P-449 Storage of vitrified oocytes up to 8 years does not affect pregnancy and live birth rates: analysis of 5,362 cycles

Study question

Does long-term storage of vitrified oocytes affect laboratory and reproductive outcomes after ICSI?

Summary answer

The time spent by vitrified oocytes in liquid nitrogen banks does not affect oocyte survival, fertilization rate nor reproductive outcomes up to live birth.

What is known already

Vitrification is the most efficient approach to oocyte cryopreservation and is commonly applied in oocyte donation programs. The survival rate can be >90% and vitrified-warmed oocytes provide comparable reproductive results to fresh oocytes. However, even with modern cryobanking technology, there are potential temperature fluctuations caused by access to cryopreserved material, transportation, stocktaking events, and regular maintenance. While some studies indicate that a multiyear storage of vitrified oocytes does not affect pregnancy rates, others found decreased reproductive outcomes after as little as 6 months, and further investigations in large cohorts are needed to confirm the safety of long-term oocyte storage.

Study design, size, duration

Retrospective cohort study of 5,362 cycles with vitrified oocytes from oocyte donors carried out between 2013 and 2021. All cycles included fresh embryo transfer (ET). Oocyte vitrification and warming were carried using the Cryotop® protocol (Kitazato). We analyzed the effect of storage time of vitrified oocytes in liquid nitrogen vapors on laboratory outcomes (oocyte survival, fertilization rate (FR), percentage of viable embryos) and reproductive outcomes (pregnancy -biochemical and clinical- and live birth (LB) rates).

Participants/materials, setting, methods

Eight categories of storage time were established: 0-0.25 years (reference group, ≤3 months), 0.25-0.5, 0.5-1, 1-1.5, 1.5-2, 2-3, 3-4, and >4 years. The effect of oocyte storage time on laboratory and reproductive outcomes was analyzed by linear and logistic regression, respectively. These multivariate analyses were adjusted by multiple factors: sperm origin (partner vs donor), sperm parameters, number of oocytes inseminated, number of embryos transferred and day of ET (2-3 vs 5), among others.

Main results and the role of chance

Mean recipient age was 42.0±4.6, while oocyte donors age was 26.1±4.6. The mean number of thawed oocytes was 8.0±2.5, all surviving oocytes were inseminated by ICSI with partner (84.9%) or donor sperm (15.1%). The oocyte storage time ranged from 3 days to 8.2 years (mean: 0.7 ± 0.9 years). We did not find significant differences in oocyte storage time between positive and negative pregnancy and LB, nor between different survival rates (<100 vs = 100%), FR (<70 vs ≥ 70%) and percentages of viable embryos (<50 vs ≥ 50%) at univariate analysis (p > 0.05 in all cases). The mean oocyte survival rate was 90.2%±14.7% and, after adjusting for confounders, did not decrease with longer storage time (i.e. 88.9% for time >4 years, p = 0.963). Similarly, the linear regression model did not show a significant effect of storage time on FR, which was close to 70% in all categories (range: 67.6-70.6, p > 0.05), nor a decrease in the percentage of viable embryos. Finally, reproductive outcomes were similar across storage times (p > 0.05 for all categories when compared to the reference 0-0.25); specifically, long-term oocyte storage (>4 years) did not affect the chances of clinical pregnancy (OR: 0.657 [0.395-1.092], p = 0.194) and LB (OR: 0.666 [0.393-1.128], p = 0.231).

Limitations, reasons for caution

These results cannot be extended to cycles using the patient’s own oocytes or involving a severe male factor (testicular spermatozoa or criptozoospermia), which were excluded. Due to the retrospective nature of the study, some uncontrolled variables could affect the results.

Wider implications of the findings

This is the first study evaluating the effect of long-term oocyte storage on a large cohort of patients undergoing oocyte donation, thus partially discarding the effect of the female factor. Reassuringly, these results indicate that long-term storage of oocytes is a safe option for young patients and oocyte banks.

Trial registration number

Not applicable

Point-of-care test for rapid assessment of blood lithium levels in women with bipolar disorder during perinatal period

Introduction

Determination of lithium levels in serum has become a standard of care due to its narrow therapeutic rang, thus an immediate test for determination of blood lithium may contribute to minimize toxicit, to avoid relapse and to ensure treatment adherence. This is particularly relevant during pregnancy and early postpartum because pharmaokinetic changes in renal physiology.

Objectives

The aim of this study is verify Medimate point-of-care method performance and systematically compare it with the routine laboratory measurement of lithium.

Methods

This cross-sectional method comparison study was conductec in the Unit of Perinatal Mental Health in the Hospital Clinic of Barcelona. Pearson and Bland-Altman analyses were performed to assess the accuracy, precision and correlation between the capillary electrophoresis technology (Medimate MiniLab) and the ion selective electrode (ISE) potentiometry method (AVL 9180).

Results

Twenty-five women with bipolar disorder in treatment with lithium during perinatal period were enrolled, corresponding to 75 blood specimens for analyses. Correlation (r), mean difference (bias), and 95% limit of agreement (LOA) of the point-of-care method [r=0.917; bias 0.0021 (95% LOA; 0.440, 0.619) mEq/L], showed that difference between ISE method and capillary electrophoresis technology was not statistically significant.

Conclusions

Considering the practicality, the microchip capillary electrophoresis technology provides a simple and highly affordable way of measuring lithium levels in a single drop of blood outside the clinical laboratory. The Medimate point-of-care system (POC) appears well adapted for the rapid and specific detection of lithium as an alternative to the current ISE procedure.

Disclosure

No significant relationships.

