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Biomedical subjects

L M Sanders

Publications and source records attributed to L M Sanders.

At least 19 recordsLinked to original sources

Urogenital diseases and their effect on reproductive performance in high-parity sows.

UNLABELLED: In a Slowakian indoor pig production unit (2423 sows), from June to December 2002 all culled sows with excessive vulval discharge at culling, and with vulval discharge and periparturient disease in their previous history were subjected to retrospective lifetime production analysis. The sows were assigned to nine groups according to parity (parity 1-9). Average total litter size, average live-born litter size, average stillbirth rate, average mummy rate, and average litter weaning weight were evaluated retrospectively for all births. Non-culled sows represented the control animals. The percentage of animals with periparturient disease and vulval discharge in their history differed between parities. Parity 2, 3, and 4 sows had a significantly lower percentage of vulval discharge and periparturient disease in their history than sows of other parities. Compared to parity 1-6 sows, parity 7-9 sows had significantly lower (P < .001) conception rates, farrowing rates, and adjusted farrowing rates. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had a significantly larger (P < .001) lifetime average total born and live-born litter size. Compared to parity 1-3 and 7-9 sows, parity 4-6 sows had a significantly lower (P < .001) rate of stillbirths over all parities. No differences in mummy rates were detected between the sows of different parities. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had significantly higher (P < .001) weaning litter weights over all parities. Sows without a history of vulval discharge and periparturient disease had higher (P < .001) production levels in parity 7-9. IMPLICATIONS: The present results indicate that parity markedly influences the production level of sows that have a history of periparturient disease and vulval discharge.

Animals↗

Changing the diffusion mechanism of Ge-Si dimers on Si(001) using an electric field.

We change the diffusion mechanism of adsorbed Ge-Si dimers on Si(001) using the electric field of a scanning tunneling microscope tip. By comparing the measured field dependence with first-principles calculations we conclude that, in negative field, i.e., when electrons are attracted towards the vacuum, the dimer diffuses as a unit, rotating as it translates, whereas, in positive field the dimer bond is substantially stretched at the transition state as it slides along the substrate. Furthermore, the active mechanism in positive fields facilitates intermixing of Ge in the Si lattice, whereas intermixing is suppressed in negative fields.

Journal Article↗

Prescribing books for immigrant children: a pilot study to promote emergent literacy among the children of Hispanic immigrants.

OBJECTIVES: To assess book-sharing activities within first-generation Hispanic immigrant families, and to assess the effect of pediatricians giving books to their patients. DESIGN: Survey. PARTICIPANTS: Convenience sample of 122 predominantly Hispanic immigrant parents of children aged 2 months to 5 years. Of these parents, 56 had received children's books from the pediatrician, and 66 had not. SETTING: House staff continuity clinic at a university children's hospital. MAIN OUTCOME MEASURE: Frequent Book Sharing (FBS) was defined as a parent's reporting more than 3 days per week of sharing books with the child. Main independent variables included the following: (1) exposure to the Reach Out and Read program, defined as having received a children's book from the pediatrician; (2) socioeconomics, as measured by parents' years of education and Medicaid enrollment; (3) acculturation, as defined by 4 questions relating to parents' proficiency with the English language; (4) parent's country of origin; (5) parent literacy, as measured by a parent's reporting more than 3 days per week of reading alone; (6) parent's age; (7) marital status; (8) household size; (9) child's age; (10) child's sex. RESULTS: Ninety percent of the parents were born outside of the United States (71% in Mexico), 85% spoke Spanish in the home, and 63% had completed less than a high-school education. Seventy-five percent of children's medical insurance was provided by Medi-Cal (Medicaid), and 9% of children were uninsured. Sixty-seven percent spoke exclusively Spanish at home, and 84% of parents want their children to learn to read in both English and Spanish. High FBS was reported among parents whose children had received books from the physician when compared with parents whose children had received no books. The odds ratio (OR) was 3.62 (95% confidence interval [CI], 1.40-9.37; P<.05). Also associated with FBS were parents reading frequently to themselves (OR = 9.52; 95% CI, 2.09-43.27; P<.05) and national origin outside Mexico (OR = 5.54; 95% CI, 1.59-19.27; P<.05). These findings were independent of parent's educational level, parent's employment, parent's age, acculturation, and family size. CONCLUSIONS: Pediatricians can promote literacy development among Hispanic immigrant children through the provision of free books at well-child visits. Our findings also suggest the independent effects of adult literacy and child age. Further research is needed to understand the effect of pediatric literacy programs on Hispanic immigrant children, their bilingual environments, and their readiness for school entry. Arch Pediatr Adolesc Med. 2000;154:771-777

Adult↗

Initial experience with laparoscopic repair of incisional hernias.

BACKGROUND: Development of a safe, unobtrusive means to repair the large incisional hernia continues to represent a challenge to surgeons. METHODS: A retrospective analysis of the first 12 patients who underwent an attempt at laparoscopic repair of an incisional hernia at a single institution was carried out. RESULTS: Of the 12 attempts at laparoscopic repair, 11 were completed. No serious perioperative morbidity was encountered. During a mean follow-up of 12.5 months, one recurrence (due to a technical shortcoming that has since been overcome) was identified. CONCLUSIONS: The laparoscopic approach to incisional hernia repair is a safe alternative to open repair of abdominal wall defects.

Adult↗

Solitary scapula mass: atypical presentation of esophageal adenocarcinoma.

