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Biomedical subjects

S L Smith

Publications and source records attributed to S L Smith.

At least 91 records · Page 5Linked to original sources
PubMed1998

Hand-assisted laparoscopic distal pancreatectomy for pancreatic cystadenoma.

A cystic lesion in the body of the pancreas was detected during staging workup of a 59-year-old woman with T-cell lymphoma of the tongue. After six cycles of chemotherapy the pancreatic lesion was unchanged. Suggestive ulceration of the vulva with edema appeared at the end of chemotherapy. After right vulvar excision, distal pancreatic resection with splenectomy was carried out by a hand-assisted laparoscopic technique utilizing a small muscle-splitting right lower quadrant incision. This allowed for palpation of the peritoneal cavity for evidence of tumor and allowed for safe and expeditious pancreatectomy. The pancreatic tumor was found to be a serous cystadenoma without evidence of malignancy. T-cell lymphoma was identified in the spleen and the vulva. The patient was discharged home on the fifth postoperative day and returned to normal activity within 2 weeks after operation. Two months after the surgery, computed tomography demonstrated a 3-cm pseudocyst in the region of the tail of the pancreas. As the patient was asymptomatic, this required no further therapy. Minimally invasive surgery together with hand assistance combines the advantages of both laparotomy and laparoscopy in the surgical management of selected lesions in the pancreas.

Cystadenoma↗
PubMed1998

Polyurethane foams: effects of specimen size when determining cushioning stiffness.

Polyurethane (PU) foams are used as inexpensive materials for reducing interface pressure in a number of rehabilitative applications, particularly seating and prosthetic limb interfaces. Specimens of three different PU foams were cut to four different sizes and compressed according to ASTM protocols to determine their stiffness capabilities. It was found that the test results varied according to the relationship between the size of the test specimen and the test indenter. It is recommended that investigators create a testing situation that reflects their application when determining the cushioning capabilities of these materials.

Compressive Strength↗
PubMed1998

The accuracy of patients' judgments of disease probability and test sensitivity and specificity.

BACKGROUND: We studied patients' understanding of the characteristics of diagnostic tests for six common conditions to determine what patients know about diagnostic uncertainties before they communicate with a doctor. We compared the accuracy of patients' estimates of disease probabilities and diagnostic test characteristics for diseases with which they did or did not have prior experience. METHODS: To measure patients' understanding of the uncertainty of diagnostic test results, questionnaires describing diseases were given to patients in clinic waiting rooms. For each of six diseases, a 2-page questionnaire presented a case history of the disease and its diagnostic test, and asked respondents to estimate the probability that the case patient has the suspected disease, the sensitivity of test, the specificity of test, and the probability that the patient has the disease if the test result is positive. It also asked whether the patient, a close friend, or family member had ever been thought to have this disease. RESULTS: One hundred eighty-four patients in the clinic waiting room responded for at least one disease. Although patients judged the disease probabilities to be higher after a positive diagnostic test, each of their four judgments was essentially the same for all diseases, including those with high and low prior probabilities, and with accurate and inaccurate tests. Past experience with the disease was associated with only a minimal increase in the accuracy of patient knowledge. CONCLUSIONS: Patients' ignorance of the uncertainties of diseases demonstrates the need for patient education when a disease is suspected. The lack of relation between knowledge and experience suggests that this need is not being effectively met. To convey the rates or probabilities, and to help the patients understand what the probabilities are based on, a physician should speak in terms that patients can easily understand.

Adolescent↗
PubMed1998

Patient certification through mutual problem lists.

OBJECTIVE: To determine whether retired military personnel and spouses are cognizant of the patient's complete list of medical problems. METHODS: Receiving help from their spouses or other personal care givers, 12 patients listed their health problems from memory plus from a page-by-page review of their permanent medical records. The personal physician produced his own lists and combined them with the patient-generated lists. After mutual review, these combined lists were accepted as the mutual problem lists. Other professionals in the clinic also audited the same patients' charts. RESULTS: Twelve patients identified an average of 4.58 problems, the physician identified an average of 7.75 problems, and the other professionals identified an average of 6.54 problems. CONCLUSION: This lack of agreement has implications for patient education and certification as full collaborators in primary care.

Aged↗
PubMed1997

Sequence of the 3' end of the simian hemorrhagic fever virus genome.

SHFV is a member of a new virus family which includes the genus arterivirus. We have cloned and sequenced 6,314 nt from the 3' end of the SHFV genome. This sequence encompasses nine complete ORFs which is three additional ORFs as compared to the other arteriviruses. We have numbered these ORFs 2a, 2b, 3, 4, 5, 6, 7, 8 and 9. At the 5' end of this sequence is a partial ORF (ORF 1b) of 1590 nt and at the 3' end is a poly(A) tract preceded by a 76 nt noncoding region. The coding capacity for each of the SHFV ORFs as well as the potential mass, pI and number of N-linked glycosylation sites for each of the encoded peptides was determined.

