The impact of blood donation on blood counts and ferritin levels: A multi-center study from the Eastern Mediterranean region.

Regular donation of whole blood may lead to iron deficiency. In this study, we aimed to assess the impact of frequent whole blood donation on hematological parameters. Whole blood donors were enrolled from four blood banks located in Saudi Arabia, United Arab Emirates (UAE), Libya and Oman, between 2016 and 2017. SPSS version 21.0 was used to generate descriptive and inferential statistics. A total number of 3096 blood donors were screened (males 93.8 %, females; 6.2 %), with a mean donor age of 35.29 ± 9.31 years. For male blood donors, the majority (1073) had 1-3 previous donations. Increased frequency of donations was significantly associated with increases in age and weight, decreases in Hemoglobin (Hb) and ferritin measures, and increases in Red Blood Cells (RBC) counts. A General Linear Model (GLM) adjusted for age and weight indicated negative impacts on White Blood Cells (WBC) counts and ferritin. A weak correlation between the Hb and ferritin levels was observed (r = 0.160, P > 0.001). For female donors, the majority (63 out of 114) were first time donors. Increased frequency of donations was significantly associated with an increase in age and a decrease in HCT readings. A GLM adjusted for age and weight indicated a negative impact on ferritin. A strong correlation was observed between the Hb and ferritin levels for the most frequent female donors (r = 0.636, P > 0.001). In conclusion, regular whole blood donation impacts hematological parameters in particular the levels of ferritin in the serum.

Three Dimensional Printed Bone Implants in the Clinic.

Implants are being continuously developed to achieve personalized therapy. With the advent of 3-dimensional (3D) printing, it is becoming possible to produce customized precisely fitting implants that can be derived from 3D images fed into 3D printers. In addition, it is possible to combine various materials, such as ceramics, to render these constructs osteoconductive or growth factors to make them osteoinductive. Constructs can be seeded with cells to engineer bone tissue. Alternatively, it is possible to load cells into the biomaterial to form so called bioink and print them together to from 3D bioprinted constructs that are characterized by having more homogenous cell distribution in their matrix. To date, 3D printing was applied in the clinic mostly for surgical training and for planning of surgery, with limited use in producing 3D implants for clinical application. Few examples exist so far, which include mostly the 3D printed implants applied in maxillofacial surgery and in orthopedic surgery, which are discussed in this report. Wider clinical application of 3D printing will help the adoption of 3D printers as essential tools in the clinics in future and thus, contribute to realization of personalized medicine.

Fat tissue: views on reconstruction and exploitation.

Transplantation of autologous fat as pedicle or transposition flaps has been a classical method in plastic surgery for tissue reconstruction. The injection of fat for soft tissue reconstruction is also an old innovation. This approach has some significant drawbacks such as resorption of the fat transplant. To regenerate additional and self-regenerating adipose tissue for reconstructive purposes, a thorough understanding of adipose tissue (mesodermal stem cells, adipoblasts, pre-adipocytes, mature, lipid-synthesizing, and lipid-storing white or brown adipocytes) on cellular and molecular levels is required. Several transcription factors that play a central role in the control of adipogenesis have been identified. Among these are the CCAAT/enhancer binding protein gene family and peroxisome proliferator-activated receptor-gamma. Hormones and growth factors, such as insulin and insulin-like growth factor (IGF), transfer external signals to differentiating adipocytes. In an attempt to improve the quality of tissue-engineered fat by culture-expanded adipocytes, various pre-adipocyte and stem cell culture conditions and expansion methods have been developed. In the presence of fetal calf serum, spontaneous differentiation of pre-adipocytes into fat cell clusters occurs to some degree. This in vitro differentiation can be enhanced by addition of inducing agents such as dexamethasone, isobutylmethylxantine, and insulin into the culture medium. Recent work has shown the multipotency of pre-adipocytes, which are fibroblast-like precursors of adipocytes. With use of specific culture conditions, human adipose tissue-derived stem cells can be induced to express markers of adipocyte, osteoblast, and myocyte cell lineages. The multipotent characteristics of adipose tissue-derived stem cells, as well as their abundance and accessibility in the human body, make them a potential cell source for tissue engineering applications.

Histologic analysis of bioabsorbable scleral buckling implants: an experimental study on rabbits.

