P–059 Association between seminal levels of Fe and semen quality

Study question

The detection of metals in semen offers a new field in the study of male infertility.

Summary answer

Normozoospermia is associated with higher amounts of Fe. In males with pathological spermiogram, the percentage of men with Fe in semen was lower than expected.

What is known already

Increased levels of Fe in human semen appear to have a significant correlation with male fertility, suggesting that Fe in human seminal plasma has an important factor in male reproductive function. Fe acts as an antioxidant being a co-factor of catalasa, which protects sperm. On the other hand, elevated Fe levels are associated with sperm damage and continues to increase the lipid peroxidation that will affect the plasma membrane and the sperm motility. Most authors associate Fe with sperm motility and higher estimated fertility potential, based on standard semen parameters in fertile men, which are associated with lower levels of Fe.

Study design, size, duration

A prospective study was carried out in 102 men in a Reproduction unit in Tenerife, from February to April 2018 as a part on an epidemiologic study of environmental contaminants and male reproduction. The participant were categorized into two groups, according to the results of semen analysis following the World Health Organization guidelines: the pathological and the normal semen group that constituted the control group. The metal was determined in semen samples.

Participants/materials, setting, methods

Semen quality and levels of Fe were measured in seminal plasma on a total of 102 men attended successively, for the initial infertility evaluation, The collected samples were used for both semen analysis following the World Health Organization (WHO) guidelines and metal detection and carried out using a Makler® counting chamber (Irvine Scientific, CA) and for metals, were determined by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) in semen samples.

Main results and the role of chance

The percentage of males with the presence of Fe was 97.1% and the average level were 0.6283 mg/Kg. When analyzing the relationship between the spermiogram parameters with the levels of Fe in the semen, significant differences were found. All men with a normal sperm analysis presented Fe in semen, but among men diagnosed with altered spermiogram, the percentage of men with Fe in semen (92.7%) was lower than expected (97%) (χ2 128 1 =4.59; p = 0.032). As for the concentration of Fe in spermiogram in the first quartile (25% lower), measuring 0.33 mg/Kg, more pathological samples were found than expected (X2 133 2 =6.921; p = 0.031) having a higher probability of being more pathological (52% vs 31.4%). On the other hand, men with pathological sperm concentration, have higher levels of Fe, in the fourth quartile (0.61 mg/kg), with more frequency than expected (90.6% vs 97%) (χ2 136 1 =6.48; p = 0.011). The association between BMI and the presence of Fe was statistically significant. In obese males (BMI ≥30.0 kg/m2), the percentage of men with Fe in semen (80%) was lower than expected (97%) (χ2 42 2 =11.302; p = 0.001).

Limitations, reasons for caution

The limitation of this study was the volume of semen that could be obtained for metal detection, only 0.8 mL. because the collected samples were used for both semen analysis and metal detection.

Wider implications of the findings: The determination of metals in semen opens a new field in the study of male infertility and many cases of unknown infertility could be due to metal presence or absence in semen, with the option of performing treatments.

Trial registration number

Not applicable

Relationships between polychlorinated biphenyls in molluscs, hydrological characteristics and human pressures, within Basque estuaries (northern Spain)

Interannual variability of polychlorinated biphenyls (PCBs), measured in the soft tissues of Mytilus galloprovincialis mussels and Crassostrea gigas oysters, collected from estuarine waters within the Basque Country (Bay of Biscay), are investigated. Samples were collected in the autumn, between 2002 and 2011. Sites located within the ports of Bilbao and Pasaia showed the highest PCBs concentrations in molluscs; the lowest were observed in the mouth of the Oka estuary, an area of low population and industrial activity. Congener profiles of PCBs in the tissues of molluscs reveal the predominance of hexachlorobiphenyls (CB153 and CB138). In addition, redundancy analysis has shown that residence time, river flow and a 'pressure index' explain 57% of the variability in the PCB congener concentrations (the higher the values of these variables, the higher the concentration). Finally, Σ7PCB median concentrations in molluscs and sediments, collected from nearby sampling sites, were found to be moderately correlated (r(2)=0.513, p<0.01).

