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Biomedical subjects

D Potter

Publications and source records attributed to D Potter.

At least 73 records · Page 4Linked to original sources
PubMed1988

A controlled trial of prehospital advanced life support in trauma.

We compared the outcome of 472 trauma patients who required ambulance attention and who received prehospital advanced life support (ALS) with another similar 589 patients who received only basic life support (BLS). Nontrapped, critically injured ALS patients were treated for an average of 13 minutes at the scene of injury, compared with 17 minutes for BLS cases (P less than .05). Seventeen of 37 ALS deaths (36%) occurred within 24 hours of injury, compared with 24 of 33 BLS fatalities (73%) (P less than .05). However, the overall case fatality rate was similar in the two groups, and regression analyses did not demonstrate an impact of ALS care on mortality. ALS resuscitation did not reduce the duration of hospital or intensive care unit stay, or the incidence of disability after head injury. However, the incidence of respiratory failure in the critically injured patients was 5% (ALS) and 19% (BLS) (P less than .025). ALS care appeared to influence patient outcome during the first 24 hours after injury, but had little impact on the later clinical course. Our sample size was too small to rule out any effect of ALS on in-hospital mortality. However, the improved 24-hour survival associated with ALS care suggests some benefit of prehospital resuscitation in major trauma.

Adult↗
PubMed1988

Diaphragm pacing.

Explore the source record for details and available documents.

Diaphragm↗
PubMed1988

Outcome of orthotopic liver transplantation in the aetiological and clinical variants of acute liver failure.

Thirty-three patients with acute liver failure underwent orthotopic liver transplantation, including 16 with fulminant hepatic failure, 15 with late-onset hepatic failure and two with severe acute liver failure (coagulopathy without encephalopathy). Twenty-three (70 per cent) survived to leave hospital and 21 of these are currently alive and well. Outcome correlated with the serum bilirubin level before transplantation (p less than 0.05) but no correlation was found with the variant of acute liver failure, grade of encephalopathy, cerebral oedema, serum creatinine, white cell count, prothrombin time or platelet count at the time of transplantation. Severe coagulation factor deficiencies did not constitute a clinical problem. One patient developed a neurological deficit secondary to cerebral oedema, but otherwise the morbidity reflected that observed in the general population after transplantation. Careful monitoring of intracranial pressure and surveillance (with early aggressive therapy) for bacterial and fungal infections is very important in achieving a successful outcome after transplantation.

Acute Disease↗
PubMed1987

Response of the mediastinal and thoracic viscera of the dog to intraoperative radiation therapy (IORT).

IORT may be a potentially useful adjunctive treatment combined with surgery and/or external beam irradiation in treating locally advanced lung and esophageal tumors. To begin investigation of this modality, the tolerance of intact mediastinal structures to IORT was studied using adult American Foxhounds (wt. 25-30 kg). Groups of six animals received IORT to doses of 20, 30, or 40 Gy to two separate intrathoracic ports, using 9 MeV electrons to treat a portion of the collapsed right upper lobe, and 12 MeV electrons to treat the mediastinal structures. A group of three dogs received thoracotomy with sham irradiation. Two dogs from each treatment dose group, as well as one sham-irradiated control, were sacrificed electively at 1, 3, and 12 months following IORT. There were no acute nor late IORT related mortalities. Post-operative weight loss was minimal (average 4.5% of pre-operative weight) for all dogs. Serial esophagrams showed no inflammation or ulceration. No cardiac nor pulmonary changes were noted clinically. At autopsy, the irradiated lung showed evidence of acute pneumonitis at 1 month with progressive fibrosis at 3 months and 1 year. Esophageal reactions were minimal, with only two dogs (one 30 Gy and one 40 Gy) demonstrating histologically confirmed esophagitis at 1 month. Tracheal changes were minimal. Cardiac damage was evident in the right atrial tissues. In several dogs, this cardiac damage ranged from myocardial vascular changes to frank ischemic necrosis noted at 1 and 3 months, and dense fibrosis at 1 year. The phrenic nerves showed normal function, but had evidence of perineural fibrosis. The large vessels demonstrated only mild histologic evidence of irradiation. The results of this large animal study suggest that intact mediastinal structures will tolerate small volume IORT to doses of 20 Gy without significant clinical sequellae. Although the histologic changes in the right atrium and contralateral lung are worrisome, no cardiac nor pulmonary problems arose over the 1 year follow-up. Irradiation of the contralateral lung and other sensitive structures can be reduced by careful selection of electron beam energy and use of custom lead shielding.