Lithium placental passage at delivery: an observational study

Introduction

Lithium is used as a first-line treatment for bipolar disorder during perinatal period. Dosing of lithium can be challenging as a result of pharmacokinetic changes in renal physiology. Frequent monitoring of lithium blood levels during pregnancy is recommended in order remain within the therapeutic window (0.5 to 1.2 mEq/L). Lower neonatal lithium blood level (<0.64 mEq/L) at time of delivery reduces the risk of lithium side effects in the neonate.

Objectives

The aim of the present study was to quantify the rate of lithium placental passage in real word.

Methods

We included a total of 68 mother-infant pairs for which a lithium measurement was performed intrapartum. Lithium serum concentrations were determined by means of an AVL 9180 electrolyte analyzer. The limit of quantification (LoQ) was 0.20 mEq/L and detection limit was 0.10 mEq/L. Pearson analyse was performer to assess the correlation between mother and umbilical cord lithium serum concentrations.

Results

The mean of umbilical cord serum concentration at delivery was 0.57 mEq/L (SD=0.26, range 0,20-1,42). The mean infant-mother lithium ratio at delivery for the 68 pairs was 1.12 (SD=0.24) across a wide range of maternal concentrations (range 0.14-1,40 mEq/L). There was a strong positive correlation between maternal and umbilical cord lithium blood levels (Peearson correlation coefficient 0.948, p<0.001).

Conclusions

Lithium demostrates complete placental passage. This finding is consistent with the results of others studies (Newport 2005; Molenaar 2021).

Disclosure

No significant relationships.

Infant exposure to lithium through breast milk

Introduction

Women who take lithium during pregnancy and continue after delivery may opt to breastfeed, formula feed, or mix these options.

Objectives

To evaluate the neonatal lithium plasma concentrations and nursing infant outcomes based on these three feeding trajectories.

Methods

We followed 24 women with bipolar disorder on lithium monotherapy during late pregnancy and postpartum (8 per trajectory). Lithium serum concentrations were determined by an AVL 9180 electrolyte analyser with a 0.10 mEq/L detection limit and a 0.20 mEq/L limit of quantification (LoQ).

Results

The mean ratio of lithium concentration in the umbilical cord to maternal serum being 1.12 (0.17). We used the Turnbull estimator for interval-censored data to estimate the probability that the LoQ was reached as a function of time. The median times to LoQ was 6–8, 7–8, and 53–60 days for formula, mixed, and breastfeeding, respectively. Generalised log-rank testing indicated that the median times to LoQ differed by feeding trajectory (p = 0.037). Multivariate analysis confirmed that the differences remained after adjusting for serum lithium concentrations at birth (formula, p = 0.015; mixed, p = 0.012). We did not found any acute observable growth or developmental delays in any of the neonates/infants.

Conclusions

Lithium did not accumulate in the infant under either exclusive or mixed-breastfeeding. Lithium concentrations declined in all trayectories. The time needed to reach the LoQ was much longer for those breastfeeding exclusively. Lithium transfer via breastmilk is much less than via the placenta. We did not found any acute observable growth or developmental delays in any infant during follow-up.

Disclosure

No significant relationships.

P–013 Sperm freezing does not affect live birth rates: results from 6,594 cycles in normozoospermic patients

Study question

Does sperm cryopreservation influence the reproductive outcomes of normozoospermic patients undergoing elective ICSI?

Summary answer

After controlling for confounders, the use of cryopreserved semen from normozoospermic patients does not affect pregnancy and live birth rates after ICSI.

What is known already

Sperm cryopreservation with slow freezing is a common practice in ART. While frozen-thawed semen typically presents reduced motility and vitality, its use for ICSI is generally considered adequate in terms of reproductive outcomes. Nevertheless, most studies comparing reproductive outcomes between fresh versus cryopreserved sperm include patients with oligo- and/or asthenozoospermia, where the altered quality of the sample can partially mask the full effect of freezing/thawing. The objective of this study is to ascertain whether ICSI using fresh or cryopreserved semen from normozoospermic patients results in similar fertilization rates and reproductive outcomes.

Study design, size, duration

Retrospective cohort of 6,594 couples undergoing their first elective ICSI cycle between January 2011 and December 2019, using normozoospermic partner semen (fresh or cryopreserved). All cycles involved a fresh embryo transfer, either at cleavage or blastocyst stage. Cycles were divided in 4 groups: fresh semen with partner’s oocytes (FSPO, n = 1.878), cryopreserved semen with partner’s oocytes (CSPO, n = 142), fresh semen with donor oocytes (FSDO, n = 2.413), and cryopreserved semen with donor oocytes (CSDO, n = 2.161).

Participants/materials, setting, methods

A slow freezing protocol using GM501 SpermStore medium (Gynemed, Lensahn) was used for all sperm cryopreservation. Sperm washing, capacitation, and selection prior to ICSI were performed equally for fresh and frozen-thawed samples, using pellet swim-up in IVF® medium (Vitrolife, Göteborg). Fertilization rate (FR), pregnancy (biochemical, clinical, and ongoing) and live birth (LB) rates were compared among study groups using Pearson’s Chi square and Student’s t-test. A p-value &lt;0.05 was considered statistically significant.

