Health-related quality of life, developmental milestones, and self-esteem in young adults with bleeding disorders.

BACKGROUND: The treatment of bleeding disorders improved in the last decades. However, the effect of growing up with bleeding disorders on developmental, emotional, and social aspects is understudied. Therefore, this study assesses HRQOL, developmental milestones, and self-esteem in Dutch young adults (YA) with bleeding disorders compared to peers. METHODS: Ninety-five YA (18-30 years) with bleeding disorders (78 men; mean 24.7 years, SD 3.5) and 17 women (mean 25.1 years, SD 3.8) participated and completed the Pediatric Quality of Life Inventory Young Adult version, the Course of Life Questionnaire, and the Rosenberg Self-Esteem Scale. Differences between patients with bleeding disorders and their peers, and between hemophilia severity groups, were tested using Mann-Whitney U tests. RESULTS: YA men with bleeding disorders report a slightly lower HRQOL on the total scale, physical functioning, and school/work functioning in comparison to healthy peers (small effect sizes). YA men with severe hemophilia report more problems on the physical functioning scale than non-severe hemophilia. YA men with bleeding disorders achieved more psychosexual developmental milestones than peers, but show a delay in 'paid jobs, during middle and/or high school.' A somewhat lower self-esteem was found in YA men with bleeding disorders in comparison to peers (small effect size). For YA women with bleeding disorders, no differences were found on any of the outcomes in comparison to peers. CONCLUSION: This study demonstrates some impairments in HRQOL and self-esteem in YA men with bleeding disorders. By monitoring HRQOL, problems can be identified early, especially with regard to their physical and professional/school functioning.

Relative potencies of gonadotropin-releasing hormone agonists and antagonists on ovarian and pituitary functions.

The abilities of various agonistic and antagonistic analogs of GnRH to modulate ovarian estrogen production were compared with their relative potencies to regulate pituitary LH release. Granulosa cells from immature hypophysectomized rats were cultured for 2 days in the presence of FSH and aromatase substrate (delta 4-androstenedione), with or without various concentrations of GnRH agonists or 10(-8) M GnRH plus various concentrations of selected GnRH antagonists. FSH treatment increased estrogen production, whereas concomitant treatment with various GnRH agonists resulted in dose-dependent decreases in estrogen production. des-Gly10-[D-Ser(TBu)6] Pro9-NHEt-GnRH proved most potent at both the ovarian and pituitary levels, being 170- and 190-fold greater than those values for the GnRH decapeptide, respectively. In general, the ovarian and pituitary potencies of all 10 agonists studied were comparable, with a correlation coefficient of 0.98. When added together with 10(-8) M GnRH, the GnRH antagonists caused dose-dependent blockage of the inhibitory effect of GnRH. Among 7 antagonists tested, [Ac-D-Phe1,D-p-cl-Phe2,D-TYrp3,6]GnRH was shown to be most potent at the pituitary level (half maximal inhibitory dose ratio: IDR50 antagonist/GnRH = 0.17) and blocked the GnRH inhibition at the ovarian level with an IDR50 value of 4.4. The potencies of the antagonists to block the GnRH effect at the pituitary and ovarian levels were comparable, yielding a correlation coefficient of 0.97. Although one cannot rule out subtle differences in the specificities of the respective GnRH target tissues due to minor disparities between pituitary and ovarian potencies of some analogs, the present results demonstrate an overall agreement of responsiveness between ovarian granulosa cells and pituitary gonadotrophs to GnRH agonists and antagonists.

Bone growth in biomimetic apatite coated porous Polyactive 1000PEGT70PBT30 implants.

We recently, developed a simple one-day one-step incubation method to obtain bone-like apatite coating on flexible and biodegradable Polyactive 1000PEGT70PBT30. The present study reports a preliminary biological evaluation on the coated polymer after implantation in rabbit femurs. The porous cylindrical implants were produced from a block fabricated by injection molding and salt leaching. This technique provided the block necessary mechanical integrity to make small cylinders (diameter 3.5 x 5 mm2) that were suitable for implantation in rabbits. The coating continuously covered the surface of the polymer, preserving the porous architecture of outer contour of the cylinders. Two defects with a diameter of 3.5 or 4 mm were drilled in the proximal and distal part of femur diaphysis. The implants were inserted as press-fit or undersized into the cortex as well as in the marrow cavity. The polymer swelled after implantation due to hydration, leading to a tight contact with the surrounding bone in both defects. The adherence of the coating on the polymer proved to be sufficient to endure a steam sterilization process as well as the 15% swelling of the polymer in vivo. The coated Polyactive 1000PEGT70PBT30 has a good osteoconductive property, as manifested by abundant bone growth into marrow cavity along the implant surface during 4-week implantation. A favorable bioactive effect of the coating with an intimate bone contact and extensive bone bonding with this polymer was qualitatively confirmed. Concerning the bone ingrowth into the porous implant in the defect of 4 mm diameter, only marginal bone formation was observed up to 8 weeks with a maximal penetration depth of about 1 mm. The pore interconnectivity is important not only for producing a coating inside the porous structure but also for bone ingrowth into this biodegradable material. This preliminary study provided promising evidence for a further study using a bigger animal model.