PURPOSE: To analyze histologically tissue reactions to bioabsorbable PLA96 in rabbit eyes. METHODS: Scleral buckling operations were carried out in 48 rabbits. Two materials were used: bioabsorbable PLA96 (polylactide 96/4; L/D molar ratio 96/4) and silicone sponge. One eye of each rabbit was operated on and the other eye served as a nonoperated control. After follow-up times of 1, 3, 5, and 12 months, the rabbits were killed and the eyes enucleated for histology. RESULTS: All rabbits recovered well. Histologically, tissue reactions were very localized; implant fragments were not seen within the sclera. The amounts of fibrous tissue and inflammatory cells (mainly macrophages) inside the implant area increased over time. One rabbit from the silicone group was killed 4 months postoperatively owing to refusal to eat. In the PLA96 group, acute or chronic infections occurred in four rabbits. The bioabsorbable implant was macroscopically easily detectable at 12 months postoperatively. CONCLUSIONS: The PLA96 material used for scleral buckling in rabbits showed good biocompatibility. The material did not undergo biodegradation during the follow-up period of 12 months. PLA96 implants were associated with thicker fibrous tissue encapsulation and more inflammatory cells compared with silicone sponge implants.

Persistence of indentation with bioabsorbable poly-L/D-lactide versus silicone sponge scleral buckling implants.

PURPOSE: To measure the amount and duration of indentation depth achieved with biodegradable poly-L/D-lactide 96/4 (PLA96) and silicone sponge implants. METHODS: Thirty rabbits underwent a scleral buckling procedure. A PLA96 buckling implant was used in 15 rabbits and a silicone sponge buckling implant was in 15 rabbits. A circumferential scleral buckling implant was sutured episclerally on the left eye of each rabbit, just temporal to the superior rectus muscle and 7 mm posterior to the limbus. Computed tomography was performed at 1 week, 3 months, and 5 months after surgery. RESULTS: The PLA96 buckling implant (implant diameter, 3-3.5 mm) used in this study created lower indentation than the silicone sponge implant (implant diameter, 4 mm). The indentation created by the PLA96 implant decreased over time compared with that created by the silicone implant. There were no complications related to either kind of implant. CONCLUSION: Both the silicone sponge implant and the PLA96 implant caused indentation that decreased in a comparable manner over the follow-up period (5 months).

A self-programmable in vitro fertilization/gamete intrafallopian transfer patient database management system for MacIntosh computers.

PURPOSE: Our purpose was to develop a data processing system for a large in Vitro Fertilization/Gamete Intrafallopian Transfer (IVF/GIFT) practice which would (1) require minimal data entry time, (2) be easy to operate, (3) be simple to construct (no knowledge of procedural language or programming necessary), and (4) quickly collate and reduce data. RESULTS: A database management system was successfully constructed on an Apple MacIntosh computer which met the above criteria. The key elements of this database were its user-friendly features (MacIntosh-based system), adaptability (user was constantly able to update and revise the program as informational needs changed), and ability to perform complex searches and data analyses imposed by the individual operators. CONCLUSIONS: The software and hardware described in this report were found to be highly effective in meeting the ever-changing administrative and clinical needs of our IVF/GIFT program.

The appearance of one-pronuclear human oocytes is associated with a better ovulation-induction response and successful pregnancy outcome.

OBJECTIVE: To study the relationship between the presence of one-pronuclear oocytes in in vitro fertilization (IVF) patients and ovulation-induction response, oocyte and embryo development, and clinical outcome. DESIGN: Retrospective analysis of 535 consecutive IVF retrievals. Retrievals in which one or more oocytes exhibited one pronucleus were compared with retrievals in which no one-pronuclear oocytes (control) were observed. The following one-pronuclear versus control subgroups were also examined: leuprolide acetate/human menopausal gonadotropin (LA/hMG) ovulation inductions, high estradiol (E2) response cases, and retrievals in which a large number of oocytes (greater than or equal to 15) were recovered. SETTING: Brigham and Women's Hospital, a tertiary care, university-affiliated hospital. PATIENTS: Three hundred forty-six IVF patients were treated between January 1989 and May 1991. MAIN OUTCOME MEASURES: Parameters examined included E2 concentration and number of follicles with maximum diameter greater than or equal to 12 mm on day of human chorionic gonadotropin administration; number of total and mature oocytes retrieved; total fertilization rates; number of embryos; and percent per retrieval of embryo transfers (ETs), clinical pregnancies, and ongoing-livebirths. RESULTS: The one-pronuclear patients had higher E2 levels and larger number of follicles, yielded significantly more total and mature oocytes, had a higher overall fertilization rate, produced more embryos, and had higher ET, clinical pregnancy and ongoing-livebirth rates per retrieval than did the control patients. Analysis of the subgroup populations revealed no significant differences in the majority of the main outcome measures studied; however, the one-pronuclear patients yielded significantly more total and mature oocytes per retrieval. CONCLUSIONS: Although there was an increase in the clinical and ongoing-livebirth pregnancy rates (PRs) in one-pronuclear patients, this was probably associated with an improved ovulation-induction response in the one-pronuclear patients. They achieved significantly higher E2 levels, recruited a larger number of follicles, and yielded more oocytes and embryos per retrieval than the control patients. When only the LA/hMG, E2 greater than or equal to 1,500 pg/mL, or the greater than or equal to 15 oocytes/case retrievals were analyzed, the PRs were no longer different; however, the one-pronuclear patients still yielded significantly more total and mature oocytes per retrieval than the controls. Therefore, the appearance of one-pronuclear oocytes is probably associated with the maturation stage of the oocytes obtained and is indicative of an ovulation induction in which a large number of preovulatory, metaphase II oocytes have been recruited.

