Early pregnancy bleeding after assisted reproductive technology: a systematic review and secondary data analysis from 320 patients undergoing hormone replacement therapy frozen embryo transfer.

STUDY QUESTION: How common is bleeding in early pregnancy after Hormone Replacement Therapy (HRT) Frozen Embryo Transfer (FET) and does bleeding affect the reproductive outcome? SUMMARY ANSWER: A total of 47% of HRT-FET patients experience bleeding before the eighth week of gestation, however, bleeding does not affect the reproductive outcome. WHAT IS KNOWN ALREADY: Bleeding occurs in 20% of spontaneously conceived pregnancies, although most will proceed to term. However, our knowledge regarding bleeding in early pregnancy after HRT-FET and the reproductive outcome is sparse. STUDY DESIGN, SIZE, DURATION: We performed a systematic review of the existing literature on early pregnancy bleeding after assisted reproductive technology (ART) to evaluate the bleeding prevalence and resulting reproductive outcome in this population. A random-effects proportional meta-analysis was conducted. Subsequently, we performed a prospective cohort study including 320 pregnant patients undergoing HRT-FET and a secondary analysis of the cohort study was performed to evaluate bleeding prevalence and reproductive outcome. The trial was conducted from January 2020 to November 2022 in a public fertility clinic. PARTICIPANTS/MATERIALS, SETTING, METHODS: A systematic literature search was performed, using MESH terms and included studies with data from ART patients and with early pregnancy bleeding as a separate outcome. The cohort study included patients with autologous vitrified blastocyst transfer treated in an HRT-FET protocol. In the event of a positive HCG-test, an early pregnancy scan was performed around 8 weeks of gestation. During this visit, patients answered a questionnaire regarding bleeding or spotting and its duration after the positive pregnancy test. The information was verified through medical files, and these were used to obtain information on reproductive outcomes. MAIN RESULTS AND THE ROLE OF CHANCE: The review revealed a total of 12 studies of interest. The studies reported a prevalence of early pregnancy bleeding ranging from 2.1% to 36.2%. The random effects proportional meta-analysis resulted in a pooled effect estimate of the prevalence of early pregnancy bleeding in the ART population of 18.1% (95% CI (10.5; 27.1)). Four of the included studies included data on miscarriage rate following an episode of bleeding. All four studies showed a significantly increased risk of miscarriage in patients with early pregnancy bleeding as compared to patients with no history of bleeding. No studies investigated bleeding after HRT-FET specifically. In our HRT-FET cohort study, we found that a total of 47% (149/320) of patients with a positive pregnancy test experienced bleeding before 8 weeks of gestation. Generally, the bleeding was described as spotting with a median of 2 days (range 0.5-16 days). Out of 149 patients with one or several bleeding episodes, a total of 106 patients (71%) had an ongoing pregnancy at 12 weeks of gestation. In comparison, 171 patients reported no bleeding episodes and a total of 115 (67%) of these patients had an ongoing pregnancy at 12 weeks of gestation. This difference was not significant (P = 0.45). Furthermore there was no difference in the live birth rate between the two groups (P = 0.29). LIMITATIONS, REASONS FOR CAUTION: Most studies included in the review were older and not all studies specified the type of ART. Moreover, the studies were of moderate methodological quality. The patients in the cohort study were treated in a personalized HRT-FET protocol using a rectal supplementary rescue regimen if serum progesterone levels were <35 nmol/l at embryo transfer. The results may not be applicable to other FET protocols, and the present data were based on self-reported symptoms. The systematic review revealed an increased risk of miscarriage following an episode of early pregnancy bleeding. However our cohort study found no such association. This discrepancy can partly be due to the fact, that the four studies in the review only included episodes of heavy bleeding. Also, none of the four studies included data on HRT-FET cycles making them unfit for direct comparison. WIDER IMPLICATIONS OF THE FINDINGS: Episodes of early bleeding during pregnancy are associated with distress for the pregnant woman, especially in a cohort of infertile patients. Our cohort study showed that at least minor bleeding seems to be a common adverse event of early pregnancy after HRT-FET. From the systematic review, it seems that this prevalence is higher than what has previously been described in relation to other types of ART. However, minor bleeding during early pregnancy after HRT-FET does not seem to affect the reproductive outcome. Knowledge regarding the frequent occurrence of bleeding during early pregnancy after HRT-FET and the fact that this should not be used as a prognostic parameter will help the clinician in counselling patients. STUDY FUNDING/COMPETING INTEREST(S): Gedeon Richter Nordic supported this investigator-initiated study with an unrestricted grant as well as study medication (Cyclogest). B.A. has received an unrestricted grant from Gedeon Richter Nordic and Merck and honoraria for lectures from Gedeon Richter, Merck, IBSA, and Marckyrl Pharma. P.H. received honoraria for lectures from Merck, Gedeon Richter, Institut Biochimique SA (IBSA), and Besins as well as unrestricted research grants from Merck, Gedeon Richter, and Institut Biochimique SA (IBSA). The other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: EudraCT no.: 2019-001539-29.