Amino Acid Sequence↗
PubMed1997

Enhanced in vitro neurotoxicity of artemisinin derivatives in the presence of haemin.

The role of haem in the neurotoxicity of artemisinin derivatives has been studied in vitro by examining neurite outgrowth measured by image analysis and cellular metabolism of the tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) measured spectrophotometrically in the neuroblastoma cell line NB2a, and by examining binding of radiolabelled dihydroartemisinin to NB2a cell and rat brain proteins. In the cases of artemether, dihydroartemisinin, and arteether, haemin (ferriprotoporphyrin IX) significantly increased the dose-related inhibition of neurite outgrowth from differentiating NB2a cells and significantly increased the dose-dependent inhibition of MTT metabolism. Inhibition of neurite outgrowth and metabolism of MTT in the presence or absence of haemin ranged from 72% to 93% and from 27% to 49% at a drug concentration of 300 nM. Haemin also significantly increased the dose-related binding of radiolabelled dihydroartemisinin to proteins from NB2a cells approximately twofold and to rat brain between three- and sixfold. Haemin did not enhance the neurotoxicity of desoxyarteether, a structural analogue of arteether with an ether linkage in the place of the endoperoxide bridge. It is suggested that haemin may catalyse the transformation of these derivatives via an interaction with the endoperoxide bridge of the artemisinin derivative to produce free radicals or electrophilic intermediates that are toxic to neuronal cells.

Animals↗
PubMed1997

Laparoscopic paraesophageal hernia repair.

BACKGROUND: Paraesophageal hernias require surgery to avoid potentially serious complications. OBJECTIVE: To evaluate paraesophageal hernia repair using the laparoscopic approach. DESIGN: Case series. SETTING: University hospital and foregut testing laboratory. SUBJECTS: Sixty-five consecutive patients (mean age, 63.6 years; range, 26-90 years). Preoperative evaluation included barium esophagogram, endoscopy, esophageal manometry, and 24-hour pH monitoring. OUTCOME MEASURES: Operative complications, postoperative morbidity, follow-up symptoms (53 patients; mean, 18 months; range, 2-54 months) and barium esophagogram (46 patients). RESULTS: Fifty-six patients (86%) had a type III hernia and 9 (14%) had a type II hernia. Twenty (65%) of 31 patients who underwent pH monitoring had a positive 24-hour pH score, and 24 (56%) of 43 patients who underwent manometry had an incompetent lower esophageal sphincter. Four patients had a gastric volvulus and 21 patients had more than 50% of their stomach in the chest. All patients underwent hernia reduction, crural repair, and fundoplication (64 Nissen procedures and 1 Toupet procedure). The average duration of surgery was 2 hours. There were 2 conversions: gastric perforation and a difficult dissection because of a large fibrotic sac. Other complications, all managed intraoperatively, were 2 gastric perforations and bleeding in 6 patients. Average length of hospital stay was 2 days (range, 1-23 days). Early re-operation was required in 3 patients: slipped Nissen; small-bowel obstruction due to trocar-site hernia; and organo-axial rotation with gastroduodenal obstruction. Four patients required esophageal dilatation after surgery. Forty-nine of 53 patients available for long-term follow-up were satisfied with the results of surgery. Time to full recovery was 3 weeks (range, 1 week to 2 months). Seven of 46 patients experienced small type I hernias observed on routine follow-up esophagograms. CONCLUSIONS: Most paraesophageal hernias are type III. A concomitant antireflux procedure is recommended. Paraesophageal hernias can be managed successfully by the laparoscopic route with good outcome.

Adult↗
PubMed1997

Effects of the neem tree compounds azadirachtin, salannin, nimbin, and 6-desacetylnimbin on ecdysone 20-monooxygenase activity.

The effects of azadirachtin, salannin, nimbin, and 6-desacetylnimbin on ecdysone 20-monooxygenase (E-20-M) activity were examined in three insect species. Homogenates of wandering stage third instar larvae of Drosophila melanogaster, or abdomens from adult female Aedes aegypti, or fat body or midgut from fifth instar larvae of Manduca sexta were incubated with radiolabeled ecdysone and increasing concentrations (from 1 x 10(-8) to 1 x 10(-3) M) of the four compounds isolated from seed kernels of the neem tree, Azadirachta indica. All four neem tree compounds were found to inhibit, in a dose-dependent fashion, the E-20-M activity in three insect species. The concentration of these compounds required to elicit a 50% inhibition of this steroid hydroxylase activity in the three insect species examined ranged from approximately 2 x 10(-5) to 1 x 10(-3).