Purines inhibit the development of mouse embryos in vitro.

The first cleavage of embryos derived from random-bred, inbred, and hybrid-inbred female mice was not arrested by purines at concentrations as high as 30 microM. Development after the first or second cleavage was arrested by hypoxanthine, adenosine or inosine, but not guanosine. In agreement with previous results, the purine-induced block was reversed when arrested embryos were transferred to purine-free media after 24 h in culture. The cleavage arrest was not due to elevations of cAMP as a result of inhibition of phosphodiesterase activity since similar concentrations of phosphodiesterase inhibitors or dibutyryl cAMP did not block development. Treatment with inhibitors of enzymes that convert IMP to AMP or to GMP did not reverse the hypoxanthine-induced block, thus demonstrating that mitotic arrest is mediated by a mechanism different from the hypoxanthine arrest of meiosis. Thymidine incorporation studies showed that the block did not prevent the onset of DNA synthesis. The results reveal a profound sensitivity to purine inhibition of a cell process that occurs during the first 30 h of mouse embryo development and is necessary for progession through the G2 or M phases of the second or third cleavage.

Ovarian ornithine decarboxylase regulation in the immature, the pubescent, and the pseudopregnant rat.

Ovarian ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) regulation was investigated in immature, pubescent, and pseudopregnant rats. After initial induction of the enzyme by injection of lutropin in the immature rat, continued daily injections resulted in a graded decrease in the activity of the enzyme. In the 32-day-old rat, the induction and subsequent decline in enzymic activity after a single injection of lutropin could only be partially reversed by injections of the hormone at 4-hr intervals. This decrease could not be attributed to a decrease in ovarian in vivo uptake of the hormone. In the pseudopregnant rat, ovarian ornithine decarboxylase is highly refractory to induction by either a single injection or repeated injections of lutropin. This refractoriness occurs despite a 2- to 3-fold increase in ovarian in vivo uptake of the hormone compared to that in the 32-day-old rat. It is suggested that the refractoriness observed with all three tissues is a function of cell differentiation.

Differentiation of the contribution of the two subunits of lutropin to its in vivo activity.

Porcine and ovine lutropins were acetimidated at amino groups to various degrees and the effects of the modification on the induction of ovarian ornithine decarboxylase activity were examined. A drastic (84%) loss of biological activity was observed upon modification of two amino groups in porcine lutropin. The results with ovine lutropin derivatives were quite similar. Circular dichroism measurements showed no conformational changes and dissociation into subunits was not observed in the derivatives. Accordingly, the loss of biological activity was not a by-product of conformational changes. It was concluded that lutropin carries a single binding site which is constructed by surface residues or regions located on both the alpha- and beta-subunits of the hormone.

Ultracentrifugal studies of human luteinizing hormone and its subunits: dependence on protein concentration and ionic strength.

Purified human pituitary luteinizing hormone (hLH) and its alpha and beta subunits have been examined by physical methods. Freshly prepared hLH showed three closely adjacent bands on electrophoresis in polyacrylamide gels under alkaline conditions, but on standing even in the freeze-dried condition additional bands appeared. alpha and beta subunits gave bands which were quite different from the main hLH bands but comparable with the additional bands, as well as traces of hLH bands. hLH was investigated at three ionic strengths (0.1, 0.2, 0.5) at pH 5.9 +/- 0.1. Sedimentation velocity experiments demonstrated a complex system of association-dissociation which was further investigated by sedimentation equilibrium. Association occurred at the higher protein concentrations at each ionic strength, but to a significantly higher level at I = 0.5. Only at I = 0.1, pH 5.8, was there a clear indication over a range of protein concentration of the occurrence of a species of molecular weight 32 000 +/- 2000, in fair agreement only with the sum of the molecular weights of the alpha and beta subunits. At higher ionic strengths, there were indications of dissociation at low protein concentration (less than 0.10 g/100 mL) as well as association at higher values (greater than 0.20 g/100 mL). In view of the occurrence of molecular weights less than 28 000 at I = 0.2, HLH was treated in terms of a monomer of molecular weight 14 000, and some evidence was obtained for tetramer formation (4M = M4). At higher ionic strength this model does not apply and it is thought that indefinite association may be occurring to some extent also. The alpha subunit gave indications of association from its sedimentation coefficient vs. concentration plot, and sedimentation equilibrium (at pH 5.9 I = 0.1) demonstrated molecular weights increasing with increasing concentration. Evidence for tetramer formation also was obtained. The beta subunit, in spite of an apparently simple sedimentation coefficient-concentration curve, showed molecular weights varying from well below 14 000 to beyond 20 000. There is evidence to suggest that the isolated alpha and beta subunits, even on standing as dry solid, are not stable but give rise to lower molecular weight products. Aged freeze-dried hLH did not show such impurity.