Biomonitoring of metals under the water framework directive: detecting temporal trends and abrupt changes, in relation to the removal of pollution sources

Temporal trends in metal concentrations, i.e. Ag, Cd, Cu, Cr, Hg, Ni, Pb and Zn, measured in soft tissues of Mytilus galloprovincialis mussels and Crassostrea gigas oysters collected from estuarine waters within the Basque Country (Bay of Biscay), have been investigated to determine if actions undertaken have improved the environmental quality of rivers and estuaries. Data compiled between 1990 and 2010 have been analysed statistically, applying the Mann-Kendall and the Mann-Whitney-Wilcoxon tests. Moreover, in those cases with significant trends, the Kolmogorov-Zurbenko Adaptive (KZA) filter was applied to detect abrupt changes. Results showed significant decreasing trends for some metals, i.e. Ni, Cu, Pb and Zn, and differences between medians. Trend lines showed abrupt changes occurring between 1998 and 2002. Therefore, observed downward trends were related to increased wastewater treatment and diversions of discharges to ocean, implemented mainly during 2000-2002.

Dissolved metal background levels in marine waters, for the assessment of the physico-chemical status, within the European Water Framework Directive

The European Water Framework Directive (WFD) has, as its ultimate aim, a reduction in the concentrations of hazardous substances in the marine environment, i.e. 'background' values. Hence, the determination of natural background levels of heavy metals, to distinguish between natural element concentrations and anthropogenically-influenced concentrations, is highly relevant. Some studies have shown the convenience in the derivation of local background levels, especially if they are necessary for environmental assessment. Nevertheless, although such studies exist for sediments, there are only a few previous investigations on metal background values in sea water. Likewise, there is not any standard procedure to determine such levels in waters, nor general agreement on the statistical methodologies to be applied. In this contribution, background levels of heavy metals (As, Cu, Mn, Ni, Pb and Zn), in estuarine and coastal waters within the Basque Country (northern Spain), according to ranges in salinity, are estimated using statistical tools. Ni and Pb have been considered elsewhere (2455/2001/EC) as priority substances under the WFD. Hence, this approach can assist further in the determination of water reference conditions, to assess chemical and physico-chemical status in other European countries; this, affects, ultimately, the ecological status, as defined within the WFD.

Maximum likelihood mixture estimation to determine metal background values in estuarine and coastal sediments within the European Water Framework Directive

Some of the recently derived European Directives, such as the Water Framework and Marine Strategy, have, as ultimate aims, to achieve concentrations of hazardous substances in the marine environment near background values. Hence, the determination of natural background levels, in marine sediments, is highly relevant. The present study proposes the use of the maximum likelihood mixture estimation (MLME) to determine regional background levels and upper threshold of metal concentration, with the Basque Country as a case study (with a data set of 575 samples, from estuarine and littoral areas, including both intertidal and subtidal sediments). The heuristic procedure is applied with unimodal data distributions (Cd, Cr, Fe and Ni) and the mixture density estimations, based upon maximum likelihood, are carried out with polypopulational data distributions (As, Cu, Mn, Hg, Pb and Zn). The upper limits of the distribution are proposed, as the limits between 'High Status' and 'Good Status' (according to the Water Framework Directive terminology). The regional upper limits were 0.45 microg g(-1) for Cd, 71 microg g(-1) for Cr, 53,542 microg g(-1) for Fe, 57 microg g(-1) for Ni, 24 microg g(-1) for As, 64 microg g(-1) for Cu, 447 microg g(-1) for Mn, 0.27 microg g(-1) for Hg, 66 microg g(-1) for Pb, and 248 microg g(-1) for Zn. The results from this study can assist further in the determination of sediment reference conditions, to assess chemical status, within the above-mentioned directives; likewise, it will be studied as a useful methodology in determining regional metal backgrounds in other European countries.

