Validation of a MALDI-TOF MS Method for SARS-CoV-2 Detection on the Bruker Biotyper and Nasopharyngeal Swabs: A Brazil-UK Collaborative Study

We developed a MALDI-TOF mass spectrometry method for the detection of the SARS-CoV-2 virus in saliva-gargle samples using Shimadzu MALDI-TOF mass spectrometers in the UK. This was validated in the USA to CLIA-LDT standards for asymptomatic infection detection remotely via sharing protocols, shipping key reagents, video conferencing, and data exchange. In Brazil, more so than in the UK and USA, there is a need to develop non-PCR-dependent, rapid, and affordable SARS-CoV-2 infection screening tests that also identify variant SARS-CoV-2 and other virus infections. In addition, travel restrictions necessitated remote collaboration with validation on the available clinical MALDI-TOF-the Bruker Biotyper (microflex^® LT/SH)-and on nasopharyngeal swab samples, as salivary gargle samples were not available. The Bruker Biotyper was shown to be almost log10³ more sensitive at the detection of high molecular weight spike proteins. A protocol for saline swab soaks out was developed, and duplicate swab samples collected in Brazil were analyzed by MALDI-TOF MS. The swab collected sample spectra that varied from that of saliva-gargle in three additional mass peaks in the mass region expected for IgG heavy chains and human serum albumin. A subset of clinical samples with additional high mass, probably spike-related proteins, were also found. Further, spectral data comparisons and analysis, subjected to machine learning algorithms in order to resolve RT-qPCR positive from RT-qPCR negative swab samples, showed 56-62% sensitivity, 87-91% specificity, and a 78% agreement with RT-qPCR scoring for SARS-CoV-2 infection.

Direct Detection of Glycated Human Serum Albumin and Hyperglycosylated IgG3 in Serum, by MALDI-ToF Mass Spectrometry, as a Predictor of COVID-19 Severity

The prefusion spike protein of SARS-CoV-2 binds advanced glycation end product (AGE)-glycated human serum albumin (HSA) and a higher mass (hyperglycosylated/glycated) immunoglobulin (Ig) G3, as determined by matrix assisted laser desorption mass spectrometry (MALDI-ToF). We set out to investigate if the total blood plasma of patients who had recovered from acute respiratory distress syndrome (ARDS) as a result of COVID-19, contained more glycated HSA and higher mass (glycosylated/glycated) IgG3 than those with only clinically mild or asymptomatic infections. A direct serum dilution, and disulphide bond reduction, method was developed and applied to plasma samples from SARS-CoV-2 seronegative (n = 30) and seropositive (n = 31) healthcare workers (HCWs) and 38 convalescent plasma samples from patients who had been admitted with acute respiratory distress (ARDS) associated with COVID-19. Patients recovering from COVID-19 ARDS had significantly higher mass AGE-glycated HSA and higher mass IgG3 levels. This would indicate that increased levels and/or ratios of hyper-glycosylation (probably terminal sialic acid) IgG3 and AGE glycated HSA may be predisposition markers for the development of COVID-19 ARDS as a result of SARS-CoV2 infection. Furthermore, rapid direct analysis of serum/plasma samples by MALDI-ToF for such humoral immune correlates of COVID-19 presents a feasible screening technology for the most at risk; regardless of age or known health conditions.

A How to Guide: Clinical Population Test Development and Authorization of MALDI-ToF Mass Spectrometry-Based Screening Tests for Viral Infections

Applying MALDI-ToF mass spectrometry as a clinical diagnostic test for viruses is different from that of bacteria, fungi and other micro-organisms. This is because the systems biology of viral infections, the size and chemical nature of specific viral proteins and the mass spectrometry biophysics of how they are quantitated are fundamentally different. The analytical challenges to overcome when developing a clinical MALDI-ToF mass spectrometry tests for a virus, particularly human pathogenic enveloped viruses, are sample enrichment, virus envelope disruption, optimal matrix formulation, optimal MALDI ToF MS performance and optimal spectral data processing/bioinformatics. Primarily, the instrument operating settings have to be optimized to match the nature of the viral specific proteins, which are not compatible with setting established when testing for bacterial and many other micro-organisms. The capacity to be a viral infection clinical diagnostic instrument often stretches current mass spectrometers to their operational design limits. Finally, all the associated procedures, from sample collection to data analytics, for the technique have to meet the legal and operational requirement for often high-throughput clinical testing. Given the newness of the technology, clinical MALDI ToF mass spectrometry does not fit in with standard criteria applied by regulatory authorities whereby numeric outputs are compared directly to similar technology tests that have already been authorized for use. Thus, CLIA laboratory developed test (LDT) criteria have to be applied. This article details our experience of developing a SAR-CoV-2 MALDI-ToF MS test suitable for asymptomatic carrier infection population screening.

Exploring the relationship of sleep, cognition, and cortisol in sickle cell disease

Background

Neurocognitive impairment is common in people with Sickle Cell Disease (SCD) and evidence is accumulating that sleep disturbances play a role. The interaction between cortisol and sleep in the general population is associated with cognition as well as general wellbeing but there are few data in SCD. We aimed to understand the relationship between cortisol and sleep in individuals with SCD and explored associations with cognition.

Methods

Forty-five participants of black heritage (SCD: N = 27, 9–29 years, 16 females; Controls: N = 18, 11–25 years, 13 females) were recruited from the community between 2018 - 2020. Participants completed standardized questionnaires about their sleep behaviour and wore actigraphy MotionWatch8 for 7 nights to assess nocturnal sleep patterns. Salivary cortisol samples were taken on wakening and 3 times after 14:00. Cognition was assessed using the Wechsler Intelligence Scales for children and adults.

Results

People with SCD took longer to fall asleep and experienced greater wake bouts, mobile minutes and fragmented sleep compared to controls. Although non-significant, people with SCD experienced lower morning cortisol, with a flattened diurnal cortisol ratio compared to controls. Interestingly, SCD participants, but not controls, with low diurnal variation scored lowest on processing speed (PSI) and perceptual reasoning index (PRI). A moderator analysis revealed that the effect of morning cortisol and diurnal cortisol ratio on PRI by group health (i.e., SCD and healthy controls) depended on sleep quality.

Discussion

Sleep and cortisol may play a crucial role in the expression of cognitive difficulties seen in SCD. This should be considered for the development of interventions to optimise cognitive functioning and sleep. This, in turn, could positively impact on secretion of cortisol and general health in SCD.

•

We examined sleep patterns, cortisol and cognition in 27 participants with Sickle Cell Disease (SCD) and 18 healthy controls.

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People with SCD had lower cognitive scores compared to healthy controls.

•

People with SCD took longer to fall asleep, had greater wake bouts, mobile minutes, and fragmented sleep.

•

People with SCD experienced a flattened diurnal cortisol profile.

•

Sleep disturbances might interfere with diurnal cortisol rhythm and contribute to lower cognitive scores .

Current Advancements in Noninvasive Profiling of the Embryo Culture Media Secretome

There have been over 8 million babies born through in vitro fertilization (IVF) and this number continues to grow. There is a global trend to perform elective single embryo transfers, avoiding risks associated with multiple pregnancies. It is therefore important to understand where current research of noninvasive testing for embryos stands, and what are the most promising techniques currently used. Furthermore, it is important to identify the potential to translate research and development into clinically applicable methods that ultimately improve live birth and reduce time to pregnancy. The current focus in the field of human reproductive medicine is to develop a more rapid, quantitative, and noninvasive test. Some of the most promising fields of research for noninvasive assays comprise cell-free DNA analysis, microscopy techniques coupled with artificial intelligence (AI) and omics analysis of the spent blastocyst media. High-throughput proteomics and metabolomics technologies are valuable tools for noninvasive embryo analysis. The biggest advantages of such technology are that it can differentiate between the embryos that appear morphologically identical and has the potential to identify the ploidy status noninvasively prior to transfer in a fresh cycle or before vitrification for a later frozen embryo transfer.

