[Changes in thrombocyte density in stored thrombocyte concentrates].
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Biomedical subjects
Publications and source records attributed to M Janssen.
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The synthesis of a series N-(4-piperidinyl)-1H-benzimidazol-2-amines and the preliminary evaluation of their in vitro and in vivo antihistaminic activity are described. Cyclodesulfurization of (2-aminophenyl)thioureas with mercury(II) oxide resulted in 2-aminobenzimidazole intermediates, which were monoalkylated on the endo-nitrogen atom. After deprotection of the piperidine nitrogen atom with 48% aqueous hydrobromic acid solution, the title compounds were obtained by three different methods, viz. alkylation, reductive amination, or oxirane ring-opening reactions. The in vivo antihistaminic activity was evaluated by the compound 48/80 induced lethality test in rats and histamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. The duration of action, for a selected number of compounds, was studied in the guinea pig. The phenylethyl derivatives showed the most potent antihistamine properties after oral administration in both animal species.
The synthesis of a series of 1-[(4-fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-ami nes and the preliminary evaluation of their in vivo antihistamine activity are described. The title compounds were obtained starting from either 1, 4, 10, or 55 by different synthetic methods. Substitution on the phenyl nucleus of the benzimidazole ring (84-87) was achieved by two different approaches. The in vivo antihistamine activity was evaluated by the compound 48/80 induced lethality test in rats and the antihistamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. The duration of action was studied in the guinea pig for three compounds (4, 51, and 55). Compound 51, "astemizole", was also studied in histamine- and serotonin-induced cutaneous reaction and for mydriatic activity in the rat and tested for peripheral and central effects not related to histamine antagonism in a variety of systems. Astemizole has been selected for clinical investigation.
To study the bioisosteric replacement of a 2-pyridyl ring for a phenyl nucleus in astemizole, a series of N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amines was synthesized and evaluated. The title compounds were obtained starting from either 8a or 8b by four synthetic methods. The in vivo antihistamine activity was evaluated by the compound 48/80-induced lethality test in rats and the histamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. Compound 37, the isostere of astemizole, showed the most potent antihistaminic properties in the rat. However, astemizole is superior to 37 as to duration of action and total potency.
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Three anaplastic seminomas of the testis were examined by transmission electron microscopy, and the ultrastructural features are described for comparison with those reported in other seminomas and related neoplasms. It is concluded that anaplastic seminomas are similar ultrastructurally to classic testicular seminomas, extragondal seminomas, and ovarian dysgerminomas, all of which are less differentiated than spermatocytic seminomas.
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Three-dimensionally localized proton-decoupled phosphorus-31 magnetic resonance (MR) spectroscopy of skeletal and cardiac muscle was performed in six patients with systemic sclerosis. Cardiac (n = 9) and skeletal (n = 6) spectra were also obtained in healthy volunteers. Metabolite ratios and intracellular pH were determined from the spectra of skeletal and cardiac muscle. The phosphocreatine-to-adenosine triphosphate ratio was normal for both skeletal and cardiac muscle in patients with systemic sclerosis. The pH values of skeletal muscle were similar in patients and control subjects (7.13 +/- 0.02 vs 7.12 +/- 0.01, respectively). In skeletal muscle, the inorganic phosphate-to-phosphocreatine ratio in patients was increased relative to that of control subjects (0.106 +/- 0.014 vs 0.086 +/- 0.006, respectively; P = .02). P-31 MR spectroscopy showed no abnormalities in the myocardium of patients with systemic sclerosis. Assessment of the inorganic phosphate-to-phosphocreatine ratio in peripheral skeletal muscle may be helpful for assessing disease activity.
Iatrogenic meningitis following lumbar puncture is a rare complication of myelography, spinal anesthesia, intrathecal chemotherapy, and epidural anesthesia. Sporadic cases and clusters of iatrogenic meningitis have been reported after intrathecal therapy, but most incidental cases are reported after myelography. Four cases of iatrogenic meningitis caused by viridans streptococci and a review of the literature are presented here. Observations and a case control study implicated a single anesthesiologist as the source. Probable cause of this cluster is non-observance of infection control measures as to the routine wearing of masks during the procedure. New infection control guidelines were implemented. A review of the literature on iatrogenic meningitis is given. Viridans streptococci have emerged as major pathogens of this complication. These findings underline the need to wear face masks since these bacteria are commensals of the oral cavity.
