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Biomedical subjects

D Ohlendorf

Publications and source records attributed to D Ohlendorf.

11 recordsLinked to original sources
PubMed2000

Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia.

The butyrate derivative isobutyramide (IBT) increases fetal hemoglobin (HbF) in patients with beta-hemoglobinopathies, but little is known about its usefulness for prolonged therapeutic use. We treated 8 patients with transfusion-dependent beta-thalassemia with 350 mg/kg of body weight per day of oral IBT for 126 to 384 days. During the trial period, the hemoglobin level was maintained between 85 g/L (range 82-87 g/L) (pretransfusion) and 115 g/L (range 110-119 g/L) (post-transfusion) (median, interquartile range), corresponding to 4-week transfusion intervals in all patients during the pretreatment phase. Adverse effects (bitter taste, epigastric discomfort) did not cause discontinuation of IBT. HbF increased in all patients from 3.1% (range 1.9%-4.8%) to 6.0% (range 3.3%-8.7) (P =.0017), while free Hb dropped from 0.48 g/L (range 0.39-0.81 g/L) to 0.19 g/L (range 0.16-0.24 g/L) (P <.0001). Transfusion intervals were consistently extended to 8 or 9 weeks in 1 patient, resulting in a decrease of daily iron load from 455 microgram/kg per day (range 451-459 microgram/kg per day) before therapy to 211 microgram/kg per day (range 203-286 microgram/kg per day) during the 12-month treatment period. Prolongation of transfusion intervals achieved by IBT was less consistent in another patient, whose parenteral iron load nevertheless decreased from 683 microgram/kg per day (range 618-748 microgram/kg per day) to 542 microgram/kg per day (340-596 microgram/kg per day). In the other 6 patients, no prolongation of transfusion intervals was achieved. Response to treatment was associated with high pretreatment HbF (> 4.5%), high parental HbF, and increased erythropoietin levels (> 150 IU/L). We conclude that IBT prolongs transfusion intervals and reduces parenteral iron burden in some patients with transfusion-dependent beta-thalassemia.

Administration, Oral↗
PubMed1996

Clinical experiences with magnetic drug targeting: a phase I study with 4'-epidoxorubicin in 14 patients with advanced solid tumors.

Anticancer drugs reversibly bound to magnetic fluids (ferrofluids) could be concentrated in locally advanced tumors by magnetic fields that are arranged at the tumor surface outside of the organism. If certain requirements are met, systemic toxicity might be minimized, and local tumor efficacy might be increased. We have conducted a Phase I clinical trial using this approach in patients with advanced and unsuccessfully pretreated cancers or sarcomas. Nine such patients received two treatment courses, 3 patients received one course, and 2 patients received three courses of magnetic drug targeting consisting of the infusion of epirubicin in increasing doses (from 5 to 100 mg/m2) that had been chemically bound to a magnetic fluid and the application of magnetic fields to the tumors for 60-120 min. In 2 of 14 patients, the same dose of epirubicin not bound to a magnetic fluid was administered systemically 3 weeks after drug targeting for intraindividual comparisons. Magnetic drug targeting with epirubicin was well tolerated. In one case, a planned second treatment was withdrawn, because of an episode of chills 130 min after infusion of the magnetic drug. Two patients received a third treatment because of good responses after the first two therapies. Based on magnetic resonance tomographic techniques, pharmacokinetics, and the histological detection of magnetites, it was shown that the ferrofluid could be successfully directed to the tumors in about one-half of the patients. Organ toxicity did not increase with the treatment, but epirubicin-associated toxicity appeared at doses greater than 50 mg/m2. Although treatment with magnetic drug targeting seems safe, improvements are necessary to make it more effective and independent of patient- or disease-related problems. A study design to compare conventional treatments with the new treatment form within one patient seems crucial to eliminate interindividual differences.

Adolescent↗
PubMed1990

[Double blind biometric study on postoperative effects of analgesics].

A double blind trial to study the effects of analgetics was carried out in patients suffering from pain after third molar osteotomy. 204 patients were evaluated after random allocation to treatment with paracetamol 500 mg and paracetamol 500 mg plus codeine 30 mg. Statistical evaluation revealed a tendency for better analgesia using the combination of paracetamol and codeine. For further studies an exact stratification for sex and age is necessary. Sample sizes of 150 patients are necessary for each parameter.

