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K Nelson

Publications and source records attributed to K Nelson.

At least 19 recordsLinked to original sources
PubMed2007

Familial trends of inheritance in gastro esophageal reflux disease, Barrett's esophagus and Barrett's adenocarcinoma: 20 families.

We reported four families with familial Barrett's esophagus (FBE) in 1993. This follow-up study includes an additional 16 families with FBE, gastroesophageal reflux disease (GERD) and BE-related adenocarcinoma (BEAC) highlighting the familial trends of inheritance. A retrospective survey of endoscopic and histopathological reports on 95 confirmed cases of BE from 1975 to 2005 was performed and a detailed family history was obtained. Five representative pedigrees from a total of 20 are discussed here. These 20 families represent one of the largest cohorts studied over three decades from a single institution. Familial BE is more common than previously thought and the prevalence of GERD, BE and BEAC in these families is distinctly higher than with sporadic cases. The conditions appear to be inherited in an autosomal dominant fashion with incomplete penetrance. Hence diligence in taking family history with BE patients is critical since the endoscopic screening of relatives is warranted in FBE. Earlier diagnosis and surveillance of FBE should hopefully improve outcomes.

Adenocarcinoma↗
PubMed2005

Influence of elastic and non-elastic external Dacron mesh support on para-anastomotic hypercompliance in end-to-end anastomoses.

OBJECTIVE: To quantify the influence of elastic and non-elastic external mesh support on para-anastomotic hypercompliance in end-to-end anastomoses (ex vivo). MATERIALS: Six end-to-end anastomoses prepared from ovine carotid arteries without mesh support and with external elastic and non-elastic dacron mesh support. METHODS: Compliance profiles of the anastomised arterial segments were measured successively, in the same anastomotic configuration without mesh support, with external elastic dacron mesh support and with external non-elastic dacron mesh support (randomized order). A pulsatile ex vivo perfusion system using a laser scan micrometer to monitor outer systolic and diastolic diameter was employed. RESULTS: Median pre-anastomotic and post-anastomotic hypercompliance without external mesh support were 1.45 and 1.19%/100 mmHg, respectively, above reference compliance. Use of the elastic mesh support significantly reduced the median hypercompliance to 0.68%/100 mmHg (pre-anastomotic) and to 0.34%/100 mmHg (post-anastomotic) above reference compliance. The non-elastic mesh support caused approximately the same significantly reduced median hypercompliance to 0.53%/100 mmHg (pre-anastomotic) and 0.43%/100 mmHg (post-anastomotic). CONCLUSIONS: Both elastic and non-elastic external mesh support significantly reduced pre- and post-anastomotic hypercompliance.

Anastomosis, Surgical↗
PubMed2005

Comparison of X-ray vs. gamma irradiation of CPDA-1 red cells.

BACKGROUND AND OBJECTIVES: Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious, potential complication of blood transfusion that is essentially prevented by blood product irradiation. Blood product irradiation is currently performed using gamma irradiation. X-ray irradiation is an alternative that has certain advantages: an X-ray irradiator is less expensive and does not have a radioactive source. However, the biochemical effects of X-ray irradiation on red blood cells (RBCs) have not been well characterized. The primary purpose of our study was to compare the effects of X-ray irradiation with gamma irradiation on RBC membrane permeability. A secondary purpose was to verify that X-ray irradiation has the same effect on lymphocytes as gamma irradiation. MATERIALS AND METHODS: Ten RBC units were split into two portions; five units of each were then irradiated with either gamma or X-ray at a dose of 35 Gy or 25 Gy, respectively. Free plasma haemoglobin and extracellular potassium levels were measured in each unit over time. Another unit was divided into three parts for lymphocyte studies; one part was not irradiated as a control and the other two received 25 Gy of irradiation via X-ray or gamma irradiation, respectively. RESULTS: Minimally increased free plasma haemoglobin was found only in X-ray-irradiated units after 25 Gy compared to gamma-irradiated units. However, extracellular potassium levels were not significantly different in these groups. Extracellular potassium levels were slightly higher only in gamma irradiated units at 35 Gy. X-ray and gamma irradiation were equivalent in affecting lymphocyte function. CONCLUSIONS: Small differences in RBC membrane permeability are found between gamma-irradiated and X-ray-irradiated units. However, these differences are not likely to be clinically important.

