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Biomedical subjects

D J Winston

Publications and source records attributed to D J Winston.

At least 55 records · Page 3Linked to original sources

Prophylaxis of infection in bone marrow transplants.

Bone marrow transplants experience severe immuno-deficiency as a consequence of pretransplant radiation and chemotherapy, transient granulocytopenia before marrow engraftment, and post-transplant prevention and treatment of graft-versus-host disease with immuno-suppressive agents. During periods of granulocytopenia, chemoprophylaxis with the oral fluorinated quinolones can prevent colonization and infection with gram-negative bacilli, is better tolerated than oral non-absorbable antibiotics or trimethoprim-sulfamethoxazole and is more cost-effective than laminar-air-flow isolation or prophylactic granulocyte transfusions. Antifungal prophylaxis with oral nystatin, ketoconazole or amphotericin B, however, has not been consistently effective; empiric intravenous amphotericin B therapy is still the most reliable way to prevent fatal fungal infections. Following marrow engraftment, cytomegalovirus infection and interstitial pneumonia can be prevented in cytomegalovirus-seronegative patients by the use of cytomegalovirus-seronegative blood products and cytomegalovirus immune globulin. In cytomegalovirus-seropositive patients, prophylactic DHPG (ganciclovir) is currently being evaluated in a controlled clinical trial. Herpes simplex and varicella-zoster infections can be treated effectively with intravenous acyclovir, but routine acyclovir prophylaxis is not cost-effective. Trimethoprim-sulfamethoxazole is used for prophylaxis of Pneumocystis carinii pneumonia and may be continued in patients with chronic graft-versus-host disease for prevention of late post-transplant bacterial infections.

Agranulocytosis↗

Norfloxacin for prevention of bacterial infections in granulocytopenic patients.

The efficacy and safety of norfloxacin were compared with those of placebo, vancomycin-polymyxin, and trimethoprim-sulfamethoxazole (TMP/SMX) for prophylaxis of bacterial infections in granulocytopenic patients. The study results showed that norfloxacin treatment, which was well tolerated and not associated with any serious systemic adverse effects, prevented acquisition of gram-negative bacillary organisms. Fewer norfloxacin-treated patients (38 of 108 patients, or 35 percent) experienced microbiologically documented infections compared with patients receiving placebo (27 of 40 patients, or 68 percent), vancomycin-polymyxin (16 of 30 patients, or 53 percent), or TMP/SMX (14 of 28 patients, or 50 percent). Gram-negative bacteremia developed in five of 108 norfloxacin-treated patients (5 percent), compared with 17 of 40 placebo-treated patients (43 percent), five of 30 treated with vancomycin-polymyxin (17 percent), and one of 28 patients treated with TMP/SMX (4 percent). The incidence of gram-positive bacteremia was similar in all study groups and was not affected by norfloxacin or any other oral prophylactic antibiotics. These results suggest that norfloxacin is both safe and effective for the prevention of serious gram-negative bacillary infections in granulocytopenic patients. More effective prophylaxis of gram-positive bacterial infections, however, is needed.

Adolescent↗

Treatment of cytomegalovirus retinopathy with ganciclovir.

Ganciclovir is an experimental antiviral drug with activity against human cytomegalovirus (CMV). Forty patients with acquired immune deficiency syndrome (AIDS) and CMV retinopathy were treated with ganciclovir on a compassionate protocol basis. Initial treatment doses ranged from 5.0 to 14.0 mg/kg/day for 9 to 26 days. Signs of drug response were a halt to enlargement of lesions, decreased opacification of retinal tissue, and resolution of hemorrhage and vasculitis. Complete response was seen in 88% of patients and incomplete response was seen in 9%. Vision improved or remained stable in 88% of patients. Initial treatment did not eradicate live virus from the eye. To prevent reactivation of disease, 26 patients received low-dose maintenance therapy ranging from 1.5 to 7.5 mg/kg/day, once or twice daily, 3 to 7 days per week. Reactivation of disease developed for unknown reasons in 50% of patients on continuous, uninterrupted maintenance therapy for longer than 3 weeks. Reversible neutropenia, requiring cessation of treatment, developed in 30% of patients on initial treatment and in 38% of patients on maintenance therapy. Rhegmatogenous retinal detachment was a late complication in seven patients. By reducing or delaying visual loss, ganciclovir appears to be useful in the management of CMV retinopathy in patients with AIDS.