Main results and the role of chance

Male and female age, sperm concentration and motility after ejaculation, and number of oocytes inseminated were similar between study groups compared (FSPO vs. CSPO, FSDO vs. CSDO). As expected, oocyte donation cycles resulted in higher LB rate than cycles in which partner’s oocytes were used (30.04% vs 18.17%, p &lt; 0.001). In cycles using partner’s oocytes, no significant differences were observed between fresh and cryopreserved sperm in FR, pregnancy and LB rates (p &gt; 0.05 for all outcomes). However, in oocyte donation, the mean FR after ICSI using cryopreserved semen (73.6 ± 19.6) was lower than the FR obtained with fresh semen (75.1 ± 19.2), p = 0.010. Similarly, in oocyte donation cycles, the biochemical pregnancy rate was significantly lower when using cryopreserved semen (48.5% in CSDO vs. 52.3% in FSDO, p = 0.009), while clinical, ongoing pregnancy and LB rates were similar between both semen status (p &gt; 0.05). In oocyte donation, a subgroup analysis including only the ICSI cycles with embryo transfer at blastocyst stage (n = 1.187 for FSDO, n = 337 for CSDO) confirmed that the LB rate was comparable between fresh and cryopreserved semen groups (34.7% vs 35.6% respectively, p = 0.76), without significant differences in pregnancy rates neither (p &gt; 0.05 for all outcomes).

Limitations, reasons for caution

Caution should be exerted when extrapolating these results to different protocols for sperm cryopreservation and selection, or to IVM and classical IVF cycles, which were excluded from analysis. Due to the retrospective nature of the study, some uncontrolled for variables may affect the results.

Wider implications of the findings: Sperm cryopreservation does not affect pregnancy and live birth rates in normozoospermic patients, although it may lower slightly fertilization rates. In line with previous studies including patients with an apparent male factor detected after routine semen analysis, sperm cryopreservation is a safe and convenient technique.

Trial registration number

Not applicable

Lithium placental passage at delivery and neonatal outcomes: A retrospective observational study

Introduction

Lithium is an effective mood stabilizer and is widely used as a first-line treatment for bipolar disorder in the perinatal period. Several guidelines have provided clinical advice on dosing strategy (dose reduction versus stop lithium) in the peripartum period to minimize the risk of neonatal complications. An association has been observed between high neonatal lithium concentrations (> 0.64 mEq/L) and lower 1-min Apgar scores, longer hospital stays, and central nervous system and neuromuscular complications.

Objectives

To quantify the rate of lithium placental passage at delivery. To assess any association between plasma concentration of lithium at delivery and neonatal outcome.

Methods

In this retrospective observational cohort study, we included women treated with llithium at least in late pregnancy. Maternal (MB) and umbilical cord (UC) lithium blood level measurement were collected at delivery. Lithium serum concentrations were determined by means of an AVL 9180 electrolyte analyzer. The limit of quantification (LoQ) was 0.20 mEq/L and detection limit was 0.10 mEq/L. From the medical records, we extracted information on neonatal outcomes (preterm birth, birth weight, Apgar scores, pH-values, and admision to NICU) and complications categoriced by organ system: respiratory, circulatory, hematological, gastro-intestinal, metabolic, neurological, and immune system (infections).

Results

Umbilical cord and maternal lithium blood levels were strongly correlated: mean (SD) range UC/MR ratio 1.15 (0.24). Umbilical cord lithium levels ranged between 0.20 to 1.42 mEq/L. We observed no associations between umbilical cord lithium blood levels at delivery and neonatal outcomes.

Conclusions

In our study, newborns tolerated well a wide range of lithemias, between 0.20 and 1.42 mEq/L.

A study on the bioequivalence of lithium and valproate salivary and blood levels in the treatment of bipolar disorder

Lithium (Li) and valproate (VPA) are used in the treatment of bipolar disorder (BD), with narrow therapeutic window requiring periodic control of serum levels. This prevents intoxication, lack of efficacy due to low serum concentrations, and allows monitoring adherence. We aimed at evaluating the bioequivalence of salivary and blood levels of LI or VPA in a sample of adult BD patients. Secondarily, lithium bioequivalence was evaluated across different patients' lifespans. BD patients treated with either Li or VPA underwent contemporary standard serum and salivary measurements. Blood levels of both drugs were taken according to standard procedures. Li salivary levels were performed by an adapted potentiometric method on the AVL9180 electrolyte analyzer. VPA salivary levels were taken with an immune-assay method with turbidimetric inhibition. A total of 50 patients (38 on Li, 12 on VPA) were enrolled. Blood-saliva bioequivalence for VPA was not found due to a high variability in salivary measures. Li measures resulted in a high correlation (r=0.767, p<0.001), showing no partial correlation with age (r=0.147, p=0.380). Li salivary test is a reliable method of measuring Li availability and is equivalent to serum levels. Potential advantages of Li salivary testing are its non-invasive nature and the possibility of doing the test during the usual appointment with the psychiatrist.

Prolonged bisphosphonate release after treatment in women with osteoporosis. Relationship with bone turnover

Bisphosphonates (BP), especially alendronate and risedronate, are the drugs most commonly used for osteoporosis treatment, being incorporated into the skeleton where they inhibit bone resorption and are thereafter slowly released during bone turnover. However, there are few data on the release of BP in patients who have received treatment with these drugs for osteoporosis. This information is essential for evaluating the possibility of BP cyclic therapy in these patients and for controlling their long-term presence in bone tissue. This study evaluated the urinary excretion of alendronate and risedronate in patients treated with these drugs for osteoporosis and analysed its relationship with bone turnover, time of previous drug exposure and time of treatment discontinuation. We included 43 women (aged 65±9.4 years) previously treated with alendronate (36) or risedronate (7) during a mean of 51±3 and 53±3 months, respectively, who had not been treated with other antiosteoporotic treatment and with a median time of discontinuation of 13.5 and 14 months, respectively. Both BP were detected in 24-hour urine by HPLC. In addition, bone formation (PINP) and resorption (NTx) markers were analysed. Both BP were also determined in a control group of women during treatment. Alendronate was detected in 41% of women previously treated with this drug whereas no patient previously treated with risedronate showed detectable urinary values. All control patients showed detectable values of both BP. In patients with detectable alendronate levels, the time of drug cessation was shorter than in patients with undetectable values (12 [6-19] versus 31 [7-72] months, p<0.001). Alendronate was not detected in any patient 19 months after treatment cessation. Alendronate levels were inversely related to time of treatment discontinuation (r=-0.403, p=0.01) and the latter was directly related to NTx (r=0.394, p=0.02). No relationship was observed with age, length of drug exposure, renal function or weight. In conclusion, contrary to risedronate, which was not detected in patients after cessation of treatment, alendronate was frequently detected in women previously treated with this agent up to 19 months after discontinuation of therapy. The relationship between alendronate levels and both bone resorption and time of treatment cessation further indicates a residual effect of this drug in bone, despite treatment discontinuation.

