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Biomedical subjects

O Oyen

Publications and source records attributed to O Oyen.

At least 19 recordsLinked to original sources

Calcineurin inhibitor-free immunosuppression in renal allograft recipients with thrombotic microangiopathy/hemolytic uremic syndrome.

Thrombotic microangiopathy (TMA) and hemolytic uremic syndrome (HUS) represent serious threats to kidney allograft recipients. During a 4-year period, among 850 kidney transplantations, seven recipients with primary HUS and seven recipients (eight transplants) with previous or de novo TMA/HUS were identified and given calcineurin inhibitor (CNI)-free immunosuppression by sirolimus (SRL), mycophenolate mofetil and steroids. Thirteen out of 15 transplantations were successful in the long term; resulting in a mean creatinine of 101 mumol/L (16.4 months follow-up). In patients maintained on CNI-free regimen, no TMA/HUS recurrences were observed. A high rate of acute rejections (53%) may indicate insufficient immunosuppressive power and/or a causative relationship between TMA/HUS and rejection. Wound-related complications were abundant (60%), and call for surgical/immunosuppressive countermeasures. Our experience supports the idea that CNI's are major offenders in TMA/HUS induction. Total CNI elimination seems essential, as the nephrotoxic combination CNI + SRL may promote TMA. Features of TMA/HUS should be carefully explored in recurrent 'high responders'.

Adult↗

Postoperative pain and convalescence in living kidney donors-laparoscopic versus open donor nephrectomy: a randomized study.

The aim of the present study was to compare postoperative pain and convalescence in patients randomized to laparoscopic or open donor surgery in a prospective, controlled trial. The donors were randomly assigned to undergo laparoscopic (n = 63) or open (n = 59) donor nephrectomy. Our end points were amount of administered analgesics in the recovery period, postoperative pain on the second postoperative day and at one month after surgery and duration of sick leave. There was a significant difference in favor of the laparoscopic group regarding administered analgesics on day of surgery (p < 0. 02). No difference was observed between groups regarding self-reported pain on the second postoperative day. One month post donation, significantly fewer donors in the laparoscopic group reported pain (p < 0. 02) or had used analgesics (p < 0.05). The duration of sick leave was significantly shorter in the laparoscopic group (p = 0.01). The laparoscopic group experienced a more rapid convalescence and a shorter period of sick leave. Although immediate postoperative pain can be managed efficiently regardless of procedure, a lower consumption of opioids and incidence of pain in the convalescent period suggest a clinically relevant patient-experienced benefit from a successful laparoscopic procedure.

Adult↗

MicroCRP: a highly sensitive CRP method applied in the monitoring of renal allograft recipients.

A new ultrasensitive fluoroimmunometric assay for C-reactive protein (CRP), called MicroCRP assay, has a lower detection limit of 0.05 mg/l, and a CV of 7.6% at concentration 0.25 mg/l. The microCRP levels in healthy adults show a skewed distribution, median 0.90 mg/l and mean 1.4 mg/l, with 2.5th and 97.5th percentiles of 0.17 and 4.7 mg/l, respectively, and no gender-related or age differences. Serial microCRP was applied in the monitoring of 37 renal allograft recipients. The operative trauma gave rise to an initial CRP peak, usually on day 2 after transplantation, with a return to preoperative value 1 week after surgery. There were significant CRP elevations (>25%) in all cases of rejections, indicating 100% sensitivity. The microCRP values started to increase about 3 days (range -1 to 9 days) before the rise in creatinine. The microCRP peak tended to be higher in rejection episodes with a vascular component, compared with episodes of cellular rejection (p=0.05). A rise in microCRP at days 7-12 after transplantation seems to predict the risk of rejections later on, and probably reflects the primary immune response to the graft. Recipients without this primary CRP response (only 6 of 37 patients) subsequently had uncomplicated courses. Tracking of values below the traditional lower limit is essential in order to recognize the different CRP peaks. Serial monitoring of microCRP is well suited for clinical use and provides clinical information previously unattainable with other assay systems.

Adolescent↗

The national kidney transplant program in Norway still results in unchanged waiting lists.