Adenocarcinoma of the esophagus is an aggressive malignancy that frequently occurs with lymph node involvement. Current management strategies may incorporate adjuvant therapeutic modalities in an attempt to improve the typical dismal outcome. There is frequent association of esophageal adenocarcinoma with Barret's metaplasia. Isolated bone and soft tissue metastases are rare and may present a diagnostic challenge in asymptomatic patients.

Adenocarcinoma↗

Ethics of fetal tissue transplantation.

Now that the Clinton Administration has overturned the ban on federal funding for fetal tissue transplantation, old ethical issues renew their relevance and new ethical issues arise. Is fetal tissue transplantation necessary and beneficial? Are fetal rights violated by the use of fetal tissue in research? Is there a moral danger that the potential of fetal tissue donation will encourage elective abortions? Should pregnant women be allowed to designate specific fetal transplant recipients? What criteria should be used to select fetal tissue transplants? Whose consent should be required for the use of fetal tissue for transplantation? We review the current state of clinical research with fetal tissue transplantation, the legal history of fetal tissue research, the major arguments against the use of fetal tissue for transplantation, and the new postmoratorium ethical dilemmas. We include recommendations for guidelines to govern the medical treatment of fetal tissue in transplantation.

Aborted Fetus↗

Parenteral peptide formulations: chemical and physical properties of native luteinizing hormone-releasing hormone (LHRH) and hydrophobic analogues in aqueous solution.

The degradation of native LHRH in aqueous buffers of pH approximately 1-10 obeyed the rate equation, kobs = kH + alpha H+ + ko + kHO-(alpha HO-)x, where x at 60-100 degrees C was approximately 0.64 and temperature independent. Extrapolation to 25 degrees C using the Arrhenius equation and secondary rate constants showed that native LHRH is reasonably stable at pH 5.4, giving a shelf life (t90) of approximately 5 years. Regarding physical properties, hydrophobic LHRH analogues nafarelin and detirelix were found to be surface active as demonstrated by a decrease in apparent surface tension with increased peptide concentration. The CMC for detirelix at pH 7.4 was determined to be 5.3 x 10(-4) M (0.88 mg/ml), and that for nafarelin, greater than 2 mg/ml. At higher concentrations (approximately 4-8 mg/ml), nafarelin and detirelix formed nematic liquid crystals of undulose extinction (birefringence, less than 0.001). The thermodynamic stability of these peptide liquid crystals was probed by determining their melting points (Tcm) in the presence of propylene glycol, a solvent which proved to be efficacious at suppressing gelation and at destabilizing liquid crystals as measured by a reduction in Tcm.

Chemical Phenomena↗

Quadtree-based data compression of abdominal CT images.

An ROC study was performed to evaluate the effect of quadtree-based data compression on the diagnostic yield of CT images. Seventy images were selected from a series of consecutive abdominal/pelvic CT scans. Following the application of quadtree-based compression, all images were reviewed independently by three radiologists. The images were analyzed at six decreasing irreversible compression ratios (30.6:1 to 7.4:1), as well as after reversible compression (2.9:1). ROC curves reveal a gradual decrease in clinical accuracy with increasing compression ratios. At a compression ratio of 7.4:1, sensitivity for all major abnormalities was 99% with a specificity of 93%. As the compression ratio was increased to 30.6:1, sensitivity and specificity dropped to 75% and 83% respectively. Execution times for compression and decompression of the CT images with a PC-AT based digital radiography system varied from 24.7 to 18.5 seconds and from 16.2 to 5.1 seconds respectively, decreasing with higher levels of compression. We conclude that quadtree-based compression of abdominal CT images may have practical applications for a PC based digital radiography system.

Algorithms↗

Application of region of interest definition to quadtree-based compression of CT images.

A quadtree-based data compression algorithm can provide different levels of compression within and outside of regions of interest (ROIs). The current study shows whether ROI compression can provide greater compression or diagnostic accuracy than uniform quadtree compression. In 75 single CT images from 75 consecutive abdominal examinations, 43 abnormalities were identified and surrounded by ROIs. Three radiologists interpreted the images following (1) 50:1 compression of the entire image; (2) ROI compression at five decreasing compression ratios (with 50:1 compression outside the ROI); and (3) reversible (lossless) compression of the entire image. Reversible compression (compression ratio 3:1) yielded a sensitivity of 96%. ROI compression of 15:1 was achieved with no loss of sensitivity; ROI compression of 28:1 yielded a sensitivity of 91% (not significantly different). At any given compression ratio, diagnostic sensitivity was greater with ROI compression than with uniform quadtree compression. For purposes of image archiving, quadtree-based ROI compression is superior to uniform compression of CT images.

Algorithms↗

Acute splenic sequestration crisis in two adults with sickle cell disease: US, CT, and MR imaging findings.

Acute splenic sequestration crisis (ASSC) is a rare complication in adults with sickle cell disease that is diagnosed clinically by means of sudden splenic enlargement and a rapid fall in hematocrit. Two cases of ASSC in adults with heterozygous sickle cell disease (sickle cell-thalassemia and sickle cell-hemoglobin C disease) were studied with use of duplex Doppler ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging. In both cases, US showed patency of the splenic vein and multiple hypoechoic lesions on the periphery of an enlarged spleen that were of low attenuation on CT scans and hyperintense on both T1- and T2-weighted MR images. These findings were believed to be suggestive of subacute hemorrhage. This was confirmed pathologically in one case and suggested in the other by the presence of a low-signal-intensity ring, probably hemosiderin, surrounding one of the lesions. Also, the remainder of the spleen in both patients was of normal signal intensity, unlike the diminished signal intensity seen in patients with homozygous sickle cell disease. Further study is needed to determine the role of imaging in the diagnosis and treatment of ASSC.

Adult↗