The PFA-100® detects sub-optimal antiplatelet responses in patients on aspirin

Although it is suspected that some patients with acute coronary syndromes (ACS) could have a sub-optimal response to aspirin (SASAR), currently a fixed dose of ASA is long-term used in all individuals. This study was designed to determine SASAR and whether a SASAR is a predictor for recurrence of ischemic events in patients on low-dose ASA with a previous ACS. One hundred patients taking ASA 100 mg/day were assessed at 1 and 6 months after a first ACS. SASAR was initially defined as a failure of the ASA treatment to significantly prolong the closure time in the Platelet Function Analyzer (PFA-100). SASAR in these samples was reconfirmed by conventional aggregometry. TXB2 levels were determined in plasma. At one month 49 patients showed SASAR in the PFA-100; only 25 of them showed SASAR by conventional aggregometry. At six months, 39 of 81 patients showed SASAR by PFA-100, but conventional aggregometry detected SASAR in only 12 of the 39 patients. TXB2 levels were significantly higher in patients with SASAR. Five patients with SASAR, by both tests, died during follow-up (p = 0.013). The PFA-100 detected a high rate of SASAR in patients with ACS. This instrument could be used to screen for suboptimal response to the antiplatelet action of ASA. Whether persistence of SASAR could relate to a higher risk of recurrence and how adjusting the dose of ASA could reduce the rate of SASAR are issues that deserve further investigations.

[Ponderal evolution in the Girona population, 1989-1999]

BACKGROUND AND OBJECTIVE

Despite the number of plans leading to lose weight among individuals in the developed countries, the prevalence of obesity has increased since 1980. The knowledge of ponderal evolution in a given population is very important because the adverse effects of obesity vary greatly among individuals and populations. The objective of the present paper was to determine the modifications in the different degrees of body adiposity in a population in Catalunya.

PATIENTS AND METHODS

A measurement was made of weight and height of 24554 users aged over 14 years (10595 males and 13959 females) attended at four basic health areas (BHA): Girona 1, Girona 4, Salt and Camprodon, and a Primary Health Center (PHC) in the Girona province, for a five-year period, 1995-1999. The prevalence of the different degrees of obesity was compared with that obtained in a previous study with 6373 individuals during the 1986-1989 period (4,579 males and 1794 females).

RESULTS

The prevalence of women with overweight (defined as a body mass index [BMI] > 25 kg/m2) increased from 7.3% (1986-1989, study 0) to 17.6% (1995-1999, study 1) for women aged 15 to 24 years ( p < 0.001), from 17.9 % to 28.1% for women aged 25 to 34 years (p < 0.001), and from 37.5% to 44.7 % for women aged 35 to 44 years (p < 0.001). In the latter age group, the proportion of women with obesity (BMI > 30 kg/m2) increased from 6.9% to 12.9%. Similar trends were observed among men, and the change in the 35-44 year age group (from 10.5 % of obese men to 16% [p < 0.001]), and 55 to 65 years (from 16.6% of obese men to 22.7% [p < 0.001] was particularly significant. And lastly, it is also noteworthy the proportion of individuals with low weight (BMI < 18.5 kg/m2) which increased from 7.3% to 11.6% for women aged 15 to 24 years, and from 0.3% to 2.2% for women aged 35 to 44 years. This trend was also observed for men aged 15 to 24 years (11% to 17.2%).

CONCLUSIONS

The relative increase in the prevalence of overweight and obesity runs in parallel to that found in other surrounding countries. Also, it is worth mentioning that among women aged 15 to 24 years the increase in the prevalence of low weight and obesity is almost identical, which invalidates the mean and median values as a means to assess the ponderal evolution in this population. The current compartmentalization between the extreme BMIs, particularly among the youngest portion of population should be addressed from a multidisciplinary perspective.

Biological monitoring of environmental exposure to manganese in blood samples from residents of the city of Barcelona, Spain

Serum manganese levels were determined in 250 healthy subjects (122 men and 128 women) living in Barcelona in northeastern Spain. The study was designed to assess the reference levels for serum manganese and to investigate its relationship to age and sex. The age distribution ranged from 15 to 90 years. The assays were performed by means of a graphite furnace atomic absorption spectrometry. The geometric mean of serum manganese concentration was 1.1 microg/l, ranging from 0.3 microg/l to 2.5 microg/l. In almost every case, the 95th upper percentiles of this element were < 1.8 microg/l. No correlation between the concentration of manganese and sex could be established, but in the younger population the manganese levels were nearly three times higher than the results obtained in the older population.

[Prevalence of obesity in the population assisted at primary health care services in Girona, 1995-1999]

OBJECTIVES

To estimate the prevalence of obesity and overweight in the population of Girona (Spain) between 1995 and 1999 and to divide the prevalences in geographical areas according to age and sex.

