Seminal plasma proteins as modulators of the sperm function and their application in sperm biotechnologies

Seminal plasma (SP) is known to play an important role in mammalian fertilization. However, the variability found in its composition among species, males and even fractions of the same ejaculate has made difficult to completely understand its effect in sperm function. Proteins are one of the major SP components that modulate sperm functionality. During the last years, intensive work has been performed to characterize the role of these proteins. They have been found to influence sperm capacitation, formation of the oviductal sperm reservoir and sperm-oocyte interaction. Sperm biotechnologies, such as sperm cryopreservation and flow cytometric sex-sorting, that involve a substantial dilution of the SP are detrimental to sperm quality. Attempts to improve the outcome of these biotechnologies include the restoration of SP, which has produced contradictory results. To overcome this variability, different research groups have proposed the application of isolated SP proteins. Herein, we will review the current knowledge in the role of the major SP proteins as modulators of sperm functionality. Furthermore, we will discuss the possible applications of the SP proteins in sperm cryopreservation and flow cytometric sex-sorting.

Non-surgical deep intrauterine transfer of superfine open pulled straw (SOPS)-vitrified porcine embryos: evaluation of critical steps of the procedure

Previous trials achieved extremely poor results when using the one-step warming method in a syringe in combination with non-surgical deep intrauterine transfer (NET) of superfine open pulled straw (SOPS)-vitrified embryos. This study aimed to assess the effect of the warming procedure on the in vitro and in vivo development of SOPS-vitrified embryos. The effect of the passage of the vitrified-warmed (VW) embryos through the NET catheter was also evaluated. Groups of 4 to 6 morulae and blastocysts, collected from weaned sows, were SOPS-vitrified in 1 μL of vitrification medium, warmed by the one-step warming method in a dish or in a 1-mL syringe and cultured in vitro for 48 h to evaluate the embryo survival (ES) and hatching rates (HR). Warming in syringe had a deleterious effect (P < 0.05) on the in vitro ES (60.5 ± 10.4%) and HR (39.6 ± 9.5%) of VW embryos in comparison with embryos warmed in a dish (85.4 ± 10.6% and 69.0 ± 8.4%, respectively). This decreased embryonic development was due to the increased time required between the removal of the straws from the liquid nitrogen and the contact of the embryos with the warming medium when the warming was performed in a syringe in comparison with that for the warming in a dish. After verifying that the passage of VW embryos through the NET catheter does not have a damaging effect on their further in vitro development, the negative effect of warming in a syringe was also confirmed after NET. Fifteen fresh and SOPS-vitrified embryos warmed in a syringe or in a dish were transferred to each recipient (n = 28) and recovered 24 h later to assess their developmental progression. All embryos from the syringe group were found to have degenerated at recovery. The in vivo ES and HR from the dish group (80.4 ± 3.4% and 14.2 ± 7.2%, respectively) were lower (P < 0.05) than those from the fresh group (94.0 ± 4.1% and 36.8 ± 7.8%, respectively). Combining the warming in a dish and the NET procedure, 35 VW embryos were transferred to each of 10 gilts. Five recipients farrowed an average of 10.4 ± 0.9 piglets. In conclusion, the method of one-step warming in a syringe has a negative effect on the in vitro and in vivo viability of SOPS-vitrified porcine embryos. In addition, NET of SOPS-vitrified embryos warmed by the one-step method in a dish showed promising reproductive performance of recipients. However, despite the great potential of this technology, further developments are required for large-scale commercial applications.

[Fiber in enteral nutrition: systematic review of the literature]

It has been suggested that adding fibre to enteral nutrition (EN) formulas may achieve a normalization of the gastrointestinal tract's functions by reducing the incidence of diarrhoea and constipation. However, this supposition is based on the demonstrated effect of fibre in natural feeding. There have so far been no firm recommendations on the use, amount or type of fibre that is most advisable in EN.

GOAL

To establish the scientific evidence existing on the benefits gained by adding fibre to EN formulas compared with the use of fibre-free formulas.

MATERIAL AND METHODS

Bibliographical search on PubMed, on the register of Randomized Prospective Trials (RPT) of the Cochrane Library and manual search.

INCLUSION CRITERIA

RPT comparing fibre-free formulas with isocaloric ad isonitrogen formulas containing fibre in total EN. Four independent reviewers revised the references selected. The data were analyzed using the RevMan 4.1 programme from the Cochrane Library.

