PubMed Health⌕ Search

Biomedical subjects

J Cameron

Publications and source records attributed to J Cameron.

At least 37 records · Page 2Linked to original sources
PubMed1985

Cloning of Bordetella pertussis outer membrane proteins in Escherichia coli.

We have cloned in Escherichia coli a 40 kb chromosomal DNA fragment of Bordetella pertussis which encoded the synthesis of two major outer membrane proteins specific to this microorganism. The clone harbouring the plasmid pFSH200 has shown modulation of the expression of these proteins when grown on complete solid medium. However, this phenomenon has not occurred in clones harbouring smaller derivatives of plasmid pFSH200 and one such derivative, plasmid pFSH201, has been isolated and further characterized. These results suggest that the large plasmid pFSH200 contained a regulatory sequence affecting the expression of the outer membrane proteins of Bordetella pertussis in Escherichia coli. This sequence is very likely responsible for the antigenic modulation observed in phase I strains of Bordetella pertussis.

Antigens, Bacterial↗
PubMed1979

Home birth in Salt Lake County, Utah.

In Salt Lake County, Utah in 1972 and 1975, 167 women had planned home deliveries. Birth certificate data indicated they did not differ from the total population in age, marital, and socioeconomic status. Eighty-four women were interviewed and reported hostility from health professionals which may have placed them at unnecessary risk.

Attitude of Health Personnel↗
PubMed1978

Nurse specialists in family planning: the results of a 3-year study.

In the first three years of a Nurse Specialist Clinic in Family Planning, 1422 new patients were seen. Oral contraception (OCs) was dispensed for 638 patients, 548 intrauterine devices (IUDs) were fitted and 126 patients received an injectable contraceptive. The continuation rate at thirty months was, 73.2 for OCs, and 68.6 for IUDs. The additional training received by the nurse specialists allowed them to practice comprehensive family planning safely and effectively, as shown by the low "problem" rate, 9.1% for OCs and 7.2% for IUDs. Continued use effectiveness, as shown by the second choice of contraception initiated in the clinic for those who stopped using their first method, was also high, 81.5% for OCs and 90.5% for IUD closures.

Contraceptive Agents↗
PubMed1978

The meaning of IQ constancy in young retarded children.

In a clinic population of 289 children (nine years of age and under) suspected of developmental delay, it was found that correlations on repeated administrations of the Bayley and/or Stanford-Binet intelligence tests were much higher than in normal children; that the magnitude of the correlations was inversely related to IQ level; that children initially tested under two years of age displayed more IQ change than those tested over the age of two, with girls more likely than boys to show a drop, and the greatest amount of fluctuation occurring the 51-80 range. The IQ constancy of this population has important developmental implications for the retarded: it suggests that they are growing intellectually at a rate proportional to normal children of their own mental rather than chronological age; that they may well have more years of maturation before reaching a plateau; and that educational programs should take into consideration this lengthened learning period.

Age Factors↗
PubMed1978

Some problems--and their solutions--in the production of DTP (diphtheria, tetanus, pertussis) vaccine.

The desirability of choosing methods and equipment to meet local needs such as yield per cycle and ready availability of components of media and other reagents, and of simple equipment such as good quality glassware, of replacement parts for more complex equipment, and, most of all, of technical assistance is emphasised. Particular emphasis is given to ways of increasing yield from agar and static-liquid culture and to simple methods of separating bacteria from large volumes of culture using bacterial-precipitants. Designs are given for simple growth and mixing vessels, including magnetically-stirred units which require a minimum of servicing. It is strongly recommended that the basic production-unit should be a simple, multipurpose, high-quality stainless-steel vessel of appropriate size: such a unit has a working-life of at least 10 years. Regardless of the type of equipment used, simple or complex, the need, at all times, for well-trained technical staff is also stressed.

Bacterial Vaccines↗
PubMed1977

The role of angiography in the diagnosis of tracheal--innominate artery fistula.

When a tracheal-innominate artery fistula is suspected, angiography is essential if the patient's condition is stable. An aggressive angiographic approach is needed to demonstrate the fistulous tract. Multiple injections in different degrees of obliquity and subtraction views should be obtained for early accurate diagnosis and for optimal demonstration of the pathologic anatomy.