METHODS

Height and weight were directly measures in 24,554 health care consumers older than 14 years (10,595 men and 13,959 women) treated in four primary health care areas: Girona 1, Girona 4, Salt and Camprodon and in one primary health care center in the province of Girona. Body mas index (BMI) was calcuted by dividing weight in kilograms bye height in meters squared. Obesity was defined as grades II and III of Garrow's index (BMI >= 30 kg/m2) and overweight as degree I (25 kg/m2 >= BMI < 30 kg/m2). Because the sample was not randomized, the prevalences were adequately weighted. The comparison between prevalences in two different primary health care areas for each sex (in the same Garrow's index and age group) was carried out using a parametric test of differences in proportions (Student's t-test). A hierarchical logistic regression was used to compare prevalences in the same grade Garrow's index, controlling for age and sex.

RESULTS

The prevalence of obesity was estimated as 15.6% in men aged from 20-74 years (from 14.0% in Girona 1 to 22.4% in Camprodon) and 17.5% for women (15.6% in Girona 1, 22.7% in Camprodon). The weighted mean was 16.7%. The prevalence of overweight was 44% in men and 33% in women and the weighted mean was 37.8%. The prevalence of obesity was graduated with statistically significant differences between Girona 1, Salt, Girona 4, Camprodon and Sils.

CONCLUSIONS

The estimates of the prevalences of obesity and overweight obtained in this study were closer to those of other studies in similar populations than previously believed. Indeed, the prevalences may be similar to those of the European Union and, in some age groups, to those of the United States.

Dietary micronutrients/antioxidants and their relationship with bronchial asthma severity

BACKGROUND

Because little is known about micronutrient/antioxidant intake and asthma severity, we investigated dietary intake and plasma/serum levels of micronutrients/antioxidants in a group of asthma patients with various degrees of severity, and compared the results with healthy subjects.

METHODS

A case control study was carried out on 118 asthma patients and 121 healthy subjects. The severity of the disease was classified by division of patients into four groups. Normal dietary micronutrient/antioxidant intake was estimated from a food frequency questionnaire. Plasma/serum levels of vitamins C, E, and A, selenium, magnesium, zinc, and platelet glutathione peroxidase (GSH-Px) activity were also determined.

RESULTS

No differences in daily micronutrient/antioxidant intake were seen between patients and healthy subjects. The severity of the disease showed no significant relationship with micronutrient/antioxidant intake. There were no differences in plasma/serum levels in any of the micronutrients/antioxidants between healthy subjects and asthmatics. Nor were any differences found between asthma groups in severity in the biochemical measures, except in platelet GSH-Px activity, which was significantly lower in the most severe groups.

CONCLUSIONS

In this study, we found no evidence of any association between micronutrient/antioxidant intake or plasma/serum levels of micronutrients/antioxidants and asthma. Reduction of platelet GSH-Px activity in the most severe patients suggests that these patients have a diminished capacity to restore part of the antioxidant defences.

Optimized procedure for lamotrigine analysis in serum by high-performance liquid chromatography without interferences from other frequently coadministered anticonvulsants

The authors have developed a simple isocratic high-pressure liquid chromatographic (HPLC) assay for the simultaneous determination of lamotrigine and other frequently coadministered antiepileptic drugs in serum samples. Lamotrigine extraction was performed on a reversed-phase Oasis HBL preparation column. The eluates containing butalbital as internal standard were separated with a 7-microm Chromsystems C18 250 x 4.0 mm I.D. reversed-phase column at a temperature of 40 degrees C using a mobile phase consisting of pH 3.8 phosphate-acetonitrile buffer (55:45, v/v), at a flow rate of 0.8 mL/min. Ultraviolet detection was carried out at 210 nm. Measurement of the peak:height ratio allowed quantitative determination of the samples. The method was linear over a concentration range of 0.2 to 20 microg/mL for lamotrigine. Recovery was >90%. Within-day and between-day coefficients of variation ranged from 1.8% to 6.7%. The mean lamotrigine concentration was 8.01 +/- 5.63 microg/mL. After studying sera from 130 patients treated with lamotrigine the authors confirmed that associated antiepileptic therapy affected the serum lamotrigine levels, which were significantly higher in patients under valproic acid treatment.

Alpha-1-acid glycoprotein in major depressive disorder. Relationships to severity, response to treatment and imipramine plasma levels

BACKGROUND

Increased plasma levels of alpha-1-acid glycoprotein (AGP) were reported in major depressive disorder. However, the relationship between AGP levels, severity of depression, treatment response and antidepressant levels are still unclear.

METHODS

Plasma AGP levels were measured in 36 subjects with major depressive disorder before and after a 6-week treatment with imipramine and in 30 controls. Free imipramine plasma levels of depressed patients were measured at 6 weeks. Comparative analysis between depressed patients and controls, between non-responders (N = 12) and responders (N = 24), and between severely depressed patients (N = 14) and moderately depressed patients (N = 22) were made.

RESULTS

Depressed patients had significantly higher mean values of AGP than control subjects. Imipramine non-responders and specially severely depressed patients had significantly greater increases of AGP levels during treatment than other depressed subgroups. There was no correlation between baseline AGP levels and severity of depression or free imipramine levels.

LIMITATIONS

The most significant limitations of this study are the small sample size and the fact that all the subjects were out-patients. Results should not be generalized to in-patient populations.

CONCLUSIONS

Depressed patients showed high baseline concentrations of AGP. AGP levels did not predict either free imipramine plasma levels or differential response after 6 weeks of treatment with imipramine. A greater increase of AGP during treatment was associated with severity of depression and treatment non-response.

CLINICAL IMPLICATIONS

The relationship between high plasma levels of AGP, severity of depression and lack of treatment response is clarified. The influence of imipramine levels is minimized.

