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Biomedical subjects

J T Robertson

Publications and source records attributed to J T Robertson.

At least 145 records · Page 8Linked to original sources
PubMed1981

Glomus jugulare tumours--combined treatment: part I.

Total en bloc removal is the ideal surgical treatment for glomus jugulare tumours. Efforts to accomplish this have been made periodically since shortly after this tumour was first identified in the early 1940s. A method of removal using a combined approach through the neck and temporal bone is described here. This method is preceded by pre-operative irradiation therapy and on occasion by embolization. The early results obtained using this method in 19 patients are reported.

Blood Transfusion↗
PubMed1981

Nervous system metastasis from carcinoma of the lung: three unusual cases.

Carcinoma of the lung, fairly common in middle aged men, may be silent and have its first manifestation as a metastatic lesion. In 25% to 35% of such cases the metastases are to the nervous system. Management is dependent upon many factors but satisfactory results can be obtained with proper screening. Three cases of nervous system metastases are presented-one occurred in an unusual site; one had an unusual clinical syndrome and one had prolonged latency.

Adenocarcinoma↗
PubMed1981

Spontaneous cervical carotid artery dissection: outpatient treatment with continuous heparin infusion using a totally implantable infusion device.

The authors report a patient with spontaneous high cervical internal carotid artery dissection and a severe reversible ischemic deficit. Successful treatment consisted of 5 months of continuous intravenous heparin using an implantable infusion device. The details of this therapy are described, and alternative therapeutic modalities are discussed.

Adult↗
PubMed1981

Cardiopulmonary effects of butorphanol tartrate in horses.

The cardiopulmonary and behavioral effects of butorphanol were evaluated in pain-free adult horses. Butorphanol tartrate was administered IV in doses of 0.1, 0.2, and 0.4 mg/kg to the same horses on 3 separate occasions. There were no significant (P less than 0.05) changes in heart rate, mean and diastolic arterial pressure, mean and diastolic pulmonary arterial blood pressure, or cardiac output recorded in the horses given these doses. Systolic arterial blood pressure was significantly (P less than 0.05) increased in only the horses given the 0.2 mg/kg dose. Significant (P greater than 0.05) changes in electrocardiographic intervals, respiratory rate, arterial blood gas values, or pH were not recorded. Increasing IV doses of butorphanol resulted in varied behavioral changes, but were predominantly excitatory.

Animals↗
PubMed1980

Randomized comparisons of radiotherapy and nitrosoureas for the treatment of malignant glioma after surgery.

Within three weeks of definitive surgical intervention, 467 patients with histologically proved malignant glioma were randomized to receive one of four treatment regimens: semustine (MeCCNU), radiotherapy, carmustine (BCNU) plus radiotherapy, or semustine plus radiotherapy. We analyzed the data for the total randomized population and for the 358 patients in whom the initial protocol specifications were met (the valid study group). Observed toxicity included acceptable skin reactions secondary to radiotherapy and reversible leukopenia and thrombocytopenia due to chemotherapy. Radiotherapy used alone or in combination with a nitrosourea significantly improved survival in comparison with semustine alone. The group receiving carmustine plus radiotherapy had the best survival, but the difference in survival between the groups receiving carmustine plus radiotherapy and semustine plus radiotherapy was not statistically significant. The combination of carmustine plus radiotherapy produced a modest benefit in long-term (18-month) survival as compared with radiotherapy alone, although the difference between survival curves was not significiant at the 0.05 level. This study suggests that it is best to use radiotherapy in the post-surgical treatment of malignant glioma and to continue the search for an effective chemotherapeutic regimen to use in addition to radiotherapy.

Aged↗
PubMed1980

Anterior cervical discectomy without fusion: long-term results.

