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Biomedical subjects

S D Smith

Publications and source records attributed to S D Smith.

At least 289 records · Page 16Linked to original sources
PubMed1983

Initial assessment of the performance of an 0.3 T permanent magnet in whole body NMR imaging.

An 0.3 Tesla permanent magnet was constructed and incorporated into a complete whole body NMR imager. Axial, sagittal and coronal images from human subjects were obtained using a two-dimensional Fourier Transform analysis of selected planes 8 mm thick, combined with an efficient multislice technique that produces sections centered 12 mm apart. Images were obtained based on inversion recovery and spin echo modes. The permanent magnetic field is uniform to 10 ppm over 38 cm. The magnet requires no special maintenance and has an extremely small fringe field. The magnet design, with its field vertical to the long axis of the subject, permits use of a solenoidal radiofrequency receiving coil for optimal signal-to-noise ratio. Images were shown that are of high quality and produced under conditions simulating those necessary for efficient patient throughout in a clinical setting. Many of the unique features of NMR imaging, such as ability to directly obtain axial, sagittal and coronal projections, the variety of imaging modes, the natural sources of contrast, and the ability to visualize clearly medium and large blood vessels, were demonstrated.

Adipose Tissue↗
PubMed1982

Cerebral edema following acute hemorrhage in a murine model: the role crystalloid resuscitation.

Unanesthetized male Sprague-Dawley rats were bled 40% of their blood volume. After 1 hour of hypovolemia, the animals were resuscitated with either lactated Ringer's solution (LRS) or hypertonic lactated saline (HLS). They received a volume of crystalloid equal to the shed blood volume or twice the shed blood volume. Twenty-four hours after resuscitation, the animals were sacrificed and the brains excised. The per cent water content was determined. Severe hemorrhage without resuscitation resulted in significantly increased intracerebral water content (77.7 +/- 1.0 vs 78.9 +/- 0.7 p less than 0.05). Resuscitation with twice the shed blood volume of either LRS or HLS prevented this increase in intracerebral water. These data support the conclusion that adequate resuscitation is the critical factor in preventing cerebral edema following acute severe hemorrhage.

Animals↗
PubMed1981

In vitro growth of lymphoma colonies from children with non-Hodgkin's lymphoma.

Growth in vitro of malignant lymphoid cells has been previously reported, but those studies involved direct establishment of cell lines from the patients' cells. In the present study, an in vitro system for both primary growth and passage of malignant lymphoblastic colony-forming cells (ML-CFC) was established, and for the first time, colony-forming cells from non-Hodgkin's lymphoma patients were cultured, and cell lines were established from individual colonies. Malignant lymphoid colonies grew from 9 of 16 (56%) bone marrow aspirates, which were histologically involved with lymphoma and from 5 of 29 (17%) morphologically normal bone marrow samples. ML-CFCs grew concomitantly with myeloid and monocytic CFCs and were distinguishable by their morphologic characteristics on agar, cytochemical staining characteristics, and cell surface markers. Successful passage of ML-CFCs was accomplished in five patients, and ten distinct cell lines (six null cell, three B cell, and one T cell) were established. This agar assay system provides an opportunity to study malignant lymphoma cell growth both as a primary colony and a cell line established from a primary colony.

Adolescent↗
PubMed1981

Vindesine and prednisone for remission induction in children with acute lymphocytic leukemia.

Vinca alkaloids are effective anticancer agents. Vindesine is a recent vinca alkaloid derivative with anti-tumor effects shown in in vitro systems and in patients with acute lymphocytic leukemia (ALL). The present study was designed to investigate the therapeutic effectiveness and toxicity of vindesine in combination with prednisone for remission induction in late stage ALL in children. Sixteen children with late-stage ALL were treated with vindesine 4.0 mg/m2/week intravenously and prednisone 60 mg/m2/day orally in four divided doses for minimum of three weeks. Thirteen children were evaluable. Of these patients, four had complete remission and four had partial response. Toxicity was well tolerated and consisted of bone pain, paresthesias, loss of deep tendon reflexes, leukopenia, and thrombocytopenia primarily. Abnormal liver function tests and fever were also noted in some patients. All patients had received vincristine and prednisone prior to vindesine prednisone combination. All patients had been resistant to vincristine prednisone combination prior to vindesine prednisone treatment. This study suggests effectiveness of vindesine in late stage ALL and lack of cross-resistance of vindesine and vincristine.

Adolescent↗
PubMed1981

Spontaneous diabetes mellitus in the New Zealand white rabbit: physiologic characteristics.