1. Of 2,670 patients starting renal replacement therapy for end-stage renal disease in Norway from 1989-1997, 76% were candidates for transplantation. The annual need for transplantations increased from 47 to 64 grafts PMP as the number of elderly patients increased. The national waiting list has remained almost stable during the period from 1989-1997 at levels of 25-30 PMP, but the dialysis population has increased from 57-105 PMP. 2. A total of 1,681 transplants was performed at an annual rate varying between 38 and 46 grafts PMP. The grafts were procured from LDs in 41% and CDs in 59% of cases. Totally 69% of all patients in need were transplanted and 54% of all patients requiring replacement therapy for end-stage renal disease received a transplant. 3. Graft survival rates in recipients of first LD grafts (n = 641) were 91% and 77% at one and 5 years, respectively. One-year graft survival was 97% in HLA-identical grafts (n = 71), 92% in haploidentical grafts (n = 419), 88% in 2 haplotype-mismatched related grafts (n = 43), and 87% in spousal donor grafts (n = 108). 4. Graft survival rates in recipients of first CD grafts (n = 801) were 84% and 65% at one and 5 years, respectively. The rates were 86% and 74% in younger (n = 557) versus 78% and 46% in older (> 65 years) (n = 244) patients. Death with a functioning graft caused approximately 45% and 75% of all graft losses in younger and older patients, respectively. Cardiovascular disease was the major cause of death. 5. A significant beneficial effect of HLA-DR matching was observed in CD grafts performed after 1989, in particular in patients older than age 65.

Adolescent↗

Cellular location and age-dependent changes of the regulatory subunits of cAMP-dependent protein kinase in rat testis.

This study was undertaken to examine the expression and cellular location of the various cAMP-dependent protein kinase (PKA) subunits in different testicular cell types, using cDNA probes, isoenzyme-specific antibodies and activity measurements. Amounts of mRNA and protein were examined in cultured Sertoli cells, cultured peritubular cells, germ cells (pachytene spermatocytes, round spermatids), Leydig cell tumours as well as whole testes from rats of various ages. In Sertoli cells, there was a good correlation between the amount of mRNA and the respective immunoreactive proteins. In other types of cell, such as germ cells and Leydig tumour cells, this was not always the case. Large amounts of RII beta mRNA were found in Leydig tumour cells, whereas the amount of immunoreactive protein was low. Furthermore, large amounts of small-sized, germ cell-specific mRNAs for RI alpha (1.7 kb) and RII alpha (2.2 kb) were also found in the developing rat testis after 30 to 40 days of age, but the large amounts of mRNA were only partially reflected at the protein level. Pachytene spermatocytes and round spermatids were practically devoid of both RII alpha and RII beta protein. During spermatid differentiation, there was a decrease in RI alpha and an increase in RII alpha protein. Cell specific distribution of the various PKA subunits in testicular cell types is described. In some types of cell, discrepancies between mRNA and protein were demonstrated, which clearly suggest cell specific differences in translational efficiencies for some of these mRNAs, particularly the small-sized mRNAs for RI alpha and RII alpha in meiotic and post-meiotic germ cells.

Aging↗

Class I and Class III malocclusion sub-groupings related to headform type.

Different headform types establish different lines of craniofacial growth resulting in anatomic sub-groupings of Classes I, II, and III with characteristic morphologic features. Several key basicranial and facial relationships are involved, with the nasal region particularly significant in group distinctions.

Adolescent↗

[History of the Norwegian Military Medical Association].

The Norwegian Military Medical Association was founded in 1882 by a small group of army doctors. The principal aim of the Association was to establish a structured military medical corps with command functions. Furthermore, the newly founded group of active military doctors was intended to develop the medical knowledge and skills unique to this branch of medicine. In 1888 a military medical organization and command structure was finally accepted. The Association was very active for the first 25 years, printing articles and giving lectures on military medical subjects. After World War II the military medical service was organized in "HQ Defence Command Norway, Joint Medical Service". For many years to come this new organization took over some of the functions of the Military Medical Association. In 1952 the Association was accepted as a special branch of the Norwegian Medical Association. The Norwegian Military Medical Association is now active again, both as an organization and professionally. The number of members is increasing, and includes military doctors in active service as well as civilian doctors with an interest in military medicine.

History, 17th Century↗

Subunits of cyclic adenosine 3',5'-monophosphate-dependent protein kinase show differential and distinct expression patterns during germ cell differentiation: alternative polyadenylation in germ cells gives rise to unique smaller-sized mRNA species.

Cyclic AMP (cAMP) and cAMP-dependent protein kinases (PKAs) are believed to be involved in the regulation of essential spermatozoal functions, such as motility, epididymal maturation, capacitation, and the acrosome reaction. In this study, we document the presence of significant mRNA levels for 5 different PKA subunits (RI alpha, RI beta, RII alpha, RII beta, and C alpha) in germ cells and demonstrate differential expression patterns for these subunits during spermatogenesis. Messenger RNAs for RI (RI alpha and RI beta) and C alpha appear to be induced at premeiotic germ cell stages, whereas mRNAs for RII (RII alpha and RII beta) are first expressed at haploid stages. The individual PKA subunits may convey specific functions in developing germ cells and mature sperm. The present study, furthermore, demonstrates the presence of unique smaller-sized mRNAs in germ cells compared with somatic cells. Specific, truncated forms of RI alpha, RII alpha, RII beta, and C alpha mRNAs appear to be selected in the germ cells. Our data suggest this to be due to the use of alternative polyadenylation site signals. The selection of shorter mRNA species, with higher stability, may be essential for the delayed translation observed in spermatids. This may ensure certain levels of mRNA for translation at late spermatid stages, after cessation of transcription.