Acquired Immunodeficiency Syndrome↗

Bone marrow transplantation in patients with leukaemia previously transfused with blood products from family members.

Transfusions are withheld, whenever possible, from patients with aplastic anaemia who are potential bone marrow transplant recipients because of the increased risk of graft failure associated with transfusions prior to transplantation. Family members are specifically excluded as blood product donors to reduce the likelihood of sensitizing the recipient to antigens shared by the blood and bone marrow donor. This policy of not using family members, particularly the HLA-matched bone marrow donor, to provide blood products prior to transplantation has been extended to leukaemia as well. To evaluate this policy we reviewed the outcome of bone marrow transplantation in 18 patients with leukaemia transfused prior to transplantation with platelets and/or leucocytes from related family members. In 15 cases in which the outcome could be evaluated, engraftment was rapid and graft failure did not occur. Transfusion of blood products from related family members to patients with leukaemia prior to transplantation does not appear, therefore, to increase the risk of graft rejection.

Blood Donors↗

Intravenous immune globulin for prevention of cytomegalovirus infection and interstitial pneumonia after bone marrow transplantation.

The effects of high doses of polyvalent intravenous immune globulin given for prophylaxis of cytomegalovirus infection and interstitial pneumonia in recipients of allogeneic marrow transplants were evaluated in a randomized controlled trial. Both symptomatic cytomegalovirus infection (21% compared with 46%, p = 0.03) and interstitial pneumonia (18% compared with 46%, p = 0.02) occurred less frequently in the recipients of intravenous immune globulin than in control patients. Prophylactic intravenous immune globulin was also associated with a lower incidence of graft-versus-host disease (34% in recipients compared with 65% in controls, p = 0.01), but its reduction in rates of interstitial pneumonia was independent of graft-versus-host disease and occurred in both patients with and without graft-versus-host disease. The high doses of immune globulin were well tolerated. Prophylactic intravenous immune globulin can modify the severity of cytomegalovirus infection and prevent interstitial pneumonia and possibly graft-versus-host disease in patients having allogeneic marrow transplantation.

Adolescent↗

Intravenous immunoglobulins as therapeutic agents.

Intravenous immunoglobulins are stable monomeric pooled human IgG preparations for therapeutic use. Three intravenous immunoglobulins licensed in the United States are generally therapeutically equivalent. Intravenous immunoglobulin is the preferred agent for replacement therapy for most patients with primary or secondary antibody immunodeficiency because of the rapidity and ease of giving large quantities of IgG, even by self-administration. Disadvantages of intravenous immunoglobulins include frequent (approximately 10%) but usually not serious side effects, the need for venous access (often difficult in infants and young children), and high cost. Intravenous immunoglobulins are also beneficial in the prevention of certain viral infections, such as cytomegalovirus pneumonia and varicella; they may also have a synergistic effect with antibiotics in certain bacterial diseases. Intravenous immunoglobulin has also been used successfully in the management of idiopathic thrombocytopenia purpura, Kawasaki disease, and certain autoimmune diseases. Intravenous immunoglobulin may also be of use in certain high-risk and premature newborns.

Animals↗

Norfloxacin versus vancomycin/polymyxin for prevention of infections in granulocytopenic patients.

Selective antimicrobial decontamination with norfloxacin was compared with vancomycin/polymyxin for prophylaxis of bacterial infections in granulocytopenic patients. In the group of patients receiving norfloxacin, there were a lower number of acquired gram-negative bacillary organisms per patient (0.88 versus 1.86, p = 0.002), fewer patients with documented infection (16 of 36 versus 20 of 30, p = 0.12), and fewer cases of gram-negative septicemia (0 of 36 versus five of 30, p = 0.02). Norfloxacin was better tolerated (30 of 36 versus 16 of 30 patients highly compliant, p = 0.02), and associated with fewer gastrointestinal side effects (eight of 36 versus 14 of 36 patients, p = 0.07). These results suggest that norfloxacin is a more tolerable and efficacious oral antimicrobial agent than vancomycin/polymyxin for the prevention of serious gram-negative bacillary infections in granulocytopenic patients.