Spontaneous diabetes mellitus has been observed in a female New Zealand white rabbit. By inbreeding of this individual and her offspring, 39 litters comprising 157 animals have been studied and a closed colony of diabetic rabbits established. Three groups of animals can be identified. Twenty-nine (19%) have overt diabetes characterized by fasting hyperglycemia and depressed intravenous glucose stimulated serum insulin levels. This abnormality is seen between 1 and 3 yr of life. Forty-three of the animals (27%) have developed abnormal glucose disposal with normal or slight elevations in fasting serum glucose levels. Glucose stimulated insulin levels are also significantly lower in the rabbits with abnormal glucose disposal. The remaining 85 animals (54%) exhibit no apparent abnormalities of glucose metabolism. All animals with overt diabetes pass through a stage in which glucose disposal as measured by k values is less than 1.0, a value not observed in normal animals. Fasting and arginine stimulated glucagon levels were no different in 4 diabetic animals and 7 normal colony rabbits. Insulin therapy corrected the hyperglycemia in the diabetic rabbits. Insulin was withheld in 5 diabetic rabbits and serum and urinary glucose and ketones were measured for 9 days. Despite marked increases in serum and urinary glucose, only mild ketonemia was observed. The relatively late onset of diabetic symptoms, lack of obesity, severe hyperglycemia, and depressed insulin secretion without ketoacidosis make this a model with many of the characteristics of insulin responsive diabetes as seen in nonobese human adults.

Acetoacetates↗
PubMed1981

Poor drug compliance in an adolescent with leukemia.

Poor drug compliance in pediatric patients is a frustrating problem for it is common, difficult to document, and difficult to change. This report describes an adolescent who was found to be noncompliant in taking his therapy for acute lymphoblastic leukemia. 17kgs assay showed noncompliance with prednisone therapy three times--the third episode thwarting a reinduction attempt. Psychological testing was performed to assess factors that may have contributed to this noncompliance. This patient was found to have low anxiety, excess hostility, borderline intelligence, and a feeling that his fate was predetermined. Intervention therapy was attempted by additional counseling and education about the basic disease, but this was unsuccessful. Drug compliance was eventually achieved only through hospitalization. Identification of psychological factors and clinical situations associated with poor drug compliance is discussed.

Adolescent↗
PubMed1980

Early confirmation of stress fractures in joggers.

Four joggers had early confirmation of clinically suspected stress fractures by radionuclide bone scans. The radioactive bone scan was abnormal as early as six weeks prior to the appearance of conventional roentgenographic changes. The stress fractures involved the bones of the lower extremities and included the femur, tibia, and calcaneus. Radioactive bone scanning also correctly identified stress fractures with bilateral involvement and referred pain. In joggers, when a stress fracture is clinically suspected and the conventional radiographs are negative, a radioactive bone scan is indicated for early confirmation and institution of appropriate treatment.

Adult↗
PubMed1979

Establishment and characterization of a human null-cell lymphoblastic lymphoma cell line (K-LL-3).

A new cell line (K-LL-3) with exceptional characteristics was derived from a bone-marrow aspirate from a patient with poorly differentiated lymphoblastic lymphoma. The cell line was established and the cells maintained on agar feeders for over 1 year. The morphology and cytochemical staining of the primary tumor and the cell line were remarkably similar. The growth characteristics, chromosome pattern, cell-surface receptors and Epstein-Barr pattern, cell-surface receptors and Epstein-Barr virus studies clearly differentiated this cell line from non-malignant lymphoblastoid cell lines. The assay technique used was able to correlate in vitro colony growth with the patient's clinical course. The cells grew on the agar as colonies rather than as a single-cell suspension, and individual colonies could be aspirated and successfully passaged. The K-LL-3 cells lacked cell-surface markers (cytoplasmic and surface immunoglobulins, Fc receptors, C3 receptors, SRBC) except HL-A and thus were classified as null cells. These cells were EBNA (Epstein-Barr virus-specific nuclear antigen) negative and had a pseudodiploid 46XY karyotype.

Adolescent↗
PubMed1979

A reliable method for evaluating drug compliance in children with cancer.

Poor drug compliance may cause a decreased survival of children with malignancies. Children who fail to take their medications are not receiving optimum amounts of chemotherapy and suboptimal therapy causes a shortened survival in children with cancer. This is a study of prednisone compliance in 52 children with cancer during three distinct phases of therapy. The patients were either known to be taking prednisone (on-therapy group), off prednisone (off-therapy group), or their compliance was unknown (unknown group). Evaluation of prednisone compliance was attempted by measuring hemoglobin level changes, weight changes, and random urinary 17-ketogenic steroids. The results obtained show that while hemoglobin and weight changes are not helpful, a random urine 17-ketogenic steroid assay is able to differentiate clearly those patients who are taking their prednisone. By the use of this assay it was found that 33% of patients who by protocol and instruction were supposed to be receiving prednisone were not complying. Separate analysis of adolescents revealed an even more alarming 59% noncompliance rate. This striking level of noncompliance strongly suggests that the survival of patients may be threatened by noncompliance.

17-Ketosteroids↗