Adenine↗
PubMed2004

[Abdominal aortic aneurysm: screening and surveillance].

A screening program for infrarenal abdominal aortic aneurysm (AAA) has limited cost-effectiveness. Yet, screening of the subpopulation of smoking men aged 60-75 years, or men and smoking women with a family history of vascular diseases or other cardio-vascular co-morbidity is cost-effective and has been demonstrated. It is suited to halve the increasing mortality of AAA. Elective repair of AAA is justified at diameters larger than 5.5 cm for men, but uncertain for women. However, aortic diameters between 4.5 and 5 cm in women probably necessitate an invasive approach. Surveillance of patients who still not meet these criteria should not only include the absolute diameter of the aneurysm, but direct individuals with aneurysms at an annual expansion rate of more than 0.5 cm to elective repair.

Animals↗
PubMed2003

Agrobacterium tumefaciens-mediated creeping bentgrass (Agrostis stolonifera L.) transformation using phosphinothricin selection results in a high frequency of single-copy transgene integration.

Genetic transformation of creeping bentgrass mediated by Agrobacterium tumefaciens has been achieved. Embryogenic callus initiated from seeds (cv. Penn-A-4) was infected with an A. tumefaciens strain (LBA4404) harboring a super-binary vector that contained an herbicide-resistant bar gene driven either by the CaMV 35S promoter or a rice ubiquitin promoter. Plants were regenerated from 219 independent transformation events. The overall stable transformation efficiency ranged from 18% to 45%. Southern blot and genetic analysis confirmed transgene integration in the creeping bentgrass genome and normal transmission and stable expression of the transgene in the T1 generation. All independent transformation events carried one to three copies of the transgene, and a majority (60-65%) contained only a single copy of the foreign gene with no apparent rearrangements. We report here the successful use of Agrobacterium for the large-scale production of transgenic creeping bentgrass plants with a high frequency of a single-copy transgene insertion that exhibit stable inheritance patterns.

Agrobacterium tumefaciens↗
PubMed2002

Bilateral third and unilateral sixth nerve palsies as early presenting signs of metastatic prostatic carcinoma.

PURPOSE: To report four cases of cranial nerve palsy, which presented to the ophthalmologist as the only or one of the earliest manifestations of prostatic carcinoma. This is an infrequent complication of metastatic prostatic carcinoma usually only occurring late in the disease process in those with a history of prostatic carcinoma. METHODS: The case records of four patients with a history of a cranial nerve palsy who attended the ophthalmology department and who had a recent or subsequent diagnosis of prostatic carcinoma were reviewed. RESULTS: Diplopia caused by lesions affecting the third and sixth nerves sometimes in association with sensory symptoms may be a manifestation of metastatic prostatic carcinoma. These findings are consistent with base of the skull metastases from the condition. Two patients are still alive 54 months and 12 months after the diagnosis. One of the patients died 13 months after the diagnosis of prostatic carcinoma was made and the other died 21 months after the diagnosis from an unrelated hypertensive brain haemorrhage. CONCLUSIONS: Any patient presenting with diplopia must have an adequate past medical history taken and in an elderly gentleman this should include symptoms of prostatic disease. If indicated urological referral and measurement of prostate specific antigen may be performed. In patients whose cranial nerve palsy is complicated by other sensory signs or those in whom no sign of recovery occurs in 2 months, a contrast CT scan asking for bone windows to be included may be helpful in delineating any pathology. Radiotherapy may be useful for the treatment of metastatic prostatic carcinoma causing cranial nerve palsies with some patients experiencing either complete or partial resolution of their symptoms. The effect of newer hormonal agents or chemotherapy on this aspect of the disease is not well documented in current literature.

