Erworbene Faktor Vlll·C-Hemmkörper bei Nichthämophilen

Antibodies against factor VIII:C occur in about 5-15 % of hemophilia A patients and induce refractoriness to factor VIII:C infusions. These antibodies are mostly of IgG class. In very rare cases factor VIII:C inhibitors also develop in nonhemophilic patients. Although there are anecdotal reports that these antibodies may disappear spontaneously, in the majority of patients the clinical course is characterized by severe hemorrhages. During the last ten years we treated 9 nonhemophilic patients with acquired factor VIII:C inhibitors at our clinic. In most cases, a sudden bleeding tendency was observed shortly after an injury or surgery. Coagulation tests showed a prolonged aPTT and a decreased F VIIL:C level. Therapy with F VIII·C concentrates did not produce the expected increase. Measurement of F VIII:C inhibitor levels (Bethesda Units = BU) revealed values in the range between 2 and 108 BU. Immunosuppressive therapy in patients with > 5 BU using azathioprine or cyclo-phosphamide in combination with prednisone lead to complete disappearance of the inhibitor, normalization of the coagulation tests, and complete remission of the bleeding tendency in 7 patients within 6 weeks. During pregnancy only prednisone should be given. On the other hand in women with post-partum factor VIII inhibitors, steroid treatment appears to be not superior to no treatment, but immunosup-pression with cyclophosphamide or azathioprine seems to be more effective. In emergency situations, therapy with high doses of human F VIII:C concentrate is recommended. When bleeding does not cease, the additional use of activated pro-thrombin concentrates or porcine factor VIII concentrate is indicated. Side effects may include hepatitis and short-lived intravascular thrombin production.

Monitoring of bone resorption after renal transplantation by measuring the urinary excretion of pyridinium cross-links

The urinary excretion of pyridinium cross-links was measured in 70 second morning urine samples from 49 patients following renal transplantation. One and three months after renal transplantation, the urinary excretion of pyridinium cross-links was higher (p < 0.05) than at one week after transplantation. At all times after transplantation, the values for the excretion of pyridinium cross-links were correlated with the bone alkaline phosphatase concentrations (p < 0.001). However, there was no correlation between parathyrin concentrations and the values for the excretion of pyridinium cross-links (p > 0.05). This rise in the excretion of pyridinium cross-links is probably due to an increase of bone resorption caused by cyclosporin A and/or glucocorticoids. In the case of 17 urines with excretion values of pyridinium cross-links above the upper reference limit (pyridinoline equivalents, 93 mumol/mol creatinine), only 2 (12%) of the corresponding sera showed increased bone alkaline phosphatase values. In patients following renal transplantation simultaneous assessment of bone formation and bone resorption (determined from bone alkaline phosphatase serum concentrations and the excretion of pyridinium cross-links) may therefore enhance the diagnostic sensitivity for detecting effects on bone metabolism.

Optimisation of a new continuous UV assay for the determination of blood coagulation factor XIII activity in human plasma

The new photometric assay described by Fickenscher et al. (Thromb. Haemostas. 65 (1991) 535-540) for the determination of factor XIII facilitates the diagnosis of factor XIII deficiency. In spite of easy handling, this test should be used critically. Patients with hyperfibrinogenaemia showed factor XIII activities of less than 20%, whereas with an optimized assay we found normal factor XIII values. Also, the use of a fixed period of incubation for the analysis is questionable, because the period of constant reaction rate occurs earlier and is shorter with high factor XIII activities and later and longer with low factor XIII activities. A linear relation between factor XIII activity and signal only exists up to 80% of activity. In some plasma samples from patients with hyperfibrinogenaemia the factor XIII determination actually shows decreased values for factor XIII. During the reaction, a fibrin clot is formed. The resulting turbidity simulates an increase in absorbance so that NADH consumption is apparently decreased. In six patients with hyperfibrinogenaemia (8.1-9.4 g/l), a factor XIII activity of 26 U/l or less was determined. Using 50 microliters instead of 100 microliters sample volume, 50% (3/6) of the patients showed a normal factor XIII activities (80-96 U/l), whereas 50% (3/6) values of 6-15 U/l were found. In our modified assay we measured normal factor XIII activities (72-151 U/l) in all 6 patients. The procedure is optimized by reducing the sample volume from 100 microliters to 50 microliters.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring of osteoblast activity with an immunoradiometric assay for determination of bone alkaline phosphatase mass concentration in patients receiving renal transplants

