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Biomedical subjects

K Winston

Publications and source records attributed to K Winston.

18 recordsLinked to original sources
PubMed2003

The cannabinoid CB1 antagonists SR 141716A and AM 251 suppress food intake and food-reinforced behavior in a variety of tasks in rats.

Cannabinoid CB1 receptor agonists, including delta-9-tetrahydrocannabinol (Delta 9-THC) (the main psychoactive ingredient in marijuana) have been shown to increase feeding in rats and humans. Conversely, it has been reported that acute administration of the CB1 receptor antagonist SR 141716A reduces food intake in rats. Based upon this observation, it has been suggested that CB1 antagonists could be useful as appetite suppressant drugs. The present studies were designed to provide a detailed examination of the effects of CB1 antagonists on food intake across a range of paradigms. Two CB1 antagonists (SR 141716A and AM 251) were administered to rats trained on fixed-ratio schedules with two different ratio requirements (fixed-ratio 1 and fixed-ratio 5). Both drugs produced a dose-dependent decrease in lever pressing, and had a relatively long duration of action (T1/2: SR 141716A, 15.1 h; AM 251, 22.0 h). Furthermore, intake of three diets with differing macronutrient composition (lab chow, high fat, high carbohydrate) was studied. Both drugs significantly suppressed intake of all three foods, and there were no significant interactions between drug dose and diet type. These findings support the hypothesis that CB1 receptor antagonists could be useful pharmacological tools for the suppression of appetite.

Animals↗
PubMed1994

Cerebrospinal fluid pressure as a function of body position in dogs.

Cerebrospinal fluid (CSF) pressure has been measured as a function of body position in dogs under pentobarbital anaesthesia. CSF pressure was higher than superior sagittal sinus pressure by an almost constant 6 cm of water, regardless of position, if 30 min were allowed for the system to reach equilibrium. The sinus pressure was found to depend on simple hydrostatic theory when the sinus was at or below the level of the heart. When the sinus was above the heart, the collapsing nature of the jugular veins prevented the sinus pressure from dropping as low as a simple hydrostatic theory would predict.

Animals↗
PubMed1990

Surgical treatment of brain metastases in malignant melanoma.

The authors report the results of a retrospective review of 13 patients who underwent 19 craniotomies for resection of metastatic malignant melanoma at the University of Colorado (Denver, CO) between 1983 and 1989. There was preoperative evidence of extracranial disease in 11 patients. Eight patients had more than one intracranial metastasis at operation. Intraoperative ultrasound was used in 18 of the 19 craniotomies to minimize surgical trauma to the brain. The 30-day mortality was zero. The 30-day morbidity was minimal. No patient acquired a new neurologic deficit as a result of surgery. All patients regained at least their preoperative level of functioning. Six of the patients who were living at the time of review have been followed for 4 to 25 months (median, 7.5 months). The seven patients who were dead at the time of review survived 4 to 18 months (median, 10 months). These results compare favorably with the survival of untreated patients with metastatic melanoma to the brain (median, 1 month), patients treated with radiation therapy alone (median, 2-4 months), and those treated with chemotherapy alone (median, 2-4 months). The excision of metastatic melanoma from the brain, although not curative, may increase survival in patients with this problem with little morbidity and mortality even in the presence of other metastases.

Adult↗
PubMed1983

Childhood subgaleal hematoma following minor head trauma.

Subgaleal hematoma developed one to eight days after minor head trauma in four children and in two infants, one with presumed trauma. These six children had no evidence of fracture or abnormality of coagulation. Hemorrhage into the subgaleal space resulted most likely from either radial or tangential forces applied to blood vessels within the subgaleal space.

Cerebral Hemorrhage↗
PubMed1983

Consequences of dural defects acquired in infancy.

Four infants underwent craniectomy for craniosynostosis and subsequently developed an expanding cranial defect with herniation of brain. All four had an unrepaired laceration of the dura. The pathophysiology of this entity and of the growing fracture of childhood are discussed, and a unified interpretation of the consequences of unrepaired dural defects is proposed.

Brain Injuries↗
PubMed1980

Psychological changes following surgery for tumors in the temporal lobe.

Twenty patients with a tumor in the temporal lobe underwent extensive neuropsychological testing pre- and postoperatively, with special regard to verbal and nonverbal memory. All patients had bilateral abnormalities preoperatively. Contralateral functions tended to improve after surgery, contrary to the outcome expected in patients with bilateral abnormalities due to atrophic lesions. Computerized tomography was the most useful neurodiagnostic test in correctly identifying the nature of the lesion in these patients.

Adolescent↗
PubMed1977

Histologic features and observational variation in cerebellar gliomas in children.

Variation existed in the recognition of histologic features commonly used in the evaluation of cerebellar gliomas of childhood. Some histologic features (e.g., perivascular pseudorosettes, leptomeningeal deposits, and calcification) were more reliably observed than were others (e.g., Rosenthal fibers, cell density, and hypervascularity). Knowledge of which features tend to have greater observational variation may lead to improved definitions, less reliance of these features in clinical decisions, further studies of the potential sources of the variation, and guidelines for minimizing observational variation.

Arachnoid↗
PubMed1977

Cerebellar gliomas in children.

We studied the relationship of histologic features to survival in a population of 132 children with cerebellar gliomas (excluding medulloblastomas). These children had their initial tumor operation at The Children's Hospital Medical Center of Boston between 1l927 and 1968. A classification system that accentuates differences in survival was derived on the basis of clustering of histologic features and survival. This division was supported by the existence of differentially distributed symptoms and signs and by differences in resectability. The two major subgroups of cerebellar gliomas had different patterns of clinical characteristics. Cerebellar glioma A had any of the four histologic features of microcyst, leptomeningeal deposit, Rosenthal fiber, or focus of oligodendroglia; children with glioma A had a 10-year survival rate of 94%. Glioma B, encompassing the histologic features of perivascular pseudorosette, high cell density, necrosis, mitosis, and calcification, was clearly defined but histologically less uniform; children with glioma B had a 10-year survival rate of 29%. These two groups accounted for 90% of the cerebellar gliomas in childhood.

Adolescent↗
PubMed1977

Secular trends of cerebellar gliomas in children.

Temporal changes in the histologic composition of cerebellar gliomas were examined in a population of 132 children operated on between 1927 and 1968 at The Children's Hospital Medical Center of Boston. Linear trends with time were examined for clinical features, histologic features, and tumor types. We found evidence of an increasing occurrence of glioma A and its associated features during the 41-year study period. This tumor type is associated with a good prognosis and is histologically well defined. Glioma B, a tumor type associated with a poor prognosis, was relatively stable with respect to time and, therefore, differed markedly from glioma A. Foci of oligodendroglia, a glioma A feature, clustered by year of surgery within a relatively short time span. This feature had a survival rate and a male sex proportion quite different from those of the other histologic features investigated.

Cerebellar Neoplasms↗
PubMedDate not supplied

The vertebral canals in lumbar disc disease.

The sagittal dimensions of the five lumbar vertebral canals tend to be more shallow in patients operated for lumbar radiculopathy than in a group of controls. The more frequent occurrence of radiculopathy in patients with small canals can be explained by the requirement for only a small protrusion of intervertebral disc, or any other structural abnormality, to impinge the nerve. The sagittal diameter can be obtained easily from the lateral roentgenogram and, therefore, requires no invasive or expensive tests. This measurement can be quite helpful in interpreting myelographic defects and in planning and doing operations on patients with radiculopathy.

Adult↗