Abducens Nerve Diseases↗
PubMed2002

Impact of weight loss on the metabolic syndrome.

AIM: Individuals with the metabolic syndrome (MS), a clustering of risk factors [triglycerides, glucose, high-density lipoprotein cholesterol, blood pressure (BP), abdominal obesity] defined by the National Cholesterol Education Program (NCEP), are at high risk for coronary heart disease and type 2 diabetes mellitus, and may benefit from aggressive lifestyle modification. METHODS: We reviewed 1 year of consecutive patients' charts to determine the prevalence of the MS in obese individuals enrolled in a medically supervised rapid weight loss programme, the correlation of weight change with the components of the MS, and response to diet-induced weight loss. RESULTS: Out of 185 individuals, 125 (68%) met the NCEP definition of the MS. A moderate decrease in weight (6.5%) induced by a very low calorie diet (VLCD) resulted in substantial reductions of systolic (11.1 mmHg) and diastolic (5.8 mmHg) blood pressure (BP), glucose (17 mg/dl), triglycerides (94 mg/dl) and total cholesterol (37 mg/dl) at 4 weeks (all p < 0.001). These improvements were sustained at the end of active weight loss (average 16.7 weeks; total weight loss 15.1%), with further significant reductions in BP and triglycerides. Weight loss was related to the changes in each criterion of the metabolic syndrome. CONCLUSIONS: The MS is prevalent in two-thirds of obese individuals enrolling in a structured weight loss programme. Moderate weight loss with a VLCD markedly improved all aspects of the MS.

Blood Pressure↗
PubMed2002

Rats' preferences for corn versus wood-based bedding and nesting materials.

Corn by-products can be used as bedding and nesting products. Corn-cob bedding resists ammonia build-up and corn-husk nesting material resists dampness. It is not clear whether these advantages are at the expense of animal comfort. Corn cob was compared to aspen chip bedding, and corn husk to paper strip nesting material. Data from 20 rats with differential early bedding experience suggested that they prefer aspen chip, but are also biased towards the bedding they were raised on. Data from 10 rats with no prior nesting material experience suggested that paper strip was preferred over cornhusk. Thus, corn-cob products are not recommended except in situations where air quality and/or flooding are significant problems.

Animal Husbandry↗
PubMed2002

Automatic patient registration in computer assisted maxillofacial surgery.

In this paper, a new approach for patient registration in computer assisted maxillofacial surgery is presented. The method uses a unique structure of markers embedded in a reference frame for the automatic detection of the coordinate system of the medical imaging data during the surgical intervention. With the new method, the inaccurate and time consuming process of manually identifying markers in the data volume and manually teaching them to a navigation system can be replaced. The method and algorithms for the automatic marker detection are described in this paper. Experiments with 45 data sets of patients proove the robustness, usability and safety of the new method. The method has been integrated into the navigation system RoboDent for dental implant surgery.

Algorithms↗
PubMed2001

Comparison of Sarcocystis neurona isolates derived from horse neural tissue.

Sarcocystis neurona is a protozoan parasite that can cause neurological deficits in infected horses. The route of transmission is by fecal-oral transfer of sporocysts from opossums. However, the species identity and the lifecycle are not completely known. In this study, Sarcocystis merozoites from eight isolates obtained from Michigan horses were compared to S. neurona from a California horse (UCD1), Sarcocystis from a grackle (Cornell), and five Sarcocystis isolates from feral opossums from Michigan. Comparisons were made using several techniques. SDS-PAGE analysis with silver staining showed that Sarcocystis spp. from the eight horses appeared the same, but different from the grackle isolate. One Michigan horse isolate (MIH6) had two bands at 72 and 25kDa that were more prominent than the UCD1 isolate and other Michigan horse isolates. Western blot analysis showed that merozoites of eight of eight equine-derived isolates, and the UCD1 S. neurona isolate had similar bands when developed with serum or CSF of an infected horse. Major bands were seen at 60, 44, 30, and 16kDa. In the grackle (Cornell) isolate, bands were seen at 60, 44, 29, and 16kDa. DNA from merozoites of each of the eight equine-derived isolates and the grackle-derived isolate produced a 334bp PCR product (Tanhauser et al., 1999). Restriction fragment length polymorphism (RFLP) analysis of these horse isolates showed banding patterns characteristic for S. neurona. The grackle (Cornell) isolate had an RFLP banding pattern characteristic of other S. falcatula species. Finally, electron microscopy examining multiple merozoites of each of these eight horse isolates showed similar morphology, which differed from the grackle (Cornell) isolate. We conclude that the eight Michigan horse isolates are S. neurona species and the grackle isolate is an S. falcatula species.

