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Biomedical subjects

M D Ellison

Publications and source records attributed to M D Ellison.

At least 19 recordsLinked to original sources
PubMed2001

The OPTN waiting list, 1988-2000.

More patients in the United states are waiting for organ transplants that at any time in the past and the remarkable growth of the UNOS waiting list has become a key issue for the transplant community. 1. On October 31, 2001, there were 84,277, registrations on the combined UNOS waiting list. Among these, 63% were awaiting kidney transplantation, and 22% were awaiting liver transplantation. 2. The majority of patients on the UNOS waiting list on October 31, 2000, were of blood type O (52%), white (55%) and male (58%), and awaiting their first transplant (87%). 3. The percentage transplanted within one year of listing has been declining for most organs, although that percentage has been somewhat stable for heart and lung between 1998-2000. 4. Blood type and medical urgency have a significant impact upon the percent transplanted within one year of listing for most organ types. Patients awaiting heart, pancreas, and intestinal transplants experience the highest probability of receiving a transplant within one year. 5. Deaths per patients waiting have declined since 1988 for most patients awaiting life-saving organs and have remained relatively low for those awaiting a kidney, pancreas, or kidney-pancreas transplant. Deaths were highest for lung and heart-lung patients, but appear to be declining.

Adolescent↗
PubMed2000

Cycloaddition chemistry of organic molecules with semiconductor surfaces.

Recent investigations have shown that cycloaddition reactions, widely used in organic chemistry to form ring compounds, can also be applied to link organic molecules to the (001) surfaces of crystalline silicon, germanium, and diamond. While these surfaces are comprised of Si=Si, Ge=Ge, and C=C structural units that resemble the C=C bonds of organic alkenes, the rates and mechanisms of the surface reactions show some distinct differences from those of their organic counterparts This article reviews recent studies of [2 + 2], [4 + 2] Diels-Alder, and other cycloaddition reactions of organic molecules with semiconductor surfaces and summarizes the current understanding of the reaction pathways.

Alkenes↗
PubMed1999

Avoidance of primary post-tonsillectomy hemorrhage in a teaching program.

OBJECTIVE: To determine the incidence of primary post-tonsillectomy hemorrhage in a teaching institution by using a uniform technique, including a 3-minute relaxation of retraction before case termination and the use of bismuth subgallate. DESIGN: Case series. SETTING: Tertiary care academic pediatric center. PATIENTS: A 7-year retrospective study was performed by using the medical records of 1286 children without a bleeding abnormality who underwent tonsillectomy (with or without adenoidectomy). A uniform technique, proposed to reduce hemorrhage, was used for 705 children and was not used for 581 children. RESULTS: No episodes of primary hemorrhage (onset < or = 24 hours after surgery) occurred, and the incidence of delayed hemorrhage (onset >24 hours after surgery) was 1.1% in the study group. The primary hemorrhage rate of the study group was significantly lower (P = .007) than the rate for the reference group (0.0% vs 1.0%), as was the total hemorrhage rate (1.1% vs 4.1%) and the delayed hemorrhage rate (1.1% vs 3.1%). CONCLUSION: A uniform technique including the use of bismuth subgallate and reassessment of the tonsillar fossae after a 3-minute observation period reduces the incidence of primary tonsillar hemorrhage in a teaching institution setting.

Academic Medical Centers↗
PubMed1999

Screening for cancers of the head and neck: addressing the problem.

More than 90% of upper aerodigestive tract (UADT) cancers occur in people with specific lifestyle risks, including tobacco and alcohol use. More than 90% of tumors occur in easily examined parts of the head and neck, therefore, there is the possibility of identifying the vast majority of patients through selective screening. Physicians should keep in mind that the mucosa's sojourn from visually suspicious (and possibly malignant) tissue is most likely less than two years, and frequent examination of asymptomatic patients is necessary. When patients wait to bring symptoms to medical attention, their cancers will be advanced 60% of the time when the chance of cure is less than 30%. Given the difficulty of implementing regular examinations in a poorly compliant, high risk population, genetic and molecular screening tools may allow very high risk individuals to be identified.

Alcohol Drinking↗
PubMed1999

The UNOS OPTN waiting list, 1988-1998.

1. On October 31, 1999, there were 71,024 registrations on the combined UNOS waiting list. Of these, 64% were awaiting kidney transplantation and 20% were awaiting liver transplantation. 2. The majority of patients on the UNOS waiting list on October 31, 1999 were blood type O (52%), White (59%) and male (58%), and awaiting their first transplant (85.9%). 3. Median waiting times have increased steadily for nearly every organ since 1988, especially for liver, kidney, and lung registrants. 4. Median waiting times to transplant were longest for kidney registrants (938 days). The shortest waiting times for this cohort were experienced by intestine registrants (161 days). 5. Death rates per patients waiting at risk have been declining for most patients awaiting life-saving organs and have remained relatively stable for those awaiting for a kidney transplant. Deaths for intestinal patients have risen every year since the list was created (1993), but appears to be stabilizing.

Adolescent↗
PubMed1998

Report of the first case of invasive fungal sinusitis caused by Scopulariopsis acremonium: review of scopulariopsis infections.

Scopulariopsis acremonium is a species of saprophytic fungus not previously reported to cause invasive disease in humans, although invasive infections from other species of Scopulariopsis have been reported and are reviewed. Deep infection with this fungus is associated with a high mortality rate. Invasive fungal sinusitis, in general, is a potentially fatal disease that typically affects immunocompromised patients, such as those receiving intensive chemotherapy or undergoing bone marrow transplantation. We report a case of invasive fungal sinusitis caused by Scopulariopsis acremonium in a patient with leukemia, who was successfully treated with amphotericin B, itraconazole, endoscopic sinus surgery, and granulocyte colony-stimulating factor.

