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Biomedical subjects

D Spence

Publications and source records attributed to D Spence.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pharmacokinetics of oral fluconazole when used for prophylaxis in bone marrow transplant recipients.

The pharmacokinetics of fluconazole was investigated in 20 bone marrow transplant patients following oral administration of 200 mg of this drug. Blood samples were collected from each patient at different time intervals within 48 h after the first dose, and fluconazole was measured in plasma by high-performance liquid chromatography with UV detection. Urine was collected from 14 of these patients and analyzed similarly. The plasma concentration-time data exhibited the characteristics of the one-compartment model with first-order absorption quite well. The means +/- standard deviations of half-lives for absorption and elimination, peak concentration, time to peak, mean residence time, apparent volumes of distribution, area under the curve, and apparent oral clearance observed in these patients were 2.84 +/- 1.34 h, 19.94 +/- 18.7 h, 4.45 +/- 1.86 microg/ml, 8.34 +/- 5.97 h, 39.57 +/- 20.5 h, 0.874 +/- 0.48 liter/kg, 156.0 +/- 60.6 microg x h/ml, and 0.0256 +/- 0.0138 liter/h x kg, respectively. The amount of fluconazole excreted in urine in 24 h was 67.1 +/- 83 mg, which represents 33.55% +/- 41.6% of the dose administered. Patients who developed hemorrhagic cystitis excreted significantly (P < or = 0.0094) more fluconazole in 24 h than did those who did not.

Administration, Oral↗
PubMed1997

Surface integrity of composite inlays following ultrasonic vibration.

PURPOSE: To assess the effect of ultrasonic vibration on the surface integrity of a resin composite inlay. MATERIALS AND METHODS: Ultrasonic vibration in the form of a scaling tip oriented either parallel or perpendicular to the surface was applied to 2 mm thick, 10 mm wide composite discs and the experiment was repeated with the probe oriented perpendicular using composite or rubber shields. The indentations produced were measured using a form Talysurf profilometer. The surfaces of the discs were also observed using scanning electron microscopy. Five discs were used for each experiment. RESULTS: Both parallel and perpendicular orientations produced an indentation with a scattering of composite debris. A significant increase in the depth of indentation occurred if the vibrations of the ultrasonic scaler were oriented parallel to the composite surface (Two sample t- test, P < 0.01). The presence of a composite shield significantly reduced (Mann-Whitney, P < 0.05) the depth of indentation but produced roughening of the surface with impaction of material from the shield onto the surface. The rubber shield, however, polished the surface significantly smoother than the control specimens (Mann-Whitney, P < 0.05). Microscope slide separation was used to measure the thickness of composite luting agent following vibration with an ultrasonic scaling tip with and without a protective sleeve. There was a significantly thinner film of luting agent when an unsleeved scaler was used (ANOVA, P < 0.001). Although an unguarded tip oriented perpendicular to the surface appears to result in the best energy transfer for a thin layer of composite luting agent, it does, however, create minimal surface damage.

Analysis of Variance↗
PubMed1996

Non-invasive ventilation.

Nasal intermittent positive pressure ventilation is an effective treatment for nocturnal hypoventilation secondary to chest wall deformity or respiratory muscle weakness. Physicians should be aware that, in these groups of patients, disabling breathlessness can be alleviated and established cor pulmonale reversed by the technique.

Humans↗
PubMed1995

A multicenter randomized double-blind placebo-controlled trial of adjunctive corticosteroids in the treatment of Pneumocystis carinii pneumonia complicating the acquired immune deficiency syndrome.