Animals↗
PubMed2001

In-use light-duty gasoline vehicle particulate matter emissions on three driving cycles.

Twenty-four properly functioning and six high carbon monoxide emission light-duty gasoline vehicles were emission tested in Denver, CO, using the Federal Test Procedure (FTP), a hot start Unified Cycle (UC), and the REP05 driving cycles at 35 degrees F. All were 1990-1997 model year vehicles tested on both an oxygenated and a nonoxygenated fuel. PM10 emission rates for the properly functioning vehicles using oxygenated fuel averaged 6.1, 3.6, and 12.7 mg/mi for the FTP, UC, and REP05, respectively. The corresponding values for the high emitters were 52, 28, and 24 mg/mi. Use of oxygenated fuel significantly reduces PM10 on the FTP, with all the reduction occurring during the cold start. MOUDI impactor samples showed that 33 and 69% of the PM mass was smaller than 0.1 microm for the FTP and REP05 cycles, respectively, when collected under standard laboratory conditions. Particle number counts were much higher on the REP05 than the FTP. Counts were obtained using secondary dilution of samples drawn from the standard dilution tunnel. FTP PM10 was mostly carbonaceous material, 36% of which was classified as organic. For the REP05, as much as 20% of the PM10 was sulfate and associated water. Forty-five percent of the REP05 PM carbon emissions was classified as organic. Driving cycle had a significant impact on the distribution of the emitted polynuclear aromatic hydrocarbons.

Automobile Driving↗
PubMed2001

Phase 1 trial of the topical microbicide BufferGel: safety results from four international sites.

AIM: To evaluate the safety of BufferGel (ReProtect LLC, Baltimore, MD), a spermicidal microbicide that acidifies semen and maintains the protective acidity of the vagina, in a high-dose tolerance trial. METHODS: HIV/STD negative, sexually abstinent, and sexually active women in India, Thailand, Malawi, and Zimbabwe were asked to insert one applicator ( approximately 5 ml) of BufferGel vaginally twice per day for 14 days. Sexually active women agreed to have sex (while using BufferGel and nonlubricated condoms) at least twice per week. RESULTS: In total, 98 women (30 sexually abstinent and 68 sexually active) were enrolled. Overall compliance with product use was 93%. Epithelial abnormalities detected by pelvic examination or colposcopy were uncommon (8 cases in 271 examinations). Irritation was reported by approximately one quarter of the women (0.58 events per woman-week) but was generally mild and of short duration. The prevalence of bacterial vaginosis (BV) fell significantly, from 30% at enrollment to 6% at one week, and 7% at two weeks of BufferGel use. Thirty-two women acquired microscopically detectable yeast during BufferGel exposure, but only 3 developed symptomatic vaginitis. CONCLUSION: BufferGel appears to be safe and well tolerated by the cervicovaginal epithelium. Its effect on BV and yeasts merits further study.

Acrylic Resins↗
PubMed2001

Rapid assays for detection of anti-islet autoantibodies: implications for organ donor screening.

