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Biomedical subjects

R Alexander

Publications and source records attributed to R Alexander.

At least 127 records · Page 7Linked to original sources
PubMed1987

Evaluation of the Cellmatics and direct monoclonal fluorescence antibody staining for detection of genital chlamydial infections.

Three methods for Chlamydia trachomatis detection were compared: the Cellmatics (Difco Laboratories, Detroit, MI), a commercially available tissue culture system which contains a rat cell line; a direct fluorescent Chlamydia antibody (DFA) (Microtrak, Syva Corp., Palo Alto, California) stain; and a standard tissue culture isolation method employing McCoy cells. Of the 121 specimens in the study, 20 were positive by the standard cell culture. All 20 of these specimens were also positive by the Cellmatics but only 10 were positive by DFA.

Cell Line↗
PubMed1985

Polycyclic aromatic hydrocarbons in rock oysters: a baseline study.

Coral-rock oysters were collected in September 1982 from six locations in the area of Mermaid Sound in North-Western Australia. Analysis was carried out by digestion of the samples, followed by solvent extraction and analysis of the extracts using HPLC-UVF and GC-MS. The levels of two- and three-ring aromatics ranged from very low for the site outside Mermaid Sound and for one site within the Sound, to low for the four other sites within the Sound. The PAH values at the latter four sites are attributed to occasional petroleum release episodes related to small boat activities and large-scale salt and iron ore shipping and general cargo activities of the Port of Dampier. The levels of PAHs with four or more rings were found to be low or very low at all sites; in fact, in most cases values measured for specific PAHs were below the limits of detection of even the very sensitive methods used in this study. Samples from sites within Mermaid Sound closest to the town and port of Dampier showed noticeably higher levels than those from outside; the present study does not allow the source of the PAHs to be determined. It is interesting to note, however, that the parent PAHs appear to form a greater proportion of the total PAH assemblage in these cases, indicating contributions from material which has been subjected to high temperature processing prior to release into the Sound.

Animals↗
PubMed1984

Trauma to the bones of small infants from passive exercise: a factor in the etiology of child abuse.

Four infants, three premature and one term, developed serious bony injury from parent- or caretaker-administered passive exercises. In the three infants born prematurely, the exercise program was prescribed by neonatal intensive care unit staff before discharge; in the fourth infant, the babysitter initiated the program. In each case the passive exercise was begun to diminish actual or presumed muscle tightness. When these infants were presented to the physician with a serious traumatic injury between the ages of 4 and 10 months, the presumptive diagnosis of child abuse was made after radiologic assessment revealed multiple bone injuries. The several traumatic injuries to bones resulting from the home-administered physical therapy were most impressive. Passive exercise in three of the four infants was a significant factor in the cause of their injuries. Caution must be used in prescribing this form of "therapy" in small infants.

Bone and Bones↗
PubMed1984

Pesticide use, alternatives and workers' health in Cuba.

Cuba provides a unique example of a country that is actively implementing a program to reduce its dependence on pesticides. This paper addresses Cuba's current efforts to develop and implement alternatives to pesticides and legislation to limit exposure and protect workers in the interim. In 1980 Cuba embarked on a national program to utilize alternatives to chemical pest control. This three-part program includes expansion of knowledge of Cuban agro-ecology in order to implement cultural control practices; research and implementation on biological control of pests; and research on plant resistance and development of resistant crop varieties. To date, the program has enabled Cuba to reduce pesticide usage in sugar cane, citrus, tobacco, corn, and vegetable crops, among others. While alternatives to chemical pest control are being developed, the Cubans are paying special attention to regulating pesticide use and the safety of workers and members of the public exposed to toxic chemicals. In addition to the Resolution on Health and Safety (1967) and the Safety and Health Law (1978) which cover all workers, including Cuba's 250,000 agricultural workers, the Ministry of Public Health promulgated Resolution 335 in 1967. This resolution addresses requirements and administration of structural pest control, production, importation, transport and storage of pesticides, as well as requirements for worker contact with pesticides, pesticides for domestic use, aerial application of pesticides, and violations of the regulations. The paper concludes with a description of how the system works on the provincial level, as exemplified by Villa Clara, and the steps that have been taken to eliminate worker exposure to pesticides, to utilize pesticides which pose less of a hazard to workers, and to assure early detection of ill effects.

