Search PubMed⌕ Search

Biomedical subjects

J S Walker

Publications and source records attributed to J S Walker.

160 records · Page 9Linked to original sources
PubMed1967

Temperature response in animals infected with Bacillus anthracis.

Rats, rabbits, swine, guinea pigs, and monkeys were infected with anthrax spores, and their temperature responses were recorded. These were characteristic for a species and appeared independent of resistance or susceptibility of the species toward establishment of the disease. The rabbit appeared unique in that it not only failed to demonstrate a dose-response relationship over an 8-log dose range, but acted independently producing erratic body temperatures depending on spore dose. This limits the usefulness of the rabbit in studying anthrax pathogenesis, and poses questions regarding published data with the rabbit as the test animal.

Animals↗
PubMed1967

In vivo growth and distribution of anthrax bacilli in resistant, susceptible, and immunized hosts.

Differences in in vivo growth rates of Bacillus anthracis in the bodies of infected rats and guinea pigs showed the effect of innate species resistance. The effect of two levels of immunity imposed on these hosts demonstrated that, as the degree of immunity increased, the growth rate of organisms decreased and was accompanied by a decrease in terminal population. It was shown that growth rates in the blood best reflected the population growth in the entire host. Data obtained from the naturally resistant rat that had been immunized with both the Belton-Strange protective antigen and live vaccine demonstrated the role of "toxins" in terminal anthrax. The in vivo morphological changes in anthrax bacilli pointed out errors regarding estimates of true terminal population of organisms when samples for counting were taken postmortem rather than at the time of death.

Animals↗
PubMed1967

Antibiotic treatment of anthrax infection in mice.

Quantitative measurements of mean time to death, percentage of survivors, and viable cell populations in the whole body were employed to determine the effects of penicillin, dihydrostreptomycin, chlortetracycline, oxytetracycline, chloramphenicol, and antiserum on the course of anthrax infection in mice. By all parameters tested, penicillin and dihydrostreptomycin were most effective in the treatment of the disease. Therapy initiated in the later stages of the disease was more effective than that initiated in the earlier stages. Quantitative studies indicated that it was more difficult to eliminate organisms from the kidney than from any other organ or tissue. These measurements for the evaluation of antibiotic therapy are suggested for the study of other bacterial diseases.

Animals↗
PubMedDate not supplied

Subacute acetaminophen overdose after incremental dosing.

A case of acetaminophen poisoning following the ingestion of 26 g of acetaminophen by incremental dosing over a 25-h period is reported. At presentation, seven h after the last ingestion, the patient experienced hematemesis, the acetaminophen level was 150 micrograms/mL, and the SGOT was normal. The patient recovered uneventfully following N-acetylcysteine therapy. A review of the pharmacology and toxicity of acetaminophen is discussed. The case illustrates the problems of judging hepatotoxic potential in a multiple-dose acetaminophen ingestion and describes the successful use of N-acetylcysteine in a patient with a "subacute" acetaminophen overdose.

Acetaminophen↗
PubMedDate not supplied

EMS response at a hazardous material incident: some basic guidelines.

Emergency medical response to a scene where hazardous materials are potentially involved is becoming more commonplace. Following routine response procedures could result in the incapacitation of the rescue crew. Unique to this paper are some suggestions from the fire fighting literature on how to deal with these incidents. As with any type of potential disaster, it has been found that response is much more effective if potential problems are examined beforehand and protocols developed. Emergency physicians in their role as on-site emergency medical services (EMS) medical controllers should play a leading part in the development and implementation of these protocols.

Accidents, Traffic↗
PubMedDate not supplied

Effects of the peripherally selective kappa-opioid asimadoline, on substance P and CGRP mRNA expression in chronic arthritis of the rat.

