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Biomedical subjects

R J Stewart

Publications and source records attributed to R J Stewart.

154 records · Page 9Linked to original sources
PubMedDate not supplied

Peritoneal cytology for suspected acute appendicitis: an economic evaluation.

Suspected acute appendicitis is a common reason for surgery. Unfortunately, diagnosis is not always simple and, in recent years, considerable attention has been devoted to developing better diagnostic techniques. Peritoneal cytology is one such technique. It is simple, minimally invasive, and has been established as clinically effective. This paper reports on an economic evaluation of peritoneal cytology, carried out at Wellington Hospital, New Zealand. The analysis is based on two trials totalling 192 patients. The perspective taken initially is that of a hospital financial manager, seeking to minimise costs. In the first trial, there was a marginal increase in overall cost per person presenting with suspected acute appendicitis, from using the test. In the second, there was a reduction. In both trials there were significant health benefits--unnecessary operations were avoided, and necessary operations done more quickly. Also, the practice developed, in the second trial, of sending patients home immediately following a negative test result. This further increased savings. We then discuss the results from a broader perspective. We conclude that the additional personal benefits--less time convalescing, and lower mortality, on average--ensure that the benefits outweigh the costs of the test.

Acute Disease↗
PubMedDate not supplied

Fine-catheter aspiration cytology of peritoneal cavity improves decision-making about difficult cases of acute abdominal pain.

Fine-catheter aspiration cytology of the peritoneal cavity was successfully undertaken in 25 of 27 hospital inpatients with acute abdominal pain because it was not clear whether they required urgent laparotomy. Cytological specimens were prepared by the cyto-sieve technique. The main test criterion was the percentage of neutrophils in the peritoneal cell sample. The decision before the test about urgent laparotomy was correct in 14 of the 27 patients, whereas the decision after the test was correct in 26 of the 27 patients (p = 0.001). 4 patients were saved unnecessary laparotomy and 8 further delay in laparotomy.

Abdomen, Acute↗
PubMedDate not supplied

Responsive hybrid hydrogels with volume transitions modulated by a titin immunoglobulin module.

The I28 immunoglobulin (Ig)-like module of human cardiac titin, an elastic muscle protein, was used to cross-link acrylamide (AAm) copolymers into hybrid hydrogels. Cross-linking was accomplished through metal coordination bonding between terminal histidine tags (His tags) of the I28 module and metal-chelating nitrilotriacetic acid (NTA)-containing side chains on the copolymer. In solution, the beta-sheet structure of the I28 module unfolded with a transition midpoint of about 58 degrees C as the temperature was elevated. Hydrogels cross-linked with the I28 module demonstrated positive temperature responsiveness; they swelled to 3 times their initial volume at temperatures above the melting temperature of the cross-links. Positive temperature responsiveness is unusual for synthetic hydrogels. The I28 hybrid hydrogels demonstrate that cross-linking synthetic polymers with natural, well-characterized protein modules is a practical strategy for creating new materials with unique environmental responsiveness predictably determined by the mechanical properties of the protein cross-links. These new materials may be useful for controlled chemical delivery.

Acrylamides↗
PubMedDate not supplied

Effect of high-dose cimetidine on pulmonary extravascular water after acute smoke inhalation injury.

An animal model utilizing gamma imaging was used to examine pulmonary edema of an inhalation injury model. Tests were conducted using radiolabeled tracers and a dual indicator dilution technique as well as gravimetric analysis of excised lungs to determine extravascular water formation. The effect of cimetidine (Tagamet, an H2 receptor antagonist) was investigated as a potential agent for reduction of pulmonary edema following inhalation injury. Control groups included no treatment; smoke only; fluids only; and smoke and fluids. These were compared with identical groups given the same treatments but with the addition of cimetidine (100-150 mg/kg body weight intravenously). Fluids administered were 5% body weight intravenous infusions of lactated Ringer's solution over two hours. Results show that pulmonary edema was evidenced in animals given an inhalation injury, and was markedly worsened by fluid resuscitation. Treatment with cimetidine at high doses, either before or after inhalation injury, did not protect the animals from formation of pulmonary edema.

Animals↗
PubMedDate not supplied

Fine catheter aspiration cytology of the peritoneal cavity in the diagnosis of a metastatic tumor. Report of a case with immunocytochemical studies.

The potential value of a new system of fine catheter aspiration (FCA) cytology of the peritoneal cavity in the diagnosis of peritoneal malignancy is illustrated by a case report. Gelman filter preparations of an FCA sample of an abdominal mass from a patient with a history of adenocarcinoma of the lung showed unequivocal malignant cells, obviating the need for further diagnostic procedures. Trial immunostaining of Cytospin preparations of part of the FCA sample showed appropriate results, suggesting that such samples may be suitable for immunoperoxidase studies to identify tumor types or to predict the source of the primary tumor in difficult cases.

Adenocarcinoma↗
PubMedDate not supplied

Immunocytochemical and ultrastructural findings in a case of rare carcinoma of the pancreas with predominance of malignant squamous cells in an intraoperative needle aspirate.

The cytologic diagnosis by intraoperative needle aspiration of a rare carcinoma of the pancreas composed predominantly of malignant squamous cells is reported. Both poorly differentiated and keratinized well-differentiated squamous cells were seen in the aspirate. Tissue for histologic confirmation was not obtained because of the position of the mass. Confirmatory ultrastructural and immunoperoxidase studies were thus done on the aspirated material to confirm the diagnosis.

Aged↗
PubMedDate not supplied

Diagnosis of the rare solid and papillary epithelial neoplasm of the pancreas by fine needle aspiration cytology. Light and electron microscopic study of a case.

A case of the rare solid and cystic papillary tumor of the pancreas in a young woman is described. The diagnosis was made by fine needle aspiration cytology, with electron microscopic examination of the needle washings. The preoperative cytologic diagnosis enabled appropriate surgical treatment to be planned and carried out without undue delay. It is important to distinguish this rare tumor from other pancreatic tumors with similar cytohistologic features since, if diagnosed correctly and managed surgically, this neoplasm is associated with a good prognosis.

Adult↗