Animals↗
PubMed1987

Donor-specific blood transfusions versus cyclosporine--the DST story.

DST provides excellent graft survival in one- and zero-haplotype-matched donor-recipient pairs as well as a trend towards improving graft survival in HLA-identical matches; serum creatinine levels are good in functioning grafts; Imuran coverage does appear to decrease DST sensitization to the blood donor in nonsensitized patients undergoing a first transplant, which encourages early DST and transplantation in this group; flow cytometry has been extremely helpful in excluding subliminal anti-class 1 antigen activity in patients with positive B warm crossmatches alone; DST, in itself, does not appear to preclude subsequent cadaveric transplantation in patients sensitized to their blood donor; and the family history of the blood donor is known, with essentially no risk to the recipients of hepatitis, AIDS, etc. In regards to the issue of whether DST or Cs is better, both have merits, and one must be aware of the circumstances that relate to the optimum application of each therapy. Only a prospective study of DST- and Cs-treated patients with a long-term follow-up will probably resolve the issue of the optimum regimen for one-haplotype-matched living related donor-recipient pairs. The ultimate strategy may involve the selective use of each regimen for the most appropriate circumstances.

Adolescent↗
PubMed1986

Assessing cultured colonies automatically.

The number of colonies formed by macrophage colony-forming cells and high proliferation potential colony-forming cells was assessed by an image processor. The processor counted and sized colonies accurately, reproducibly, rapidly (2 s/dish) and objectively. The processor also measured the amount of light (in grey levels) the colonies transmitted. The optical density of a colony (the sum of its grey levels) was related to its cellularity. Thus the image processor compared both the number of colonies in samples and their cellularity. Samples of marrow containing high proliferation potential colony-forming cells of different proliferative capacity were prepared by injecting fluorouracil into mice and collecting their marrow 2-10 days later (marrow samples called FU2-FU10). These samples were cultured with one of three sources of synergistic factor titrated over seven dilutions. Colonies contained approx. 5 X 10(4) cells after 11 days culture but the way that FU2-FU10 marrow grew depended on the interval between treating donors with fluorouracil and collecting their marrow. Samples collected 2-4 days after fluorouracil formed more colonies containing more cells with small increases of synergistic factor whereas samples collected after 8-10 days did neither. It was important to culture samples of marrow with the appropriate synergistic factor for the interval after fluorouracil. Factor(s) derived from the 5637 cell line acted optimally on high proliferation potential colony-forming cells in samples collected 2-8 days after fluorouracil, and factor(s) derived from Wehi 3B cells on high proliferation potential colony-forming cells in samples collected 6-10 days after fluorouracil. Factor(s) derived from placental conditioned medium acted well on samples collected between 2 and 10 days. The proliferative capacity of samples of marrow could also be compared by estimating growth curves for high proliferation potential colony-forming cells in samples collected at successive intervals after fluorouracil.

Animals↗
PubMed1986

Indications for and diagnostic efficacy of open-lung biopsy in the patient with acquired immunodeficiency syndrome (AIDS).