Adolescent↗

Ureidopenicillins, aztreonam, and thienamycin: efficacy as single-drug therapy of severe infections and potential as components of combined therapy.

The ureidopenicillins (piperacillin, mezlocillin, and azlocillin), aztreonam, and thienamycin are new broad-spectrum beta-lactams with more potent antibacterial activity than the older cephalosporins and penicillins. However, therapy of severe infections with the ureidopenicillins alone is limited by the potential for emergence of resistant organisms, while monotherapy with aztreonam does not provide adequate coverage for Gram-positive aerobic organisms and anaerobes. In combination therapy with the aminoglycosides, the ureidopenicillins may be preferred to carbenicillin or ticarcillin in the treatment of Pseudomonas aeruginosa infections and in institutions with a high prevalence of carbenicillin or ticarcillin-resistant organisms. Double beta-lactam therapy with piperacillin plus either latamoxef (moxalactam) or ceftazidime may be advantageous in patients for whom aminoglycoside toxicity is a concern. Thienamycin is the most promising of the new beta-lactams for single-agent therapy of severe infections but may also be associated with the emergence of resistant P. aeruginosa during monotherapy. In febrile granulocytopenic patients or other severely ill patients at risk of severe P. aeruginosa infections, thienamycin or another antipseudomonal beta-lactam should be combined with an aminoglycoside.

Aminoglycosides↗

Infection and transfusion therapy in acute leukaemia.

Granulocytopenia is the single most important risk factor for infection in patients with acute leukaemia. There are limitations to the effective prophylaxis of infection in granulocytopenic patients, but practical measures include the management of the patient in a private hospital room, the requirement of all medical personnel and visitors to wash their hands carefully and to wear masks, restricting the patient to a low-bacteria diet devoid of fresh fruit, vegetables and salads, and the administration of oral antimicrobial agents for gastrointestinal decontamination. When fever develops, empirical therapy with a combination of an aminoglycoside plus an antipseudomonal beta-lactam should be started promptly. A double beta-lactam combination of cefoperazone or ceftazidime plus piperacillin can be substituted if nephrotoxicity is a concern. The addition of empirical intravenous amphotericin may be useful in patients who remain febrile and granulocytopenic on broad-spectrum antibiotics, especially if surveillance cultures indicate fungal colonization. Amphotericin is also the most reliable agent for the treatment of established fungal infections. Acyclovir is not recommended for prophylaxis in acute leukaemia patients but should be reserved for the treatment of well-documented and clinically significant herpes simplex viral infections. During periods of remission, most patients with AML remain free of infection except when they become granulocytopenic again during intensification or consolidation chemotherapy. On the other hand, children with ALL in remission may experience frequent infections unrelated to granulocytopenia as a consequence of their maintenance chemotherapy. Pneumocystis carinii, varicella zoster, and other viruses are common pathogens. Trimethoprim-sulphamethoxazole is effective prophylaxis against Pneumocystis carinii pneumonia in patients with ALL, while intravenous acyclovir is the drug of choice for treatment of varicella zoster infection. Transfusion therapy in the acute leukaemia patient is guided by the patient's peripheral blood counts and degree of sensitization to blood products. Generally, packed red blood cells are given in order to maintain the haematocrit at greater than 30%, while random-donor platelets are administered to keep the platelet count at greater than 20 X 10(9)/l. If refractoriness to platelet transfusions develops, HLA-matched platelets from family members or selected unrelated donors can be used. Similarly, washed or filtered red blood cells may be given to patients with previous and recurrent non-haemolytic febrile reactions to red blood cell transfusions.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗

Perineal gangrene in the patient with granulocytopenia: the importance of early diverting colostomy.