The purpose of the current study was to develop and evaluate rapid assays for autoantibodies to GAD65 (GAA), ICA512bdc/IA-2 (ICA512AA), and insulin (microIAA, mIAA) as a potential tool for identification of cadaveric pancreas donors who were at high risk for developing diabetes. The study included 154 new onset diabetic, prediabetic, and healthy control subjects. Subjects were evaluated for all three autoantibodies in three separate assays: (1) standard (std) assay with a 24-h or 72-h incubation at 4 degrees C (combined GAA/ICA512AA or mIAA, respectively), (2) rapid assay with 1-h room temperature (RT) incubation, and (3) rapid assay with 2-h RT incubation. The serum samples from 777 organ donors were also evaluated for all three autoantibodies and all the positive samples from standard assay evaluated with the 1-h incubation assay. Simple linear regression analyses revealed excellent correlation between the standard assay and the rapid assays for all three autoantibodies, as follows: (1) GAA: std vs. 1 h (R2=0.85) and std vs. 2 h (R2=0.83), (2) ICA512AA: std vs. 1 h (R2=0.85) and std vs. 2 h (R2=0.84), and (3) mIAA: std vs. 1 h (R2=0.70) and std vs. 2 h (R2=0.64). Comparison of assay correlation rates between subject cohorts revealed no significant differences. Compared to their respective standard assays, the 1-h RT GAA assay missed 3.2% and identified an additional 1.3% of samples, the 1-h RT ICA512AA assay had no discordant samples, and the 1-h RT mIAA assay missed 7.1% and identified an additional 5.8% of samples. We analysed a series of 777 stored serum samples from cadaveric donors. Two of 777 (0.25%) were positive for two autoantibodies (both GAA and ICA512AA) and 23 of 777 (3.0%) one autoantibody (11 IAA; 12 GAA). The rapid analysis for all three autoantibodies could be completed in less than 3 h with comparable concordance rates to the more time-consuming standard assays, making these assays an attractive option for organ donor screening to identify potential pancreata for immunopathogenetic research.

Adolescent↗
PubMed2001

[Quantitative computerized tomography of bone mineral density of the mandible. Imaging of topographic distribution of bone mineral density in automated segmentation of mandibular structures].

PURPOSE: Confirmation of a new technique for evaluating bone mineral density (BMD). Colored coded imaging of topographical distribution of bone mineral density in the spongy substance. METHOD: For 20 patients, dental CT examinations of the mandible were made in axial slices. Spongy substance and cortical bone pixels were automatically segmented at foramina mentalia level by means of threshold fixation. The segments were separated in areas relevant to implantology. For each region, BMD was measured by means of quantitative computed tomography (QCT). Spongiose substance of 20 mandibles was segmented by using three threshold intervals to image topographical BMD distribution. RESULTS: Cortical bone and spongy substance could be automatically segmented for 20 mandibles. BMD could be measured in each region. The results were comparable with those of other techniques. Three threshold intervals were segmented for 20 mandibles in the spongy substance to depict topographical BMD distribution. CONCLUSIONS: Areas of low BMD can be detected by imaging topographical BMD distribution. This way, subjective rating by the examiner is eliminated.

Adolescent↗
PubMed2001

Evaluation and treatment of cancer-related fluid deficits: volume depletion and dehydration.

Fluid deficits should be divided into two categories (dehydration and volume depletion) according to pathophysiology and into 3 categories (hyponatremic, hypernatremic, and isotonic) according to the plasma sodium concentration. Dehydration (total water deficit especially intracellular) is always hypernatremic, while volume depletion (intravascular water and sodium deficit) is either hyponatremic, hypernatremic, or isotonic. There are no clear clinical differences among the various categories, but a delay of capillary refill, tachycardia, and orthostatic hypotension are more common with early volume depletion. An Evans blue and mannitol test can be used to distinguish between hypernatremic volume depletion and dehydration. Careful clinical assessment and laboratory tests (especially serum sodium) are the key to diagnosis and effective management. According to the type (hypernatremic, hyponatremic, or isotonic), severity of fluid deficit, and associated symptoms, oral or parenteral fluid should be given along with treatment of the underlying cause. In hemodynamically compromised individuals with orthostatic hypotension and oliguria, replacement with isotonic saline until hemodynamic stabilization is crucial. Terminal hydration is still controversial. Important ethical principles govern clinical decision-making about hydration at the end of life.

Dehydration↗