Pulmonary infiltrates in the patient with acquired immunodeficiency syndrome (AIDS) may be associated with a spectrum of unusual neoplastic and infectious process. Transbronchial biopsy frequently reveals the cause of these infiltrates; however, when transbronchial biopsy is nondiagnostic or contraindicated, or if the patient fails to improve after a diagnostic transbronchial biopsy, further investigation is warranted to direct appropriate therapy. Efficacy of 23 open-lung biopsies in 19 AIDS patients with pulmonary infiltrates was evaluated to define the indications for and the diagnostic yield of open-lung biopsy. Pulmonary infiltrates were recognized for a mean duration (+/- standard error) of 16 +/- 2 days before open-lung biopsy and were associated with fever and cough. These patients did not have prior transbronchial biopsy, and open-lung biopsy was diagnostic in all of these. Prior transbronchial biopsy performed in the remaining 16 patients was nondiagnostic in 10. Open-lung biopsy was diagnostic in 70% of these patients (Pneumocystis carinii pneumonia, 2 patients; Kaposi's sarcoma, 3 patients; Kaposi's sarcoma and Legionella pneumophila, 1 patient; cytomegalovirus, 1 patient). The other 6 patients having a previous diagnostic transbronchial biopsy failed to improve with therapy, and open-lung biopsy resulted in a therapeutic change in 67% of these patients. Two deaths were attributable to open-lung biopsy in patients with postoperative thrombocytopenic hemorrhage. Open-lung biopsy should be performed in AIDS patients when transbronchial biopsy is nondiagnostic or contraindicated, or in patients who fail to improve with appropriate therapy after diagnostic transbronchial biopsy, especially in patients with Kaposi's sarcoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1986

Twenty years of renal transplantation in children.

Two-hundred three children 1 to 16 years of age received kidney transplants during a 20-year period, 100 from living donors and 103 from cadaver donors. The overall survival rate was 79%. Actuarial patient and kidney survival rates at 15 years were 79% and 52%, respectively, for recipients of living donor kidneys and 57% and 19%, respectively, for recipients of cadaver donor kidneys. One of two children who received transplants in 1964 was alive 20 1/2 years later. Twenty-nine children had kidneys that had functioned more than 10 years; their mean serum creatinine concentration was 1.7 mg/dL and 24 were fully rehabilitated. Eighteen were more than 2 SD below the mean height of normal children, however. Comparison of survival rates during successive 5-year intervals showed significant improvement in patient survival during the 20-year period and smaller improvements in kidney survival after 1979. Patient survival after living donor transplants during the last 10 years was 100%, and kidney survival during the last 5 years was 92%. Improvement was attributed to the effect of experience, as well as to changes in immunosuppressive therapy in 1972 and the introduction of donor-specific transfusions in 1978.

Adolescent↗
PubMed1985

Peritonitis in children undergoing continuous ambulatory peritoneal dialysis.

During a four-year period there were 77 episodes and 15 recurrences of peritonitis in 30 children treated with continuous ambulatory peritoneal dialysis for periods of one to 39 months (mean, 15.3 months). The incidence was one episode per 6.0 patient-months. Organisms cultured included Staphylococcus epidermidis (17 episodes), Staphylococcus aureus (15 episodes), and fungi (four episodes). Special culture techniques were needed to ensure a high yield of positive cultures. Peritonitis was usually treated with intraperitoneal administration of cefazolin sodium, and 61% of the episodes were treated at home. There was one death, from Candida peritonitis, and catheters were removed in 11 children because of resistant or recurrent peritonitis (eight cases) or fungal peritonitis (three cases). Peritonitis rates were highest in children who had difficulty performing bag changes aseptically but who could not be transferred to hemodialysis and in hospitalized patients.

Adolescent↗
PubMed1985

Prospective randomized study of open lung biopsy versus empirical antibiotic therapy for acute pneumonitis in nonneutropenic cancer patients.

Diffuse pulmonary infiltrates and acute respiratory compromise frequently occur in patients with cancer who are undergoing chemotherapy, and treatment remains controversial. We initiated a prospective randomized trial in 22 nonneutropenic patients to compare the efficacy of immediate open lung biopsy with that of empirical trimethoprim-sulfamethoxazole and erythromycin therapy with delayed open lung biopsy if no clinical improvement occurred after 4 days of therapy. Diagnoses included non-Hodgkin's lymphoma (15 patients), T-cell lymphoma (2), acute lymphoblastic leukemia (3), Hodgkin's disease (1), and breast cancer (1). The median age was 40 years, and fever (18) and tachypnea (13) were the most frequent signs. Median room air arterial oxygen tension in 18 hypoxic patients was 53 mm Hg; 19 patients had diffuse pulmonary infiltrates. Eight of the 10 patients randomized to empirical antibiotic therapy showed improvement after 4 days. The 2 patients whose condition did not improve and who underwent delayed open lung biopsy had Pneumocystis carinii pneumonia. One of them did show improvement, and the other died of respiratory failure. Time to clinical resolution in the 9 surviving patients was 14 days; 4 required prolonged ventilation (longer than 24 hours). Findings for the 12 patients randomized to immediate open lung biopsy were P. carinii pneumonia in 7 and nonspecific pneumonitis in 5; there were 3 deaths related to open lung biopsy. Time to resolution in the surviving patients was 13 days for those with P. carinii pneumonia and 5 days for those with nonspecific pneumonitis; 7 required prolonged ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1985

A seven-year experience with donor-specific blood transfusions. Results and considerations for maximum efficacy.