Amplification of a 500-base-pair fragment from cultured isolates of Mycobacterium bovis

The presence of a 500-bp fragment which amplifies a region from the genome of Mycobacterium bovis (J. G. Rodriguez, G. A. Meija, P. Del Portillo, M. E. Patarroyo, and L. A. Murillo, Microbiology 141:2131-2138, 1995) was evaluated by carrying out PCR on 121 M. bovis isolates. The M. bovis strains, previously characterized by culture and biochemical tests, were isolated from cattle in different regions of Argentina, Mexico, and Colombia. Four additional strains isolated from sea lions that belong to the M. tuberculosis complex were also included in the study. All of the isolates tested were PCR positive, rendering the expected 500-bp band and giving a correlation of 100% with previous microbiological characterization. Southern blot analysis revealed a common band of 1, 800 bp and a polymorphic high-molecular-mass hybridization pattern. The results show that this assay may be useful for diagnosis and identification of M. bovis in cattle.

Adolescent student's compliance with testicular self examination

To determine what adolescents students know or feel about testicular cancer, (TC) and the testicular self examination, (TSE), technique, 127 males students (mean age 16.14 years) were given a 21 item questionnaire. The role of the primary physician and the role of written and visual educational material were assessed for effectiveness in increasing the regular performance of monthly testicular self examination by male students at a Health Education Course at Cervantes Public School at Bayamón, P.R. Out of 127 male student, only 2.4%, (n = 3), initially knew about the symptoms of TC. Analysis of the attitude and knowledge questions revealed that respondents were not sure about general concepts in TC and, were not sure that this cancer could be self diagnosed. This study pretends to assess the effects of modeling and guiding practice as components within a comprehensive testicular self examination education program for adolescents male students. Three groups were studied from 10th, 11th, and 12th, grade. The variables investigated were knowledge of testicular cancer, attitudes toward testicular cancer, and frequency of self reported testicular self examination. The participants then received written material plus a physician's lecture on TC and TSE. Upon follow up, 87.5%, (n = 113) of the students reported performing monthly TSE, (P < 0.001), a statistically significant increase in performance. Although 20.3% (n = 26) reported having a physical examination by a physician within the previous 3 months, less than 4.7%, (n = 6) reported being taught TSE by a physician. Physicians need to educate males about testicular cancer and its early detection.

Cell wall proteins in seedling cotyledons of Prosopis chilensis

Four cell wall proteins of cotyledons of Prosopis chilensis seedlings were characterized by PAGE and Western analyses using a polyclonal antibody, generated against soybean seed coat extensin. These proteins had M(r)s of 180,000, 126,000, 107,000 and 63,000, as determined by SDS-PAGE. The proteins exhibited a fluorescent positive reaction with dansylhydrazine suggesting that they are glycoproteins; they did not show peroxidase activity. The cell wall proteins were also characterized by their amino acid composition and by their amino-terminal sequence. These analyses revealed that there are two groups of related cell wall proteins in the cotyledons. The first group comprises the proteins of M(r)s 180,000, 126,000, 107,000 which are rich in glutamic acid/glutamine and aspartic acid/asparagine and they have almost identical NH2-terminal sequences. The second group comprises the M(r) 63,000 protein which is rich in proline, glycine, valine and tyrosine, with an NH2-terminal sequence which was very similar to that of soybean proline-rich proteins.

[Enamel resistance to acid dissolution. Its relation to cariogenic activity]

Relationship existing between enamel resistance (by developed colorimetric technique) and previous experience of caries and with further incidence, at a term of a year, was studied in schoolchildren aged 6, 8, 10 and 12 years. The study comprised 336 children in 1985-1986 period and 385 children in 1985-1987 period. Non significant positive correlation was found between values of colorimetric test and previous experience of caries; but, certainly, positive correlation was found with further incidence on permanent dentition. It is concluded that colorimetric test is useful for the selection of children with a very susceptible enamel, as well as for the prognosis of cariogenic activity valued together with other parameters.