A multicenter placebo-controlled trial of early short-term high-dose methylprednisolone enrolled 78 patients with moderate to severe Pneumocystis carinii pneumonia (PCP) complicating HIV infection. The mean pressure of oxygen (PO2) at study entry was 55 mm Hg for the 71 patients who had blood gases monitored while breathing room air. Patients were randomized to receive methylprednisolone (40 mg) or placebo parenterally twice daily for 10 days, and the first dose of study medication was given within 24 h of the first dose of antimicrobial therapy for PCP. The primary end point included death, need for mechanical ventilation for > 6 days, or a partial PO2 < 70 mm Hg while breathing room air 10 days after initiation of treatment. There was no statistically significant difference in the primary end point between patients randomized to corticosteroid (CS) or placebo (PL) (p = 0.522; 95% CI = -0.30, 0.16). The incidence of superinfections during therapy or of other HIV-associated infections or malignancies in the 6 months following treatment for PCP was not significantly different between the two groups. More patients randomized to placebo had to discontinue treatment with trimethoprim-sulfamethoxazole because of hypersensitivity than those randomized to corticosteroids (p = 0.039). We conclude that addition of corticosteroids does not significantly affect the outcome of PCP in patients with HIV and a PO2 < 70 mm Hg on room air at presentation but lowers the incidence of hypersensitivity reactions to trimethoprim-sulfamethoxazole.

AIDS-Related Opportunistic Infections↗
PubMed1995

Systemic amphotericin B versus fluconazole in the management of antibiotic resistant neutropenic fever--preliminary observations from a pilot, exploratory study.

A pilot exploratory study was undertaken to collect preliminary information relating to safety and overall outcome in using intravenous fluconazole (FLUC) for managing antibiotic resistant neutropenic fever (ARNF), with the objective of assessing feasibility of performing a larger prospective controlled study. Patients who were neutropenic from treatment for leukaemia or bone marrow transplantation, received either fluconazole (FLUC) or amphotericin B (AB). Eight of 16 patients (50%) on FLUC and 21 of 25 patients (84%) on AB defervesced; the mean time to defervescence was 11.0 +/- 10.0 days for FLUC compared to 7.7 +/- 6.3 days for AB, and a similar proportion in each treatment group defervesced within 5 days (50% vs. 52%), respectively. Six of 16 patients (37.5%) on FLUC and three of 25 patients (12%) on AB developed overt invasive fungal disease, including pulmonary aspergillosis (FLUC 4 cases, AB 2 cases) and invasive candidiasis (FLUC 2 cases, AB 0 cases). The mean time to these events was 19.5 +/- 13.4 (FLUC) and 9.0 +/- 3.6 (AB) days. The fungal related mortality rates were higher in the FLUC group: five of 16 patients (31%) vs. two of 25 patients (18%) died respectively; the time to fungal death was 43.2 +/- 18.2 (FLUC) and 25.0 +/- 18.4 (AB) days. This tendency towards a more favourable outcome in patients on AB may have been due to absence of prior fluconazole prophylaxis in patients subsequently receiving IV FLUC. Analysis of a small subgroup of patients who had all received prior prophylaxis with clotrimazole only, indicated that a greater number of patients subsequently receiving IV FLUC died from fungal disease (5/16 vs.0/6, P = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Bone marrow transplantation for infantile malignant osteopetrosis.

PURPOSE: Most patients diagnosed with malignant osteopetrosis die during infancy or early childhood from hemorrhage and infection due to bone marrow failure. Allogeneic bone marrow transplantation (BMT) has been reported to provide curative therapy for this disorder. We report our experience with eight patients with malignant osteopetrosis who underwent BMT. PATIENTS AND METHODS: Between May 1987 and August 1992, eight children with malignant osteopetrosis underwent allogeneic BMT. Median age at BMT was 9 months (range, 2-36 months). Six patients received marrow from HLA-identical sibling donors, one from phenotypically matched father, and one from a one antigen mismatched father. BMT conditioning for all patients was busulfan 16 mg/kg and cyclophosphamide 200 mg/kg each administered over 4 days. Graft versus host disease (GVHD) prophylaxis included cyclosporin A in six patients or cyclosporin A and methotrexate in two patients. RESULTS: Six patients, including those who received bone marrow from their father's, engrafted as documented by bone marrow biopsy showing an increase in osteoclasts in all cases and by chromosomal analysis in four patients. Two patients died without engraftment. Three out of six patients engrafted are alive and well at the follow-up of 48, 63, and 81 months. Serum calcium, alkaline, and acid phosphatase levels normalized within 2 months. These patients have full bone marrow reconstitution. Serial radiologic studies revealed bone marrow remodelling and a new nonsclerotic bone formation. Vision improved dramatically in the youngest patient. CONCLUSION: BMT offers cure to patients with malignant osteopetrosis with reconstitution of bone marrow and correction of metabolic disturbances. In our experience, reversibility in neurosensory deficit is possible when BMT is done at an early age.