MALDI-ToF Mass spectra phenomic analysis for human disease diagnosis enabled by cutting-edge data processing pipelines and bioinformatic tools

Currently, methodologies of human disease diagnosis are still far from capable of rapidly and accurately screening for multiple diseases, simultaneously in a large population, at affordable costs. MALDI-ToF mass spectrometry is an ultra-sensitive, ultra-fast and low-cost high-throughput technology which has a huge potential in clinical laboratory medicine to achieve this goal. Such clinical analysis is starting the first steps towards human phenotype detection and hence phenomic screening for multiple disease states. In this review, we will discuss the main advances achieved so far; putting forward targeted applications of MALDI-ToF mass spectrometry in the service of human disease detection. Here, we will focus mostly on methodological workflow, namely MALDI-ToF data processing for phenomic analysis, using state-of-the-art bioinformatic pipelines and software tools. We will further focus on the role of mathematical modelling, machine learning and artificial intelligence algorithms for disease screening. Moreover, we will present some already developed tools for disease diagnostics and screening based on MALDI-ToF analysis. We will discuss the remaining challenges that are ahead when implementing MALDI-ToF into clinical laboratories. The move from identifying a normal to a single disease phenotype is challenging, but the step towards simultaneously running multiple algorithms screens for multiple different disease phenotype may only be limited by computing power once the first hurdle is passed. The road map to reaching the full potential of human clinical phenomics may be clearer than imagined and give an insight as to the huge benefits this technology may bring for the future of diagnostics.

Development of a Clinical MALDI-ToF Mass Spectrometry Assay for SARS-CoV-2: Rational Design and Multi-Disciplinary Team Work

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus has stretched national testing capacities to breaking points in almost all countries of the world. The need to rapidly screen vast numbers of a country's population in order to control the spread of the infection is paramount. However, the logistical requirement for reagent supply (and associated cost) of RT-PCR based testing (the current front-line test) have been hugely problematic. Mass spectrometry-based methods using swab and gargle samples have been reported with promise, but have not approached the task from a systematic analysis of the entire diagnostic process. Here, the pipeline from sample processing, the biological characteristics of the pathogen in human biofluid, the downstream bio- and physical-chemistry and the all-important data processing with clinical interpretation and reporting, are carefully compiled into a single high-throughput and reproducible rapid process. Utilizing MALDI-ToF mass spectrometric detection to viral envelope glycoproteins in a systems biology-multidisciplinary team approach, we have achieved a multifaceted clinical MALDI ToF MS screening test, primarily (but not limited to) SARS-CoV-2, with direct application to other future epidemics/pandemics that may arise. The clinical information generated not only includes SARS-CoV-2 coronavirus detection-(Spike protein fragments S1, S2b, S2a peaks), but other respiratory viral infections detected as well as an assessment of generalised oral upper respiratory immune response (elevated total Ig light chain peak) and a measure of the viral immune response (elevated intensity of IgA heavy chain peak). The advantages of the method include; (1) ease of sampling, (2) speed of analysis, and much reduced cost of testing. These features reveal the diagnostic utility of MALDI-ToF mass spectrometry as a powerful and economically attractive global solution.

Substantial urinary concentrations of material resembling beta-core fragment of chorionic gonadotropin beta-subunit in mid-menstrual cycle

We measured the day-to-day variations in concentrations of beta-core, luteinizing hormone (LH), and alpha-subunit in urine during the menstrual cycle. The alpha-subunit concentrations showed a pattern similar to that of the LH concentrations. beta-Core-like material was increased during and up to 3 to 4 days after the surge in urine LH. The urine LH concentration was associated with the presence of beta-core immunoreactivity during the urine LH peak. Chromatography showed that, at the peak LH concentration and at 2 days after the LH peak, beta-core immunoreactivity could be accounted for by the presence of a peptide of low molecular mass similar to the beta-core molecule of hCG, but probably originating from the degradation of LH. The prolonged excretion of gonadotropin metabolites in the midcycle must be considered when beta-core is being assessed as a tumor marker.

Secretome profile selection of optimal IVF embryos by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

Purpose

Selecting an embryo at the transfer stage with the best chance of a successful pregnancy is still largely dependent on preceding subjective evaluation of morphokinetics. Expensive prenatal genomic profiling has been so far proved ineffective. Proteomics and metabolomics are promising new approaches to assess embryo viability, but methodologies are often complex and do not lend themselves to rapid analysis in the critical time between blastocyst formation and embryo transfer. Here, we used matrix-assisted laser desorption ionization time-of-flight (MALDI ToF) mass spectrometry to assess the secretome of blastocysts in the minutes prior to embryo transfer and correlated spectral features with pregnancy outcome.

Methods

Four hundred one samples of spent blastocyst culture media were collected from embryo cultures at the time of embryo transfer, of which 136 were used to construct the predictive model. The media samples were frozen at − 20 °C and stored for analysis. Sample analysis was conducted in batches using 1 μl of spent embryo in direct MALDI ToF mass spectral analysis. Quantitative characteristics within this mass range (2000–17,000 m/z) were used to generate a score for selected mass regions (bins) in order to predict pregnancy outcome for each sample.

Results

With a simple algorithm based on nine mass bins within the 2000–10,000 m/z region, it was possible to identify samples with the best chance of becoming an ongoing pregnancy (positive predictive value of 82.9%, p = 0.0018).

Conclusion

A simple, direct and rapid analysis of spent culture fluid from blastocysts at the point of embryo transfer can quickly identify optimal embryos with the best chance of achieving ongoing pregnancy. Methods like this, which take less than 20 min to perform, could dramatically improve the approach to embryo selection and live births.

Direct and rapid mass spectral fingerprinting of maternal urine for the detection of Down syndrome pregnancy

Background

The established methods of antenatal screening for Down syndrome are based on immunoassay for a panel of maternal serum biomarkers together with ultrasound measures. Recently, genetic analysis of maternal plasma cell free (cf) DNA has begun to be used but has a number of limitations including excessive turn-around time and cost. We aimed to develop an alternative method based on urinalysis that is simple, affordable and accurate.

Method

101 maternal urine samples sampled at 12–17 weeks gestation were taken from an archival collection of 2567 spot urines collected from women attending a prenatal screening clinic. 18 pregnancies in this set subsequently proved to be Down pregnancies. Samples were either neat urine or diluted between 10 to 1000 fold in dH₂O and subjected to matrix assisted laser desorption ionization (MALDI), time of flight (ToF) mass spectrometry (MS). Data profiles were examined in the region 6,000 to 14,000 m/z. Spectral data was normalised and quantitative characteristics of the profile were compared between Down and controls.

Results

In Down cases there were additional spectral profile peaks at 11,000-12,000 m/z and a corresponding reduction in intensity at 6,000-8,000 m/z. The ratio of the normalised values at these two ranges completely separated the 8 Down syndrome from the 39 controls at 12–14 weeks. Discrimination was poorer at 15–17 weeks where 3 of the 10 Down syndrome cases had values within the normal range.

Conclusions

Direct MALDI ToF mass spectral profiling of maternal urinary has the potential for an affordable, simple, accurate and rapid alternative to current Down syndrome screening protocols.