Myocardial oedema in acute myocarditis detected by echocardiographic 2D myocardial deformation analysis.

AIMS: The clinical diagnosis of acute myocarditis is based on symptoms, electrocardiography, elevated myocardial necrosis biomarkers, and echocardiography. Often, conventional echocardiography reveals no obvious changes in global cardiac function and therefore has limited diagnostic value. Myocardial deformation imaging by echocardiography is an evolving method used to characterize quantitatively longitudinal systolic function, which may be affected in acute myocarditis. The aim of our study was to assess the utility of echocardiographic deformation imaging of the left ventricle in patients with diagnosed acute myocarditis in whom cardiovascular magnetic resonance (CMR) evaluation was performed. METHODS AND RESULTS: We included 28 consecutive patients (mean age 32 ± 13 years) with CMR-verified diagnosis of acute myocarditis according to the Lake Louise criteria. Cardiac function was evaluated by a comprehensive assessment of left ventricular (LV) function, including 2D speckle-tracking echocardiography. We found no significant correlation between the peak values of cardiac enzymes and the amount of myocardial oedema assessed by CMR (troponin: r= 0.3; P = 0.05 and CK-MB: r = 0.1; P = 0.3). We found a larger amount of myocardial oedema in the basal part of the left ventricle [American Heart Association (AHA) segments 1-6] in inferolateral and inferior segments, compared with the anterior, anterolateral, anteroseptal, and inferoseptal segments. In the mid LV segments (AHA segments 7-12), this was more pronounced in the anterior, anterolateral, and inferolateral segments. Among conventional echocardiographic parameters, LV function was not found to correlate with the amount of myocardial oedema of the left ventricle. In contrast, we found the wall motion score index to be significantly correlated with the amount of myocardial oedema, but this correlation was only present in patients with an extensive amount of oedema (>11% of the total left ventricle). Global longitudinal systolic myocardial strain correlated significantly with the amount of oedema (r = 0.65; P < 0.001). We found that both the epicardial longitudinal and the endocardial longitudinal systolic strains were significantly correlated with oedema (r = 0.55; P = 0.003 and r = 0.54; P < 0.001). CONCLUSION: In patients with acute myocarditis, 2D speckle-tracking echocardiography was a useful tool in the diagnostic process of acute myocarditis. Global longitudinal strain adds important information that can support clinical and conventional echocardiographic evaluation, especially in patients with preserved LV ejection fraction in relation to the diagnosis and degree of myocardial dysfunction.

Activation of persistent Streptococcus equi subspecies zooepidemicus in mares with subclinical endometritis.