Antineoplastic Agents↗
PubMed1998

Race and socioeconomic factors influencing early placement on the kidney transplant waiting list.

This cohort study investigates whether there are inequities in the current system for listing patients for cadaveric renal transplantation, using univariate and multivariate analyses to identify factors associated with early registration before initiation of dialysis. It includes patient registrations for the kidney and kidney-pancreas waiting lists between April 1, 1994, and June 30, 1996 (n = 41,596) from all 238 United Network for Organ Sharing renal transplant centers. Patient and center factors predicting dialysis status (pre- or postdialysis initiation) at the time of registration were examined. Independent predictors of listing before dialysis (P < 0.001) included: female (odds ratio [OR] = 1.14, reference: male, i.e., listing before dialysis was 14% more likely in females than in males); age < or =17 and age 18 to 55 (OR = 1.91 and 1.14, respectively, reference: age >55); prior transplant (OR = 1.80, reference: no prior transplant); 0 to 8 yr education, attended college, and received a college degree (OR = 0.78, 1.18, and 1.37, respectively, reference: high school degree); black race, Hispanic, and Asian/other (OR = 0.47, 0.59, and 0.55, reference: white); full-time employment (OR = 1.98, reference: less than full time); payment with Medicare and private insurance (OR = 0.35 and 1.24, respectively, reference: other pay); receiving insulin (OR = 1.29, reference; not on insulin); listed for kidney-pancreas (OR = 1.43, reference: listed for kidney only); listed at a center with volume >400 (OR = 1.22, reference: volume <400). To remove possible bias for general access to health care and referral for transplantation, the analysis was limited to patients who had a previous transplant and found similar results. It is concluded that racial and ethnic minorities, those less well educated, and those with fewer financial resources are less likely than their counterparts to be listed for renal transplantation before dialysis. These results suggest there may be remediable inequities in the current system for registration for renal transplantation in the United States. Education efforts directed at patients and providers, as well as recently mandated uniform listing criteria for cadaveric organ transplantation, may help to reduce these inequities.

Adolescent↗
PubMed1998

The UNOS OPTN waiting list and donor registry.

1. On October 31, 1998, there were 62,994 registrants on the combined UNOS waiting list. Of these, 66% were awaiting kidney transplantation, and 18% were awaiting liver transplantation. 2. The majority of patients on the UNOS waiting list on October 31, 1998 were blood type O (52%), White (60%) and male (58%). 3. Median waiting times (MWTs) have increased steadily for nearly every organ since 1988, especially for liver, kidney, and lung registrants. 4. For patients added to the waiting list in 1996. MWTs to transplant were longest for heart-lung registrants (742 days). The shortest waiting times for this cohort were among heart registrants (223 days). No median could be calculated for kidney registrants added in 1996. 5. Death rates per patients waiting at risk declined during 1988-1997. Death rates were higher for patients awaiting life-saving organs (liver, heart, lung, heart-lung) than for non-lifesaving organs (kidney, pancreas, kidney-pancreas). 6. There were 5,478 cadaveric and 3,820 living donors recovered in 1997, a 34% and 109% increase over those recovered in 1988. 7. Large increases were seen in the number of liver (45-84%), pancreas (14-24%), and lung (3-15%) donors between 1988-1997. 8. The number of cadaveric donors aged 50 or older has increased from 12% of all donors in 1988 to 28% of all donors in 1997. 9. The typical cadaveric donor in 1997 was a white male with ABO blood type O, between the ages of 18-34. In 1997, a typical living donor was a white female with ABO blood type O between the ages of 35-49. 10. Between 1988-1997, the percentage of minority donation increased for cadaveric donors (17-24%), and for living donors (23-27%). 11. The number of living donors who were either spouses or unrelated to the recipient increased from 4% in 1988 to 15% in 1997.

ABO Blood-Group System↗
PubMed1996

When perfectly HLA-matched kidneys are refused for transplant: implications for a national cooperative sharing system.

BACKGROUND: The transplant community attempts to maximize overall renal graft survival rates through nationwide sharing of perfectly-matched cadaveric kidneys. Although the number of such transplants is determined annually, the number available but not transplanted has never been assessed. There has also been no verification of the widespread claim that kidneys transplanted as paybacks for perfect matches are inferior. STUDY DESIGN: From records of the United Network for Organ Sharing, a complete accounting of six-antigen-matched kidney disposition was obtained, including a frequency distribution of reasons for refusal given when kidneys were refused for matched patients. Actuarial graft survival (GS) rates for matched, payback, and other cadaveric renal transplants were determined. RESULTS: Of the six-antigen-matched kidneys available, 97 percent were transplanted; 71 percent of those were accepted for matched patients. The two-year GS rate for matched patients was 84 percent, significantly higher than that for kidneys available for matched patients but transplanted into other patients (71.3 percent) and that for all other cadaveric kidneys (75.5 percent). Most reasons for refusal were related to donor quality. Kidneys refused for such reasons showed a 67.7 percent two-year GS rate in nonmatched patients and the highest rates of acute and chronic rejection and primary failure. The two-year GS rate for kidneys accepted as paybacks for matched kidneys (75.7 percent) was equivalent to that for all non-matched cadaveric kidneys (75.5 percent). CONCLUSIONS: If all normal-quality grafts refused for perfectly matched patients during 1990 through 1992 had been accepted for those patients, the number of transplants with typically superior survival rates could have increased by 25 percent, from 1,365 to 1,704. The payback requirement of the United Network for Organ Sharing does not seem to reduce the overall benefits of sharing perfectly matched kidneys nationwide.

Cadaver↗