Aedes↗
PubMed1997

Factors that predict malignant thyroid lesions when fine-needle aspiration is "suspicious for follicular neoplasm".

OBJECTIVE: To assess clinical factors that may improve the ability to predict the presence of a malignant lesion in thyroid nodules that are found to be "suspicious for follicular neoplasm" by fine-needle aspiration (FNA) cytology. MATERIAL AND METHODS: We undertook a retrospective review of the medical records of all patients at the three Mayo Clinic facilities who underwent a thyroid surgical procedure between January 1992 and December 1994 and had a preoperative FNA report of "suspicious for follicular neoplasm." Patient and nodule characteristics were analyzed statistically for associations with the presence of cancer. RESULTS: The study cohort consisted of 219 patients with a mean age of 54.3 years. Eighty-four percent of resections were done for benign disease. Of the 35 malignant lesions, 9 were incidental papillary cancers separate from the primary nodule; thus, only 26 cancers were found in the index nodule, and only 19 (9% of the total group) were follicular carcinomas. Clinical findings associated with a malignant index nodule were larger diameter, fixation of the mass, and younger age of the patient. CONCLUSION: Clinical characteristics may be used for more accurate assessment of the risk of the presence of a malignant lesion when FNA cytology of a thyroid nodule is reported as "suspicious for follicular neoplasm."

Adenocarcinoma, Follicular↗
PubMed1997

Management of the failed antireflux operation.

A further operation is required in a small proportion of patients who have had prior antireflux surgery. This has a surprisingly good chance for success in appropriately evaluated patients. The surgeon must make very specific decisions regarding the surgical approach. The use of laparoscopy for redo surgery is being defined.

Deglutition Disorders↗
PubMed1997

Neutrophil maturation of CD34+ cells from peripheral blood and bone marrow in serum-free culture medium with PIXY321 and granulocyte-colony stimulating factor (G-CSF).

Bone marrow (BM) or peripheral blood (PB) CD34+ cells were cultured for 12 days in serum-free culture medium containing PIXY321 (IL-3/ GM-CSF fusion protein) with or without periodic supplements of granulocyte-colony stimulating factor (G-CSF). The cultures were evaluated at day 12 for total cell proliferation (fold increase from day 0), neutrophil differentiation by flow cytometry, using dual staining with CD15-FITC and CD11b-PE, and morphology using Wright-Giemsa and granule staining. In cultures containing PIXY321 where 6000 U/ml of G-CSF was added days 0 and 6, there was no significant difference (p > or = 0.05) in cell proliferation or the percent of CD15+/CD11b+ cells when compared with cultures with PIXY321 alone. ELISA analysis showed G-CSF levels had declined by 90% after 3 days of culture. Further studies were performed to assess the benefit of supplementing lower concentrations of G-CSF (600 U/ml) at more frequent intervals. A significant increase (p < or = 0.05) in cell proliferation and percent CD15+/CD11b+ was observed when G-CSF was added on days 0, 3, 6, and 9 (every 3 days) as compared with those cultures with PIXY321 alone. CD34+ cell proliferation without G-CSF was 19.6 +/- 4.8-fold, with G-CSF added on days 0 and 6 was 28.7 +/- 6.4-fold, and with G-CSF added on days 0, 3, 6, and 9 was 45.9 +/- 10.6-fold. Percent of CD15+/CD11b+ cells was 19.0 +/- 4.6%, 38.2 +/- 7.2%, and 58.5 +/- 6.5%, respectively, in these cultures. We observed more CD15+/CD11b+ cells, myelocytes/metamyelocytes, and secondary granule staining in cultures with G-CSF added on day, 0, 3, 6, and 9 as compared with cultures with G-CSF added on days 0 and 6 or no G-CSF added. We conclude that PIXY321 and G-CSF act synergistically on the in vitro proliferation and neutrophil differentiation of BM and PB CD34+ cells and that frequent supplements of G-CSF facilitate neutrophil differentiation.

Adult↗
PubMed1997

Ex vivo expansion of frozen/thawed CD34+ cells isolated from frozen human apheresis products.