Endometritis in horses caused by Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) may be underdiagnosed due to traditional diagnostic methods lacking sensitivity and specificity. We serendipitously identified a bacterial growth medium (bActivate) that appeared capable of inducing growth of dormant S. zooepidemicus, which subsequently allowed detection by standard diagnostics. To assess the effect of bActivate we compared its ability to activate dormant S. zooepidemicus in a group of potentially infected subfertile mares with phosphate-buffered saline (PBS). All mares had to test negative for S. zooepidemicus on a low-volume uterine lavage, be negative on endometrial cytology and without clinical signs of endometritis to be included in the investigation. The mares were instilled with bActivate or PBS in the uterus. Growth of S. zooepidemicus was induced by bActivate in 64% (16/25) and PBS in 8% (1/12) of the mares, respectively (p<0.002). In vitro studies supported that some strains of S. zooepidemicus were able to form persister cells tolerating 32-times of the minimal inhibitory concentration of penicillin compared to normal growing cells. Persister cells had not acquired penicillin resistance, but seemed to tolerate the antimicrobial due to dormancy. This is, to our knowledge, the first description of controlled growth induction of dormant bacteria from a subclinical infection. Moreover we demonstrated how endometritis can origin from a reservoir of dormant bacteria residing within the endometrium, and not only as an ascending infection. Further studies should aim at determining the prevalence of dormant S. zooepidemicus, impact of activation on diagnostic and treatment efficacy, uterine health and mare fertility.

The effect of the interval from PGF treatment to ovulation on embryo recovery and pregnancy rate in the mare.

The objective of this study was to determine the effect of the interval from induced luteolysis to ovulation on fertility of mares from two different farms. At farm 1, 215 mares were inseminated with frozen/thawed semen during 513 estrous cycles over seven consecutive breeding seasons. Estrus was induced with analogues of PGF2α in 179 cycles. At farm 2, 375 embryo flushings were performed in 65 donor mares inseminated with fresh semen; of which, 327 were performed following artificial insemination after PGF-induced luteolysis. In both farms, the intervals from PGF treatment to ovulation (ITO) data were divided into three interval groups: less than 6 days, 6 to 8 days, and greater than 8 days. A mixed regression model was created to determine the effect of different factors on the pregnancy rate (PR) and embryo recovery rate (ERR). Of all factors analyzed, the ITO was the only one that significantly influenced the PR and ERR (P < 0.05). In farm 1, the PR of mares with an ITO of less than 6 days, 6 to 8 days, and greater than 8 days was 26.6%, 39.4%, and 55.9%, respectively (P = 0.01). The PR for mares inseminated after spontaneous luteolysis (without PGF) was 42.5%. In farm 2, the ERR of donor mares for the same ITO groups was 55.0%, 62.6%, and 73.7%, respectively (P = 0.02). The ERR for mares flushed after a previous spontaneous estrus was 75.0%. In conclusion, the ITO had a significant effect on the PR and ERR in the mare. Fertility was reduced as the ITO became shorter.

Relevance of IL7R genotype and mRNA expression in Dutch patients with multiple sclerosis.

BACKGROUND: The interleukin 7 receptor (IL7R) has been recognized as a susceptibility gene for Multiple Sclerosis (MS). Analysis of rs6897932 (the most strongly MS-associated single nucleotide polymorphism (SNP)), showed effects of genotype on the relative expression of membrane-bound to total amount of IL7R mRNA. OBJECTIVE: We assessed the relevance of IL7R on MS phenotype (including clinical and magnetic resonance imaging (MRI) parameters) at DNA and mRNA level in Dutch patients with MS. METHODS: The genotype of rs6897932 was analyzed in 697 patients with MS and 174 healthy controls. The relevance of genotype and carriership of the C allele on MS phenotype (disease activity and severity, using clinical and MRI parameters) was assessed. In addition, relative gene expression of membrane-bound to total IL7R mRNA was analyzed with respect to disease phenotype in a subgroup of 95 patients with early relapsing MS. RESULTS: In particular, homozygosity for the risk allele is a risk factor for MS in our population (OR(CC vs CT and TT) = 1.65 (95% CI: 1.18-2.30), two-sided p = 0.004). However, no effect of genotype or the relative expression of membrane-bound IL7R (presence of exon 6-7) to total amount of IL7R mRNA (presence of exon 4-5) was found on MS phenotype. DISCUSSION: Homozygosity for the IL7R exon 6 rs6897932 C allele is associated with a higher risk for MS in our Dutch population. No effect was found of genotype or mRNA expression on disease phenotype.

Disease progression in multiple sclerosis: combining physicians' and patients' perspectives?