Adolescent↗

Molecular cloning of a tissue-specific protein kinase (C gamma) from human testis--representing a third isoform for the catalytic subunit of cAMP-dependent protein kinase.

Two different mammalian genes for the catalytic subunit (C) of cAMP-dependent protein kinase have previously been characterized (C alpha, C beta). In the present study, we report the molecular cloning of a third isoform of C, from a human testis cDNA library, as well as the isolation of human cDNAs for C alpha and C beta. This third form of C, which we will designate C gamma, is clearly derived from a distinct gene and shows a tissue-specific expression. A close evolutionary relation between C gamma and C alpha was suggested by nucleotide homologies (86% inside the open reading frame, 81% in the 3'-untranslated region). Thus, the C gamma cDNA cross-hybridized with the 2.8 kilobase (kb) C alpha mRNA, present at high levels in most human tissues, as well as with a 1.8 kb C gamma-specific mRNA, which was only found at detectable levels in human testis. However, at the amino acid level, C alpha and C beta showed a close relationship (93% homology), whereas C gamma diverged significantly from both C alpha (83%) and C beta (79%). Taken together with the tissue-specific expression of C gamma, this suggests a pressure on C gamma during evolution, acting to modulate it in a functionally specific way. Certain amino acid substitutions make C gamma a distinct member of the cAMP-dependent subfamily of protein kinases, and suggest that C gamma may be distinct in its protein substrate specificity or its interaction with the different regulatory subunits.

Amino Acid Sequence↗

[Facial symmetry and functional symmetry (3)].

The literature abounds in analyses of the causes, diagnosis and treatment schemes for handling dental-facial asymmetries. In the course of time, however, our understanding of the subject has improved considerably, thanks to efforts and findings contributed by different researchers.

Animals↗

[Postnatal growth of the facial skeleton (2)].

As suggested in the first article of this series, much of what we know, or believe to know, about growth of the craniofacial skeleton, is but an oversimplification and an underestimation of the real nature of this extremely complex phenomenom. This second part is a brief compendium of research and principles on which the previous paper is based. Information included is partly the result of several years of research, as well as some notions of a speculative nature. In both cases, emphasis centers on the type of information deemed necessary if we pretend some day to understand fully why the face grows as it does. Additionally, some forms are proposed to prove ideas which aim to explain craniofacial growth. The main objective of this article is to provide elements that may allow us to understand the interrelation between structure and function in craniofacial anatomy, thereby establishing the bases of "functional symmetry" as a promising attempt to provide new elements leading to a better understanding of craniofacial biology.

Animals↗

Human testis cDNA for the regulatory subunit RII alpha of cAMP-dependent protein kinase encodes an alternate amino-terminal region.

Phosphorylations catalyzed by cAMP-dependent protein kinase are essential for sperm motility, and type II cAMP-dependent protein kinase in mature sperm has been shown to be firmly bound to the flagellum via the regulatory subunit, RII. The present study documents high-levelled expression of a human, testis-specific RII alpha mRNA (2.0 kb) analogous to the rat mRNA which is induced in haploid germ cells [(1988) FEBS Lett. 229, 391-394]. We report the molecular cloning of a full-length human cDNA corresponding to this unique testis mRNA, and the presence of an alternative amino-terminal region (amino acids 45-75) of the predicted RII alpha protein (404 amino acids) compared with the previously published mouse and rat sequences. However, this alternate region is also shown to be present in RII alpha mRNA (7.0 kb) of human somatic cells. Our data indicate the divergent amino-terminal sequence to be due to species differences, suggesting an active evolutionary pressure on this particular region, which could be involved in subcellular attachment of RII alpha and thereby localization of kinase activity to certain targets within the cell.

Amino Acid Sequence↗

Molecular cloning of the human transmembrane secretory component (poly-Ig receptor) and its mRNA expression in human tissues.

A 2.5 kilobase (kb) cDNA clone containing 92% of the coding region for human transmembrane secretory component (SC) or poly-Ig receptor, was isolated from a mammary gland cDNA library. The cDNA clone encoded a protein of 693 amino acids which showed 99% homology with the primary amino acid sequence of human free SC as reported by Eiffert et al. (1), and 54% homology with the deduced amino acid sequence of rabbit transmembrane SC for which cDNA was cloned by Mostov et al. (2). Northern blot analysis showed mRNA expression in various human exocrine tissues in good agreement with our previous immunohistochemical studies of SC.

Amino Acid Sequence↗