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Biomedical subjects

K Rogers

Publications and source records attributed to K Rogers.

144 records · Page 8Linked to original sources
PubMedDate not supplied

Reduced GAP-43 message levels are associated with increased neurofibrillary tangle density in the frontal association cortex (area 9) in Alzheimer's disease.

We previously suggested the hypothesis that defective neuronal plasticity is a major neurobiological deficit causing the dementia of Alzheimer's disease (AD). We used message levels of the growth-associated protein, GAP-43, as a marker of axonal plasticity to examine the hypothesis of defective neuronal plasticity in AD. When all AD cases are combined, the average level of GAP-43 message in area 9 of the AD frontal association cortex was not significantly different from the level in the comparably aged control cortex. Differentiation of AD cases on the basis of neurofibrillary tangle (NFT) density revealed that in AD cases with high tangle density average GAP-43 message level was reduced fivefold relative to levels in AD cases with low NFT density. AD cases with low neurofibrillary tangle density had levels of GAP-43 message that were not significantly different from the levels of normal controls. Differentiation of AD cases on the basis of neuritic plaque density did not indicate as strong a relationship to GAP-43 message level. The association between neurofibrillary tangle density and GAP-43 message level suggests the hypothesis that neurofibrillary tangles may reduce GAP-43 expression. Data of others show a relationship between high NFT density and reduced levels of synaptophysin-like immunoreactivity and reduced cerebral glucose metabolism. These data combine to suggest a set of AD cases with high NFT density, reduced axonal plasticity, reduced synaptic density, and reduced cerebral glucose metabolism--all variables that may be directly related to the functioning of the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

Parameters for and safety of contact Nd:YAG laser irradiation of early gastric cancer: an in vitro study.

Early gastric cancers have been treated by endoscopic contact Nd:YAG laser irradiation. The extent of thermal damage produced by this laser system has been inadequately investigated. In an in vitro study we have shown that contact laser probes produce consistent and reproducible thermal lesions in the human stomach wall. Contact laser energies of 40 to 60 joules are optimal for the ablation of early gastric cancer. Energies greater than 90 joules are associated with a high incidence of gastric perforation. Contact laser probes may have advantages over non-contact laser techniques for the endoscopic treatment of early gastric cancer in patients who are unfit for major surgery.

Adenocarcinoma↗
PubMedDate not supplied

Efficacy of 24-hour shifts: prepared or impaired? A prospective study.

BACKGROUND: The effect of duty duration on performances is unknown. In a prospective cohort study model using repeated measures, we evaluated the effect of shift length on a battery of neuropsychologic performance indicators using our flight program as the test site. METHODS: Flight nurses completing 24- and 12-hour shifts were tested on memory, attention, reasoning, motor, and speed measures. Ratings of stress, fatigue, sleep quality, and logged amount of work and sleep were evaluated from personal journals kept for this purpose. Data were analyzed by linear regression and repeated measures multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA). Clinical significance was set at P < 0.05. RESULTS: Fifteen subjects completed the testing and evaluation process. Neuropsychologic testing demonstrated that performance was not predicted by shift length, time of shift (day versus night), amount or quality of sleep before or during shift, or fatigue ratings. Age, gender, and education did not mediate shift length/test performance relationships. Uninterrupted sleep, stress ratings, and number of flights per shift modestly reduced some test scores. Predictably, repeated testings resulted in practice effects that reduced analysis power. We found that 24-hour shifts per se do not result in a cognitive decline compared with 12-hour shifts. Inconsistent sleep, number of flights, and the stressfulness of flights may have greater impact.

Air Ambulances↗
PubMedDate not supplied

Surgery for gastric cancer.

Radical dissection for gastric cancer is not widely practiced in the West. This paper reviews the evidence in support of lymphadenectomy and the techniques of radical resection as practiced by Japanese surgeons. We believe the published results support increased use of radical surgery in the treatment of gastric cancer and would recommend further adoption of this technique as there is minimal associated morbidity.

Gastrectomy↗
PubMedDate not supplied

The effect of ambient temperature on the shoe-surface interface release coefficient.