BACKGROUND: To assess disease progression in multiple sclerosis (MS) several outcome measures are available. The interrelation of changes on different scales has not been studied extensively and the concept of combining scales has only recently been introduced in MS. OBJECTIVE: To explore combining different clinical outcome measures in the evaluation of disease progression in MS. METHODS: In 553 patients we studied the presence of relevant changes according to standard definitions on the Expanded Disability Status Scale (EDSS), Nine-Hole Peg Test (9HPT), Timed 25-Foot Walk (T25FW) and the Multiple Sclerosis Impact Scale (MSIS-29). We examined 'exclusive worsening' (worsening on one measure while not worsening on any other measure) and 'opposing changes' (worsening on one measure while improving on another measure). Finally, we investigated the impact of combining assessments. RESULTS: Based on the EDSS alone, 140 patients progressed. However, almost twice as many (275) showed worsening on any of the clinical outcome measures. Exclusive worsening was observed in 37 patients on the EDSS, 13 on the 9HPT, 39 on the T25FW and 44 on the MSIS physical. Of all worsened patients 76 (28%) showed opposing changes, a phenomenon predominantly observed when combining physician-based and patient-derived outcome measures. CONCLUSION: When assessing disease progression in MS, sensitivity to change can be increased by combining different outcome measures. The added value is especially present when combining measures from different perspectives. However, further research is needed to evaluate the optimal way to combine outcome measures before implementing this strategy in clinical studies.

Decreasing candidaemia rate in abdominal surgery patients after introduction of fluconazole prophylaxis*.

Although abdominal surgery is an established risk factor for invasive candidiasis, the precise role of antifungal prophylaxis in these patients is not agreed upon. In 2007, fluconazole was added to the prophylactic antibiotic treatment for patients with gastrointestinal tract perforations or reoperation after colorectal surgery in two university hospitals in Copenhagen. Changes in candidaemia rates associated with this intervention were examined and potential interfering factors evaluated. Rates and clinical characteristics of candidaemias and other blood stream infections (BSIs) in abdominal surgery patients were compared before (1 January 2006 to 30 June 2007) and after the intervention (1 January 2008 to 30 June 2009). The departments' activity was assessed by number of bed-days, admissions and surgical procedures, and the consumption of antifungals was analysed. The candidaemia rate decreased from 1.5/1000 admissions in the pre-intervention to 0.3/1000 admissions in the post-intervention period (p 0.002). Numbers of BSIs and bed-days remained stable, and numbers of admissions and surgical procedures performed increased during the study period. Fluconazole consumption in the two abdominal surgery departments increased from 4.6 to 12.2 defined daily doses per 100 bed-days (p <0.001), and 3.2 to 5.0 (p 0.01), respectively, but remained unchanged in the intensive care units. We could not detect any increase in fluconazole-resistant strains (14/29 pre- and 2/7 post-intervention, p 0.43). The introduction of fluconazole prophylaxis was followed by a significantly decreased candidaemia rate. However, the observational study design does not allow conclusions regarding causality. No increase in resistance was detected, but follow-up was short and continuing surveillance is needed.

Comparison of two sulfonylureas with high and low myocardial K(ATP) channel affinity on myocardial infarct size and metabolism in a rat model of type 2 diabetes.

