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F O'Keeffe

Publications and source records attributed to F O'Keeffe.

10 recordsLinked to original sources
PubMed1997

A persubstituted cationic beta-cyclodextrin for chiral separations.

The applications of a novel polycationic derivative of beta-cyclodextrin (beta-CD), heptakis(6-hydroxyethylamino-6-deoxy-beta-cyclodextrin) (beta-CD-EA), as a chiral host--guest additive for the enantioseparation of various classes of chiral anionic analytes are presented. The cationic beta-CD described in this paper is persubstituted with seven ethanolamine side arms at the primary rim of each cyclodextrin (CD) molecule. It is found that the electrophoretic mobility of beta-CD-EA can be adjusted to influence the chiral selectivity by changing the pH of the background electrolyte. Most of the observed CD capillary zone electrophoresis (CZE) separations of anionic drugs and herbicides were accomplished in the pH range of 4.0-7.0 with a reverse polarity configuration. At pH 5.0, enantioseparation of a mixture of three structurally related antiinflammatory agents (fenoprofen, flurbiprofen, and ibuprofen) was possible in about 30 min. However, other chiral acids, such as a series of phenoxypropionic acid herbicides and dansylated amino acids (glutamic acid and aspartic acids), were best separated at pH 6.0 or 7.0. An impressive separation of a mixture of six structurally related anionic herbicides [(+/-)-2-phenoxypropionic acid, (+/-)-2-(2-chlorophenoxy)propionic acid, (+/-)-2-(3-chlorophenoxy)propionic acid, (+/-)-2-(4-chlorophenoxy)propionic acid, (+/-)-2-(2,4-dichlorophenoxy)propionic acid, and (+/-)-2-(2,4,5-trichlorophenoxy)propionic acid] was achieved for the first time in about 15 min during a single run with 20 mM beta-CD-EA. The analytical applicability of this cationic CD molecule for chiral separations is discussed in detail.

Amino Acids↗
PubMed1990

Radiological features of extraskeletal Ewing sarcoma.

The radiological features of extraskeletal Ewing sarcoma were reviewed in 22 patients whose average age was 22 years. Tumours were located in the extremities (11 patients), abdomen or pelvis (six patients) and the chest (five patients). The tumours ranged in size from 2 cm to 20 cm, were mainly well circumscribed and showed no evidence of calcification prior to treatment. Most tumours (13 out of 14) were of low attenuation or contained areas of lower attenuation than muscle on computed tomographic examination, and in six out of seven patients studied by ultrasound the tumours were hypoechoic or partly anechoic. No distinctive post-contrast medium enhancement pattern on CT examination (11 patients) or angiographic features (three patients) were evident. Tumour haemorrhage was a frequent microscopic finding and changes consistent with this were present in one patient on magnetic resonance imaging examination. Distant metastases or local recurrence developed in 13 patients with lung being the most frequent metastatic site (eight patients). Although its radiological features are non-specific, extraskeletal Ewing sarcoma should be included in the differential diagnosis of noncalcified soft-tissue tumours especially in a young age group and where located in an extremity or paravertebral region of the chest.

Abdominal Neoplasms↗
PubMed1990

[Bilateral encasement of the internal saphenous vein in a patient with lymphoma].

Sonographic findings in a case of bilateral, almost symmetrical encasement of the terminal segment of the great saphenous vein by superficial sub-inguinal lymphomatous masses are presented. Duplex and color Doppler sonography also demonstrated abnormal Doppler signals within the mass. When peripheral, coalescent nodal masses are detected surrounding intact normal vessels, malignant lymphoma should be suspected.

Aged↗
PubMed1989

Ultrasound findings in carcinoma of the gallbladder.

The ultrasound findings in 5 cases of primary carcinoma of the gallbladder are described. A mass protruding into or replacing the gallbladder or abnormal gallbladder wall were found in all cases. Four of the patients had gallstones and a dilated biliary tree. With careful technique in evaluation of the gallbladder wall in patients with gallstones early carcinoma of the gallbladder may be detected with greater frequency.

Aged↗
PubMed1989

Percutaneous drainage and feeding gastrostomies in 100 patients.

Percutaneous gastrostomy was performed in 100 cancer patients. In 67 patients with bowel obstruction, the procedure was performed for gastric drainage with 24-28-F Malecot catheters inserted in one sitting. The remaining 33 patients had supragastric obstructions or fistulas and required 10-14-F pigtail catheters for feeding purposes. Average postgastrostomy hospitalization was 3.6 days. Drainage gastrostomies were ready for use immediately after the procedure, whereas use of feeding gastrostomies started on average within 2 days of tube insertion. There were no major complications or deaths related to the procedure. Percutaneous gastrostomy is a simple and safe procedure even when large-caliber catheters are used, and it does not require gastric fixation to the abdominal wall to prevent spillage into the peritoneum.

Adult↗
PubMed1989

Chemotherapy and embolization via the inferior epigastric artery for the treatment of primary and metastatic cancer.

We evaluated the results of arterial chemotherapy and embolization via the inferior epigastric artery and its branches in 10 patients with a variety of primary and metastatic neoplasms supplied by that vessel. A total of 15 infusions and five occlusions were performed. There were no complications related to arteriography, indwelling catheters, or arterial occlusion. The effects on tumor bulk ranged from complete necrosis in one patient to partial necrosis in three patients. Surgical resection was facilitated in four of six patients. Local recurrence of tumor occurred in two of these patients. Three of four patients with intractable pain had effective relief. Our experience suggests that transarterial therapy of tumors supplied by the inferior epigastric artery or its branches is a safe procedure and may be useful in tumor management.

Abdominal Neoplasms↗
PubMed1986

Giant cell astrocytoma in tuberous sclerosis: computed tomographic findings.

Clinical presentation and computed tomography (CT) findings in four tuberous sclerosis patients with large ventricular tumours situated near the foramina of Monro, and causing obstructive hydrocephalus are described. These tumours (so-called giant cell astrocytomas) demonstrated uniform post-contrast enhancement. This finding, along with their location, distinguished them from the much commoner cortical and subependymal tubers of tuberous sclerosis.

Adult↗