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Biomedical subjects

R P Baker

Publications and source records attributed to R P Baker.

32 records · Page 2Linked to original sources
PubMed1985

Regional cerebral blood flow and metabolism in reversible ischemia due to vasospasm. Determination by positron emission tomography.

Regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) were measured by positron emission tomography (PET) in four patients with subarachnoid hemorrhage and hemiparesis due to cerebral vasospasm. With resolution of the vasospasm, two patients recovered and two remained hemiparetic. Contralateral to the hemiparesis, rCBF was slightly higher in the two patients who eventually recovered (15.0 and 16.2 ml/100 gm/min) than in the two who remained hemiparetic (12.0 and 11.7 ml/100 gm/min). The rCMRO2 measurements showed similar differences, with values of 1.34 and 2.60 ml/100 gm/min in the patients who recovered, and 0.72 and 1.66 ml/100 gm/min in those who did not. These preliminary findings indicate that with PET studies it may be possible to prospectively differentiate patients with neurological deficits due to reversible ischemia from patients with irreversible infarction.

Adult↗
PubMed1984

Cerebral blood volume, blood flow, and oxygen metabolism in cerebral ischaemia and subarachnoid haemorrhage: an in-vivo study using positron emission tomography.

A characteristic sequence of metabolic and haemodynamic changes has been shown to occur in the brain as cerebral perfusion pressure is reduced in experimental animals. Increased cerebral blood volume (CBV) occurs initially, followed by a fall in blood flow (CBF) and, finally, a fall in oxygen metabolism (CMRO2). By measuring CBV, CBF, and CMRO2 with positron emission tomography in patients with vasospasm associated with subarachnoid haemorrhage and in patients with arteriosclerotic occlusion or stenosis of extraparenchymal cerebral arteries, we have demonstrated the presence of similar changes distal to such lesions in man. These findings suggest the presence of a local decrease in perfusion pressure. This study demonstrates the utility of positron emission tomography in the assessment of cerebral circulation and metabolism in man. Measurements of regional CBV must be included for a complete assessment of the dynamics of the cerebral circulation.

Blood Volume↗
PubMed1984

Drug information services: how health care professionals use the information provided.

This study has shown that the Drug Information Service is providing useful information to health professionals and that the information is being applied to patient-specific problems. More research, however, is needed to more concretely document patient outcomes in terms of the length of hospitalization, the number of laboratory tests ordered and the total number and expense of the drugs received.

Consumer Behavior↗
PubMed1984

Shunt fluid examination: risks and benefits in the evaluation of shunt malfunction and infection.

A combined retrospective and prospective study was designed to assess the efficacy of shunt fluid examination in the evaluation of shunt malfunction and/or infection, and to ascertain the complication rate associated with this procedure. Ninety-one patients with shunts for the treatment of hydrocephalus underwent a total of 209 diagnostic shunt "taps." Of 72 instances of mechanical obstruction documented at surgery, 70 were correctly identified by abnormal shunt fluid dynamics, either an opening cerebrospinal fluid (CSF) pressure in excess of the expected valve pressure or absent flow of fluid. The organisms responsible for 12 of 13 shunt-related infections were correctly isolated on initial and all subsequent shunt fluid cultures obtained prior to the institution of appropriate antibiotics. With one infection, a bacterial pathogen was not identified until the third tap. In all instances in which lumbar or ventricular CSF, blood, or wound cultures disclosed an organism, shunt fluid cultures also identified the agent. In addition, these procedures were less reliable. No complications occurred during or immediately following any of the shunt taps. Long-term consequences were assessed in 53 patients with an average follow-up period of 26 months. Some shunt systems subsequently required revision and two infections were documented. The uniformly long interval between the shunt fluid examination and these complications makes it unlikely that the taps contributed to the development of malfunction or infection. Shunt fluid examination appears to be a simple, benign, and yet accurate means of diagnosing shunt malfunction and/or shunt-related infection.

Cerebrospinal Fluid↗
PubMed1983

Complete fracture-dislocation of cervical spine without permanent neurological sequelae. Case report.

A case of complete fracture-dislocation of the lower cervical spine in which there were no permanent neurological sequelae is presented. The absence of permanent neurological deficits with this type of injury is rare. The primary mechanism of injury in this patient was believed to be hyperextension with rupture of the ligamentous structures, allowing complete dislocation of the C-6 body while the posterior elements remained in good alignment due to multiple fractures which "decompressed" the spinal cord.

Fractures, Bone↗
PubMed1975

Serum hepatitis.

Explore the source record for details and available documents.

Hepatitis B↗
PubMedDate not supplied

Vasopressin's effects on acquisition and extinction of conditioned avoidance response to smoking.

Lysine-8-vasopressin (LVP) 5 I.U. or NaCl was administered intranasally daily for 5 days in a double blind study to 14 women and 7 men volunteers, 30 minutes prior to aversive conditioning sessions designed to assist them to stop smoking. Subjects were asked to record the number of urges to smoke, the strength of their strongest urge to smoke and the number of cigarettes smoked on a daily basis. Adequate data was obtained from 17 subjects for the Lead-in (pretreatment) week and for the Treatment week. Of these, 10 continued to supply sufficient responses through the sixth week of follow-up. During the week of aversive conditioning those subjects receiving LVP smoked significantly fewer cigarettes than the saline treatment group (p less than 0.01). During the Follow-up period the LVP group had significantly more urges to smoke than the saline group (p less than 0.01). The LVP group also smoked significantly more cigarettes than the saline group 4 weeks (p less than 0.05) and 6 weeks (0.01) after the Treatment week. LVP was associated with a facilitation of the acquisition of the avoidance response to smoking followed by an apparent acceleration of the extinction of the avoidance response compared to saline.

Adolescent↗