RESULTS

Of 286 references, 25 fulfilled the inclusion criteria. The data were grouped by population and outcome variable. The addition of fermentable fibre to the EN formulas tends to reduce the incidence of diarrhoea in critically-ill and post-surgery patients (OR = 0.66; 95% CI 0.46-0.95; p = 0.19). The use of formulas with insoluble fibre seems to increase the frequency of depositions and reduce the need for laxatives in immobilized patients receiving long-term EN but the data are insufficient. In people with normal gastrointestinal functions, the frequency of depositions is similar when using formulas with and without fibre (DPM = -0.97; 95% CI -0.12-[-0.02]; p < 0.0001).

CONCLUSION

There is currently insufficient evidence to recommend the systematic use of formulas containing fibre in total EN. However, in critically-ill and post-surgery patients, the use of formulas with fermentable fibre tends to reduce the incidence of diarrhoea. Although information is still lacking. The formulas with insoluble fibre seem to diminish constipation in chronic EN, whereas in other situations where the digestive system is working appropriately, no benefit has been shown. It is necessary to increase the number and quality of these trials in order to be able to establish firm recommendations on the use of EN formulas containing fibre.

IGF-1 and its binding proteins IGFBP-1 and 3 as nutritional markers in prepubertal children

OBJECTIVE

To assess the validity of the use of IGF-1, IGFBP-1 and IGFBP-3 as biochemical markers of nutritional status in prepubertal healthy children.

DESIGN

Cross-sectional survey.

SETTING

Healthy children from the Madrid area.

PARTICIPANTS

Prepubertal children (aged 7-10 years) with a body mass index (BMI) above the 90th percentile (n = 25) and below the 10th percentile (n = 31) were selected from 2,559 included in the CAENPE study (Food Intake and Nutritional Status in Schoolchildren from Madrid).

RESULTS

Overweight children were found to have higher serum levels of IGF-1 (306+/-162.2 vs. 209+/-71.2 ng/ml, p<0.001) and IGFBP-3 (3.3+/-1.0 vs. 2.9+/- 0.5 mg/l, p<0.01) and lower serum levels of IGFBP-1 (4.3+/-3.9 vs. 13.8+/-7.4 microg/l, p<0.01). There was a positive correlation with BMI, for IGF-1 and IGFBP-3, and negative correlation for IGFBP-1. No differences in albumin and transferrin concentrations were observed between both groups of children.

CONCLUSION

IGF-1, IGFBP-1 and IGFBP-3 clearly classify over- and underweight prepubertal children, showing a good correlation with BMI. They can be used as biochemical markers of caloric nutritional status in this population.

[Thyroid disorders associated with interferon treatment in patients with chronic viral hepatitis or multiple sclerosis]

BACKGROUND

Alpha and beta interferon (IFN-alpha and beta) treatment is associated with the synthesis of thyroid autoantibodies and the development of autoimmune thyroid diseases.

METHODS AND RESULTS

We have retrospectively evaluated their effect in patients with chronic viral hepatitis (CH) (n = 118) and multiple esclerosis (ME) (n = 10). Thyroid dysfunction has been detected in 7.4% of patients, and seroconversion in 4.7%.

CONCLUSIONS

Pre-treatment antithyroid antibodies do not predispose to altered thyroid function, after IFN therapy; their presence should not contraindicate IFN treatment.

[Critical analysis of the evolution of commercial preparations for enteral nutrition during 1988-1996]

Enteral nutrition is a form of nutritional support that is continually growing and expanding, and within this area especially the enteral preparations or formulae. The object of the present is to analyze the evolution of the commercially available nutritionally complete enteral preparations between 1988 and 1997, illustrating the variations that have occurred both from the quantitative and form the qualitative points of view. A progressive increase is seen in the absolute number of available enteral formulae, with the increase in both polymeric formulae with dietary fiber, and that of formulae designed for specific diseases being significant (p < 0.05). The standard polymeric formulae and the oligomeric formulae decrease, but not in a significant manner. There is a special discussion or the characteristic and the usefulness of the polymeric formulae with dietary fiber ad the formulae designed especially for specific diseases. The clinical efficacy of most of these special formulae is controversial, with there not being sufficient objective clinical evidence at present that justifies their routine use.