Bone Marrow Transplantation↗
PubMed1995

Open lung biopsy provides a higher and more specific diagnostic yield compared to broncho-alveolar lavage in immunocompromised patients. Fungal Study Group.

In order to examine the feasibility and safety of undertaking a larger prospective study to compare the diagnostic yield from concurrent open lung biopsy (OLB) and bronchoalveolar lavage (BAL) in febrile neutropenic patients with pulmonary infiltrates and the impact of such knowledge on clinical outcome, a pilot exploratory study was performed. 13 immunocompromised patients (mainly with haematological malignancy or bone marrow transplantation recipients) were investigated. At least one diagnostic finding in 12 of 13 patients was provided by OLB compared to 4 of 13 patients by BAL. BAL provided 7 specific diagnoses (pneumocystis 1, fungal infection 3, bacterial pneumonia 1, pulmonary haemorrhage 2) whilst OLB provided 12 specific diagnosis (CMV 2, pneumocystis 3, fungal infection 1, bacterial pneumonia 1, pulmonary haemorrhage 4, pulmonary embolism 1). Five patients with nonspecific interstitial/alveolar inflammation were diagnosed only by OLB. The concordance that the exact same specific diagnoses present in the OLB were found in the BAL was zero. There were 2 minor complications (1 wound infection by OLB, 1 moderate haemorrhage by BAL). Mortality at 28 days was 8 of 13 patients which in no case was related to either procedure. We suggest that OLB is a safe procedure in such patients, provides superior and more complete diagnostic information compared to BAL and a larger controlled study to investigate the impact of early OLB on the outcome of these patients appears to be justified.

Adolescent↗
PubMed1994

Controlled study of fluconazole in the prevention of fungal infections in neutropenic patients with haematological malignancies and bone marrow transplant recipients.

The efficacy and safety of oral fluconazole versus a polyene regimen in preventing mycoses in neutropenic patients was compared. Patients with haematological malignancy or bone marrow transplantation received as antifungal prophylaxis either fluconazole 200 mg daily or a regimen consisting of clotrimazole trouches 10 mg twice daily with mycostatin, 500,000 I.U. four times daily, benadryl and cepacol mouthwash. Ninety patients at risk for fungus infection were evaluable. Four of 42 patients (9.5%; confidence interval 2%-23%) on fluconazole and 17 of 48 patients (35.4%; confidence interval 22%-52%) (p < 0.01) on the clotrimazole regimen developed a clinically significant fungal infection, including 3 (7.1%) and 11 (22.9%) patients respectively who had severe fungal infection, mainly pulmonary aspergillosis. Death directly due to a fungal infection within 100 days of the start of prophylaxis occurred in 2 of 42 patients (4.8%) and 9 of 48 patients (18.8%) respectively (p < 0.06). Kaplan-Meier analysis showed that the chance of survival on fluconazole was statistically greater than for the clotrimazole regimen (p < 0.04). A decrease of candidal colonisation of the gastrointestinal and genitourinary tracts occurred only in patients receiving fluconazole. No significant toxicity occurred. A 200 mg daily dose of fluconazole given to these patients thus appears to be well tolerated and to provide a protective effect against the development of fungal infection and death from severe fungal disease.

Adolescent↗
PubMed1993

Myoblast transfer in Duchenne muscular dystrophy.

One biceps muscle of 8 patients with Duchenne muscular dystrophy was injected at 55 sites with a total of 55 million viable, purified, and contamination-free normal myoblasts (myoblast transfer). The other biceps of each patient was injected with a placebo to serve as a control. The procedure was blinded to the patients, parents, and investigators. Myoblasts derived from a biopsy specimen of the fathers were cultured and purified under strict conditions and carefully screened for microbial contamination. All patients received cyclophosphamide for immunosuppression for 6 or 12 months. No serious complications were observed after myoblast transfer, indicating that the procedure is safe. The overall therapeutic efficiency of myoblast transfer was poor as judged by the results in maximal voluntary force generation, dystrophin content of the muscle, magnetic resonance imaging of the muscle, and the lack of donor-derived DNA and dystrophin messenger RNA in the injected muscle. An improved efficiency of the take of myoblasts might be achieved by using younger cells and injecting the myoblasts with a myonecrotic agent (to increase the prevalence of regeneration) and a basal laminal fenestrating agent.