We have previously shown that the kappa-opioid agonist, asimadoline, produces time-dependent changes in neuropeptide concentrations in the joints of rats with chronic arthritis. We hypothesized that asimadoline acts on peripheral terminals to modulate substance P (SP) release. To address this hypothesis, here we have examined neuropeptide expression in their source cells in dorsal root ganglia (DRG) that innervate the joint, as well as in non-neuronal tissue, after treatment with asimadoline. We found an increased production of SP and CGRP in untreated chronic arthritic animals which supports our previous finding of increased SP content in the joint. More importantly, the kappa-opioid asimadoline reduced the expression of both SP and calcitonin gene-related peptide-alpha (alpha-CGRP) in DRG cells but had no effect on the very low expression of neuropeptides in non-neuronal tissue. The fact that SP synthesis is attenuated by asimadoline accords with our hypothesis that the increased tissue levels of SP result from kappa-mediated pre-synaptic inhibition of release leading to augmented tissue stores. These in vivo data confirm literature findings that opioids inhibit SP release from peripheral endings of primary afferent fibres.

Acetamides↗
PubMedDate not supplied

The effects of familial voice interventions on comatose head-injured patients.

PURPOSE: Opportunities for family interaction with comatose patients are often strictly limited. Some studies have indicated that family visits to the ICU have detrimental effects on physiologic parameters such as blood pressure and heart rate. This study was undertaken to investigate the effects of taped messages by a family member on key measures of physiological functioning in comatose head-injured patients in intensive care units. METHODS: A convenience sample of 10 comatose patients was used. Paired t-tests were performed to determine changes in physiologic measures with the introduction of family member taped messages. FINDINGS: None of the subjects exhibited any statistically significant variables in physiologic criteria after introduction of the tapes. CONCLUSIONS: Research to date represents conflicting results. This study demonstrated no untoward effects with exposure to taped familial messages, including no changes in intracranial pressure (ICP), blood pressure, pulse, respiratory rate, mean arterial pressure, oxygen saturation level, or level of restlessness. The findings support allowing family interactions with comatose head-injured patients in the ICU.

Adult↗
PubMedDate not supplied

Clinical pharmacokinetics of the non-depolarising muscle relaxants.

Muscle relaxants are of great benefit to the anaesthetist as adjuncts to anaesthesia. These drugs are used to facilitate endotracheal intubation and to reduce muscle tone during surgery, and may also find application in assisting ventilator care in the intensive care situation. The pharmacological effect of the relaxants may be readily assessed by the anaesthetist by means of a variety of techniques to quantify muscular activity in response to electrical stimulation. A number of factors may modify the effects of the muscle relaxants including anaesthetic agents, hypothermia, patient age and disease status and a variety of drugs. The disposition kinetics of the muscle relaxants have been well characterised although information on protein binding and placental transfer is somewhat scanty. A common characteristic of their pharmacokinetics is multicompartmental behaviour. Clearance of the relaxants ranges from total elimination by the kidneys (gallamine) to substantial hepatic clearance (fazadinium), and thus their clearance may be adversely affected by renal or hepatic disease. Dosage regimens have been designed using knowledge of the disposition kinetics of the relaxants to provide for continuous adequate relaxation during prolonged surgical procedures. With the use of sophisticated pharmacokinetic and pharmacodynamic models good relationships have been demonstrated between plasma concentrations of the relaxants throughout the entire range of relaxant response.

Adolescent↗
PubMedDate not supplied

Statistics as a tool in practice management.

As managers, dentists must be concerned with the daily control of their practices. Traditional management reports and graphs are not capable of indicating when specific action or intervention has become necessary. They fail to recognize that all processes--including the administrative functions of a dental office--exhibit variability. Only a control technique that can differentiate unacceptable from tolerable variation will offer any help with day-to-day managing. A simple application of statistics and probabilities is required to provide a workable solution. With results from an actual dental office, this article describes the steps for creating and using a statistical "control chart" to monitor a key practice variable--production revenue per hour.

Humans↗
PubMedDate not supplied

Using an interactive video disk in breast cancer patient support.

A randomised-controlled trial compared outcomes for women recently diagnosed with breast cancer who either received support and information from a multidisciplinary team or used a shared decision-making programme on an interactive video disk (IVD) system. Using the IVD did not have a significant effect on the decisions women made about treatment, yet it was evaluated positively by those who used it. The results suggest that the role of clinical staff is more significant than the form of information provided. Potential benefits for the IVD were apparent such as standardising the information received by patients, promoting evidence-based practice and providing a measure for quality assurance.

Adult↗