Agricultural Workers' Diseases↗
PubMed1982

[Changes in the number of T and B lymphocytes in the blood of pigs after experimental ascaridiosis].

The changes in the number of the T and B dependent cells in the peripheral blood were studied after experimental invasion of piglets (live weight 8-10 kg) with the eggs of Ascaris suum (50 000 eggs per piglet). The detection of both cell populations by two rosette methods (E and EAC) showed that their first rise set in on the third day from invasion. The maximum occurrence of the T and B cells was recorded 17 days from invasion; on the 20th day from invasion their number returned to the initial level. At the same time, the test animals were studied as to the white component of their blood picture. The results of the haematological study were found to show a direct relationship with the results of the rosette methods. It follows from the study that in the specific host the susceptibility of the T and B lymphoid cells to the antigenic signal starts already in the early stage of invasion.

Animals↗
PubMed1981

[Pathogenesis of experimental rabies infection in foxes and cats infected with viruses isolated from hamsters (Cricetus cricetus)].

All the infected foxes (9) contracted the disease and died from rabies the 20th-21st day from infection with the virus isolated from hamster. Out of the total number of 9 cats experimentally infected by intramuscular infection, seven showed symptoms of clinical disease on the 18th-34th day from infection. The infected dogs, wolves and rabbits did not show clinical disease. In the post mortem examination of eight foxes the rabies virus or rabies antigen was detected in all parts of the CNS and in n. ischiadicus. Of the extraneural organs, the virus was present, in all animals, in the pharyngeal salivary glands, and in one fox also in the tongue. The bioassay on the eye was positive in all cases. The rabies antigen was detected in 4 foxes in the thigh muscle, in liver and spleen, and in all 8 foxes in lungs and cornea, in 5 cases in kidney, and in 3 cases in heart and tongue. Seven cats were examined post mortem by the inoculation test on mice and the PMIF-staining test; it was found that the rabies virus, or rabies antigen, was distributed in the same manner as in foxes.

Animals↗
PubMed1981

[Distribution of rabies antigen in the central nervous system of rats and mice experimentally infected with rabies strains isolated from hamsters (Cricetus cricetus)].

The comparative experiments were carried out to study the distribution of the rabies antigen in the central nervous system (CNS) of sewer-rats and mice experimentally infected with three "hamster" strains (for comparison also with "fox" strain 1151); it was found out that with microscopical observation of preparations stained by the method of direct immunofluorescence the "hamster" strains produced a blended picture of fluorescing particles characteristic of strains with a reduced virulence and virulent strains. As for mice infected with strains 3 O and 7 E the rabies antigen was detected in all parts of CNS as early as 24 hours after infection. In this period the rabies antigen strain 9 E was not detected in lumbar spinal cord and that with strain 1151 was detected only in the Ammonian horns. After 48 hours the rabies antigen in mice was detected in all parts of CNS with all four strains used. In sewer-rats, with regard to their lower susceptibility to the rabies virus, the first detection of rabies antigen in CNS was recorded on the 6th day after infection with strains 3 O, 7 E and 1151, whereas with strain 9 E as late as the 9th day in lumbar spinal cord and not in all animals.

Animals↗
PubMed1980

Pericardiodiaphragmatic hernia.

Twenty-seven reported cases of pericardial diaphragmatic hernia are reviewed and another case is added. This entity may be congenital or traumatic in origin, the latter being more frequent at a ratio of 2:1. All patients except one were male and the mean age at diagnosis was 40 years. The patients were usually symptomatic, the most frequent complaints being of cardiac or respiratory origin. Pneumoperitoneum may be diagnostic although chest roentgenograms and contrast studies may suggest the diagnosis. Computed axial tomography and echocardiography may prove useful in the future. We believe the anterior abdominal approach is preferable to the transthoracic approach in reducing the hernia and repairing the defect because it affords better exposure and easier accessibility to other intraabdominal disease and can easily be converted into a median sternotomy if needed. The stomach and transverse colon became herniated most frequently and in only three cases was a sac found. The defect involves the central leaflet of the diaphragm and primary repair generally results in a good prognosis.

Adolescent↗