Previous studies of the shoe-surface interface correlated foot fixation with cleat length, configuration, and material composition as well as turf type and surface conditions. Our study examined the effect of temperature on the rotational torsion resistance of artificial turf football shoes. Five football shoe models, a flat-soled basketball-style turf shoe, a natural grass soccer-style shoe, and three multistudded turf shoes, were studied on dry Astro Turf at five temperatures (range, 52 degrees F to 110 degrees F). An assay device, a prosthetic foot mounted on a loaded stainless steel shaft, was used to determine the force necessary to release a shoe from the turf's surface. We used a torque wrench to apply a rotational force so that each shoe was pivoted counterclockwise through an arc of 60 degrees. Our results indicated that release coefficients differ within and among the shoe models at various turf temperatures. We also found that an increase in turf temperature, in combination with cleat characteristics, affects shoe-surface interface friction and potentially places the athlete's knee and ankle at risk of injury. Based on an established risk criterion, which correlated shoe-surface interface combinations in the laboratory with documented clinical occurrences, only the flat-soled basketball-style turf shoe could be designated "safe" or "probably safe" at all five temperatures.

Ankle Injuries↗
PubMedDate not supplied

Long-term health and predictors of survival for hyperthyroid cats treated with iodine 131.

Two hundred thirty-one cats treated with radioactive iodine at the Texas Veterinary Medical Teaching Hospital were followed for a median of 25 months by means of an ambidirectional (prospective, retrospective) cohort study design. Cox proportional hazards models were used to determine predictors of survival based on data at the time of hyperthyroid diagnosis (collected retrospectively) and found that only age at diagnosis and sex of the cat were predictors of survival. Increasing age (for each year of age, relative risk [RR] = 1.2, 95% confidence interval [CI] = 1.1-1.3) and being male (RR = 0.68, 95% CI = 0.5-0.9) increased likelihood of death. Tables predicting survival after diagnosis and treatment of hyperthyroidism for various age and sex combinations were created. In addition, Cox proportional hazard models were run with all data available at the end of the study (collected retrospectively and prospectively) including number and type of major health problems reported at the time of death or censoring. In this model, significant factors were age at diagnosis, sex, and either type of major health problem or number of health problems. Cats with renal disease or cancer were more likely not to survive and increasing from none to 2 health problems also decreased survival. Renal problems and cancer were the most common health problems at the time of death or censoring. This study provides estimates of duration of survival for cats successfully treated for hyperthyroidism with radioactive iodine, which can be useful in assisting with client treatment decisions.

Age Factors↗
PubMedDate not supplied

A patient pathway to renal replacement therapy: implementation in the progressive renal insufficiency population.

Care paths and patient pathways are collaborative interdisciplinary tools developed to provide quality care. One goal in progressive renal insufficiency (PRI) care is to provide patients and family members with relevant and timely information to help them cope with medical therapy and lifestyle changes required to slow the progression of renal insufficiency. At Halton Healthcare Services, clinical and patient pathways have been widely used with success. Recognizing the potential benefits of a patient pathway for the PRI population, our interdisciplinary team developed a pathway that outlines the journey to renal replacement therapy. The pathway provides the patient with some insight into the future, as their disease process continues to have impact on their life. Reviewed by a patient within our PRI program during the development process, we have tailored this pathway to meet the needs of this unique population. We predict this patient pathway will have positive impact on the patient's understanding of the role of the PRI clinic and the partnership between the team members, the patient, and the family.

Continuity of Patient Care↗
PubMedDate not supplied

Treatment of cytomegalovirus gastrointestinal ulceration in a heart transplant patient.

A 62-year-old man developed cytomegalovirus gastrointestinal infection associated with moderate cardiac rejection. The patient was successfully treated with a new therapeutic agent 9-(1,3-dihydroxy-2-proproxymethyl) guanine during maximal immunosuppression. The medication was well-tolerated, and the patient had an excellent response to therapy. We believe this has significant implications for cytomegalovirus-induced gastrointestinal disease in the heart transplant patient.

Acyclovir↗