Shotgun metabolomic profiles in maternal urine identify potential mass spectral markers of abnormal fetal biochemistry - dihydrouracil and progesterone in the metabolism of Down syndrome

In Down syndrome (DS) in particular, the precise cellular mechanisms linking genotype to phenotype is not straightforward despite a clear mapping of the genetic cause. Metabolomic profiling might be more revealing in understanding molecular-cellular mechanisms of inborn errors of metabolism/syndromes than genomics alone and also result in new prenatal screening approaches. The urinary metabolome of 122 maternal urine from women with and without an aneuploid pregnancy (predominantly Down syndrome) were compared by both zwitterionic hydrophilic interaction chromatography (ZIC-HILIC) and reversed-phase liquid chromatography (RPLC) coupled to hybrid ion trap time of flight mass spectral analysis. ZIC-HILIC mass spectrometry resolved 10-fold more unique molecular ions than RPLC mass spectrometry, of which molecules corresponding to ions of m/z 114.07 and m/z 314.20 showed maternal urinary level changes that significantly coincided with the presence of a DS fetus. The ion of m/z 314.20 was identified as progesterone and m/z 114.07 as dihydrouracil. A metabolomics profiling-based maternal urinary screening test modelled from this separation data would detect approximately 87 and 60.87% (using HILIC-MS and RPLC-MS, respectively) of all DS pregnancies between 9 and 23 weeks of gestation with no false positives.

Novel insights into the expression of CGB1 & 2 genes by epithelial cancer cell lines secreting ectopic free hCGβ

BACKGROUND

Ectopic secretion of human chorionic gonadotrophin free beta (hCGβ) by epithelial cancer is associated with aggressive tumors which more readily metastasize, possibly by acting as an autocrine anti-apoptotic agent. hCGβ is encoded by six homologous CGB genes, with poorly-understood variable transcriptionally active expression profiles; CGB1 and CGB2 have always been considered pseudogenes. However, transcripts from CGB1 and -2 can be detected in placental, testicular and pituitary tissues. The expression and function of these genes in cancer is less well-known.

MATERIALS AND METHODS

Expression profiles of CGB genes in epithelial cancer cells by quantitative polymerase chain reaction (qPCR) were explored, along with the consequence of specific siRNA silencing of CGB1 and 2. Immunohistochemical and immunoassay techniques were used to detect the translation and secretion of hCGβ in these cells.

RESULTS

CGB1 and -2 gene transcripts were only detected in cells which secreted hCGβ. siRNA-mediated silencing of CGB1 and -2 transcripts significantly reduced secreted protein in concordance with a reduction in cell survival to a greater degree than that of other CGB genes.

CONCLUSION

CGB genes 1 and 2, previously considered as pseudogenes, are notably expressed by epithelial cancer cell lines. The transcription of these genes, but not other CGB genes, correlates with a functionally expressed protein and propensity for cancer growth.

Stable knockdown of hCGβ mRNA expression in bladder cancer cells results in significant growth inhibition

BACKGROUND

Expression of human chorionic gonadotropin beta subunit (hCGβ) by epithelial carcinomas is associated with a poor prognosis and has a proposed autocrine growth effect on cancer cells by inhibition of apoptosis.

MATERIAL AND METHODS

We transduced the hCGβ-expressing bladder cancer cell line SCaBER with short hairpin (sh) RNA lentiviral gene-specific (CGB) constructs and determined its impact on the synthesis of hCGβ and the resultant effect on cancer cell growth.

RESULTS

Stable CGB gene-silenced clones exhibited a 60%-80% reduction in the level of hCGβ expressed and a reduced growth rate of more than 40% compared to wild-type SCaBER cells.

CONCLUSIONS

shRNA Lentiviral particles achieve stable knockdown of hCGβ translation in the bladder cancer cell line SCaBER. This transforms the phenotype by reducing hCGβ expression and cell growth rate. This is consistent with the proposed autocrine/paracrine function of ectopic hCGβ expression during oncogenesis.

Differential proteolysis of insulin-like growth factor binding protein-1 (IGFBP-1) in pregnancy

The insulin-like growth factors and their binding proteins are important for placental and foetal growth. In this study, we have investigated the presence of proteolytic activity directed against insulin-like growth factor binding protein-1 (IGFBP-1) in pregnancy. In addition, the effect of protease activity on IGFBP-1 immunoreactivity and IGF binding was characterised. 125I-IGFBP-1 was incubated with maternal and foetal serum, amniotic fluid and placental extracts. Breakdown of 125I-IGFBP-1 was determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and autoradiography. The size distribution of endogenous IGFBP-1 was determined by Western immunoblotting. Protease inhibitor studies characterised the proteolytic activity, and Western ligand blotting with 125I-IGF-I was used to determine IGF binding capacity of proteolysed IGFBP-1. Amniotic fluid samples collected after labour onset contained proteolytic activity that generated 12- and 19-kDa IGFBP-1 fragments that did not bind to 125I-IGF-I. This activity was not detected in amniotic fluid collected prior to labour onset or in other tissues. Activity was blocked by aprotinin, leupeptin, phenyl methyl sulphonyl fluoride, and Kunitz soybean trypsin inhibitor but not by ethylene diamine tetraacetic acid or pepstatin. Incubation of IGFBP-1 with trypsin generated fragments of a similar size to the amniotic fluid protease. In conclusion, we have demonstrated the presence in vivo of a trypsin-like proteolytic activity that alters the IGF-binding function of IGFBP-1 in pregnancy.

Human chorionic gonadotropin (hCG) in the secretome of cultured embryos: hyperglycosylated hCG and hCG-free beta subunit are potential markers for infertility management and treatment

Human chorionic gonadotropin (hCG) is produced by trophoblast cells throughout pregnancy, and gene expression studies have indicated that hCG-beta subunit (hCGβ) expression is active at the 2 blastomere stage. Here, we investigated the qualitative hCG output of developing embryos in culture and hCG isoforms expressed in the secretome as a novel sensitive method for detecting hCG. Culture media was collected from the culture plates of 118 embryos in culture (including controls and embryos at different stages of culture) from 16 patients undergoing routine fertility treatment. The hCGβ was detectable in media from 2 pronuclear (2PN) stage embryos through to the blastocyst stage. The hCGβ was absent in 1PN and arrested embryos as well as all media controls. Prior to hatching, hyperglycosylated hCG (hCGh) was observed selectively in 3PN embryos, but after hatching, along with hCG, became the dominant hCG molecule observed. We have reported at the 2PN stage the earliest evidence of hCGβ expression in embryos. There is a suggestion this may be indicative of quality in early embryos, and hCGh seen at the pronuclear stage may suggest triploid abnormality. The dominance of hCG, and hCGh expression, seen after blastocyst hatching may be indicative of potential implantation success. Thus, hCG isoforms have potential roles as biomarkers of embryo viability for embryo/blastocyst transfer.

Does hCG or hCGβ play a role in cancer cell biology?

The role that hCG might play in the oncogenic process in cancer is certainly complex. We know that the expression of hCG and its beta subunit is a widespread phenomenon which has been described in many cancer subtypes. However, hCG's involvement in breast cancer has been antithetical: the detection of ectopically expressed hCG(β) by breast tumors has been employed as a biomarker of malignancy, and hCG has been proposed as a ligand vehicle for toxic drugs, with the aim of targeting the LH/hCG receptor which is reported to be expressed by malignant breast tissue. However, it has also been proposed that hCG is a protective agent against the development of breast cancer, leading some to advocate hCG administration to non-pregnant women as a prophylactic measure against cancer. Nevertheless, suggestions that hCG is involved in the angiogenesis, metastasis and immune escape that are central to cancer progression - are phenomena which clearly apply to breast cancer. Indeed, a tumor vaccine based upon hCG has very recently been shown to protect against mammary tumors in mice. We propose that this apparent paradox is resolved if the free beta subunit of hCG produced by tumors acts as an autocrine anti-apoptotic and angiogenic growth factor, whilst intact heterodimeric hCG, as in pregnancy, is part of developmental signaling that initiates tissue differentiation (including breast ductal tissue development), and hence reduces the population of stem-like cells which are susceptible to oncogenic factors.