The long-term follow-up of patients operated by one surgeon by simple anterior discectomy without fusion have been presented. The results are much better in patients with soft extruded discs than with painful discs or degenerative discs with varying degrees of radiculopathy or myelopathy. The same statement can be made for the posterior approach. The anterior approach appears to be superior for soft central extruded discs compressing the spinal cord. There appears to be a greater incidence of another disc at an adjacent level with the anterior approach than when the operation is done posteriorly. The anterior operation is an easier surgical procedure than the posterior operation in the average surgeon's hands; otherwise, it would not be as popular as it is. Interbody fusion has no long-term advantages over simple discectomy. Complications of the anterior approach, particularly with fusion, appear greater than the limited posterior approach. Rather than continue the controversy over the anterior vs. the posterior approach, it is recommended that each surgical case be evaluated to determine the preferred approach. With the passage of time, I have preferred to operate the C4, 5, and 6 ruptured discs anteriorly, as well as all central discs or hard central cervical spondylotic bars. This seems preferable to the extensive laminectomy recommended by many for spondylotic myelopathy. However, the anterior approach has been limited to two spaces rather than multiple spaces. On the rare occasions when an extensive decompression of the cervical canal is indicated, the posterior approach has been chosen. In addition, the C7 or rare T1 soft ruptured disc have been done posteriorly. When there is a doubt about the diagnosis, e.g., when a tumor is suspected or a multiple root defect associated with atypical findings on myelography, the posterior approach is preferred.

Chronic Disease↗
PubMed1980

Experimental intracranial aneurysms in rats. A gross and microscopic study.

Experimental cerebral aneurysms were induced in rats in which the left carotid artery was ligated. The rats were rendered hypertensive by the Goldblatt procedure, and fed a diet containing beta-aminopropionitrile. These intracranial aneurysms have significant gross and microscopic similarities to human berry aneurysms. The procedures and microscopic observations indicate that this experimental model could be useful for studying the development, pathophysiology, and therapy of saccular aneurysms.

Aminopropionitrile↗
PubMed1980

Cerebral vasodilation and prostacyclin. The effects of aspirin and meclofenamate in vitro.

The effects of aspirin and meclofenamic acid on the diphasic responses produced by prostacyclin in isolated canine basilar arteries were compared. Meclofenamate enhanced the relaxant action of prostacyclin in low concentrations (10(-8)M to 10(-6)M) and also significantly inhibited the contractions caused by the highest concentration (10(-5)M) of this prostaglandin. Aspirin had no such effects. The results indicate that some drugs classified as prostaglandin synthetase inhibitors can directly enhance the vasodilator action of prostacyclin on cerebral arteries, and suggest that this enhancement could be of value in the clinical applications of prostacyclin.

Animals↗
PubMed1980

Cerebral vasospasm: effects of prostaglandin synthetase inhibitors in vitro.

Because previous studies suggest that prostaglandins (PGs) are involved in the contraction of cerebral arteries, the present study was undertaken to assess the direct effects of arachidonic acid, the precursor of PGs, on isolated dog basilar arteries and to ascertain the actions of three prostaglandin synthesis inhibitors, aspirin, indomethacin, and meclofenamate, on contractions induced by agonists of diverse chemical structure. Arachidonic acid induced sustained contractions and in optimal concentrations produced constriction that was 56% as great as that produced by serotonin. These responses were markedly inhibited (95%) by meclofenamate (10(-5) M), but aspirin (10(-3) M) had no such effect. Moreover, this concentration of meclofenamate reduced resting tension and inhibited by 16% the optimal responses caused by PGF2 alpha, while having no significant effect on serotonin contractions. Higher doses of meclofenamate (10(-4) M, 10(-3) M) produced increasing degrees of inhibition of contractions caused by serotonin or PGF2 alpha. Conversely, aspirin had no effect on PGF2 alpha contractions and slightly enhanced serotonin effects. The actions of indomethacin resembled those of meclofenamate. The results show clearly that different prostaglandin synthesis inhibitors have different effects on cerebral vasomotion in vitro. Aspirin, known to inhibit platelet function markedly, seems to have little effect on isolated vascular smooth muscle. On the other hand, the pharmacodynamic effects of meclofenamate and some related drugs may afford a new approach in the treatment of cerebral vasospasm.

Animals↗