Circular dichroism of human pituitary luteinizing hormone and its glycopeptides. Curve resolution and band assignments to the peptide chromophore, aromatic residues, disulfides, and N-acetylated amino sugars.

The circular dichroic (CS) spectrum of the glycoprotein hormone, human pituitary luteinizing hormone (hLH), has been determined between 195-320 nm and resolved into gaussian constituents. Below 230 nm the CD spectrum is characterized by a negative extremum at 207 nm with a shoulder at 217 nm. Resolution into gaussian constituents of the 200-230 nm CD spectrum resulted in two resolved negative bands, one at 206 nm and the other at 215 nm. The latter band is assigned to beta-structure which is estimated to be about 25%. The 206 nm resolved band is assigned to the N-acetylated carbohydrate groups (e.g. N-acetyl glucosamine, galactosamine, and neuraminic acid). This is based partly on the evidence that the CD spectrum of the hLH glycopeptide fraction (prepared by a pronase digestion of s-carboxymethylated hLH) exhibited a negative extremum at 207.5 nm, which is close to the resolved 206 nm band in hLH. Above 230 nm the CD spectrum is characterized by a negative extremum at about 275 nm. Most of the ellipticity in this region is attributed to the disulfides in hLH. Both strong acid (0.1 N hcl) and concentrated guanidine hydrochloride (4 M) affect the ellipticity in the vicinity of 275 nm, but only the latter (as well as concentrated urea) has a major effect on the CD spectrum below 230 nm indicating extensive conformational changes. There is, however, some loss of beta-structure in 0.1 N hcl. Thus, it appears that the conformation of the hLH subunits in these subunit-dissociating agents is rather different. There was no dramatic change in the magnitude of the 207 nm extremum of native hLH between 10-50C.

Chemical modification of amino groups and guanidino groups of trypsin. Preparation of stable and soluble derivatives.

1. Isoionic chemical modification of amino groups of trypsin (EC 3.4.21.4) was studied for the purpose of obtaining a well-defined modified trypsin with minimum changes in physicochemical properties and with sufficient stability at neutral pH. Acetamidination with methyl acetimidate hydrochloride proceeded very rapidly at pH9.8 and 5degrees C and all 14 epsilon-amino groups were modified in 2h. The reaction was limited to epsilon-amino groups. The alpha-amino group of N-terminal isoleucine was modified only by repeated reactions in the presence of 5.5 M-guanidine or 8 M-urea. 2. The epsilon-acetamidinated derivative of beta-trypsin retained enzymic activity at values comparable with those of native enzyme tested with alpha-N-benzoyl-L-arginine ethyl ester and alpha-N-benzoyl-L-arginine p-nitroanilide as substrates; it also showed substrate activation comparable with that of native enzyme. The acetamidination of alpha-trypsin resulted in approx. 50% decrease in its esterolytic activity. 3. The epsilon-acetamidinated beta-trypsin was very stable at pH8 and 25degrees C in the absence of Ca2+. The activity of 0.04% (W/V) enzyme solution remained practically unchanged for 10h, and after 24h 90% of the activity was still retained. Possible autolytic cleavage of peptide bonds of acetamidinated enzymes was followed by N-terminal analysis by using automated Edman degradation. Only the Arg(105)-Val(106) bond was found to be cleaved to an appreciable extent. Thus beta-trypsin can be stabilized simply by complete acetamidination of epsilon-amino groups without modifying guanidino groups of arginine residues. Acetamidinated alpha-trypsin was unstable, but its inactivation at a neutral pH could not be attributed to the cleavage of a single specific peptide bond. 4. The acetamidination of the alpha-amino group of the N-terminal isoleucine results in the inactivation of esterolytic activity. However, this enzyme retained the ability to react with p-nitrophenyl p'-guanidinobenzoate. 5. It was concluded that acetamidination of beta-trypsin is a convenient method for preparing a well-defined stable and soluble trypsin derivative without appreciable change in its physical properties.