Cyclical etidronate versus sodium fluoride in established postmenopausal osteoporosis: a randomized 3 year trial

To compare the effects of sodium fluoride and etidronate in severe postmenopausal osteoporosis, we conducted a 3 year, prospective, trial in 118 postmenopausal osteoporotic women with at least one vertebral fracture, who were randomly assigned to receive sodium fluoride (25 mg twice daily, as enteric-coated tablets) plus calcium (1000 mg/day) or intermittent etidronate (400 mg/day for 14 days) followed by calcium (1000 mg/day for 76 days). Lateral spine X-ray films and dual-energy X-ray absorptiometry (DXA) measurements of the lumbar spine and proximal femur were performed at enrollment and yearly. Nonvertebral fractures were recorded every 6 months. Thirty-one women in the fluoride group and 47 in the etidronate group completed the trial. At 36 months, the mean change from baseline of the lumbar bone density in the fluoride group was 8.5 +/- 2.04% (p = 0.001) and in the etidronate group was of 3.6 +/- 0. 84% (p < 0.001). The changes in the fluoride group were significantly higher than in the etidronate group (p = 0.01). Both groups showed nonsignificant changes in femoral neck bone density. There was no significant difference between groups in the cumulative proportion of women with new vertebral fractures, with an incidence in the fluoride group of 16% vs. 17% in the etidronate group. However, the number of new vertebral fractures was significantly lower in the fluoride group (6 fractures) than in the etidronate group (19 fractures) (p = 0.05). The number of patients with nonvertebral fractures was similar in both groups. A high incidence of side effects, mainly gastrointestinal symptoms and lower extremity pain syndrome, was observed in the fluoride group. Etidronate was well tolerated. We conclude that, in women with severe osteoporosis, although sodium fluoride is more favorable than cyclical etidronate for increasing lumbar bone mass, no differences were observed in the incidence of fractures.

Blood chromium determination in assessing reference values in an unexposed Mediterranean population

Plasma chromium levels were determined in 243 healthy subjects. The study group consisted of 134 men and 109 women, ages 19-71 yr, all residing in Barcelona in northeastern Spain. The study was designed to assess the reference levels for plasma chromium and to investigate its relationships to age and sex. The assays were performed by means of a graphite-furnace atomic absorption spectrometer. The mean plasma chromium concentration was 3.01 +/- 1.45 nmol/L, ranging from 0.6 to 6 nmol/L. The upper reference values in the 0.95 percentile for this population was 5 nmol/L. No significant differences were observed with respect to the subjects' sex.

Serum and urine fluoride concentration: relationships to age, sex and renal function in a non-fluoridated population

Serum and urine fluoride levels were determined in 250 healthy subjects (15-90 years, 122 men and 128 women) residing in Catalonia, Spain, and in 150 patients (20-81 years, 84 men and 66 women) with chronic renal failure undergoing regular dialysis treatment, living in the same geographical area, to determine normal range and to investigate its relationships to age, sex and renal function. Serum and urine fluoride were determined by a fluoride ion specific electrode system. Mean (+/- S.D.) serum fluoride concentration was 17.5 +/- 9.5 micrograms/l, ranging from 1 to 47 micrograms/l, in the control group and 58 +/- 31 micrograms/l, ranging from 28 to 185 micrograms/l, in renal patients. Urine fluoride concentration in the healthy group was 671 +/- 373 micrograms/24 h, ranging from 156 to 1900 micrograms/24 h. Fluoride status in the patient group was significantly greater than the control group. There was significant correlation between serum fluoride and age. No sex related difference was found.

Serum and urine ionic fluoride: normal range in a nonexposed population

The present study was undertaken to evaluate the fluoride status in the general healthy population of Barcelona. Serum and urine fluoride ionic concentration was determined in a random sample of 250 subjects (age range 15-90 yr) by the Orion fluoride electrode system to determine the normal range of fluoride in this population. The results obtained show that in the general population of Barcelona, fluoride ionic serum concentration ranges between 1 and 47 microg/L (x = 17.5 +/- 9.7 microg/L) and fluoride ionic urine concentration ranges between 156 and 1990 microg/24 h (x = 671 +/- 373 microg/24 h). The mean serum fluoride concentration of the younger population was shown to be significantly greater (p < 0.05) than that of the older group. No sex-related difference was found.

Etidronate versus fluoride for treatment of osteopenia in primary biliary cirrhosis: preliminary results after 2 years

BACKGROUND & AIMS

Because osteopenia increases morbidity of primary biliary cirrhosis (PBC), the effects of cyclical etidronate vs. sodium fluoride on bone mass were compared in patients with PBC.

METHODS

Thirty-two women with PBC were randomly assigned to receive etidronate (400 mg/day during 14 days every 3 months) or fluoride (50 mg/day, enteric-coated tablets). Bone mineral density of the lumbar spine and proximal femur were measured initially and every 6 months. Bone fractures were also evaluated.

RESULTS

Sixteen patients were allocated into each group, which were comparable with respect to the severity of PBC and osteopenia. Thirteen patients with etidronate and 10 patients with fluoride completed 2 years in the study. In the etidronate group, bone mineral density increased in the lumbar spine (P = 0.02) and did not change in the proximal femur. In the fluoride group, lumbar bone mineral density did not change but femoral bone mass decreased, particularly in the Ward's triangle. Two patients in the fluoride and none in the etidronate group developed new vertebral fractures, and the number of new nonvertebral fractures was similar in both groups. Neither treatment impaired liver function or cholestasis.

CONCLUSIONS

Cyclical etidronate is more effective and better tolerated than sodium fluoride in preventing bone loss in PBC.

