IFN-gamma-mediated prevention of graft-versus-host disease: pharmacodynamic studies and influence on proliferative capacity of chimeric spleen cells

Recently we demonstrated that prolonged administration of IFN-gamma prevented the development of GVHD in a MHC-mismatched murine BMT model. Treatment with IFN-gamma allowed the development of mature donor-derived allo-tolerant immunocompetent cells in complete chimeric recipients. Here we present data on the pharmacodynamics of this cytokine-mediated protection against GVHD. Treatment with 50000 U IFN-gamma twice weekly for a period of 5 weeks, starting at the day of BMT, was shown to be the optimal treatment protocol, resulting in complete prevention of GVHD-related mortality. Treatment during 1 week with a three-fold higher weekly dose of IFN-gamma (50000 U six times) did not result in significantly improved survival. The start of IFN-gamma administration was a critical factor since a delay of 3 days from the time of BMT resulted in substantial GVHD-induced mortality. Furthermore, it was shown that IFN-gamma treatment inhibited the spontaneous and Con-A-induced proliferation of T cells at 7-14 days after BMT, which is the critical period for the initiation of acute GVHD. However, long-term survivors after IFN-gamma treatment showed a recovery of immunity in contrast to long-term survivors of saline-injected animals, as tested by Con-A responsiveness. It seems that injection of high dose IFN-gamma suppresses the response of potentially alloreactive donor T cells during what normally is the initiation phase of the GVH reaction (GVHR), resulting in the abrogation of GVHD.     

Bracing of patients after fusion for degenerative problems of the lumbar spine--yes or no?

The majority of spine fusions currently performed are for degenerative conditions. Controversy exists regarding whether to routinely brace patients during the postoperative period. The benefits of a rigid orthosis have yet to be documented in a scientific study, and the cost of a custom-molded orthosis can be quite high. An extensive literature search reveals few articles dealing with the subject, and none with an adequate study design to convincingly support or refute the use of external braces. In addition to the questions of whether an external brace is effective, the mechanism of action also remains unclear. It has been difficult to document mechanical effectiveness, so perhaps the effect is psychologic. In addition, it is possible that some, not all, fusion patients may benefit from a brace--yet our ability to select such a patient is poor. As a result, we have solicited the views of two experienced surgeons on the topic. Dr. Connolly argues that an external orthosis is advisable in many cases; Dr. Grob feels that the rigidity of internal fixation should be adequate to obviate the need for external bracing.     

Cephalometric analysis of a Sotho-Tswana group

A cephalometric study was conducted on 50 male and 54 female Sotho-Tswana children 11-16 years of age. The subjects were selected for excellence of occlusion and balance of facial proportions. Various analyses, including Steiner, Wits, and McNamara, were used for the evaluations. The mean measurements were compared with those of other Southern African Black groups and Caucasoids. Our study shows that cephalometric analyses for other groups cannot be used with confidence for the Sotho-Tswana people and our data provides norms for them.     

The Dental Subscale of the Children's Fear Survey Schedule: a factor analytic study in The Netherlands

The Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS) is a well-known instrument for assessing dental fear in children. Previous studies have shown that the scale has acceptable reliability and validity. Factor analysis using scores of a group of Finnish schoolchildren resulted in three factors. No other data on the factor structure have been published. In order to report on the factor structure of the Dutch parental version of the CFSS-DS, the present study was undertaken. Factor analysis using scores from a group of Dutch children (n= 150) demonstrated a factor pattern fairly similar to the results found in the Finnish study. Three factors were found: 1) fear of highly invasive dental procedures, 2) fear of less invasive aspects of treatment and 3) fear of medical aspects. Considering that almost all items load substantially (> or =0.20) on more than one factor, it seems that one primary underlying dimension exists: fear of invasive treatment aspects. The CFSS-DS is proposed as a reliable, one-dimensional measure of dental fear.     