This study examined the seasonal variation in three semen parameters (total sperm count, % grade a progressive motility and sperm morphology according to strict criteria) with an identical abstinence period of 24 h. A total of 340 spermiograms of 107 different men enrolled in an intrauterine insemination (IUI) program were examined. To reduce variation due to interindividual disparities in semen quality, differences of each test result from the mean value obtained for that individual were analyzed. Mean values resulted from at least 3 observations during different IUI cycles. Using ANOVA and spectral analysis, no differences in semen parameter results in function of the month of the year were observed. The lack of any significant periodicity may be explained by the large biological variation for individual semen parameters and/or the lack of significant differences regarding light exposure and temperature between summer and winter months in moderate climates.
The hemizona assay is an important diagnostic tool in assessing human sperm fertilizing potential. Previous hemizona assay results have proven that this functional test is a good predictor of fertilization in vitro and can be used in clinical practice to supply additional information in male factor subfertility cases. The objective of this study was to compare two methods for cutting human zona pellucida into equal halves (manual handcutting versus micromanipulation) in order to examine the necessity of an expensive micromanipulator in performing this assay. Comparable results for recovery rate, diameter size of the hemizonae, and sperm binding were achieved with both methods. According to these results, the use of an expensive micromanipulator is not essential in performing the hemizona assay.
Sperm morphology has always been considered an important tool in evaluating a man's fertilizing potential. The objective of this multicentric study was to evaluate intra- and interindividual variability and between-laboratory variation using the same or different criteria of sperm morphology assessment. Semen samples were obtained from 20 males and 32 smears were made of all samples. Eighty coded smears (4 per patient) were sent to 8 laboratories for morphology assessment. The centers applied different classification systems (strict criteria, WHO 1987, Düsseldorf criteria) and participants were asked to analyze the 80 smears twice, with an interval of 1 week between each participant's two analyses. Intraclass correlations between repeats showed that sperm morphology can be assessed with acceptable within observer reproducibility. Expected increases in imprecision were observed up to coefficients of variation of >30% with decreasing morphology scores, regardless of the classification system used. Agreement in correct classification of samples as normal/abnormal was obtained in 80% of cases. Differences in reproducibility between slides may reflect an important source of heterogeneity due to smear preparation. These results emphasize the importance of external quality control systems to improve the value of sperm morphology assessments in the investigation of the male partner in a subfertile couple.
Between 1984 and 1997, a total of 444 children (< 15 years) received an orthotopic liver transplant (OLT) at Saint-Luc University Clinics. Biliary atresia constituted the indication for OLT in 304 cases (68%). Median age (range) at OLT was 2.1 years (0.3-14.5). 177 children (40%) received a whole liver graft, 184 (41%) a reduced-size graft, 26 (6%) a split liver graft, whereas a living-related donor graft was used in 57 children (13%). Most grafts were ABO-identical or -compatible, in 395 cases (89%) and 40 (9%), respectively. Overall actuarial patient survivals at one and five years were 85% and 81%. The overall retransplantation rate was 19%. The results of uni- and multivariate statistical analyses showed a significant impact of year of transplantation (learning curve effect), with a 15% improvement of patient survival between the 1984-7 and the 1995-7 periods (p < 0.002). Results differed according to the indications for OLT, the best survivals being recorded for familial cholestasis, the worst for liver tumor (p = 0.004). Five year patient survival was significantly better after elective OLT (82%), when compared to highly urgent OLT (63%) (p < 0.001). Patient survivals were comparable in the children receiving primary cyclosporin-A microemulsion or tacrolimus immunosuppression, which were significantly higher than in the historical group treated with cyclosporin-A. No impact of the age at OLT, type of graft and ischemic time could be reported. In conclusion, this series illustrates the progressive improvements introduced in our pediatric liver transplant program between 1984 and 1997, including the technical variants allowing pediatric OLT using adult donors as well as the introduction of new immunosuppressive strategies.