[Description and evaluation of the adequacy of parenteral nutrition in our hospital]

INTRODUCTION

Parenteral nutrition (PN) is a form of nutrition that can be very beneficial, but it does have some indications and complications that should be taken into consideration. With this work we would like to describe the characteristics of our patients with PN, as well as their follow up, and to evaluate the appropriateness of its prescription.

MATERIAL AND METHODS

Retrospective study carried out at a hospital with 415 beds. All patients who received PN during the first six months of 1996 were reviewed. Inadequacy criteria are established and a nutritional assessment was carried out by means of clinical and analytical parameters. Catheter infections were recorded according to specific criteria and the clinical and analytical evolution of the patients was followed.

RESULTS

A total of 83 patients were given parenteral nutrition. The most frequent indication was prolonged fasting after a surgical resection of the digestive apparatus. The most common nutritional status when beginning the PN was severe protein malnutrition (23%). There were 33 cases (39.7%) of PN that was not indicated and/or potentially avoidable. A catheter infection was reported in 7 cases (8.4%).

[Nutritional status of patients with HIV infection. Spontaneous evolution during the hospital stay]

BASICS: Evaluate the nutritional status of HIV positive patients who are admitted to hospital for some acute process, and their evaluation, without nutritional support, during the admission.

METHODS

Prospective study in HIV positive patients. Nutritional evaluation (on admission and on release); (1) anthropometric (weight, size, triceps, fold, circumference of the arm, and muscular circumference of the arm, and (2) biochemical (albumin, cholesterol, triglycerides, lymphocytes, pre-albumin, and transferrin). Statistical study: comparison of the paired means and chi squared test.

RESULTS

60 patients. Mean age 32 +/- 4.8 years, 76% men and 23% women. Staging: AIDS 84.8%, non-AIDS 15.2%. Main reason for admission: Infection (80%). Mean stay: 14 days +/- 9.5. Initial nutritional evaluation: normal: 1.7%, protein malnutrition: 5.3%, caloric malnutrition: 38.5%, mixed malnutrition: 54.3%, 85% of the patients refer weight loss. 21 patients (35%) were followed up. There were no significant differences in the anthropometric nor in the biochemical parameters, except in the levels of pre-albumin and transferrin, which improved (p < 0.001). Nutritional evaluation on release: normal: 9.5%, caloric malnutrition: 66.5%, mixed malnutrition: 23.7%. There were no cases of protein malnutrition.

CONCLUSIONS

The vast majority of the HIV+ patients who are admitted, are malnourished, and after curing the acute process, 90.5% of them remain malnourished. The anthropometric measurements, albumin, cholesterol, and triglycerides do not vary during the hospital admission, despite the treatment and the clinical improvement. The increase of proteins with a short half life is due to controlling the infection, which is why these are not good parameters for the nutritional evaluation in these patients.

[Consumption of sweets and snacks by a population of school children in the Autonomous Community of Madrid. The CAENPE Group]

BACKGROUND

In our society advertising compaigns promote consumption of superfluous foods, such as sweets and snacks, displacing the intake of other basic nutrients. The aim of this study is to assess the intake of these foods by children, their relative contribution to overall macronutrient intake and their effects on health.

SUBJECTS AND METHODS

A dietary assessment was performed on a representative sample of scholar children from the Autonomous Community of Madrid. It reflects food consumption for a 4-days period (3 week-days and 1 weekend day) in 2,698 boys and girls aged 6 to 15 years. The intake is expressed as grams per 1,000 kcal to standardize nutrient consumption in boys and girls. Lipid profile and several markers of nutritional status are also determined.

RESULTS

The consumption of sweets and snacks items per 1,000 kcal is higher in boys than in girls (35.8 +/- 20.0 and 34.2 +/- 19.6 g/1,000 kcal, respectively; p = 0.01) and increases during adolescence (12 and 13 years) in both sexes. Sweets and snacks provide 16.1% of dietary total caloric intake, 7.1% of saturated fatty acids, 10.7% of monounsaturated fatty acids, 10.4% of polyunsaturated fatty acids and 11.3% of cholesterol. Children of ages 6, 7, 8 and 9 years with high calculated LDL-cholesterol levels (> or = 120 mg/dl) consume significative higher amounts of sweet foods than children with low calculated LDL-cholesterol levels (< or = 90 mg/dl).

CONCLUSIONS

Children from the Autonomous Community of Madrid, Spain consume excessive sweets, which could be responsible for a higher prevalence of diseases related to this intake, such as caries, obesity and obesity-related associate diseases.