Perirectal and perineal infections represent a life-threatening complication of hematologic diseases associated with granulocytopenia. Early and aggressive surgical management is essential. This should include hemodynamic support and monitoring, broad-spectrum antibiotics, wide surgical debridement, and a totally diverting colostomy. The prognosis of these infections parallels that of the underlying hematologic disease. Three patients seen on a university surgical service whose clinical management and course underscore these principles are presented.

Adolescent↗

Molecular epidemiology of cytomegalovirus infections associated with bone marrow transplantation.

Restriction endonuclease analysis of purified viral DNA was used to study the molecular epidemiologic characteristics of cytomegalovirus infection in 18 patients having bone marrow transplantation. Four patients who had had asymptomatic excretion of cytomegalovirus in urine before transplantation subsequently developed a cytomegalovirus infection after transplantation (pneumonia in 2 patients, fever and viremia in 1 patient, and asymptomatic viruria in 1 patient). In each patient, the infection that developed after transplantation was caused by a cytomegalovirus strain genetically identical to the isolate detected in urine before transplantation. Cytomegalovirus isolates from different sites (buffy coat, lung, and urine) of the same patient were also identical, but cytomegalovirus isolates from different patients were never identical. Our results suggest that some cytomegalovirus infections after bone marrow transplantation may be caused by strains present before transplantation. The great structural and genetic variability of cytomegalovirus isolates must be considered in the development of effective diagnostic and immunoprophylactic measures for infection after marrow transplantation.

Adolescent↗

[Use of a polyvalent intravenous immunoglobulin or specific cytomegalovirus hyperimmunoglobulin for modification of cytomegalovirus infections and prevention of interstitial pneumonias following bone marrow transplantation].

The effects of prophylactic, polyvalent intravenous immune globulin on cytomegalovirus infection and interstitial pneumonia in allogenic marrow transplants were evaluated in an ongoing, randomized controlled trial. Thirty-eight patients were given weekly doses (20 cc/kg) of polyvalent intravenous immune globulin before and after transplantation, and 37 patients were controls. Both symptomatic cytomegalovirus infection (17 of 37 or 46% vs. 8 of 38 or 21%, p = 0.04) and interstitial pneumonia (17 of 37 or 46% vs. 7 of 38 or 18%, p = 0.02) occurred less frequently in the recipients of polyvalent intravenous immune globulin. In separate kinetic studies, a 5 cc/kg dose of a cytomegalovirus-specific hyperimmune globulin produced cytomegalovirus antibody titers in patients equivalent to those achieved after the 20 cc/kg dose of polyvalent intravenous immune globulin. All immune globulin preparations were well-tolerated. These preliminary results suggest that intravenous immune globulin can modify the severity of cytomegalovirus infection and prevent interstitial pneumonia in marrow transplants. Additional trials are now needed to define the minimal effective dose of intravenous immune globulin and to compare the effectiveness of different intravenous immune globulin formulations.

Anemia, Aplastic↗

Do androgens enhance the response to antithymocyte globulin in patients with aplastic anemia? A prospective randomized trial.

We analyzed the effect of antithymocyte globulin (ATG) with or without androgens in 121 patients with aplastic anemia. Fifty-three patients with moderate to severe aplastic anemia were prospectively randomized to receive ATG with or without oral androgens. Eleven of 26 patients (42%) receiving ATG plus androgen responded, including three complete and eight partial responses. Twelve of 27 patients (44%) receiving ATG plus placebo responded, including five complete and seven partial responses. The difference in response rates was not significant (P greater than .9). Survival was also comparable in the two groups; for patients with severe aplastic anemia, actuarial survival at two years was 55% +/- 24% (95% confidence interval) in patients receiving ATG plus androgen compared with 50% +/- 24% in the ATG plus placebo group (P = .65). Furthermore, results in both groups were indistinguishable from those obtained in 68 historical controls receiving ATG without androgens. These data indicate that androgens are not required in order to respond to antithymocyte globulin and the addition of androgens, as used in this trial, did not significantly improve response rates to ATG treatment.

