PubMed Health⌕ Search

Biomedical subjects

A Pousette

Publications and source records attributed to A Pousette.

At least 37 records · Page 2Linked to original sources
PubMed1997

Structure of sperm activating protein.

Serum is used as an additive in the preparation of human spermatozoa for fertilization in vitro, as it is superior to other body fluids in supporting sperm motility. We recently purified the major sperm activating macromolecule present in serum and showed it to be a complex of immunoglobulin and apolipoprotein A-I. This complex, which we named sperm activating protein (SPAP), has now been further characterized using partial proteolysis in combination with different immunological methods. SPAP was shown to interact only with antibodies against immunoglobulin G and more specifically with those against IgG4. The bacterial expression products C23 and ZZ-T (which bind to specific sites on the IgG molecule) bound in similar ways to SPAP as to IgG4 and did not hinder proteolytic cleavage of SPAP, indicating that apolipoprotein A-I is not bound closely to the binding sites of these proteins. Purified F(ab')2 fragment from SPAP was also shown to contain apolipoprotein A-I, and had a higher MW than the corresponding fragment from IgG4. Taken together, the most plausible (and in our view only possible) structure of SPAP shows an apolipoprotein A-I molecule bound in the pocket formed between the Fab arms of an IgG4 molecule. Anti-SPAP antibodies visualized by secondary fluorescein isothiocyanate (FITC)-labelled antibodies were bound to the postacrosomal part of the spermatozoa, indicating that SPAP is specifically bound to this area, and directly interacts with the spermatozoa. Based on these and earlier experiments it is speculated that SPAP acts in the lower part of the female genital tract. The benefit of SPAP should be at its greatest in these regions, and it is also possible that SPAP exerts a selection mechanism, as those spermatozoa affected by SPAP acquire increased motility, which might be important in order to reach the upper part of the female genital tract. Further exploration of the biological role of SPAP may indicate its diagnostic and therapeutic possibilities.

Antibodies↗
PubMed1997

Serum FSH levels in women with polycystic ovary syndrome during ovulation induction using down-regulation and urofollitropin.

OBJECTIVE: To evaluate retrospectively the use of serum FSH levels and to correlate them with follicular growth in a clinical ovulation induction program. METHODS: Twenty women with infertility due to anovulation associated with polycystic ovary syndrome (PCOS) were studied. The patients were down-regulated with a long GnRH agonist protocol and stimulated with purified urofollitropin, using a low-dose step-up regimen. Repeated serum samples were drawn and transvaginal ultrasound scans were-performed. During the exogenous FSH therapy serum FSH levels resulting in continuous follicular growth were analyzed, as well as the rates of ovulation, pregnancy, cancellation and conversion to in vitro fertilization (JVF). RESULTS: Thirty-two out of fifty treatment cycles led to ovulation, resulting in five term pregnancies. Eight cycles were converted to IVF/embryo transfer due to multiple follicular growth. They resulted in two pregnancies. Ten cycles were cancelled because of impaired follicular growth. The serum FSH levels (median 6 IU/I) resulting in continuous growth of the follicles were relatively stable within patients (variation 15%) but varied considerably between patients (45%). The relationship between FSH dose and serum level was different for lean and obese PCOS patients after subcutaneously injected urofollitropin CONCLUSIONS: There seems to be a difference in resorption/metabolism between lean and obese PCOS patients with regard to s.c. injected FSH. The intra-patient coefficient of variation (C.V.) of the serum FSH response level was quite low, as was the C.V. of the FSH dose at the response level. This allowed a more rapid dose adjustment in subsequent cycles. Analysis of serum FSH during induction of ovulation with gonadotropins seems to be of limited value in clinical programs.

Adult↗
PubMed1996

Pharmacokinetics and testosterone suppression of a single dose of polyestradiol phosphate (Estradurin) in prostatic cancer patients.

The pharmacokinetics and endocrine effects of polyestradiol phosphate (PEP; Estradurin) were studied by determination of the concentrations of estradiol (E2), unconjugated (E1) and total estrone (tE1; > or = 85% estrone sulfate), and testosterone in serum from 11 prostatic cancer patients after administration of a single intramuscular injection (320 mg). After injection of PEP, serum concentrations of E2, E1, and tE1 increased during 2-3 weeks. Thereafter serum E2 declined monophasically with a mean half-life of 70 days. The elimination of E1 and tE1 seemed to be governed by the formation of E2. The testosterone concentration decreased inversely to the raising E2 level and reached castration levels within 3 weeks and remained at this level for about 2 weeks, whereafter it increased inversely to the decreasing E2 concentrations.

Aged↗
PubMed1996

Influence of a diet regimen on glucose homeostasis and serum lipid levels of male elite athletes.

Physical training affects carbohydrate metabolism and results in an increased insulin-stimulated glucose disposal. To investigate if carbohydrate and lipid metabolism would be affected by nutritional factors in optimally trained elite athletes, during a 1-year period we studies elite ice-hockey players on two Swedish top-performance teams. Players on one team were subjected to extensive dietary monitoring and intervention, whereas players on the second team continued their ordinary diet. Blood levels of insulin, C-peptide, glucose, hemoglobin A1C (HbA1c), lipids, and lipoproteins were measured repeatedly. Basal insulin levels and insulin resistance (IR) were significantly lower among athletes on both teams compared with a sedentary group, and muscle weight and body mass index were significantly higher. During the course of the study in the intervention group, insulin levels decreased (3.6 +/- 0.3 v 6.2 +/- 0.6 [mean +/- SEM], P <.05) in conjunction with a decreased relative fat energy content, but returned toward baseline levels when relative fat energy content increased. IR decreased in parallel (0.59 +/- 0.05 v l.12 +/- 0.12, P <.05) and followed a similar pattern, reverting toward baseline levels. Also, levels of HbA1c changed during dietary manipulation. No changes in these parameters were observed among the elite players from the team not participating in the diet regimen. In contrast to the parameters for glucose homeostasis, no significant changes were found in serum lipid or lipoprotein levels in either team during the course of the study. The results verify the presence of an improved carbohydrate metabolism in elite athletes. The observed changes in glycemic control and glucose homeostasis as a consequence of dietary modification demonstrate further that nutritional factors may affect carbohydrate metabolism also in well-trained athletes.

