Plasma levels of amino acids correlate with motor fluctuations in parkinsonism

Seven patients with Parkinson's disease who experienced severe motor fluctuations in response to levodopa were studied in detail with relation to the effect of dietary protein on their motor function. The levodopa dose for each patient was not changed during the period of study, and no other antiparkinsonian drugs were used. Regular and high-protein diets resulted in a marked elevation in the plasma concentrations of large neutral amino acids (LNAAs) that are known to compete with levodopa for transport across the blood-brain barrier. Despite elevated plasma levodopa levels, all patients with elevated LNAA levels experienced parkinsonian symptoms. When the amino acid level dropped while plasma levodopa levels were elevated, patients experienced relief of these symptoms. On a low-protein diet, LNAA levels remained low and all patients were consistently dyskinetic throughout the day, even though the mean plasma levodopa levels were somewhat lower than when the patients consumed a high-protein diet. A redistribution diet that is virtually protein free until supper and then unrestricted until bedtime is tolerated by patients because this simple manipulation permits near-normal daytime motor function.     

Obstetrician-gynecologists as primary care physicians: The Oregon experience—Early perceptions regarding the effects of legislative action

OBJECTIVE: Our purpose was to assess whether legislative action influenced the role of obstetrician-gynecologists as primary care physicians. STUDY DESIGN: An observational study was performed on the basis of a questionnaire sent to 410 obstetrician-gynecologists and 27 medical directors of managed-care organizations. RESULTS: Of 67% of obstetrician-gynecologists and 96% of medical directors who responded, there was agreement as to the content of primary care, but a minority (38%) of obstetrician-gynecologists identified themselves as primary care providers. A minority of medical directors (35%) felt that obstetrician-gynecologists should serve in that role. Both obstetrician-gynecologists and medical directors felt that legislation had little impact. CONCLUSION: The reticence of obstetrician-gynecologists to assume a major role in primary care appears to be the result of an uneasiness with accepting a more comprehensive role in patient management and gatekeeping. They appear comfortable with the more traditional roles but feel that training and experience has not prepared them well for the management of more complex medical problems. (Am J Obstet Gynecol 1998;178:1222-8.)     

An analysis of paramagnetic centers in irradiated dentin using electron spin resonance

Summary The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to 25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite size to the differences in ESR spectra are discussed.     

Allopurinol influences aminophenazone elimination

The authors observed an interaction between allopurinol and both theophylline and warfarin in 2 patients. To determine the possible effect of allopurinol on hepatic oxidative metabolism a [14C]-aminophenazone (aminopyrine) breath test was performed before and during treatment with allopurinol 100mg daily in 5 patients with hyperuricaemia. Allopurinol prolonged the [14CO2]-aminophenazone half-life from 72 +/- 13 to 104 +/- 16 minutes (mean +/- SEM, p less than 0.05). It is possible that allopurinol may produce clinically significant drug interactions through an inhibitory effect not only on xanthine oxidase metabolism but also on oxidative metabolism.     

A New Technique for CT/MR Fusion For Skull Base Imaging

This paper presents our initial experience utilizing a new technique which allows CT and MR image fusion in patients with skull base lesions. Eleven patients with a variety of skull base lesions underwent CT and MR imaging prior to surgery. Both sets of images were coregistered using customized software. The CT and MR data sets were then combined and viewed in a single interactive image formar using a high-speed graphic computing system. Image fusion allowed simultaneous visualization of the bony skull base anatomy (CT) and detailed soft tissue anatomy (MR) using a single image format. Combining both modalities was felt to provide a better assessment of the extent of lesions and improve understanding of their relationship to adjacent bony and neurovascular anatomy. Specifically, image fusion enhanced awareness of location of skill base lesions with respect to the cavernous sinuses. Gasserian ganglia, carotid arteries, and jugular foramina. For tumors arising within the internal auditory canal (IAC), fused images allowed better delineation of the lateral aspect of the lesion with respect to the fundus of the IAC. Thus, fusion of CT and MR studies provides a unique image format which has advantages over single modality display. We believe image fusion is beneficial for surgical planning and for treatment planning of complex skull base malignancies treated with radiotherapy.     

Patients'attitudes to rectal drug administration

One hundred adult patients attending for day case surgery were surveyed by anonymous questionnaire in order to determine their attitudes to rectal drug administration. Fifty four patients did not want an analgesic drug (diclofenac sodium) administered rectally whilst under anaesthesia, all preferring to take it orally if available. Ninety eight patients thought that drugs administered per rectum should always be discussed with them beforehand and a few had very strong feelings about this route of administration. We suggest that prescribers of rectal diclofenac should always discuss it with patients pre-operatively. Whilst many are happy to have suppositories, some young patients are sensitive about this and prefer to take such medication by mouth.     

Anesthesia for trauma

Trauma is the leading cause of death for persons aged 1 to 38 years. Successful management is facilitated by prehospital endotracheal intubation, transport to regional trauma centers, rapid resuscitation by an on-site team of trained physicians, timely operative intervention, and provision of care by well-prepared anesthesiologists familiar with the potential complications typical of traumatized patients. No particular anesthetic agent or technique is ideal. Causes for intraoperative hypotension include hypovolemia, hemopneumothorax, pericardial tamponade, an intracranial mass, acidosis, and hypothermia. The anesthesiologist should play an active role in all phases of trauma management, including provision of postoperative intensive care and pain relief.