AIMS/HYPOTHESIS: Sulfonylureas (SUs) may impair outcome in patients with acute coronary syndrome. Most experimental studies of the myocardial effects of SU treatment are performed in non-diabetic models. We compared the effect of two widely used SUs, glibenclamide (gb) and gliclazide (gc), with high and low myocardial K(ATP) channel affinity, respectively, at therapeutic concentrations on infarct size, left ventricular (LV) function and myocardial glycogen, lactate and alanine content before and after ischaemia/reperfusion (I/R). METHODS: Non-diabetic Wistar and diabetic Goto-Kakizaki rat hearts were investigated in a Langendorff preparation. Gb (0.1 µmol/l) and gc (1.0 µmol/l) were administrated throughout the study. Infarct size was evaluated after 120 min of reperfusion. Myocardial metabolite content was measured before and after ischaemia. RESULTS: Infarct size was smaller in diabetic hearts than in non-diabetic hearts (0.33 ± 0.03 vs 0.51 ± 0.05, p < 0.05). Gb increased infarct size (0.54 ± 0.04 vs 0.33 ± 0.03, p < 0.05) and reduced post-ischaemic LV developed pressure (60 ± 3 vs 76 ± 3 mmHg, p < 0.05) and coronary flow (4.9 ± 0.5 vs 7.1 ± 0.4 ml min(-1) g(-1), p < 0.05) in gb-treated diabetic rats compared with untreated diabetic rats. On comparing gb-treated diabetic rats with untreated diabetic rats, glycogen content was reduced before (9.1 ± 0.6 vs 13.6 ± 1.0 nmol/mg wet weight, p < 0.01) and after ischaemia (0.9 ± 0.2 vs 1.8 ± 0.2 nmol/mg wet weight, p < 0.05), and lactate (4.8 ± 0.4 vs 3.2 ± 0.3 nmol/mg wet weight, p < 0.01) and alanine (1.38 ± 0.12 vs 0.96 ± 0.09 nmol/mg wet weight, p < 0.05) contents were increased during reperfusion. Gc-treatment of diabetic and non-diabetic rats did not affect any of the measured variables. CONCLUSIONS/INTERPRETATIONS: Gb, but not gc, exacerbates I/R injury and deteriorates LV function in diabetic hearts. These effects of gb on diabetic hearts may be due to detrimental effects on myocardial carbohydrate metabolism.

Performance of the Swanton multiple sclerosis criteria for dissemination in space.

New diagnostic criteria for multiple sclerosis (MS) have been proposed by Swanton and co authors, but were not yet evaluated in patients suspected of MS, but diagnosed with another disease. The dissemination in space (DIS) criterion of these Swanton criteria was investigated in such a patient group and compared with the present McDonald criteria. We found that with the Swanton criteria for DIS, simplicity can be combined with some gain in sensitivity, without major loss of specificity.

Cardioprotective effect of L-glutamate in obese type 2 diabetic Zucker fatty rats.

1. Because diabetic hearts have an increased threshold for cardioprotection by ischaemic preconditioning (IPC), we hypothesized that protection by L-glutamate during reperfusion is restricted in Type 2 diabetic hearts. Previously, we found that L-glutamate-mediated postischaemic cardioprotection mimics IPC. 2. Rat hearts were studied in a Langendorff preparation perfused with Krebs'-Henseleit solution and subjected to 40 min global no-flow ischaemia, followed by 120 min reperfusion. L-Glutamate (0, 15 and 30 mmol/L) was added to the perfusate during reperfusion of hearts from non-diabetic (Wistar-Kyoto) and diabetic (Zucker diabetic fatty (ZDF)) rats, studied at 16 weeks of age. The infarct size (IS)/area-at-risk (AAR) ratio was the primary end-point. Expression of L-glutamate excitatory amino acid transporter (EAAT) 1 (mitochondrial) and EAAT3 (sarcolemmal) was determined by quantitative polymerase chain reaction and immunoblotting. 3. The ISS/AAR ratio did not differ between control hearts from Wistar-Kyoto and ZDF rats (0.52 ± 0.03 and 0.51 ± 0.04, respectively; P = 0.90). L-Glutamate (15 mmol/L) significantly reduced the IS/AAR ratio in non-diabetic hearts, but not in diabetic hearts, compared with their respective controls. The higher concentration of L-glutamate (30 mmol/L) reduced infarct size in diabetic hearts to the same degree as in non-diabetic hearts (IS/AAR 0.35 ± 0.03 (P = 0.002) and 0.34 ± 0.03 (P = 0.004), respectively). The mitochondrial L-glutamate transporter EAAT1 was downregulated in hearts from ZDF rats at both the mRNA and protein levels (P < 0.0005 and P < 0.0001, respectively). However, there was no change in EAAT3 expression at the protein level. Myocardial L-glutamate content was increased by 43% in diabetic hearts (P < 0.0001). 4. Hearts from obese diabetic rats have an elevated threshold for metabolic postischaemic cardioprotection by L-glutamate. These findings may reflect underlying mechanisms of inherent resistance against additional cardioprotection in the diabetic heart.