Two hundred thirty-nine transplants have been performed following donor-specific blood transfusions (DSTs) since 1978. Graft and patient survival in 1- and 0-haplotype-matched transplants with DST pretreatment is comparable to HLA-identical results through 4 years. Graft survival in 174 consecutive nondiabetic, non-HLA-identical DST recipients shows that the transfusion effect persists for at least 4 years, with graft survival of 88 +/- 3% at that time, compared with 83 +/- 4% in the concurrent HLA-identical group. Graft function, as determined by serum creatinine, was the same in both groups. Graft and patient survival in 20 0-haplotype matched pairs with DST pretreatment is 100% at 2 years. Low-dose Imuran coverage during DST administration (n = 91) was compared with a concurrent group with no Imuran (n = 93). Imuran had its maximum effect in patients undergoing their first transplant and with a pre-DST PRA less than 10% (12% vs. 21% sensitization rate in the no-Imuran group). Imuran did not appear to confer any beneficial effect in primary transplants with high PRAs and in patients undergoing a second or third transplant. The majority of patients formally excluded from transplantation because of a post-DST positive B-warm crossmatch can now be successfully transplanted with the use of flow cytometry analysis to rule out previously undetectable low levels of anti-T-lymphocyte antibodies. Of 62 patients with a positive B-warm crossmatch alone since 1982, 73% had a subsequent negative fluorescence-activated cell sorter (FACS) crossmatch permitting transplantation. Preliminary results of a DST and cyclosporine treatment study are described. In conclusion, a long-term immunologic effect of DST has been confirmed and the indications and considerations for optimum use of the DST protocol have been more clearly defined.

Adolescent↗
PubMed1985

Effect of donor-specific transfusions on renal transplantation in children.

Most family members who are evaluated as kidney donors for children have high reactivity in a mixed lymphocyte culture test and are thus excluded from donation. Fifty children, most of whom had highly reactive mixed lymphocyte cultures with their donors, were challenged with three blood transfusions from their donors before transplantation and were tested for the development of lymphocytotoxic antibodies. Ten children (20%) became sensitized and had a positive T-cell or B-cell crossmatch. Sensitization occurred less frequently in children treated with azathioprine during donor-specific transfusions (11%) than in those not treated (26%), but the difference was not significant. Thirty-seven children received renal transplants from their blood donors after the donor-specific transfusions. There were no deaths, and only two patients had kidney failure. Actuarial kidney survival was 93% after 6 years. The use of donor-specific transfusion has increased the number of related-donor transplants performed and the results have been highly successful.

Actuarial Analysis↗
PubMed1984

Kaposi's sarcoma of the head and neck in the acquired immune deficiency syndrome.

Since 1981 a new syndrome of acquired immune deficiency (AIDS) has been recognized. Male homosexuals, male and female intravenous drug abusers, and recipients of blood products (i.e., hemophiliacs) appear to be the populations at risk. The syndrome has been manifested by community-acquired opportunistic infections and/or Kaposi's sarcoma (KS). Otolaryngologic manifestations of AIDS are not infrequent. Thirteen AIDS patients at the National Institutes of Health with KS of the head and neck region are presented. All 13 patients were homosexual or bisexual males. Nine initially presented with KS, five with KS of the head or neck. As a group the patients demonstrated lesions involving the oropharyngeal, tracheobronchial, and gastrointestinal regions. Their clinical course and complications are presented in detail. The mortality rate in this subgroup of AIDS patients is extraordinarily high (62%), with an average longevity of 11 months following initial diagnosis.

Acquired Immunodeficiency Syndrome↗