗
PubMed1978

Radioimmunoassay and radioenzymatic assay of a new aminoglycoside antibiotic, netilmicin.

A radioimmunoassay and a radioenzymatic assay for netilmicin, a new aminoglycoside, were developed in our laboratories to assist in the study of the pharmacology of the drug and to establish values for use in its monitoring. The assays are sensitive, precise, and rapid, giving results that correlate (r = 0.90) with each other and with those of a microbiological assay in which Klebsiella pneumoniae is used as the test organism. Preliminary pharmacological studies show the drug to have a biological half-life of 135 min. which is comparable to that for other aminoglycosides.

Biological Assay↗
PubMed1976

Effects of leached mirex on experimental communities of estuarine animals.

Experimental communities of various estuarine animals in outdoor tanks were exposed to a continuous flow of water containing mirex for 10 weeks. The mirex was leached from fire ant bait (0.3% active ingredient) by fresh water which was then mixed with salt water to yield exposure concentrations averaging 0.038 mug/L. The experiment simulated runoff from treated land into estuarine areas. Mortality of grass shrimp (Palaemonetes vulgaris), pin, shrimp (Penaeus duorarum), common mud crabs (Panopeus herbstii), and striped hermit crabs (Clibanarius vittatus) was significantly high in tanks containing the toxicant. Mortality of ribbed mussels (Modiolus demissus) and American oysters (Crassostrea virginica) was significantly lower in treated tanks, probably because numbers of both species of crabs, which ate the bivalves, were reduced. Sheepshead minnows (Cyprinodon variegatus) were least affected by mirex. Almost all deaths occurred after 10 or more days of exposure. All exposed animals accumulated mirex, with maximum concentrations ranging from 5,500X (pink shrimp) to 73,700X (soft tissues of oysters) above the concentration in the water. Sand substratum contained mirex up to 1,500X that in the water. The study demonstrated that mirex can be leached from bait by fresh water and concentrated by and affect survival of members in an experimental estuarine community.

Animals↗
PubMedDate not supplied

A child-to-child programme in rural Jamaica.

A child-to-child programme was carried out in six rural schools in Jamaica. School children in grades 4 and 5 were taught concepts of nutrition, environmental and personal hygiene, and child development. The children were encouraged to take messages home to their parents and improve the care of their younger siblings. Four hundred and twenty-three children and 90 mothers and guardians from four of the project schools were evaluated and compared with 199 children and 47 parents from two control schools. The project children showed higher scores on a test of knowledge in the topics at the end of the year. They also improved in some practices at home. The mothers improved in knowledge in some areas but not in their practices. We consider the results sufficiently encouraging to justify incorporating the programme into the country's education curriculum for primary schools.

Adult↗