Long-term follow-up of suspected though unconfirmed MS.

OBJECTIVE: There is no gold standard diagnostic test for MS, and evaluation of present diagnostic criteria has almost exclusively been done in populations of which the vast majority is prone to develop MS. Patients referred for a potential MS diagnosis in whom ultimately another or no diagnosis is made are seldomly reported in a systematic way. We report, after 7 years, on the diagnoses made in a cohort of patients with suspected though unconfirmed MS. METHODS: We retrieved information on the current diagnosis of all patients who had visited our center between 1998 and 2001 for a second opinion concerning a possible MS diagnosis and in whom no diagnosis had been made at that time. RESULTS: Seventy-five patients (86%) could be retrieved and cooperated. In seven patients, a diagnosis of MS, in eight patients another neurological diagnosis had been made. In the remaining 60 patients, still no neurological diagnosis had been made. CONCLUSIONS: In potential MS patients seen in a tertiary referral center, the likelihood that a patient who is not diagnosed with MS will in the future develop a neurological disease is small. This study suggests that, in addition to playing a role in diagnosing MS, MRI can be helpful to exclude MS in clinically doubtful cases.

Classification of patients with a clinically isolated syndrome based on signs and symptoms is supported by magnetic resonance imaging results.

BACKGROUND: Recently, a clinical classification system was described to determine whether symptoms and signs of patients presenting with a first episode suggestive of multiple sclerosis (MS) indicate the presence of monofocal or multifocal disease. OBJECTIVES: To evaluate the value of this new classification system by comparing the results with those of simultaneously obtained magnetic resonance imaging (MRI) scans. METHODS: The 487 patients, randomised in the BENEFIT study, were centrally assessed using the new system and classified as monofocal or multifocal, based on clinical information by two neurologists masked for the MRI results. MRI analyses were performed by expert readers masked for the clinical classification. RESULTS: Patients classified as multifocal had more T2 hyperintense (median: 21 versus 15.5) and more T1 hypo-intense lesions (median: 2 versus 1) than those classified as monofocal. Patients classified at the local site as having evidence of a single clinical lesion, but reclassified centrally as having a clinical multifocal central nervous system presentation, had more T2 lesions than monofocal patients. In addition, patients with a multifocal presentation more often fulfilled the MRI criteria for dissemination in space, as incorporated in the International Panel (IP) diagnostic criteria for MS. CONCLUSION: These data provide justification for the recently proposed clinical classification system to be used in patients who present with a first episode suggestive of MS, in that ;multifocal', based on symptoms and signs, is associated with more lesions on MRI.

Diagnosing MS: recent guidelines and future goals focusing on magnetic resonance imaging.

Previous diagnostic guidelines for MS relied largely on clinical evidence and cerebrospinal fluid analysis. In 2001, guidelines were published that allowed partial substitution of the required clinical evidence by magnetic resonance imaging findings and defined primary progressive multiple sclerosis (PPMS). Recently, revised guidelines on MS diagnosis were published, mainly to improve definitions of dissemination in space (using spinal cord imaging) and in time (using T2 lesions), enabling a faster and more accurate MS diagnosis. Criteria for PPMS were also revised. Current research is concentrating on the definition of uniform clinical terms, to allow a more standardized diagnosis, and aims to simplify the criteria while improving diagnostic accuracy.

Clinical impact of 20% worsening on Timed 25-foot Walk and 9-hole Peg Test in multiple sclerosis.