We examined the diagnostic validity of an immunoradiometric assay for determination of mass concentration of bone alkaline phosphatase (EC 3.1.3.1) in 134 sera from 35 patients receiving renal transplants. Comparison between bone alkaline phosphatase concentration and total alkaline phosphatase activity yielded a strong correlation (r = +0.860; P < 0.001). Nine (17%) of 54 sera which were characterized by a total alkaline phosphatase activity between 100 units/l and the upper reference limit (178 units/l (males) and 160 units/l (females), respectively) showed an increased bone alkaline phosphatase concentration (> 21.3 micrograms/l (males) and > 15.0 micrograms/l (females), respectively). There was also a correlation between bone alkaline phosphatase values and parathyroid hormone levels both before (r = +0.640 (n = 23), P < 0.001) and after renal transplantation (r = +0.528 (n = 111), P < 0.0001). A follow-up of 15 patients after renal transplantation revealed that the median of bone alkaline phosphatase values increased from 5.5 micrograms/l before transplantation to 14.9 micrograms/l 3 months after transplantation (P < 0.0001). Nevertheless no correlation could be observed between parathyroid hormone concentrations and bone alkaline phosphatase values at any time following renal transplantation in these 15 patients (P > 0.1). Rise of bone alkaline phosphatase concentration following renal transplantation is most probably due to an activating effect of cyclosporin A upon osteoblasts.

Efficacy of transferrin determination in human sera in the diagnosis of iron deficiency

Apparently healthy persons (n = 425) as well as 264 patients characterized by an iron concentration in serum < 7.2 mumol/l were examined. A latent iron deficiency was defined as a concentration of ferritin < 20 micrograms/l (males) and < 15 micrograms/l (females), without anaemia; manifest iron deficiency defined by an additional presence of hypochromic microcytic anaemia. Fifty-nine of 425 (= 14%) apparently healthy persons showed a latent iron deficiency. In the remaining 366 we established the following reference intervals for the concentration of transferrin in serum [mumol/l]: 25.2-45.3 (males), 29.1-54.5 (females, < or = 25 years of age) and 25.3-48.6 (females, > 25 years of age). Eight of 59 (= 14%) apparently healthy persons with latent iron deficiency had a transferrin concentration above the reference interval. Sixty-one of 264 (= 23%) patients with an iron concentration < 7.2 mumol/l showed a ferritin concentration < 20 micrograms/l (males) and < 15 micrograms/l (females). Thirty-eight of these 61 patients (= 62%) had a manifest iron deficiency. In 18 of these 38 patients (= 47%) the transferrin concentration was increased. For our 264 patients we determined the diagnostic validity of an increased transferrin concentration for diagnosis of iron deficiency, assuming an iron deficiency if the concentration of ferritin remained below the discrimination values mentioned above: The diagnostic sensitivity was 36%, the diagnostic specificity 97%, the predictive value of the positive test result 79% and the predictive value of the negative test result 83%.(ABSTRACT TRUNCATED AT 250 WORDS)

Nocturnal asthma: slow-release terbutaline versus slow-release theophylline therapy