The effects of the systemic antimycotics, itraconazole and fluconazole, on the pharmacokinetics and pharmacodynamics of intravenous and oral midazolam

We studied the interaction of azole antimycotics with intravenous (IV) and oral midazolam using a cross-over design in 12 volunteers, who ingested placebo, itraconazole, or fluconazole for 6 days. A 7.5-mg dose of midazolam was ingested on the first day, 0.05 mg/kg was administered IV on the fourth day, and 7.5 mg orally on the sixth day. Itraconazole reduced the clearance of IV midazolam by 69% and fluconazole reduced the clearance of IV midazolam by 51% (P < 0.001). A single dose of itraconazole and fluconazole increased the area under the oral midazolam concentration-time curve [AUC(0-infinity)] 3.5-fold (P < 0.001) and the peak concentration two-fold (P < 0.05) compared to placebo. On the sixth day the AUC(0-infinity) of oral midazolam was almost seven times greater with itraconazole (P < 0.001) and 3.6 times greater with fluconazole (P < 0.001) than without the antimycotics. The psychomotor effects of midazolam were also profoundly increased (P < 0.001). The psychomotor tests demonstrated only a weak interaction between the antimycotics and IV midazolam. When bolus doses of midazolam are given for short- time sedation, the effect of midazolam is not increased to a clinically significant degree by itraconazole and fluconazole, and it can be used in normal doses. However, the use of large doses of IV midazolam increases the risk of clinically significant interactions also after IV midazolam. Use of oral midazolam with itraconazole and fluconazole should be avoided.     

Induced luteolysis in the primate: rapid loss of luteinizing hormone receptors

The molecular mechanisms involved in luteolysis are still unclear in the primate. This study aimed to investigate the effect of induced luteolysis on the ovarian luteinizing hormone (LH) receptor and the steroidogenic enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset monkey. Luteolysis was induced in the mid-luteal phase either directly by systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal using systemic gonadotrophin releasing hormone antagonist (GnRHant) treatment. The LH receptor was studied by isotopic mRNA in-situ hybridization and in-situ ligand binding and 3beta-HSD expression was studied using isotopic mRNA in-situ hybridization and immunohistochemistry. Induced luteolysis was associated with a reduction in the expression of LH receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a reduction in the LH receptor (P < 0.05) and 3beta-HSD protein concentrations within 24 h. There were no differences in the findings whether luteolysis was induced with PGF2alpha or GnRHant. This study shows that disparate mechanisms to induce luteolysis in the primate result in an identical rapid loss of the LH receptor and 3beta-HSD. In conclusion, induced luteolysis leads to rapid loss of the steroidogenic pathway in luteal cells.     

Management of hyperparathyroidism in an endemic goiter area

In an endemic goiter area patients with hyperparathyroidism (HPTH) frequently also have thyroid abnormalities. In a retrospective study of 95 patients with HPTH we assessed the diagnostic accuracy of imaging techniques (ultrasonography or radionuclide scanning) for preoperative localization of parathyroid adenomas. Altogether 86% of our patients had goiter, requiring thyroid resections in 37%. For 19 patients the parathyroid exploration was the second or third cervical operation, most of them due to goiter. We found that the overall rate of transient and permanent recurrent nerve paralysis is considerably increased in patients with previous neck surgery (26% vs. 7%). The combination of ultrasonography and radionuclide scanning can lead surgeons to the site of parathyroid lesions responsible for HPTH in 85% of cases, although frequent nodular goiters can produce pitfalls for correct imaging in iodine-deficient countries. In endemic goiter areas preoperative localization studies can be recommended in patients with primary HPTH--for evaluation of thyroid pathology possibly leading to resection or its accuracy in localizing parathyroid adenomas. These studies also seem justified in patients with previously unsuccessful neck explorations for HPTH.     

Cardioprotective effect of probucol in the atherosclerosis-prone JCR:LA-cp rat

The second epidermal growth factor (EGF)-like domain of human coagulation factor VII is a potent inhibitor of the FVIIa/tissue factor complex, the predominant initiator of coagulation in vivo. This domain has now for the first time been cloned and expressed in Escherichia coli as an affinity fusion protein. The fusion protein was secreted into the periplasm of E. coli and purified by affinity chromatography. The purified protein consisted of a fusion protein with the expected molecular weight, and in addition, a significant fraction of oligomers cross-linked by intermolecular disulfide bonds. Despite the presence of oligomers, the purified protein was a potent inhibitor of the extrinsic blood coagulation pathway with an IC50 value of about 20 microM. The biological activity was retained after liberation of the EGF domain by proteolytic cleavage.