Estradiol, progesterone, testosterone profiles in human follicular fluid and cultured granulosa cells from luteinized pre-ovulatory follicles

BACKGROUND

The production of sex steroids by follicular cells is proposed to be influenced by the maturity of the incumbent oocyte. Thus steroid levels may reflect suitability of an oocyte for IVF. We examined follicular fluids and granulosa cell production of steroid from IVF patients in order to test the relationship between steroid levels and fertilization.

METHODS

Follicular fluid and granulosa cells were extracted from 206 follicles of 35 women undergoing controlled ovarian stimulation. Follicular fluid was assayed for estradiol, progesterone and testosterone. Granulosa cells were cultured from individual follicles and their culture media assayed for production of these hormones after 24 hrs in vitro. Levels of steroids were correlated with follicular diameter, oocyte recovery and subsequent fertilization.

RESULTS

Follicular fluid levels of progesterone were 6100 times higher than that of estradiol, and 16,900 times higher that of testosterone. Despite the size of follicle triggered after controlled luteinization, the levels of progesterone and testosterone were maintained at relatively constant levels (median 98.1 micromoles/L for progesterone, and 5.8 nanomoles/L for testosterone). However, estradiol levels were slightly lower in the larger follicles (follicular diameter 10-15 mm, median 25.3 nanomoles/L; follicles > = 15 mm, median 15.1 nanomoles/L; linear correlation r = -0.47, p < 0.0001). With respect to oocyte recovery, no steroid showed a significant association in follicular fluid levels. Similarly no difference in follicular fluid steroid levels was found for those oocytes that did or did not fertilize. Significant quantities of progesterone were produced by the granulosa cells but production was constant regardless of the size of follicle from which the cells originated. Estradiol levels were only detectable in 10 of 121 cultures examined, and testosterone in none. Interestingly, when an oocyte was present follicular estradiol levels correlated with progesterone levels. However, when absent, follicular estradiol levels correlated with testosterone levels but not with progesterone.

CONCLUSIONS

The principle steroid product of luteinized pre-ovulatory granulosa is progesterone, a differentiation triggered by the gonadotropin surge. However, absolute steroid levels are associated with follicular size, not oocyte maturation/ability to fertilize.

High follicular fluid adenosine levels may be pivotal in the metabolism and recycling of adenosine nucleotides in the human follicle

This study investigated the biochemical relationship between human follicular/oocyte maturity and the levels of follicular fluid purines. Intrafollicular levels of purine metabolites and creatinine are associated with oocyte presence, and the presence of such high levels of adenosine indicates a privileged site with no adenosine deaminase activity. Subgrouping according to oocyte recovery and fertilization revealed differences in correlation between the purine metabolites: Only where an oocyte was recovered and subsequently fertilized did follicular fluid adenosine, adenine, and hypoxanthine levels correlate with each other. Significantly, purines' correlation with levels of the terminal degradation product, uric acid, could only be seen in failed fertilization samples. Given the established metabolic pathways for adenosine triphosphate/adenosine diphosphate/adenosine monophosphate degradation, the results indicate maximization of 2 purine salvage pathways (from adenine and hypoxanthine) that pivot on the presence of high adenosine levels. Such optimized recovery may be necessary to build a store of salvaged adenosine phosphate for oocyte survival.

Bony metastases from breast cancer - a study of foetal antigen 2 as a blood tumour marker

Background

Foetal antigen 2 (FA-2), first isolated in the amniotic fluid, was shown to be the circulating form of the aminopropeptide of the alpha 1 chain of procollagen type I. Serum concentrations of FA-2 appeared to be elevated in a number of disorders of bone metabolism. This paper is the first report of its role as a marker of bone metabolism in metastatic breast cancer.

Methods

Serum FA-2 concentrations were measured by radioimmunoassay in 153 women with different stages of breast cancer and in 34 normal controls.

Results

Serum FA-2 was significantly elevated in women with bony metastases (p < 0.015). Its levels were not significantly different among women with non-bony metastases, with non-metastatic disease, as well as among normal controls.

Conclusions

FA-2 is a promising blood marker of bone metabolism. Further studies to delineate its role in the diagnosis and management of bony metastases from breast cancer are required.

Capillary electrophoresis of human follicular fluid

Some of the major serum proteins that are also found in follicular fluid, including transferrin, alpha-macroglobulin and albumin, are thought to play a role in oocyte maturation. This study set out to identify proteins in human follicular fluid by capillary zone electrophoresis and to investigate their relationship to follicular/oocyte maturity and fertility outcome. 176 individual follicular fluid samples, from 30 women undertaking in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), were run using an optimized capillary zone electrophoresis method that gave a good separation of sixteen peaks in most samples. Nine of the peaks were identified and quantified but seven remain unknown and require further proteomic identification. Of the identified protein peaks, levels of each were corrected for follicular volume and total content calculated. No significant difference in protein levels was found with regard to oocyte recovery and fertilization. Protein concentrations tended to decrease as the follicular sphere increased whilst total content in follicular fluid increased in proportion to size. This is consistent with simple transudation across a sphere surface area which does not increase in proportion to the follicular fluid. This is not true of the concentration and content pattern of other proteins/biomolecules which are produced by follicular cells locally. In conclusion, neither concentration nor absolute levels of nine major proteins identified in follicular fluids correlated with oocyte presence and fertility outcome. Future work to remove more concentrated proteins (e.g. albumin) would enhance separation of smaller peaks and identification of the unknown molecules.

Clinical and endocrinological changes after electro-acupuncture treatment in patients with osteoarthritis of the knee

Neurobiological mechanisms invoking the release of endogenous opioids and depression of stress hormone release are believed to be the basis of acupuncture analgesia. This study compared plasma beta-endorphin and cortisol levels with self assessment scores of intensity of pain, before and after 10 days of electro-acupuncture treatment in patients suffering from chronic pain as a result of osteoarthritis knees. Forty patients of either sex over 40 years with primary osteoarthritis knee were recruited into a single-blinded, sham-controlled study. For electro-acupuncture group the points were selected according to the Traditional Chinese Medicine Meridian Theory. In the sham group needles were inserted at random points away from true acupoints and no current was passed. Both groups were treated for 10 days with one session every day lasting for 20-25min. Pre- and post-treatment Western Ontario and McMaster Universities (WOMAC) index of osteoarthritis knee and Visual Analogue Scale (VAS) for pain were recorded and blood samples were taken for the measurement of plasma cortisol and beta-endorphin levels. Following electro-acupuncture treatment there was a significant improvement in WOMAC index and VAS (p=0.001), a significant rise in plasma beta-endorphin (p=0.001), and a significant fall in plasma cortisol (p=0.016). In conclusion electro-acupuncture resulted in an improvement in pain, stiffness and disability. Of clinical importance is that an improvement in objective measures of pain and stress/pain associated biomarkers was shown above that of a sham treatment; hence demonstrating acupuncture associated physiological changes beyond that of the placebo effects.

hCG beta expression by cervical squamous carcinoma--in vivo histological association with tumour invasion and apoptosis

AIMS

To investigate the correlation of beta-subunit of human chorionic gonadotrophin (hCG beta) expression by cervical carcinomas with measures of tumour apoptosis.