Analysis of Variance↗
PubMed1993

Glanzmann's thrombasthenia with mild von Willebrand's disease.

A Saudi Arabian family is reported in which Glanzmann's thrombasthenia and von Willebrand's disease occurred simultaneously. The daughter presented with menorrhagia and gave a history of gastrointestinal bleeding and a strong family history of bleeding disorder. Full haematological investigations were performed on the propositus, parents, and siblings, including complete blood count, bleeding time, prothrombin time, partial thromboplastin time, factor VIII:C, von Willebrand factor, ristocetin cofactor, platelet aggregometry, platelet glycoprotein Ib and IIb/IIIa and platelet antigen PLT-1 (Coulter Clone). The propositus had Glanzmann's thrombasthenia, both parents had mild von Willebrand's disease and were carriers of Glanzmann's thrombasthenia. Three symptomatic brothers had both Glanzmann's thrombasthenia and von Willebrand's disease; two asymptomatic brothers had von Willebrand's disease only and one had completely normal results. Those family members with both diseases were more severely affected than those with just one disease. In areas where consanguineous marriage is common, such as Saudi Arabia, multiple haemostatic abnormalities may occur, and investigation should not stop with the discovery of a single abnormality. The increased clinical severity of bleeding, including haemarthroses, in those patients having both congenital defects emphasises the importance of von Willebrand factor in glycoprotein Ib-mediated platelet adhesion.

Adolescent↗
PubMed1992

Risk factors for coronary artery disease in patients with systemic lupus erythematosus.

PURPOSE: To estimate the frequency of and examine risk factors for coronary artery disease (CAD) in patients with systemic lupus erythematosus (SLE) in a prospective longitudinal study. PATIENTS AND METHODS: Patients were SLE are enrolled in The Johns Hopkins Lupus Cohort, a prospective study of outcomes in 229 subjects with SLE. CAD was defined as angina, myocardial infarction, or sudden death. Data on CAD risk factors were obtained prospectively every 3 months and were analyzed using univariate and multiple logistic regression. RESULTS: CAD occurred in 19 (8.3%) of 229 patients with SLE and accounted for 3 (30%) of 10 deaths as of December 31, 1990. Compared to subjects without CAD, those with CAD were more likely to have been older at both diagnosis of SLE (37.1 years versus 28.9 years, p = 0.004) and at entry into the cohort (47.1 years versus 34.7 years, p < 0.0001), to have a longer mean duration of SLE (12.3 years versus 8.1 years, p = 0.013) and a longer mean duration of prednisone use (14.3 years versus 7.2 years, p < 0.0001), to have a higher mean serum cholesterol (271.2 mg/dL versus 214.9 mg/dL, p < 0.0001) or a cholesterol level greater than 200 mg/dL (odds ratio [OR] 14.5, 95% confidence intervals [CI] 1.9, 112.1), and to have both a history of hypertension (OR 3.5, 95% CI 1.3, 9.6) and a history of use of antihypertensive medications (OR 5.5, 95% CI 1.8, 17.2). There were no significant associations with other known CAD risk factors such as smoking, diabetes, family history of CAD, race, or sex, or variables related to steroid therapy including the presence of cushingoid features or ever use of corticosteroids. The best multiple logistic regression model for CAD included age at diagnosis, duration of prednisone use, requirement for antihypertensive treatment, maximum cholesterol level, and obesity (using NHANES-II [National Health and Nutrition Examination Survey] definitions). CONCLUSION: Primary and secondary prevention strategies directed at hypertension, hypercholesterolemia, and obesity, as well as other known CAD risk factors, should be routinely employed in the management of patients with SLE.

Adult↗