A new automated method for the determination of true creatinine in serum by means of the centrifichem centrifugal analyzer, based on Slot's principle; with special reference to low substrate concentrations.

A new automated method is proposed for the accurate determination of the true creatinine concentration in 20 microliter serum, based on the measurement of the initial rate of the decomposition reaction of the creatinine picrate complex caused by decreasing the pH. The results of this method, performed with a Centrifichem centrifugal analyzer system (type 300 F), are compared with the results obtained by two other methods: a manual method based upon the adsorption on Fuller's earth, and the Auto Analyzer method. In these comparative studies special attention is paid to the analysis of sera containing low (normal) substrate concentrations. Calculation of the orthogonal regression between the results obtained by the adsorption method (x) and the proposed method (y) gave: y=0.97x +/- 5 mumol/l (x=91.3 mumol/l, y-93.5 mumol/l), while for the correlation coefficient (r) 0.9721 was found. All sera (n=113) had creatinine concentrations between 40 and 180 mumol/l.

In vitro and in vivo degradation of biomimetic octacalcium phosphate and carbonate apatite coatings on titanium implants.

Calcium phosphate (Ca-P) coatings have been applied onto titanium alloys prosthesis to combine the srength of metals with the bioactivity of Ca-P. It has been clearly shown in many publications that Ca-P coating accelerates bone formation around the implant. However, longevity of the Ca-P coating for an optimal bone apposition onto the prosthesis remains controversial. Biomimetic bone-like carbonate apatite (BCA) and Octacalcium Phosphate (OCP) coatings were deposited on Ti6Al4V samples to evaluate their in vitro and in vivo dissolution properties. The coated plates were soaked in alpha-MEM for 1, 2, and 4 weeks, and they were analyzed by Back Scattering Electron Microscopy (BSEM) and by Fourier Transform Infra Red spectroscopy (FTIR). Identical coated plates were implanted subcutaneously in Wistar rats for similar periods. BSEM, FTIR, and histomorphometry were performed on the explants. In vitro and in vivo, a carbonate apatite (CA) formed onto OCP and BCA coatings via a dissolution-precipitation process. In vitro, both coatings dissolved overtime, whereas in vivo BCA calcified and OCP partially dissolved after 1 week. Thereafter, OCP remained stable. This different in vivo behavior can be attributed to (1) different organic compounds that might prevent or enhance Ca-P dissolution, (2) a greater reactivity of OCP due to its large open structure, or (3) different thermodynamic stability between OCP and BCA phases. These structural and compositional differences promote either the progressive loss or calcification of the Ca-P coating and might lead to different osseointegration of coated implants.

An extremely simple and fast microlitre method for the determination of total carbon dioxide in biological samples.

For those clinical laboratories equipped with a microprocessor-controlled gas analyser, an extremely simple method is described for the determination of the total carbon dioxide content in various biological fluids. Since this method needs only 20 microL of blood plasma or is less dependent on the original total carbon dioxide content, it is especially suited for paediatric purposes. With our procedure the time necessary for one determination equals the time for one capillary blood gas analysis.

The diagnostic value of the urine to blood carbon dioxide tension gradient for the assessment of distal tubular hydrogen secretion in pediatric patients with renal tubular disorders.

The urine to blood carbon dioxide tension gradient (U-B PCO2) following alkalinization of the urine (pH = 7.8) has been widely used to assess distal tubular hydrogen secretion. The magnitude of the U-B PCO2 is influenced not only by the rate of hydrogen secretion but also by bicarbonate concentration and water abstraction. Simultaneous administration of sodium bicarbonate and dDAVP improve the reliability of the test in healthy children. Children with distal renal tubular acidosis were not able to increase urinary PCO2, while a normal increase was found in patients with proximal renal tubular acidosis and the Fanconi Syndrome. Four out of nine patients with urolithiasis failed to increase urinary PCO2 following NaHCO3 and dDAVP-administration, despite a normal ability to acidify the urine following NH4Cl administration. To assess the effect of acute alterations in urinary concentration on urinary PCO2, the test was carried out in children with central diabetes insipidus. Despite sharp increase in urinary bicarbonate concentration these patients failed to increase urinary PCO2.

Osteointegration of biomimetic apatite coating applied onto dense and porous metal implants in femurs of goats.