METHODS AND RESULTS

Eighty-nine cervical carcinoma patients' samples were subject to hCG beta immunohistochemistry and scored with respect to intensity of immunopositivity and percentage of positive cells. Apoptosis was evaluated by three independent parameters: morphological characteristics [haematoxylin and eosin (H&E)], terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) and poly (ADP-ribose) polymerase (PARP) immunopositivity. Of the 12 adenocarcinomas, only one (8%) was hCG beta+. However, 87% (61/70) of the squamous cell and 100% (7/7) of adenosquamous cell carcinomas were hCG beta+. hCG beta reactivity and intensity was predominantly confined to peripheral tumour cells at the stromal-epithelial interface. Correlation analysis showed that H&E and PARP apoptotic immunopositivity negatively correlated with hCG beta expression (P < 0.001 and P = 0.028 respectively), whereas TUNEL did not (P = 0.12). However, immunopositivity for apoptotic cells by TUNEL was significantly less in tumours where hCG beta expression was greater (scoring >or= 6) and vice versa. hCG beta immunopositivity was also observed in newly formed blood vessels, as well as tumour cells within lymphatic vessels. When tumour vascularization was taken into account, samples with noted vascularization positively correlated with hCG beta scoring.

CONCLUSIONS

hCG beta expression correlates with reduced tumour cell apoptosis and may be involved in tumour vascularization and dissemination.

Human granulosa-lutein cell in vitro production of progesterone, inhibin A, inhibin B, and activin A are dependent on follicular size and not the presence of the oocyte

OBJECTIVE

To investigate inhibin A, inhibin B, activin A, and P production by cultured granulosa cells (GCs) and what relationship this hormone production has to fertility.

DESIGN

Luteinized GCs from individual follicles were cultured, and inhibin A, inhibin B, activin A, and P production were measured by ELISA at 24 and 72 hours.

SETTING

Research laboratory and university hospital.

PATIENT(S)

Fifteen women who undertook an IVF-ICSI program, yielding 58 follicles.

INTERVENTION(S)

Individual follicular aspiration and preparation of GCs for culture.

MAIN OUTCOME MEASURE(S)

Inhibin A, inhibin B, activin A, and P production; oocyte retrieval; and fertility outcome.

RESULT(S)

Inhibin A, inhibin B, and P continued to be secreted by GCs in vitro, and activin A levels were detected only marginally in 56% of cultures. The rate of production also was dependent on the size of follicle from which the GCs originated but not on oocyte presence or ability to fertilize. Granulosa cell stimulation with hCG had no effect on inhibin A but increased P and decreased inhibin B production.

CONCLUSION(S)

A marked effect of luteal differentiation appears to be the inhibition of inhibin B production in response to hCG stimulation. Luteinized GC function, with respect to inhibins, activin A, and P production, was not influenced by the presence or absence of an oocyte and did not correlate with fertility outcome. However, follicle size did influence rates of local hormone production.

Designing a new generation of anti-hCG vaccines for cancer therapy

The heterodimeric 'pregnancy-specific' hormone human chorionic gonadotropin (hCG) has been used as the basis for a contraceptive vaccine. More recently, the observation that hCG, particularly in the form of the beta-chain expressed in the absence of alpha-chain, is aberrantly expressed in a number of different tumors has opened up a second potential application for such vaccines. Drawbacks of the currently available vaccines are that they are either relatively weakly immunogenic or that they induce antibodies that cross-react with human leuteinizing hormone (hLH). We have explored the possibility of creating mutated versions of the hCG beta-chain with improved immunologic properties.

Ectopic hCGbeta expression by epithelial cancer: malignant behaviour, metastasis and inhibition of tumor cell apoptosis

Ectopic expression of the beta-subunit of human chorionic gonadotropin (hCG) is now a recognized phenomenon in 20-40% of all common epithelial carcinoma arising from mucosal epithelia such as bladder, cervix, lung and naso-pharynx. Recent studies have shown that it acts as an autocrine growth factor by inhibiting apoptosis. Structural homology and in vitro studies suggest that it may achieve this by inhibition of the transforming growth factor beta (TGFbeta) receptor complex. Such a molecular mechanism would go some way to explaining ectopic hCGbeta's association with poor prognosis and tumors that will rapidly progress to metastasis.

An introduction to mass spectrometry based proteomics-detection and characterization of gonadotropins and related molecules

This review introduces fundamental aspects of mass spectrometry (MS) based proteomics and illustrates how MS is an effective tool for the analysis of glycoprotein hormones. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and electrospray ionization (ESI) MS are complementary approaches that have been applied for the analysis of gonadotropins, e.g. to characterize differences in the oligosaccharide distribution of commercial human chorionic gonadotropin preparations, for isolated nicked beta-subunit, and identification of a metabolite of placental transforming growth factor in pharmaceutical hCG preparations. Immunoaffinity trapping and concentration of digested sample extract prior to MS analysis confers analytical sensitivity akin to immunoassay. A desirable objective would be to develop for clinical purposes a rapid procedure for MS detection and characterization of gonadotropins. Refinement of on-target immobilization and digestion for subsequent ionization by MALDI may eventually help to provide this capability. The advent of hybrid mass spectrometers will further advance the characterization of these complex molecules.

Follicular fluid levels of inhibin A, inhibin B, and activin A levels reflect changes in follicle size but are not independent markers of the oocyte's ability to fertilize

OBJECTIVE

To investigate the biochemical relationship between follicular/oocyte maturity and follicular inhibins and activin levels.

DESIGN

Prospective study.

SETTING

Research laboratory in university hospital.

PATIENT(S)

Thirty-five women undertook IVF/ICSI program.

INTERVENTION(S)

Individual follicular fluid aspirations, oocyte isolation, follicular fluid storage.

MAIN OUTCOME MEASURE(S)

Inhibin A, inhibin B, and activin A concentrations, oocyte retrieval, and fertility outcome.

RESULT(S)

Inhibin A, inhibin B, and activin A concentrations varied from 7.9 to 436 ng/mL, 9.7 to 786 ng/mL, and 1.7 to 267.9 ng/mL, respectively. There was no change of inhibin A concentrations, whereas inhibin B and activin A concentrations dropped dramatically as the follicles enlarged. Total follicular content of inhibin A and activin A increased, and inhibin B remained constant. Both inhibin A and inhibin B levels were significantly higher in those follicles from which an oocyte could be recovered, but they did not differ with respect to subsequent oocyte fertilization.

CONCLUSION(S)

Inhibin A is actively produced throughout follicular growth to retain a set concentration. In contrast, inhibin B appears not to be actively produced, and the concentration drops as follicles enlarge. Activin A concentrations also decrease, but there is some extra synthesis. Higher levels of inhibin A and B are associated with oocyte presence but not with fertilization rates.

Serum Amino-Terminal Propeptide of Type 1 Procollagen (P1NP) in Prostate Cancer: A Potential Predictor of Bone Metastases and Prognosticator for Disease Progression and Survival

INTRODUCTION

To determine if amino-terminal propeptide of type 1 procollagen (P1NP) is reliable as a predictor of prostate cancer bone metastases and assess its value as a prognostic indicator of disease progression and survival.

MATERIALS AND METHODS

A cohort of patients with prostate cancer between January 1999 and July 2001 were recruited. Prostate-specific antigen (PSA) and P1NP levels were measured. Two years following completion of recruitment, patient notes were reviewed for symptoms of bone metastases and survival.

RESULTS

24 negative and 12 equivocal or positive bone scans were reported for 36 recruited patients. Mean PSA values for patients with negative, equivocal and positive scans were 18.3, 24.9 and 122.5 ng/ml while mean P1NP for the same groups were 38.2, 73.4 and 119.9 ng/ml. For patients with equivocal and positive scan, mean P1NP with and without bone symptoms were 111.5 and 65.7 ng/ml while for surviving and dead patients the values were 63.9 and 120.8 ng/ml, respectively.

CONCLUSIONS

Though this study involved a small number of patients, it demonstrates P1NP's potential as a predictor of bone metastases and a prognosticator for disease progression and survival.