Adolescent↗

Intravenous immunoglobulin for modification of cytomegalovirus infections associated with bone marrow transplantation. Preliminary results of a controlled trial.

The effects of immune globulin intravenous, 5 percent in 10 percent maltose, on cytomegalovirus infection and interstitial pneumonia in bone marrow transplants were evaluated in a randomized controlled trial. Eighteen patients were given weekly doses (20 cc/kg) of intravenous immunoglobulin before and after transplantation, and 18 patients were controls. The incidence of cytomegalovirus infection was similar in the control and intravenous immunoglobulin-treated groups, but symptomatic cytomegalovirus infection (eight of 18 versus three of 18, p = 0.14) and interstitial pneumonia (10 of 18 versus four of 18, p = 0.08) occurred less frequently in the group receiving intravenous immunoglobulin. Cytomegalovirus pneumonia developed in eight control patients and in three patients receiving intravenous immunoglobulin (p = 0.14), whereas two control patients and one patient receiving intravenous immunoglobulin experienced idiopathic interstitial pneumonia. These preliminary results suggest that intravenous immunoglobulin can modify the severity of cytomegalovirus infection and prevent interstitial pneumonia in bone marrow transplant recipients.

Adolescent↗

Moxalactam plus piperacillin versus moxalactam plus amikacin in febrile granulocytopenic patients.

In a prospective randomized trial, febrile granulocytopenic patients received either moxalactam plus piperacillin or moxalactam plus amikacin as initial empiric antimicrobial therapy. Most patients were also given prophylactic vitamin K. The overall response rates for the two regimens were similar (105 of 136, or 77 percent, for moxalactam plus piperacillin versus 107 of 136, or 79 percent, for moxalactam plus amikacin). For Pseudomonas aeruginosa infections, the response rate was better in patients receiving moxalactam plus amikacin (seven of nine versus one of five, p = 0.06); two patients treated with moxalactam plus piperacillin experienced relapse of P. aeruginosa bacteremia in association with the emergence of beta-lactam-resistant P. aeruginosa isolates. On the other hand, bacteremic enterococcal superinfections occurred in seven patients receiving moxalactam plus amikacin but in none given moxalactam plus piperacillin (p = 0.02). Serious side-effects were minimal with both regimens, and nephrotoxicity was less common in patients receiving moxalactam plus piperacillin (two of 136 versus six of 136, p = 0.28). There was no antibiotic-related hemorrhage. These results suggest that the overall efficacy and toxicity of moxalactam plus piperacillin and moxalactam plus amikacin are similar. Moxalactam/piperacillin therapy may be limited in certain patients by the emergence of beta-lactam-resistant P. aeruginosa, whereas enterococcal superinfections may complicate moxalactam/amikacin therapy.

Adolescent↗

Imipenem therapy of Pseudomonas aeruginosa and other serious bacterial infections.

Imipenem is the first of a new class of beta-lactam antimicrobial agents with remarkable and extremely potent in vitro activity against most commonly isolated bacterial pathogens, including Staphylococcus aureus, enterococcus, members of the family Enterobacteriaceae, Pseudomonas aeruginosa, Bacteroides fragilis, and Hemophilus influenzae. The clinical efficacy and toxicity of imipenem were evaluated in 35 patients with 38 different infections. The overall clinical response was favorable (infections cured or improved) in 89% of the infections (34 of 38). Of the 17 infections with P. aeruginosa, 15 were cured or improved. However, P. aeruginosa isolates resistant to imipenem emerged during the therapy of six infections, and two cases of P. aeruginosa septicemia later relapsed after imipenem therapy. Gastrointestinal toxicity (nausea with or without emesis) occurred in 17% of the patients (6 of 35) but was ameliorated by slowing the rate of intravenous infusion or lowering the dose of imipenem. Except for certain severe P. aeruginosa infections, imipenem is effective and relatively safe therapy for infections caused by susceptible organisms.

Adolescent↗