Biomimetic calcium phosphate (Ca-P) coatings were applied onto dense titanium alloy (Ti6Al4V) and porous tantalum (Ta) cylinders by immersion into simulated body fluid at 37 degrees C and then at 50 degrees C for 24 h. As a result, a homogeneous bone-like carbonated apatitic (BCA) coating, 30 microm thick was deposited on the entire surface of the dense and porous implants. Noncoated and BCA-coated implants were press-fit implanted in the femoral diaphysis of 14 adult female goats. Bone contact was measured after implantation for 6, 12, and 24 weeks, and investigated by histology and backscattered electron microscopy (BSEM). After 6 weeks, bone contact of the BCA-coated Ti6Al4V implants was about 50%. After 12 and 24 weeks, bone contact was lower in comparison with the 6-week implantations at, respectively 24 and 39%. Regarding the BCA-coated porous Ta implants, bone contacts were 17, 30, and 18% after 6, 12, and 24 weeks, respectively. However, bone contact was always found significantly higher for BCA-coated dense Ti6Al4V and porous Ta cylinders than the corresponding noncoated implants. The results of this study show that the BCA coating enhances the bone integration as compared to the noncoated implants.

Regulation of progestin biosynthetic enzymes in cultured rat granulosa cells: effects of prolactin, beta 2-adrenergic agonist, human chorionic gonadotropin and gonadotropin releasing hormone.

Prolactin (Prl), beta 2-adrenergic agents and human chorionic gonadotropin (hCG) are luteotropic in rats, whereas gonadotropin releasing hormone (GnRH) exerts direct inhibitory effects on ovarian steroidogenesis. The present study examined the modulation of the progestin biosynthetic pathway by the luteotropic agents, as well as the actions of GnRH. Rat granulosa cells were primed with follicle-stimulating hormone (FSH) to increase their responsiveness to the luteotropic agents. Subsequent treatment for 2 days with Prl, terbutaline (a beta 2-adrenergic agonist) or hCG stimulated the production of progesterone, 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OH-P), pregnenolone and the activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD). In contrast, treatment with Prl or terbutaline, but not hCG, inhibited 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity by decreasing the apparent maximal velocity of the enzyme with no change in its Km value. Concomitant treatment with GnRH inhibited progesterone, but increased 20 alpha-OH-P production stimulated by Prl or terbutaline. These effects were associated with a stimulation of 20 alpha-HSD activity, while neither 3 beta-HSD activity nor pregnenolone biosynthesis was decreased. In contrast, GnRH inhibited progesterone production in hCG-treated cells without affecting 20 alpha-OH-P production. This was associated with an inhibitory effect of GnRH on pregnenolone biosynthesis with no effect upon 3 beta-HSD activity. Thus, Prl and the beta 2-agonist stimulate progesterone production in granulosa cells by increasing pregnenolone production and 3 beta-HSD activity as well as by decreasing 20 alpha-HSD activity, while hCG stimulates progesterone production by increasing pregnenolone production and 3 beta-HSD activity. The inhibitory effect of GnRH on Prl- or terbutaline-stimulated progesterone production appears to result from a preferential increase in 20 alpha-HSD activity, while the GnRH inhibition of hCG-stimulated progesterone production appears to result from a preferential inhibition of pregnenolone production.

A case of transient renal tubular acidosis type 1,4 hybrid RTA: a study of the pathophysiologic characteristics of the acidification defect.

The diagnosis of transient renal tubular acidosis was made in a 16 months old boy. Bicarbonate titration studies revealed that the acidification defect consisted of an association of proximal and distal tubular acidosis. The effect of experimentally induced potassium depletion revealed that hyperkalemia contributed to the acidification defect. After correction of the acidification disorder a defect in urinary concentration was still present.

Influence of octacalcium phosphate coating on osteoinductive properties of biomaterials.

In this study, we investigated the influence of octacalcium phosphate (OCP) coating on osteoinductive behaviour of the biomaterials. Porous titanium alloy (Ti6Al4V), hydroxyapatite (HA), biphasic calcium phosphate (BCP) and polyethylene glyco terephtalate/polybuthylene terephtalate (PEGT-PBT) copolymer, all uncoated and coated with biomimetically produced OCP, were implanted in back muscles of 10 goats for 6 and 12 weeks. Uncoated Ti6Al4Vand HA did not show any bone formation after intramuscular implantation. All OCP coated implants, except PEGT-PBT, did induce bone in the soft tissue. The reason for the non-inductive behaviour of the copolymer is probably its softness, that makes it impossible to maintain its porous shape after implantation. Both uncoated and OCP coated BCP induced bone. However, the amount of animals in which the bone was induced was higher in the coated BCP implants in comparison to the uncoated ones. Osteoinductive potential of biomaterials is influenced by various material characteristics, such as chemical composition, crystallinity, macro- and microstructure. OCP coating has a positive effect on osteoinductivity of the biomaterials. The combination of the advantages of biomimetic coating method above traditional methods, and a good osteoinductivity of OCP coating that is produced by using this method, opens new possibilities for designing more advanced orthopaedic implants.