Detection of Human Chorionic Gonadotrophin-β in Serum or Urine of Prostate Cancer Patients Is of No Clinical Significance

The aim of this study was to prospectively evaluate the potential role of elevated urinary/serum human chorionic gonadotrophin-beta (hCGbeta) in prostate cancer prognosis. 104 patients with newly diagnosed prostate cancers were included; 68 patients had organ-confined, 18 had locally advanced and 18 had metastatic disease. A control group consisted of 115 patients presenting with benign prostatic disease. Serum and urinary total hCGbeta was measured prior to treatment and serum PSA was measured at diagnosis. The patients were treated along conventional lines and progression-free survival was assessed. Four patients had elevated serum and 10 had elevated urinary, total hCGbeta. There were no significant correlations between serum/urinary levels of hCGbeta and tumour stage, Gleason score or PSA. In contrast, serum PSA had significant linear correlations with both clinical tumour stage and Gleason score (p = 0.0001). At a median follow-up of 36 months, 22 (21.2%) patients had died while 17 (16.3%) others had progressed. Kaplan-Meier plots and log-rank test revealed no significant difference in progression-free survival between patients with elevated or normal levels of serum and/or urinary total hCGbeta. Clinical tumour stage, grade and PSA were statistically significant prognostic variables. Immunoassay measurement of serum or urinary hCGbeta has no significant role in the clinical management of prostate cancer.

Identification of placental transforming growth factor-beta and bikunin metabolites as contaminants of pharmaceutical human chorionic gonadotrophin preparations by proteomic techniques

A contaminant protein complex found in pharmaceutical urinary human chorionic gonadotrophin preparations is reported to have anti-human immunodeficiency virus-associated Kaposi's sarcoma activity. The aim of this study was to isolate and characterize this protein complex by proteomic approaches. Size exclusion chromatography was used in the isolation of these human chorionic gonadotrophin-associated fragments. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the presence of a protein complex that dissociated into two protein bands under reducing conditions. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of this complex showed three polypeptides at approximately 6.2, 11.4, and 15.8 kDa. Peptide mass mapping and N-terminal amino acid sequencing identified two polypeptides as metabolites of placental transforming growth factor-beta (11.4 kDa) and bikunin (15.8 kDa). Subsequent matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of the anti-human immunodeficiency virus-associated Kaposi's sarcoma active preparations CG-10 (Sigma), Pregnyl (Organon), and Profasi (Serono) revealed the presence of metabolites of placental transforming growth factor-beta in all three; no other non-human chorionic gonadotrophin-related protein species were observed in these preparations. Our findings present evidence that urinary human chorionic gonadotrophin preparations are contaminated with metabolites of placental transforming growth factor-beta, which may have transforming growth factor-beta agonist actions, and metabolites of bikunin, which is a protease inhibitor. In combination these molecules may be responsible for the anti-human immunodeficiency virus-associated Kaposi's sarcoma activity demonstrated for these urinary human chorionic gonadotrophin preparations.

Characteristics of populations of granulosa cells from individual follicles in women undergoing ‘coasting’ during controlled ovarian stimulation (COS) for IVF

BACKGROUND

The aim of this study was to evaluate the functional characteristics of granulosa cell populations of individual follicles of women undergoing controlled ovarian stimulation (COS) for IVF/ICSI in whom gonadotrophin had been withheld ('coasted') for the prevention of OHSS.

METHODS

Follicular fluid and granulosa cells were isolated from 224 individual follicles in 41 women who had been coasted and from 257 individual follicles in 50 women who had a 'normal' response to COS. Cells were cultured at 10,000 cells per well, to evaluate progesterone secretion. Follicular fluid was assayed for progesterone and estradiol (E2).

RESULTS

No significant differences were observed between the two groups with respect to granulosa cell number or follicular fluid progesterone and E2 and follicle size, the retrieval of an oocyte and the subsequent fertilization of the oocyte. However, the granulosa cells derived from the coasted group showed a higher rate of progesterone secretion per cell at 72 h which was sustained for longer. Differences were also seen at 72 and 120 h of culture with a loss of correlation between progesterone secretion and follicle diameter in the coasted group.

CONCLUSIONS

Our findings suggest that coasting has an effect on the functional capacity of the granulosa cells and the duration of their function. It is likely that in women at risk of OHSS who are not coasted, the granulosa cells have the capacity to produce significantly more chemical mediators per cell and for a more prolonged period of time.

The free monomeric beta subunit of human chorionic gonadotrophin (hCG beta) and the recently identified homodimeric beta-beta subunit (hCG beta beta) both have autocrine growth effects

The ectopic production of free hCG beta is a common phenomenon in epithelial tumours, a phenomenon originally believed to have no biological significance. However, it is now apparent that hCG beta may significantly effect tumour development by increasing cell populations through inhibition of apoptosis. The recently identified hCG beta beta homodimer, with topological similarities to cystine knot growth factors, has been suggested to be the responsible mediator of these novel tumourigenic responses. In this study we isolated hCG beta monomer from hCG beta beta homodimer using size exclusion chromatography and confirmed the separation by Western blotting. Using a tetrazolium bromide incorporation cell number quantification assay (MTT), we measured the growth effects of separated hCG beta fractions corresponding to monomeric (hCG beta) and dimeric (hCG beta beta) forms on the hCG beta responding cell line T24. Maximal increases in cell number corresponded to the elution peak of dimeric and monomeric hCG beta. In conclusion, it would appear that the recently observed hCG beta beta homodimer is no more bioactive than its monomeric counterpart, in stimulating bladder cancer cell growth. This strengthens the proposition that hCG beta may exert its antiapoptotic effects by antagonistic inhibition of other cystine knot growth factor receptors and not by a specific receptor-mediated homodimeric interaction as seen for its topological counterparts TGF, PDGF-B and NGF.

Reduction of bladder cancer cell growth in response to hCGbeta CTP37 vaccinated mouse serum

The free beta-subunit of human chorionic gonadotrophin (hCGbeta) is well established as an ectopic product of epithelial tumors. Originally explained as an epi-phenomenon, hCGbeta production by many types of carcinoma is increasingly regarded as a significant tumor event. Studies in bladder cancer have shown that hCGbeta production, while not diagnostic, is a very good indicator for poor prognosis through correlations with resistance to radiotherapy and rapid metastasis. These clinical findings led to in vitro studies that have shown a direct response to hCGbeta by bladder carcinoma cell lines. This response is linked by inhibition of apoptosis to an increase in cell population. More recently, studies on hCGbeta as a marker for poor prognosis in other epithelial cancers now suggest that this phenomenon may not be restricted to bladder carcinoma. Thus, ectopic hCGbeta represents an ideal target for immunodepletive therapy. Antisera were generated from mice vaccinated with full-length hCGbeta carboxy terminal peptide (CTP37) and a truncated region comprising 24 of the amino acids of the CTP (CTP24), expressed on the surface of cowpea mosaic virus (CPMV). The effect of the resultant murine antiseras on bladder carcinoma cell growth in vitro was investigated. When CTP37 antisera, at dilutions of 1:50 and 1:100, were incubated with two hCGbeta-producing cell lines, SCaBER and RT112, significant reductions in cell number, up to 43%, were observed. In the bladder cancer cell line T24, which does not produce hCGbeta, CTP37 antisera had no growth effects. CTP24 antiserum, like control sera from mice immunized with wild-type CPMV, had no effects on the in vitro growth of any cell lines. This implies that full-length CTP37, but not CTP24, is involved in the oncogenic inhibition of apoptosis by hCGbeta. hCGbeta CTP37 vaccines are available as well-tested antifertility vaccines in the Third World. They have now been tested on cancer patients. This study is the only in vitro evidence that such a vaccine would have beneficial antitumor effects via immunodepletion mechanisms. We propose that vaccines such as this could be used as an adjuvant therapy in the treatment of hCGbeta-producing bladder cancers.