In a double-blind cross-over study, the effects of slow release (S-R) terbutaline tablets (b.i.d. 0.25 mg/kg per day) and S-R theophylline (5.31 mg/kg morning and 10.62 mg/kg evening) were compared in eleven patients with nocturnal asthma. On day seven of each treatment period, drug serum concentrations and peak expiratory flow (PEF) were measured every 2h over a 24-h period. During daytime, terbutaline concentrations ranged from 1.6-14.1 (median 4.5) microgram/l and during the night from 2.1-18.7 (median 4.9) micron/l. Theophylline concentrations ranged from 3.9-24.3 (median 11.5) mg/l during the day and from 3.3-20.9 (median 10.4) mg/l at night. Nocturnal wheezing occurred during theophylline treatment in four patients 7 times and during terbutaline treatment in six patients 22 times. Daytime PEF values were 472 +/- 161 l/min during theophylline therapy versus 445 +/- 169 l/min during terbutaline therapy (p less than 0.05). In the night and early morning there was no significant difference between PEF values with the two treatment forms. During theophylline treatment, fewer inhalations of beta 2-sympathomimetics were used, and there were fewer side effects. One patient experienced severe asthmatic attacks during the terbutaline treatment period. The patients preferred theophylline for the treatment of nocturnal asthma.

Nocturnal asthma: slow-release terbutaline versus slow-release theophylline therapy

In a double-blind cross-over study, the effects of slow release (S-R) terbutaline tablets (b.i.d. 0.25 mg/kg per day) and S-R theophylline (5.31 mg/kg morning and 10.62 mg/kg evening) were compared in eleven patients with nocturnal asthma. On day seven of each treatment period, drug serum concentrations and peak expiratory flow (PEF) were measured every 2h over a 24-h period. During daytime, terbutaline concentrations ranged from 1.6-14.1 (median 4.5) microgram/l and during the night from 2.1-18.7 (median 4.9) micron/l. Theophylline concentrations ranged from 3.9-24.3 (median 11.5) mg/l during the day and from 3.3-20.9 (median 10.4) mg/l at night. Nocturnal wheezing occurred during theophylline treatment in four patients 7 times and during terbutaline treatment in six patients 22 times. Daytime PEF values were 472 +/- 161 l/min during theophylline therapy versus 445 +/- 169 l/min during terbutaline therapy (p less than 0.05). In the night and early morning there was no significant difference between PEF values with the two treatment forms. During theophylline treatment, fewer inhalations of beta 2-sympathomimetics were used, and there were fewer side effects. One patient experienced severe asthmatic attacks during the terbutaline treatment period. The patients preferred theophylline for the treatment of nocturnal asthma.

Treatment of nocturnal asthma: the role of sustained-release theophylline and oral beta-2-mimetics

In two double-blind, multiple-dose cross-over studies the therapeutic effects of SR theophylline preparations given once each night (mean 11.2 mg/kg per day) versus twice daily in equal doses (mean 10.3 mg/kg per day) (study I) and SR-terbutaline in equal doses (mean 0.25 mg/kg per day) versus SR theophylline in unequally divided daily doses (mean 5.3 mg/kg morning dose, 10.6 mg/kg evening dose) study II) were compared in 19 patients with nocturnal asthma. At the end of each treatment period drug serum concentrations and PEFR were measured every 2 hr over a 24-hr period. With the twice-daily, equally divided regimen, serum theophylline concentrations were lower at night than during the day (mean 9.4 +/- 0.9 versus 11.3 +/- 1.0 mg/l). With the single evening administration, serum theophylline concentrations were considerably higher at night (Cmax 16.3 +/- 1.4 mg/l) and the circadian variation of PEFR was significantly reduced. PEFR was higher during night and early morning (283 +/- 14 versus 217 +/- 11 l/min, P less than 0.005). During daytime in study II, PEFR values were slightly higher with theophylline than terbutaline. There was no significant difference in peak flow between either treatment during the night and early morning. However, additional use of inhaled beta-2-mimetics because of asthmatic attacks occurred more often during terbutaline (79 times in 8/10 patients) than theophylline treatment (29 times in 5/10 patients). Symptom scores, number of attacks and side-effects clearly favor the theophylline regimen. We conclude that for patients with nocturnal asthma a once-nightly dose of SR theophylline can be sufficient for stabilization of the airways.