Serum selenium concentration of a healthy northwest Spanish population

Selenium (Se) is an essential element, cofactor for glutathione peroxidase (GSHPx) activity, whose deficiency may induce modifications in the cellular antioxidative status and induce the appearance of different diseases. Current views suggest that a serum Se concentration inferior to 45 micrograms/L may correlate with an increased risk of coronary hearth diseases, coronary atherosclerosis and cancer. Since the Se concentration in human blood varies between geographical areas, we initiated a study to evaluate the Se status in the general healthy population of Barcelona. Serum Se concentration was investigated in a random sample of 150 subjects (age range 18-70 yr) by graphite furnace atomic spectrometry (FLAAS). L'vov platform, Zeeman background correction, and other specifications of stabilized temperature platform furnace (STPF) concept were followed. The results show that in the general population of Barcelona, Se serum concentration ranges between 60 and 106 micrograms/L (X = 80.7 +/- 10 micrograms/L). These values can be considered within the safe limits, since no subject was found with a concentration lower than the threshold of 45 micrograms/L.

[Exposure to lead among the population of Barcelona: chronologic trends from 1984 to 1995]

BACKGROUND

This study was designed to determine current lead exposure in the Barcelona population and to evaluate the changes occurred during the last 10 years. Blood lead concentration was investigated in a random sample of 694 healthy subjects (age range: 0-65 years).

PATIENTS AND METHODS

Adults were random selected from a group of blood donors. Samples of children analysed were selected from subjects with a preoperatory analyses without any disease that could modify blood lead levels. Lead levels were determined by atomic absorption spectrometry.

RESULTS

Blood lead concentration was 4.06 +/- 1.4 micrograms/dl in umbilical cord, 8.9 +/- 2.9 micrograms/dl in the paediatric population and 7.8 +/- 4.2 micrograms/dl in the total of adults analyzed. There was statistical differences between the younger subjects and the older population. In 1984 the results found were 18.6 +/- 6.6 micrograms/dl.

CONCLUSIONS

The results obtained show that in the last 10 years a reduction on the blood lead levels was occurred. This reduction is parallel with a diminish in the lead petrol concentration in the ambient air.

Comparative analysis of tacrolimus (FK506) in whole blood liver transplant recipients by PRO-TRAC enzyme-linked immunosorbent assay and microparticle enzyme immunoassay IMX methods

The macrolide tacrolimus (FK506) is a powerful immunosuppressive drug that acts early in the T-cell activation process and inhibits cytokine gene transcription. Data from several trials in liver transplantation have shown the efficacy of tacrolimus in the prevention of allograft rejection and its potent hepatotrophic effect, which could explain its great success in liver transplantation. However, tacrolimus is not devoid of adverse effects (mainly nephrotoxicity and neurotoxicity) requiring careful blood level monitoring, which is an essential aid in the adjustment of drug dosing. Several methods of analysis are available to measure tacrolimus in whole blood. A new assay based on the enzyme-linked immunosorbent assay (ELISA) technology has been developed. The INCSTAR PRO-TRAC FK506 is a sensitive immunoassay (range, 0.5 to 60 ng/ml), which uses a mouse monoclonal antibody to FK506. Samples are extracted into methanol and dried under nitrogen. The reconstituted extracts are analyzed by ELISA by using 2-h incubation. The aim of this study was to evaluate the ELISA method in routine monitoring of liver transplant patients and to compare the whole blood results with those obtained by Abbott microparticle enzyme immunoassay (MEIA) IMx. Precision studies with 20 samples from 4.37 and 17.1 ng/ml gave within-run total coefficients of variance of 14.4 and 17.4%, respectively. A total of 63 blood samples was analyzed. The mean +/- SD were 9.68 +/- 5.92 and 10.52 +/- 7.54 ng/ml by ELISA and MEIA assays, respectively. There was an acceptable correlation between the methods: ELISA = 1.419 + 0.785 MEIA; Sy x x = 2.639; r = 0.804. Serial tacrolimus measurements (n = 13) in two patients with bilirubin levels > 20 mg/dl yielded mean +/- SD (range) of 11.64 +/- 7.59 ng/ml (2.60-25.40 ng/ml) and 15.55 +/- 10.78 ng/ml (3.60-34.4 ng/mL) by ELISA and MEIA assays, respectively. These discrepancies in concentrations can result from variation in matrix or different cross-reactivities or both in the two tests. We concluded that the INCSTAR PRO-TRAC FK506 is suitable for routine whole blood tacrolimus monitoring.

Cadmium and zinc relationships in the liver and kidney of humans exposed to environmental cadmium

Concentrations of cadmium and zinc were determined in the liver and in the kidney (cortex and medulla) of subjects from the general population of Barcelona (Spain) by atomic absorption spectrometry. Tissues were collected from necropsies of 50 selected subjects without any occupational exposure to heavy metals. Cadmium levels calculated on a fresh tissue basis were 14.6 +/- 5.9 micrograms/g (2.4-31) in the kidney cortex, 8.6 +/- 4.3 micrograms/g (1.5-16.7) in the kidney medulla and 0.98 +/- 0.50 micrograms/g (0.32-2.32) in the liver. Zinc concentrations ranged between 18-53 micrograms/g, (mean +/- S.D.: 38.0 +/- 10 micrograms/g) in the kidney cortex, 25.0 +/- 7.7 micrograms/g (12-42 micrograms/g) in the kidney medulla and 41.7 +/- 18.3 micrograms/g (20-84 micrograms/g) in the liver. The aim of the present work was to study the association of cadmium and zinc in the kidney and in the liver of a human population with cadmium accumulation from an environmental origin. The results obtained showed a significant correlation between cadmium and zinc concentration in the liver (r = 0.86, P < 0.001), but not in the kidney.