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OBJECTIVE: To evaluate the impact of standardized operative and peri-operative care on the outcome of liver transplantation in a single center series of 395 adult patients. METHOD AND MATERIAL: Between February 1984 and December 31, 1998, 451 orthotopic liver transplantations were performed in 395 adult patients (> or = 15 years) at the University Hospitals St-Luc in Brussels. Morbidity and mortality of the periods 1984-1990 (Gr I--174 pat.) and 1991-1998 were compared (Gr II--221 pat.). During the second period anti-infectious chemotherapy and perioperative care were standardized and surgical technique changed from classical orthotopic liver transplantation with recipients' vena cava resection (and use of veno-venous bypass) towards liver implantation with preservation of the vena cava (without use of bypass). Immunosuppression was cyclosporine based from 1984 up to 1996 and tacrolimus based during the years 1997 and 1998. Immunosuppression was alleviated during the second period due to change from quadruple to triple and even double therapy and due to the introduction of low steroid dosing and of steroid withdrawal, once stable graft function was obtained. Indications for liver grafting were chronic liver disease (284 pat--71.9%), hepatobiliary tumor (52 pat--13.2%), acute liver failure (40 pat--10.1%) and metabolic disease (19 pat--4.8%). Regrafting was necessary because of graft dysfunction (21 pat), technical failure (12 pat), immunological failure (18 pat) and recurrent viral allograft disease (5 pat); three of these patients were regrafted at another institution. Follow-up was complete for all patients with a minimum of 9 months. RESULTS: Actuarial 1, 5 and 10 years survival rates for the whole group were 77.9%, 65.7% and 58.3%. These survival rates were respectively 77.3%, 69.7%, 62.5% and 73.2%, 59.6% 51.4% for benign chronic liver disease and acute liver failure; those for malignant liver disease were 80.6%, 44.3% and 36.7%. Early (< 3 months) and late (> 3 months) posttransplant mortalities were. 14.4% (57 pat) and 21.2% (84 pat). Early mortality lowered from 20% in Gr I to 9.4% in Gr II (p < 0.02); this was due to a significant reduction during the second period of bacterial (99/174 pat.--56.9% vs 82/221 pat.--37.1%), fungal (14 pat.--8% vs 7 pat.--3.2%) and viral (87 pat.--50% vs 49 pat.--22.2%) infections (p < 0.05) as well as of perioperative bleeding (92 pat.--52.9% vs 39 pat.--17.6%--p < 0.001). Late mortality remained almost identical throughout the two periods as lethal outcome was mainly caused by recurrent allograft diseases, cardiovascular and tumor problems. Morbidity in these series was important considering that almost, half of the patients had a technical complication, mostly related to bleeding (131 pat--33.2%) and biliary problems (66 pat--16.7%). Retransplantation index was 1.1 (54 pat.--14%). Early retransplantation mortality was 24%; it lowered, although not yet significantly, during the second period (8/25 pat.--32% vs. 5/29 pat.--17.2%). CONCLUSION: Despite a marked improvement of results, liver transplantation remains a major medical and surgical undertaking. Standardization of operative and perioperative care, less haemorraghic surgery and less aggressive immunosuppression are the keys for further improvement.