Adolescent↗
PubMed1977

Pertussis vaccine--fact and fiction.

The present paper indicates a number of unresolved problems in the metabolism of Bordetella pertussis and in the standardization of pertussis vaccines. The use of chemically defined media should enable the metabolic problems to be clarified. The problems concerned with the control and standardization of vaccines can largely be resolved in the laboratory with the introduction of reference preparations but the question of the reactivity of vaccine remains for the future.

Adjuvants, Immunologic↗
PubMed1977

Irreversibility of toxoids. An improved method of testing.

Reversion of toxoid to toxin has been described by several authors yet present day regulations of all National Control Authorities have no specific requirements to check for this possibility. Most producers however have included some form of test in their own protocols for release. We have developed a satisfactory test for both diphtheria and tetanus toxoids which involves storing diluted toxoid at 20 degrees C and 34 degrees C for 6 weeks and performing a full toxicity test on the samples. In the case of diphtheria toxoid we have evidence that it may be dangerous to rely on the simpler guinea-pig skin test, since we have shown that several lots, while giving a negative skin reaction, exhibit diphtheria toxicity when given systemically. It is felt that an in vivo conversion to toxin may occur in some lots which would not be detected by the skin test.

Animals↗
PubMed1977

Pertussis vaccine: mouse-weight-gain (toxicity) test.

Toxicity tests based on mouse-weight-gain (whether control of pertussis, DPT, cholera or typhoid vaccine) are not satisfactory, particularly since the vaccines may be adsorbed and non-adsorbed preparations. Comparison between results of tests in animals some of which were treated with vaccine and others with saline does not allow to make conclusions as valid as those supplied by a standard control vaccine (adsorbed and not adsorbed) instead of saline.

Animals↗
PubMed1977

Interdigital cell death during limb development of the turtle and lizard with an interpretation of evolutionary significance.

Cell death accompanies the formation of free digits in birds and mammals. However, in species with webbing between the adult digits, little or no cell death occurs in the prospectively webbed region of the developing interdigit. Cell death does not occur during the formation of free digits in amphibians. In this paper we report that cell death accompanies the formation of the digits in snapping and painted turtles and in the skink (a lizard). We conclude that cell death accompanying the formation of free digits had its origin at the point of amniote emergence during evolution.

Animals↗
PubMed1976

Nurse specialist in family planning.

In an experimental clinic, run by nurse specialists in family planning, a total of 768 patients were seen in the first year. Oral contraception was dispensed for 377 patients and 187 intrauterine devices (IUCDs) were inserted; a further 204 IUCD patients attended only for follow-up visits. All side effects were adequately diagnosed by the nurse specialist.

Community Health Services↗
PubMed1975

The excretion of individual adenocartical steroids during normal childhood and adolescence.

The excretion of 7 individual 17-oxosteroids and 7 individual corticosteroids in 24 h urine samples from 62 normal infants, children and adolescents, based on an accurate and specific paper chromatographic method for their separation and quantitation, is reported. The excretion of the 11-deoxy-17-oxosteroids gradually increases from 7 years of age and the increase becomes more rapid 2 or 3 years before the clinical signs of puberty appear. The rise continues throughout puberty and beyond it until the adult level is reached. The increase far exceeds that which would be accounted for by the growth of the individual. The increase in the excretion of the 11-oxy-17-oxosteroids with age is much more gradual. Androgens favour the formation of 5alpha metabolites and the 5alpha:5beta ratio of the total 5alpha 17-oxosteroids and the total 5beta 17-oxosteroids shows a statistically significant increase with age. In addition, a relatively high 5alpha:5beta ratio is noted in male infants, which is likely to be related to their relatively high plasma testosterone levels. The excretion of the 17-hydroxycorticosteroids and the alpha-ketolic metabolites of cortisol gradually rises with age and correlates with body weight. The alpha-ketolic metabolites of corticosterone are relatively high in infancy, but after the age of 4 years their excretion also correlates with body weight. An increase in the 5alpha:5beta ratio of allo-THF to THF is noted at puberty similar to that found with the 5alpha:5beta ratios of the 17-oxosteroids.

17-Hydroxycorticosteroids↗