The effects of 'coasting' on follicular fluid concentrations of vascular endothelial growth factor in women at risk of developing ovarian hyperstimulation syndrome

BACKGROUND

The aim of this study was to assess the effect of withholding gonadotrophins (coasting) during controlled ovarian stimulation (COS) on individual follicle concentrations of follicular fluid vascular endothelial growth factor (VEGF) in women at high risk of developing ovarian hyperstimulation syndrome (OHSS).

METHODS

Twenty-two women who had been coasted and 26 optimally responding women (control group) undergoing COS for IVF were studied. At the time of oocyte retrieval, the follicular fluid from four to six individual follicles of different sizes was collected for VEGF analysis.

RESULTS

A total of 118 follicles was analysed in the coasted group and 137 in the control group. A negative correlation was observed between the follicle size and VEGF concentration (r = -0.18, P = 0.03) in the control group, which was not seen in the coasted group. Similarly, the correlation between oestradiol (E(2)) and VEGF (r = 0.4, P < 0.0001) observed in the control group was not apparent in the coasted group. Significantly lower concentrations of VEGF were seen in the follicular fluid of the coasted patients.

CONCLUSIONS

It is clear that there are differences in follicular fluid VEGF concentrations between the two groups. It is possible that coasting alters the capacity of the granulosa cells to produce VEGF and/or their response to hCG and in this way acts to reduce the severity and incidence of severe OHSS.

Human chorionic gonadotropin isoforms in the diagnosis of ectopic pregnancy

BACKGROUND

Early diagnosis of ectopic pregnancy uses ultrasound with serial measurements of total human chorionic gonadotropin (hCG). The objective of this study was to explore the possibility that an isolated measurement of hCG isoforms/subunits rather than total hCG could be used as a single test for ectopic pregnancy.

METHODS

Total and intact hCG, free hCG beta- and alpha-subunits (hCGbeta and -alpha), and hCG beta-core fragment were measured by RIA and IRMA in the serum and urine of 76 women presenting at outpatient emergency departments with a positive pregnancy test, lower abdominal pain, and/or vaginal bleeding. Final diagnoses were based on outcomes of pregnancies and tissue histology.

RESULTS

Twenty-seven of the 76 women were subsequently diagnosed with viable pregnancies, 37 with spontaneous miscarriage, and 12 with ectopic pregnancy. Concentrations of all forms of hCG were lower in cases of ectopic pregnancy and spontaneous miscarriage than in viable pregnancies. Serum samples gave better results than urine samples. The free hCGbeta isoform (P <0.0001) had 100% sensitivity at a specificity of 79% at a 281 pmol/L (6.5 micro g/L) cutoff. Total hCG (P = 0.005) had comparable ROC characteristics with a 100% sensitivity and 68% specificity at a cutoff value of 1053 pmol/L (375 IU/L). Neither hCGbeta (P = 0.7) nor total hCG (P = 0.4) could distinguish ectopic pregnancies from spontaneous miscarriage.

CONCLUSION

Measurement of serum free hCGbeta at the time of presentation can identify women with a high probability of ectopic pregnancy who may benefit from closer surveillance, reducing the risk of tubal rupture.

Ectopic human chorionic gonadotropin beta secretion by epithelial tumors and human chorionic gonadotropin beta-induced apoptosis in Kaposi's sarcoma: is there a connection?

Since it was first claimed in 1995 that human chorionic gonadotropin (hCG) inhibits HIV-associated Kaposi's sarcoma (KS), focus has been lost on establishing a credible hypothesis to explain a novel action ascribed to hCG, which is, after all, a pregnancy hormone. After 7 years, no real progress has been made, and there remains no consensus as to which component of hCG preparations is responsible for inducing apoptosis of HIV-associated KS. It would certainly seem apparent that many basic experiments on hCG species have been overlooked in the studies that have been published. Furthermore, the much wider literature concerning the association of hCG with promoting oncogenesis has been ignored. This review puts into context the numerous studies on hCG, HIV-associated KS, and oncogenesis.

Identification of post-translational modifications resulting from LHbeta polymorphisms by matrix-assisted laser desorption time-of-flight mass spectrometric analysis of pituitary LHbeta core fragment

Metabolism of the human chorionic gonadotrophin (hCG)- and LHbeta-subunits (hCGbeta, LHbeta) terminates with the urinary excretion of core fragment (hCGbetacf, LHbetacf) molecules that retain antigenic shape and constituent N-linked carbohydrate moieties. We have previously demonstrated the resolved mass spectra of hCGbetacf, from which the carbohydrate moieties present at two N-linked glycosylation sites were identified. LHbetacf was subjected to the same mass spectrometric analysis. As LHbeta shares 82% homology with hCGbeta but possesses only one glycosylation consensus site a simpler spectral fingerprint of LHbetacf glycoforms was expected. LHbetacf was reduced with dithiothreitol and analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Glycoforms were predicted by subtracting the peptide mass from the m/z values of the observed peaks and then sequentially subtracting the masses of the monosaccharide residues of hCGbeta N-linked carbohydrates reported in the literature. The mass spectra of LHbetacf revealed a broad single peak ranging from m/z 8700 to 10 700. Following reduction, this peak was replaced by a set of partially resolved peaks between m/z 4130 and 5205 corresponding to glycosylated forms of the peptide LHbeta6-40. A peak at m/z 4252.2 corresponded to the non-glycosylated peptide LHbeta55-93. Remaining peaks indicated that the pooled sample comprised a wide set of glycoforms, contained LHbetacf with two N-linked carbohydrate moieties and indicated evidence of further glycosylation due to amino acid substitution in polymorphic variants. This is evidence that a single nucleotide polymorphism alters the post-translational modification of a protein and hence its structural phenotype.

Enhanced affinity capture MALDI-TOF MS: orientation of an immunoglobulin G using recombinant protein G

Although immobilization of antigen-specific immunoglobulins onto matrix-assisted laser desorption/ionization (MALDI) targets allows the specific detection and enrichment of an antigen from complex biological fluids, the process of antibody immobilization is not optimal. The principal reason is that the antibody can bind to the template in various orientations, many of which block antigen recognition. An affinity capture MALDI mass spectrometry methodology was developed by covalently immobilizing an Fc receptor (recombinant protein G) onto MALDI gold targets for the purpose of orientating an immunoglobulin G, with the Fab domains pointing away from the target surface. The pregnancy and cancer marker, human chorionic gonadotropin beta core fragment (hCGbetacf), was our chosen test substance. To optimize the methodology, different surface densities of protein G and immunoglobulin were achieved by employing varying concentrations for immobilization. Captured amounts of hCGbetacf were compared using an external standard (cytochrome c). Orientation of immunoglobulin resulted in an approximately 3-fold increase in MALDI signal compared to using randomly immobilized antibody. Higher antibody concentrations resulted in diminished MALDI signals, which were explained by steric hindrance. Purification and enrichment of hCGbetacf was achieved from a test solution containing contaminant peptides and proteins using oriented immunoglobulins on-target.

High concentrations of CA 125 in uterine flushings: influence of cause of infertility and menstrual cycle day

Uterine flushings were obtained under transvaginal ultrasonographic control from 132 women presenting for investigation and treatment of infertility. Levels of CA 125 were measured by radioimmunoassay and results expressed in relation to the total protein concentration of the same flushings. CA 125 was detected in uterine fluid at levels higher than those previously reported in peripheral blood. Uterine fluid CA 125 concentrations varied throughout the menstrual cycle, being highest in the mid-follicular phase (days 6 to 10). Uterine fluid CA 125 concentrations may reflect endometrial secretion of this protein more directly than serum levels. CA 125 concentrations did not vary according to the cause of infertility but further work in larger numbers of women is required.