Effects of long-term antiepileptic therapy on the catabolism of testosterone

The serum levels of testosterone, sex hormone binding globulin, and free testosterone index were measured in 51 epileptic men (age 18-45) in order to assess the possible effects of antiepileptic drugs on sexual dysfunction. An analytical gas chromatography-mass spectrometry method was developed to assess the urinary excretion of testosterone, epitestosterone, androsterone, etiocholanolone, 11-OH androsterone and 11-OH etiocholanolone and to evaluate if the catabolism of testosterone had been increased. Twenty normal healthy males of similar age, 18-45 years, served as control group. Patients receiving polytherapy (n = 34) or monotherapy with carbamazepine (n = 8) or phenytoin (n = 9) showed higher levels of sex hormone binding globulin and testosterone, and lower levels of free testosterone than did the controls (P < 0.03). Urinary excretion of the metabolites androsterone and 11-OH androsterone was significantly reduced (P < 0.02) in the polytherapy group, while the monotherapy group showed only significant differences (P < 0.02) in the elimination of 11-OH androsterone. Our results suggest that an induction of the hepatic synthesis of sex hormone binding globulin may be the mechanism by which the antiepileptic drugs lower the levels of free testosterone in serum. However, the reduced excretion of androsterone and the normal levels of etiocholanolone show that the antiepileptic drugs do not produce an increase in the main catabolism pathway of testosterone.

Accumulation of hexachlorobenzene in humans: a long standing risk

1. Hexachlorobenzene (HCB) internal dose in the general population of Barcelona (Spain) was estimated after new indications of the carcinogenicity of this chemical in humans were recently reported. Hospital blood bank facilities and randomly selected volunteers were used for HCB analyses in serum (n = 100) and cerumen (n = 25). Other main organochlorine residues often found in human tissues and blood (pp DDE, beta-HCH,) were also determined. 2. HCB serum levels currently found (Range 0.7-19.7 ng Ml-1; X +/- s.d.: 4.13 +/- 3.61; GM: 3.05) were compared to those found in a similar survey made in 1986 on the same population. The serum HCB levels showed a significant decrease (P < 0.001) when compared to the former results and correlated with age (P < 0.001) suggesting a progressive preponderance of a stable blood-adipose equilibrium with fewer variations due to recent and variable intake of the chemical. 3. Cerumen analyses revealed detectable concentrations of HCB in all samples (Range: 160-4790 ng g-1 in extractable lipid basis) and confirmed the suitability of this matrix to assess the body burden of residues accumulated in adipose and lipid-rich tissues. The set of results shows that, although HCB exposure has been reduced, the overall population under study still accumulates significant amounts of this possible carcinogen.

Evaluation of serum zinc-binding capacity during childbirth, in newborn infants and during the menstrual cycle

This is a study of the value of total serum zinc, serum zinc per g of protein, serum zinc-binding capacity and serum zinc-binding capacity per g of protein in 102 pregnant women during childbirth and in the cord blood of their newborn infants. A control group is established by analyzing these parameters in 10 healthy non-pregnant women on the first day of menstruation and on the day of ovulation during two consecutive menstrual cycles. The total serum zinc and serum zinc per g of protein values found were significantly higher in cord blood than in maternal blood, and the binding capacity of zinc and of zinc per g protein were significantly higher in maternal blood. There is a negative correlation between total zinc and binding capacity and total zinc and binding capacity per g protein both in maternal and in cord blood. In the control group, the values of total zinc and zinc per g protein vary from one menstrual cycle to the next and between the different phases of each cycle. Zinc-binding capacity per g protein during ovulation is significantly lower than during menstruation. These results allow us to conclude that the rise of zinc-binding capacity and zinc-binding capacity per g protein in maternal blood during childbirth, and during menstruation in the control group, can be due to the effect of progesterone. The fact that zinc-binding capacity and zinc-binding capacity per g of protein are higher in maternal blood than in cord blood would confirm the existence of mechanisms which tend to increase binding of zinc in the fetus.

Inhibition of intratesticular testosterone synthesis by inorganic lead

The alterations in testicular testosterone synthesis produced by exposure to inorganic lead were investigated in BALB/c+ mice. Lead concentration in blood and testes and the levels of testosterone and delta 4-androgen biosynthesis pathway precursors (4-androstenedione, 17-hydroxyprogesterone, and progesterone) were measured in animals which were exposed to lead acetate in the drinking water (366 mg/l, 0.97 +/- 0.12 mg lead/animal/day) during 6 months. The results showed a significant reduction of the intratesticular testosterone levels after 30 days of exposure and of the androstenedione levels after 150 days. Intratesticular progesterone and hydroxyprogesterone levels showed no changes during the assay.

Distribution and changes of glycoconjugates in rat colonic mucosa during development. A histochemical study using lectins

A study was made of the modifications of glycoconjugates in rat colonic mucosa during development. Sections of the caecum, and proximal and distal portions of the colon from Sprague Dawley rats at different stages of development (embryos, fetuses, suckling, weaning and adult rats) were examined. The sections were incubated with a battery of eight fluoresceinated lectins: DBA, SBA, WGA, LFA, PNA, GS-I, UEA-I and Con A. Some sections were treated with neuraminidase, and others were submitted to sequential saponification-neuraminidase treatment prior to incubation with the lectin (WGA, PNA or LFA). The intensity of the fluorescence was evaluated and graded from absent (-) to very positive (4+). Gradual and progressive changes were seen in colonic glycoconjugates during development. These changes revealed a unique developmental pattern for each lectin, which was independent for each cellular compartment (goblet cells, luminal surface and supranuclear region). Local and regional differences, observed between the different colonic sections, were already present from early stages of development. Moreover, our study showed that for several glycoconjugates, the differentiation process in colonic mucosa began in the distal region and continued through to the proximal region, the former being the first to reach the adult pattern. In the caecum, some lectins maintained a fetal pattern throughout all the periods of development up to the adult stage.