Perceptions of medical school faculty members and students on clinical clerkship feedback

The authors in this study investigated faculty members' and students' perceptions of the feedback they provided or received, respectively, during the clerkships in all clinical departments at a university hospital. All faculty members who teach students in the clinical years and all third- and fourth-year medical students were surveyed. Respondents were asked to indicate, on a 7-point scale, the importance they attributed to eight feedback categories and to rate the frequency of actual feedback they felt was provided or received in these eight categories. The results indicate that while both faculty members and students perceived six of the eight feedback categories as equally important, they differed substantially in their ratings of the actual feedback provided or received.

Perceptions of medical school faculty members and students on clinical clerkship feedback

The authors in this study investigated faculty members' and students' perceptions of the feedback they provided or received, respectively, during the clerkships in all clinical departments at a university hospital. All faculty members who teach students in the clinical years and all third- and fourth-year medical students were surveyed. Respondents were asked to indicate, on a 7-point scale, the importance they attributed to eight feedback categories and to rate the frequency of actual feedback they felt was provided or received in these eight categories. The results indicate that while both faculty members and students perceived six of the eight feedback categories as equally important, they differed substantially in their ratings of the actual feedback provided or received.

Perceived stress in medical, law, and graduate students

Students in the medical and law schools and graduate students in chemistry and psychology at a single institution were asked to complete a questionnaire about events and activities related to their educational programs which they perceived to be stressful. The questionnaire was designed to elicit information about stress associated with academic activities, personal relationships, time pressures, and financial concerns. Information was also obtained about time utilization, health behaviors, crises, and support systems. The authors' hypothesis that medical students would report higher perceived stress levels than students in the other programs was not supported, as the highest total stress score was reported by law students. Factor analysis of a 31-item stress scale produced six separate factors pertaining to the sources of stress: academic concerns, time concerns, fear of failing, classroom interactions, economic issues, and world issues. Time restrictions and economic and academic issues had the highest mean stress scores. The hypotheses by the authors that students would report program-specific stresses and that utilization of support services would differ among the four groups of students were both supported. Implications of these findings are discussed.

Attitudes of pediatricians toward maternal employment

The largest number of women in history is employed outside the home including 55% of mothers with children less than 18 years of age. The attitudes of pediatricians toward employed mothers were assessed by a mail survey to the entire membership of the American Academy of Pediatrics. Usable responses were received from 5,758 pediatricians (31%). Adequacy of child care and economic necessity were ranked as the most important factors considered by responding pediatricians when advising a mother inquiring whether she should work outside the home. One third of the respondents stated the child can be any age when the mother becomes employed. The majority of respondents did not feel there was a difference between children of employed mothers and homemaker mothers. Special considerations for employed mothers were provided by half of the respondents, more frequently by female than male pediatricians. Most respondents are supportive of mothers working outside the home, but bias against employed mothers does exist. Pediatricians whose spouses do not work outside the home, those in older age groups, and male pediatricians tended to hold more traditional attitudes toward maternal employment.

Effect of immediate student evaluations on a multi-instructor course

Immediate student feedback and peer evaluation by a single physician were used to evaluate and monitor an interdisciplinary multi-instructor course. Clinical Correlations with Pathology is taught during the second year of medical school by 50 instructors, each of whom has a limited exposure to sophomore medical students. The format of the course, in which the same students evaluate multiple lecturers in multiple content areas, provided a unique opportunity to demonstrate the reliability and validity of student evaluations. About one-half of the lectures were repeated by the same instructors the following year to the next class of medical students, who also evaluated all of the lectures. Comparison of two consecutive sophomore classes of medical students documented overall course improvement and showed higher ratings given to instructors who presented the same lecture both years. Student evaluation is a powerful technique that can result in positive changes leading toward course improvement.