Acetaminophen↗
PubMed1989

Changes in plasma epinephrine concentration after dental infiltration anesthesia with different doses of epinephrine.

To define the cardiovascular risk as a result of epinephrine in local anesthetic solutions used in dental anesthesia, we measured the plasma epinephrine levels, the mean arterial brachial pressure (MAP), and heart rate for 15 min, after infiltration anesthesia in the area buccal to the upper permanent left lateral incisor and canine. For this purpose, 12 dental student volunteers received 2.0 mL 2% lidocaine with and without 20 or 80 micrograms epinephrine, in a double-blind cross-over trial. --Plain lidocaine solution cause no significant changes in the parameters under study when compared with the baseline values. --Lidocaine with 20 micrograms epinephrine caused a sustained doubling of the plasma epinephrine concentration two min after injection, and at the same time, a slight but significant (p less than 0.05) decrease in MAP. Two min and 45 s after injection, the heart rate increased by four beats/min when compared with the baseline rate. --Lidocaine with 80 micrograms epinephrine caused a doubling of the basal plasma epinephrine value as early as one min and 25 s after injection, and a ten-fold increase above the basal value at the end of the observation period (15 min). The heart rate increased significantly (p less than 0.01) by five beats/min above the baseline value starting two min after injection, and rose to a maximum of 13 beats/min until the end of the observation period. The time-point of the decrease in MAP was earlier, but the amount of the decrease equaled that measured after submucosal injection of 20 micrograms epinephrine with 40 mg lidocaine.

Adult↗
PubMed1979

Screening methods using sulfamethazine for determining acetylator phenotype.

Analysis of sulfamethazine (SMZ) kinetics in man has revealed complexities including wide intersubject variability. In our study, an attempt was made to assess the potential influence of changes in nonmetabolic parameters (absorption and urinary elimination rate constants) on the markers of acetylation capacity normally used in clinical screening procedures to determine phenotype. Seven normal subjects were classified as slow (SA) or fast acetylators (FA) according to their metabolic rate constant for SMZ (Km), plasma SMZ half-life, and percentage of N-acetyl SMZ in a 6-hr blood sample (PI6), a 5- to 6-hr urine collection (UI5--6), or a 6-hr total urine collection (UI6). Computer simulations were applied to baseline SMZ kinetic data from these subjects, varying nonmetabolic kinetic parameters over experimentally defined ranges singly, or in parallel with 1 or more of the other parameters. The simulations indicate that all the usual phenotyping procedures were sensitive to changes in absorption and urinary elimination rate constants. While these predictions require experimental confirmation, results show that the PI6 method is least sensitive to such changes, suggesting this method may minimize errors in phenotyping screening.

Absorption↗
PubMedDate not supplied

Dithranol in an emulsifying oil base (bio-wash-oil) for the treatment of psoriasis of the scalp.

On the scalp, dithranol has been studied in only a few trials. The dithranol molecule that contains both hydrophilic and lipophilic centers can be incorporated into detergents and allows easy removal from hair. This property has led to the incorporation of dithranol in an emulsifying oil base (bio-wash-oil). The formulation has been used routinely for more than two decades in East Germany. We reexamined the efficacy and safety of dithranol in bio-wash-oil and compared it to dithranol embedded in crystalline monoglycerides (Micanol) in patients with psoriasis of the scalp. In a prospective, parallel group study, 64 patients attending a day-care clinic were randomly allocated to 3 treatment groups: (1) dithranol in bio-wash-oil; (2) Micanol cream, and (3) Micanol cream in bio-wash-oil. Treatment was carried out for 3 weeks and results assessed using a modified Psoriasis Area and Severity Index score. Dithranol in bio-wash-oil resulted in a reduction in the score of 34% on day 7 and 57% on day 14. This was significantly better than in groups 2 and 3, as were the overall response and patients' assessment at the end of treatment (p < 0.05). Dithranol in a bio-wash-oil is an effective, well-tolerated and low-priced treatment in psoriasis of the scalp.

Administration, Topical↗