The analysis of human amniotic fluid using capillary electrophoresis

This study has investigated the composition of amniotic fluid (AF) using capillary electrophoresis (CE). A detailed optimisation investigation was undertaken to obtain the best resolution of the major peaks in amniotic fluid. In the final method, capillary zone electrophoresis (CZE) of AF was performed on a Hewlett Packard3D CE instrument using a fused-silica capillary of 44 cm total length (36 cm to the detector) with in internal diameter of 50 microm. The background electrolyte was 20 mM sodium tetraborate containing 0.8 mM EDTA adjusted to pH 9.0. AF was diluted 1 plus 1 with deionised water prior to hydrodynamic injection for 3 s at 50 mbar. The separation was performed at +22.5 kV and resulted in a current of 65 microA. The capillary temperature was 28 degrees C. Using this CZE method, some eight peaks were consistently resolved in AF samples and several other more transient peaks have been separated from AF in less than 10 min. A scheme for the identification of peaks once they had been separated was also developed. Four peaks have been identified as proteins, i.e., gamma-globulin, alpha1-antitrypsin, transferrin and albumin. Surprisingly, one major peak was shown to be the purine catabolite, xanthine.

Regulation of endometrial cancer cell growth by luteinizing hormone (LH) and follicle stimulating hormone (FSH)

Gonadotrophin releasing hormone analogues (GnRHa) have been used to treat recurrent endometrial cancer. However, the mode of action is uncertain. Our previous studies showed no direct effect of GnRHa on endometrial cancer cell growth in vitro. We have now examined the effect of luteinizing hormone (LH) and follicle stimulating hormone (FSH) on endometrial cancer cell growth. The aim was to determine whether suppression of pituitary LH and FSH by GnRHa could explain the tumour regression seen in up to 44% of patients treated with this drug. We show that recombinant human LH and FSH (rhLH and rhFSH) produce a concentration dependent stimulation of the endometrial cancer cell line HEC-1A, in serum-free medium (maximum increase of 62 and 50% respectively relative to untreated controls). This increase is equivalent to that obtained by addition of 10% newborn calf serum. Growth of the Ishikawa cell line in culture increases in the presence of rhLH (maximum increase of 67%) but not with rhFSH. Using RT-PCR, we show that the Ishikawa cell line intermittently expresses receptor mRNA of LH but not of FSH; there is no expression of either mRNA by HEC-1A. Classically, both LH and FSH act via cAMP linked membrane receptors. However, neither rhLH nor rhFSH elicit cAMP production in either of our endometrial cancer cell lines. Thus, although a growth response to LH and FSH can be shown, and some cells express the LH receptor, stimulation appears to be via a pathway separate from that of the classical gonadotrophin receptor.

Determination of the Glycoforms of Human Chorionic Gonadotropin β-Core Fragment by Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Background: Metabolism of human chorionic gonadotropin (hCG) in the serum and kidney yields the terminal urinary product hCG β-core fragment (hCGβcf), comprising two disulfide-linked peptides (β6-β40 and β55-β92) of which one (β6-β40) retains truncated N-linked sugars. Hyperglycosylated hCGβcf may indicate choriocarcinoma or Down syndrome, but the glycosylation profile of hCGβcf has not been thoroughly evaluated.

Methods: hCGβcf, purified from pregnancy urine, was reduced by “on-target” dithiothreitol (DTT) reduction and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass ([M+H]+) of the primary sequence of the glycosylated peptide β6-β40 was subtracted from the m/z values of the discrete peaks observed to give the masses of the carbohydrate moieties. Carbohydrate structure was predicted by sequentially subtracting the masses of the monosaccharide residues corresponding to N-linked carbohydrates of the hCG β-subunit reported in the literature.

Results: Mass spectra of hCGβcf revealed a broad triple peak at m/z 8700–11300. After reduction, the triple peak was replaced by a discrete set of peaks between m/z 4156 and 6354. A peak at m/z 4156.8 corresponded to the nonglycosylated peptide (β55-β92). The remaining nine peaks indicated that urinary hCGβcf comprises a set of glycoforms smaller and larger than the trimannosyl core.

Conclusions: hCGβcf comprises a wider set of glycoforms than reported previously. Peaks of highest mass indicate evidence of hyperglycosylated carbohydrate moieties. The data support previous reports that hCGβcf oligosaccharides lack sialic acid and galactose residues. No indication was found of a β6-β40 peptide that was entirely devoid of carbohydrate.

Determination of the glycoforms of human chorionic gonadotropin beta-core fragment by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

BACKGROUND

Metabolism of human chorionic gonadotropin (hCG) in the serum and kidney yields the terminal urinary product hCG beta-core fragment (hCGbetacf), comprising two disulfide-linked peptides (beta6-beta40 and beta55-beta92) of which one (beta6-beta40) retains truncated N-linked sugars. Hyperglycosylated hCGbetacf may indicate choriocarcinoma or Down syndrome, but the glycosylation profile of hCGbetacf has not been thoroughly evaluated.

METHODS

hCGbetacf, purified from pregnancy urine, was reduced by "on-target" dithiothreitol (DTT) reduction and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass ([M+H](+)) of the primary sequence of the glycosylated peptide beta6-beta40 was subtracted from the m/z values of the discrete peaks observed to give the masses of the carbohydrate moieties. Carbohydrate structure was predicted by sequentially subtracting the masses of the monosaccharide residues corresponding to N-linked carbohydrates of the hCG beta-subunit reported in the literature.

RESULTS

Mass spectra of hCGbetacf revealed a broad triple peak at m/z 8700-11300. After reduction, the triple peak was replaced by a discrete set of peaks between m/z 4156 and 6354. A peak at m/z 4156.8 corresponded to the nonglycosylated peptide (beta55-beta92). The remaining nine peaks indicated that urinary hCGbetacf comprises a set of glycoforms smaller and larger than the trimannosyl core.

CONCLUSIONS

hCGbetacf comprises a wider set of glycoforms than reported previously. Peaks of highest mass indicate evidence of hyperglycosylated carbohydrate moieties. The data support previous reports that hCGbetacf oligosaccharides lack sialic acid and galactose residues. No indication was found of a beta6-beta40 peptide that was entirely devoid of carbohydrate.

The increase in bladder carcinoma cell population induced by the free beta subunit of human chorionic gonadotrophin is a result of an anti-apoptosis effect and not cell proliferation

Ectopic production of free beta human chorionic gonadotrophin (hCGbeta) by bladder carcinoma is well described and occurs in approximately 35% of cases. hCGbeta secreting tumours are more aggressive, radioresistant and have a greater propensity to metastasize. We proposed that the ectopic production of hCGbeta was contributing in an autocrine fashion to the radioresistance and metastatic potential of such secreting tumours. Though we demonstrated that the addition of hCGbeta to the culture media of bladder, cervical and endometrial carcinoma cell lines brought about an increase in cell populations this was not accompanied by a significant increase in the rate of replication. Since a cell population size is a balance of mitosis and mortality, we proposed that hCGbeta was inhibiting apoptosis. Here we have demonstrated that following incubation with recombinant hCGbeta, bladder carcinoma cells refrain from undergoing apoptosis. Quantitation of apoptotic bodies was carried out by immunoassay and corrected to cell number as determined by MTT assay. In each cell line, addition of hCGbeta reduced the number of apoptotic bodies dose-dependently, indicating a diminished apoptotic rate. Furthermore, TGFbeta1-induced apoptosis could be dose-dependently inhibited by co-incubation with hCGbeta. We propose, therefore, that such a decline in apoptosis may account for the cell population increase previously reported. It may also explain the radioresistance and aggressive nature of hCGbeta-secreting tumours and the poor prognosis associated therein.