Human CD34+ cells purified from frozen mobilized peripheral blood apheresis products (n = 7) were studied immediately (freshly isolated) or refrozen and studied after > 30 days storage in liquid nitrogen (refrozen/thawed). The proliferation and differentiation of freshly isolated or refrozen/thawed CD34+ cells were examined after 10 days of serum-supplemented suspension culture with recombinant human hematopoietic growth factors. The proliferative capacity (fold increase) of the refrozen/thawed CD34+ cells (mean +/- SD, 54.3 +/- 34.3) was comparable to the freshly isolated CD34+ cell cultures (49.0 +/- 42.4). Two-color flow cytometry of the CD34+ cultured cell populations, fresh and refrozen/thawed, displayed typical patterns of neutrophil differentiation into CD15/CD11b neutrophil precursors. The colony-forming ability of freshly isolated and refrozen/thawed CD34+ cells showed no significant differences (p > 0.05) in the total number or type of colony-forming units (CFU-GM, CFU-M, BFU-E, CFU-GEMM) obtained. In addition, the cloning efficiencies of freshly isolated (19.5 +/- 7.6%) and refrozen/thawed CD34+ cells (21.9 +/- 12.7%) were comparable (p = 0.366). These data suggest that CD34+ cells enriched from frozen apheresis blood products can be either used immediately or stored in liquid nitrogen and thawed with minimal effect on their ability to proliferate and differentiate in liquid culture.

Antigens, CD↗
PubMed1997

In vivo antiviral activity and pharmacokinetics of (-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine in woodchuck hepatitis virus-infected woodchucks.

The (-) enantiomer of cis-5-fluoro-1l-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine [(-)-FTC)], a substituted oxathiolane compound with anti-hepatitis B virus activity in vitro, was assessed for its efficacy in woodchucks with naturally acquired woodchuck hepatitis virus (WHV) infection. Pharmacokinetics and in vitro anabolism were also determined. (-)-FTC was anabolized to the 5'-triphosphate in a dose-related fashion, reaching a maximum concentration at about 24 h in cultured woodchuck hepatocytes. Following administration of a dose of 10 mg/kg of body weight intraperitoneally (i.p.), the clearance of (-)-FTC from plasma was monoexponential, the terminal half-life was 3.76 +/- 1.4 h, and the systemic clearance was 0.12 +/- 0.06 liters/h/kg. The antiviral efficacy of (-)-FTC in the woodchuck model was assessed by quantitation of serum WHV DNA levels and by WHV particle-associated DNA polymerase activity at two dosages, 30 and 20 mg/kg given i.p. twice daily (b.i.d.), respectively. The level of WHV DNA in serum was reduced 20- to 150-fold (average, 56-fold) in the 30-mg/kg-b.i.d. treatment group and 6- to 49-fold (average, 27-fold) in the 20-mg/kg-b.i.d. treatment group. Viral DNA polymerase levels diminished accordingly. One week after treatment was discontinued, WHV levels returned to pretreatment levels in both studies. These animals were biopsied before and following treatment with 30 mg of (-)-FTC per kg. Their livers were characterized by a mild increase in cytoplasmic lipid levels, but this change was not associated with altered liver enzyme levels. Serum chemistry and hematology results were within the normal ranges for all treated animals. We conclude that (-)-FTC is a potent antihepadnaviral agent and that it has no detectable toxic effects in woodchucks when given for up to 25 days. Further development of (-)-FTC as an anti-hepatitis B virus therapy for patients is warranted.

Animals↗
PubMed1997

Mental health and health care utilization in geriatric primary care patients.

OBJECTIVE: This study examines the effect of mental health factors on health care utilization in a group of community dwelling elderly subjects followed in a primary care setting. METHOD: Data on utilization was obtained prospectively from computerized billing records for a one-year period following completion of a structured survey. Relationships between variables were characterized by Spearman's rank correlation. Multivariate linear regression modeling was employed to relate health care utilization, as measured by total cost, to the baseline variables. RESULTS: No significant relationship was found between mental health measures and health care utilization as measured by total costs in this elderly population. However, total costs were found to be related to medical comorbidity and total daily medication use. CONCLUSION: The present study did not find the relationship of psychiatric distress and increased use of health care services to apply to a group of community dwelling elderly. Future research will need to focus on larger data sets and improvement of models that attempt to examine the relationships between mental health and health care utilization in the elderly.

Aged↗
PubMed1997

A description of general health risks in adult liver transplant recipients.

The focus of posttransplant care and clinical research has been on the management of rejection and short-term side effects associated with immunosuppressive therapy. Long-term side effects have only recently been recognized as potential health problems in liver transplant recipients. The aim of this pilot study was to determine the feasibility of using the Healthier People Version 4.0 Health Risk Appraisal as a tool for identifying existing and potential risk factors for premature disease and death among asymptomatic liver transplant recipients and to describe health risks in adult liver transplant recipients. The sample consisted of 50 adult first-time liver transplant recipients. It was found that this tool highlights health risks affecting life expectancy and pinpoints risks that an individual can control. It also provides practitioners with information necessary to design appropriate prevention and health promotion strategies to assure better health and quality of life for patients following liver transplantation.

Adult↗