Biomedical subjects

M Cross

Publications and source records attributed to M Cross.

At least 109 records · Page 6Linked to original sources

PubMed1996

IT update. A sum of the whole.

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Computer Security↗

PubMed1996

Computed tomography of the brain in acute carbon monoxide poisoning.

Of 107 patients admitted to the South Western Hyperbaric Medical Centre with acute carbon monoxide poisoning for hyperbaric oxygen therapy 19 had cerebral imaging performed: 17 patients had CT, one patient had MRI and CT and one patient MRI alone. The role of brain CT is established in determining the prognosis from acute carbon monoxide poisoning. Brain imaging was indicated because of unconsciousness on admission and failure or delayed improvement in neurological status after initiation of hyperbaric oxygen therapy. Of the 18 patients who underwent brain CT, seven were found to have the characteristic changes of bilateral low attenuation areas within the globus pallidus and six had low attenuation changes within cerebral white matter. In two patients there were both globus pallidus and cerebral white matter changes. Out of the total of the 19 patients who were studied, four patients died, 10 recovered fully and five had variable disabilities ranging from short term memory loss to more severe cognitive impairment and physical disability. The role of CT and the practicalities of hyperbaric oxygen therapy for acute carbon monoxide poisoning are discussed in the light of the experience from a regional dedicated medical diving centre.

Acute Disease↗

PubMed1996

Advance directives in the emergency department: too few, too late.

OBJECTIVE: To determine: 1) the number of patients arriving at the ED who had executed an advance directive (AD), 2) how many of the patients who had an AD brought the AD with them, and 3) whether those patients who did not have an AD had ever discussed ADs with their primary care providers (PCPs) or had ever heard of an AD. METHODS: A cross-sectional, observational survey of a convenience sample of high-risk patients presenting to the ED of a university hospital was performed. Patients presenting to the ED for acute complaints who were elderly or had an underlying disease that suggested a risk of death in the near future were considered high risk. RESULTS: Of the 238 patients surveyed, 90% had PCPs. However, only 22% had ADs. Of these, only 23% brought the AD to the ED. Of the patients who did not have ADs, 95% had never discussed ADs with their PCPs, and 42% did not know what an AD was. Blacks were less likely than whites to have ADs (p < 0.0002) or to know about them (p < 0.004). CONCLUSION: The majority of high-risk patients presenting to this ED do not have ADs. Among those high-risk patients who did have ADs, fewer than 25% brought the ADs with them. The development of ADs for high-risk patients and the availability of ADs in the ED are woefully inadequate. Emergency physicians need to collaborate with PCPs to remedy these deficiencies.

Adolescent↗

PubMed1996

Does an incremental filling technique reduce polymerization shrinkage stresses?

It is widely accepted that volumetric contraction and solidification during the polymerization process of restorative composites in combination with bonding to the hard tissue result in stress transfer and inward deformation of the cavity walls of the restored tooth. Deformation of the walls decreases the size of the cavity during the filling process. This fact has a profound influence on the assumption--raised and discussed in this paper--that an incremental filling technique reduces the stress effect of composite shrinkage on the tooth. Developing stress fields for different incremental filling techniques are simulated in a numerical analysis. The analysis shows that, in a restoration with a well-established bond to the tooth--as is generally desired--incremental filling techniques increase the deformation of the restored tooth. The increase is caused by the incremental deformation of the preparation, which effectively decreases the total amount of composite needed to fill the cavity. This leads to a higher-stressed tooth-composite structure. The study also shows that the assessment of intercuspal distance measurements as well as simplifications based on generalization of the shrinkage stress state cannot be sufficient to characterize the effect of polymerization shrinkage in a tooth-restoration complex. Incremental filling methods may need to be retained for reasons such as densification, adaptation, thoroughness of cure, and bond formation. However, it is very difficult to prove that incrementalization needs to be retained because of the abatement of shrinkage effects.

Bicuspid↗

PubMed1996