INTRODUCTION: Quantitative tests of motor function, like the Timed 25-foot Walk (T25FW) and 9-hole Peg Test (9HPT), are increasingly being applied as outcome measures in multiple sclerosis (MS) clinical trials. The quantitative nature of the data has a favorable impact on responsiveness, but the clinical impact of the changes is uncertain. The goal of this study was to assess whether a change on T25FW and 9HPT does indeed have a clinical meaning. This was accomplished by comparing 20% changes on these quantitative measurements to concomitant changes on the Guy's Neurological Disability Scale (GNDS), a scale which measures patient-perceived daily life disability. METHODS: From a longitudinal database, we selected patients with at least two measurements of T25FW, 9HPT and GNDS with a minimal time interval of 350 days. In those patients who experienced at least a 20% change on T25FW or 9HPT, GNDS score changes were examined more closely. RESULTS: Of 527 patients, 143 experienced a >20% worsening on their T25FW and 71 on their 9HPT, respectively. Patients with a 20% increase in T25FW or 9HPT had more GNDS worsening than patients without such an increase. GNDS worsening associated with an increase in T25FW was mainly due to an increase in perceived disability related to lower extremity function and fatigue; GNDS worsening associated with an increase in 9HPT was more diffuse with respect to domains involved. CONCLUSION: Worsening on T25FW or 9HPT has a clinical impact on disability, as perceived by MS patients during daily life functioning.

Fluoride exposure of East African consumers using alkaline salt deposits known as magadi (trona) as a food preparation aid.

The fluoride content of Tanzanian and Kenyan magadi has been estimated to be in the range 0.1-17.9 mg F(-) g(-1), which is comparable with that reported elsewhere, but indicating a considerable variation in levels. The median fluoride content of crystalline magadi harvested from the alkaline lakes was 2.1 mg g(-1), which was higher than the median of 1.4 mg g(-1) for scooped magadi harvested from the surface soil. The highest median fluoride contents of 3.2 and 2.9 mg g(-1) were found in magadi originating from Lake Magadi, Kenya, and Lake Natron, Tanzania, respectively. It was found that the fluoride content varied significantly even for magadi originating from the individual lake, e.g. the fluoride content in magadi from Lake Magadi was between 0.1 and 8.7 mg g(-1). In a lump of magadi originating from Lake Magadi, it was found that the fluoride content in 20 smaller part samples was subject to considerable variation indicating that the fluoride-bearing minerals were unevenly distributed in the lump. Results show that the fluoride is mainly present in grains <1.0 mm that made up 25% of the magadi sample. When daily eating the popular meal makande as in Tanzania, the exposure to fluoride through magadi in 70% of cases was estimated to be <4 mg per adult day(-1), as recommended by the WHO. Thus, the health hazard from magadi-fluoride is estimated to be significant in cases where the magadi is heavily contaminated.

Allogeneic bone marrow transplantation for childhood relapsed acute lymphoblastic leukemia: comparison of outcome in patients with and without a matched family donor.

We evaluated the role of BMT in a cohort of 56 children with ALL relapsing after uniform initial treatment protocols in a single institution between 1990 and 1997. The patients were commenced on a single intensive chemotherapy regimen. All patients with a matched family donor (MFD) were recommended to receive BMT. The outcome was significantly better for patients with a MFD. The overall survival at 8 years was 60.0% (95% CI 35.7-77.6%) and 13.5% (95% CI 4.0-28.6%) for patients with and without MFDs (log-rank chi = 7.50 P = 0.0062). The event-free survival at 8 years was 55.0% (95% CI 11.1-31.3%) and 9.2% (95% CI 2.0-23.3%) for patients with and without MFDs (log-rank chi = 8.87 P = 0.0029). Multivariate analysis confirmed the survival advantage of BMT. There was no statistically significant difference in survival for patients initially relapsing within 3 years of first remission compared to children relapsing beyond 3 years. BMT provides a clear survival advantage for children following their first relapse of ALL. We recommend BMT for all children following first relapse of ALL if a MFD is available.

Structure-function relationships based on ATP binding and cation occlusion at equilibrium in Na,K-ATPase.