The incentive to develop intrafamilial living related liver transplantation (LRLT) originated from the shortage of cadaveric organ supply. We report our experience with LRLT in 63 children during 1993-1998 in the frame of a protocol approved by the Ethics Committee of our Institution. During this period, 152 potential intrafamilial (mostly parental) donors were evaluated; 44 (28.5%) were excluded because of surgical (n = 4), medical (n = 39) or psychosocial reason (n = 1). Out of 108 who matched all medical, surgical and psychological criteria of selection, 45 did not underwent living donation because their child received a cadaveric graft (n = 22; LRLT was their second option) or because one of the parents who had both been selected was chosen [by the surgical team because of more favourable anatomy (n = 8) or by mutual agreement between the two parents (n = 5)]. Sixty-three living donors (36 mothers, 24 fathers, one grand mother, one aunt and one uncle) underwent procurement of the left lobe (n = 52), the left lobe extended to part of segment IV (n = 8) or a left hepatectomy (n = 3) without mortality or any serious morbidity. Their median hospital stay was 7 days (range: 6-12); full physical rehabilitation and normalization of liver tests were usually obtained within three weeks. Their psychological follow-up did not disclose any longstanding serious sequellae. The median age of the recipients was 13 months (range 5-189); 30 were younger than one year at the time of transplant. Their median weight was 8.1 kg (range: 4.3 to 60); 36 had an actual weight under 10 kg. Fifty-two received an ABO identical and 11 received an ABO compatible transplant. The native liver diseases were similar to common data in children, with biliary atresia being the most frequent indication (74.6%). The median weight of the graft was 260 gr (range: 138-680) with a median ratio between the graft weight and the recipient body weight of 3.17% (range: 0.75-8.08). All grafts were implanted orthotopically with semi-microvascular reconstruction of the hepatic vein, portal vein and hepatic artery [end to end anastomosis in 58 (2 arteries were reconstructed in 7 patients) and interposition of an iliac arterial allograft from the infrarenal aorta in 5]. Base line immunosuppression consisted of a triple drug regimen including steroids, Azathioprine and either Cyclosporine-Sandimmun (n = 9), Cyclosporine Microemulsion formulation-Neoral (n = 13) or Tacrolimus-Prograft (n = 41). Biopsy-proved acute rejection was treated with intravenous bolus of steroids; steroid-resistant acute rejection was treated by a switch from Cyclosporine to Tacrolimus or addition of Mycophenolate-Mofetil (Cellcept) in Tacrolimus treated patients. Actuarial patient survival was 91.8% and 89.6% after LRLT at one and five years post-transplant, respectively, and 87.5% and 82.8% at one and five years, respectively, in 90 patients who received a cadaveric graft during the same interval. Actuarial graft survival was 91.8% and 84.1% after LRLT at one and five years, respectively, and 76.4% and 73.3% at one and five years, respectively, after cadaveric transplants. Vascular thrombosis was observed in 9.5% of the patients (arterial thrombosis: 1.6%; portal thrombosis: 7.9%) without graft loss. Biliary complications were observed in 26.9% (bile leak from cut surface in 3.1%, anastomotic stricture in 22.2% and intrahepatic stricture in 1.5%); two patients died from septic shock possibly related to uncompletely relieved anastomotic stricture; all other biliary complications were successfully treated either conservatively or surgically. The incidence of acute rejection was 90.9% in 22 patients with Cyclosporine-based immunosuppression; acute rejection was corticoresistant in 50%. It was 46.3% in 41 patients with Tacrolimus-based immunosuppression (64% with Prograft in capsules and 18.7% with Prograft in granules); no acute rejection was corticoresistant. (ABSTRACT TRUNCATED)
The Brussels series of living related liver transplantation (LRLT) in 77 children (< 15 years) is reviewed. Median (range) recipient age at liver transplantation was 1.1 year (0.4-13.1). The main indication for LT was biliary atresia in 55/77 cases (71%). The living-related donor was one of the parents in 74 instances. Hepatic segments 2-3 (n = 67) or 2-3-4 (n = 10) were implanted orthotopically, with a median (range) graft weight to recipient body weight ratio of 3.17% (0.91-8.08). No severe complications or significant long-term sequelae were encountered in the living donors. One and five year survival rates were 92% and 89% for the patients, and 90% and 86% for the grafts, respectively. The retransplantation rate was 2/77 (2.6%), the indication being chronic rejection in both instances. In conclusion, LRLT is now a validated procedure in the living donors as well as in pediatric recipients with chronic or acute liver diseases. In the current context of organ shortage, it provides a valuable alternative to cadaveric LT.