This work evaluates the results of measurements of equilibrium binding of ATP and cations in lethal or partially active mutations of Na,K-ATPase that were expressed at high yield in yeast cells. ATP binding studies allowed estimation of the expense in free energy required to position the gamma-phosphate in proximity of the carboxylate groups of the phosphorylated residue Asp369 and the role of this residue in governing long range E1-E2 transitions. An arginine residue (Arg546) appearing to be involved in ATP binding has been identified. Wild type yeast enzyme was capable of occluding two T1(+)-ions per ouabain binding site or alpha 1 beta 1 unit with high apparent affinity (Kd(T1+) = 7 +/- 2 microM), like the purified Na,K-ATPase from pig kidney. The substitutions to Glu327(Gln,Asp), Asp804(Asn,Glu), Asp808(Asn,Glu) and Glu779(Asp) completely abolished occlusion or severely reduced the affinity for T1+ ions. The substitution of Glu779 for Gln reduced the occlusion capacity to one T1+ ion per alpha 1 beta 1 unit with a 3-fold decrease of the apparent affinity for the ion (Kd(T1+) = 24 +/- 8 mM). These carboxylate groups in transmembrane segments 4, 5, and 6 therefore appear to be essential for high affinity occlusion of K(+)-ions.

[Heat of polymerization of bone cement can induce cardiac arrest]. / Knoglecementens haerdningsvarme kan udløse hjertestop.

Total hip arthroplasty is associated with cardiopulmonary complications including cardiac arrest. We present one of four cases of cardiac arrest, two of the cases were fatal. The pathogenesis suggested to explain these complications is venous air embolism, generated by the methylmethacrylate bone cement polymerization causing thermal blood damage. To prevent this happening cortical bone allotransplantation around the prosthesis and bone cement with a low temperature of polymerization may be used.

Structure-function relationships of E1-E2 transitions and cation binding in Na,K-pump protein.

Fully active Na,K-ATPase and lethal mutations can be expressed in yeast cells in yields allowing for equilibrium ATP binding, occlusion of T1+, K+ displacement of ATP, and Na(+)-dependent phosphorylation with determinations of affinity constants for binding and constants for the conformational equilibria. Removal of the charge and hydrophobic substitution of the phosphorylated residue (Asp369Ala) reveals an intrinsic high affinity for ATP binding (Kd 2.8 vs. 100 nM for wild type) and causes a shift of conformational equilibrium towards the E2 form. Substitution of Glu327, Glu779, Asp804 or Asp808 in transmembrane segments 4, 5, and 6 shows that each of these residues are essential for high-affinity occlusion of K+ and for binding of Na+. Substitution of other residues in segment 5 shows that the carboxamide group of Asn776 is important for binding of both K+ and Na+. Differential effects of the relevant mutations identify Thr774 as specific determinant of Na+ binding in the E1P[3Na] form, whereas Ser775 is a specific participant of high-affinity binding of the E2[2K] form, suggesting that these residues engage in formation of a molecular Na+/K+ switch. The position of the switch may be controlled by rotating or tilting the helix during the E1-E2 transition.

Importance of intramembrane carboxylic acids for occlusion of K+ ions at equilibrium in renal Na,K-ATPase.

Site-directed mutagenesis and assay of Rb+ and Tl+ occlusion in recombinant Na,K-ATPase from yeast were combined to establish structure-function relationships of amino acid side chains involved in high-affinity occlusion of K+ in the E2[2K] form. The wild-type yeast enzyme was capable of occluding 2 Rb+ or Tl+ ions/ouabain binding site or alpha 1 beta 1 unit with high apparent affinity (Kd(Tl+) = 7 +/- 2 microM), like the purified Na,K-ATPase from pig kidney. Mutations of Glu327(Gln,Asp), Asp804(Asn, Glu), Asp808(Asn, Glu) and Glu779(Asp) abolished high-affinity occlusion of Rb+ or Tl+ ions. The substitution of Glu779 for Gln reduced the occlusion capacity to 1 Tl+ ion/alpha 1 beta 1-unit with a 3-fold decrease of the apparent affinity for the ion (Kd(Tl+) = 24 +/- 8 microM). These effects on occlusion were closely correlated to effects of the mutations on K0.5(K+) for K+ displacement of ATP binding. Each of the four carboxylate residues Glu327, Glu779, and Asp804 or Asp808 in transmembrane segments 4, 5, and 6 is therefore essential for high-affinity occlusion of K+ in the E2[2K] form. These residues either may engage directly in cation coordination or they may be important for formation or stability of the occlusion cavity.