Adult↗
PubMed1996

Temporal expression of platelet-derived growth factor (PDGF)-A and its receptor in human preimplantation embryos.

In order to improve assisted fertilization in humans it is important to elucidate the mechanisms of control of growth and development in the early pre-embryo. Increasing evidence shows that growth factors are of importance for such control mechanisms. As platelet-derived growth factor (PDGF) has been shown to enhance growth in a number of tissues, it may also be important in human pre-embryo development. PDGF acts as a dimer (AA, BB or AB) through its receptors: alpha alpha, beta beta and alpha beta. In order to study the role of PDGF and its receptors, we have used reverse transcription-polymerase chain reaction (RT-PCR) to examine the presence of transcripts in human pre-embryos that were surplus from the in-vitro fertilization treatment of infertile couples. Transcripts for PDGF A were present in the oocyte, 8-cell, morula and blastocyst stages but not in the 4-cell stage. Transcripts for PDGF B were not detected at any stage. PDGF receptor (PDGFR)-alpha transcripts were found in the 4-cell, 8-cell and blastocyst stages but not in the oocyte or morula stages. Transcripts for PDGFR-beta were detected from the 8-cell, morula and blastocyst stages but not in the oocyte or 4-cell stages. These results show that mRNA synthesis of both PDGF A and the two receptor subunits alpha and beta takes place from the 8-cell stage onwards, suggesting an autostimulatory pathway as a possible mechanism for growth factors during pre-embryo development.

Blastocyst↗
PubMed1995

[Intramuscular depot estrogens (Estradurin) in treatment of patients with prostate carcinoma. Historical aspects, mechanism of action, results and current clinical status].

More than 50 years ago, orally given estrogen was already used in the treatment of prostate cancer. Due to cardiovascular side-effects with a high morbidity of 25%, this treatment has not become standard. Recent investigations show that parenteral application reduces the risk of cardiovascular side-effects, because it avoids the first passage through the liver with high concentrations of estrogen which normally occur after oral application. Therefore, an increased synthesis of so-called "steroid-sensitive" liver proteins, such as coagulation factors (especially factor VII) can be avoided. This newer parenteral estrogen application shows encouraging results of a cheap and effective hormonal therapy with a low rate of side-effects in patients with prostate cancer.

Antineoplastic Agents, Hormonal↗
PubMed1994

Derivatives of 2-nitrofluorene cause changes of human sperm motility.

The effects on human sperm motility characteristics of 2-nitrofluorene and selected derivatives were studied in vitro, using computer aided sperm analysis (Cellsoft). Substances to be tested were dissolved in acetone and added to separated spermatozoa in culture media to final concentrations of 100 and 1000 microM. Aliquots were removed immediately (< 5 min.) and 24 hr after the addition and tested for sperm motility characteristics. Four of the substances tested; 2,4,7-trinitrofluoren-9-one (2,4,7-tNFO), 2,5-diaminofluorene (2,5-dAF), 7-hydroxy-2-nitrofluorene (7-OH-NF) and 2,7-diaminofluorene (2,7-dAF) showed strong detrimental effects on the sperm motility. Slight detrimental effects were also recorded using 2-nitrofluorene and 2,5-dinitrofluorene (2,5-dNF). Weak stimulatory effects were obtained using 2-acetoamidofluorene (AAF) and 2,7-dinitrofluorene (2,7-dNF). No significant effects were seen with 5-hydroxy-2-nitrofluorene (5-OH-NF), 2-aminofluorene (AF), 2-aminofluoren-9-one (AFO), 2-amino-9-hydroxyfluorene (9-OH-AF) or 9-hydroxy-2-nitrofluorene (9-OH-NF). The mechanism behind this effect is not known but it could be speculated that these lipophilic substances interact with the membranes or the cellular respiration.

Culture Media↗
PubMed1993

Basal concentrations of anabolic and catabolic hormones in relation to endurance exercise after short-term changes in diet.

This study aimed to use a classical model to analyse whether alterations in performance due to short-term changes in diet are reflected in peripheral basal anabolic and catabolic hormone concentrations. Six healthy students (two women and four men) performed a cross-over study including three test situations. The reference test was preceded by each subject's normal unrestricted diet of western type (N). After this, three of the subject's were provided a carbohydrate-rich diet (CHO) for 3 days followed by the second test. Following this test, a carbohydrate deficient, protein/fat rich diet (F) was provided for another 3 days followed by the third test. The remaining three subjects had these diets in reverse order. Basal concentrations of cortisol (C), sex hormone-binding globulin (SHBG), insulin-like growth factor (IGF-I), total-testosterone and non-SHBG-bound-testosterone (NST), the NST:C ratio and an ergometer cycle endurance test with measurements of submaximal as well as measurements of maximal oxygen uptake, heart rate, respiratory exchange ratio (R), free fatty acids (FFA), glycerol and lactate were investigated. All the subjects were involved in athletics for recreation and during the study they performed daily physical exercise according to their normal routine. After the F diet only two of the subjects completed the test. One woman dropped out after 16 min, two men dropped out after 14 min and one after 13 min of cycling. After the CHO diet all six subjects completed the ergometer cycle test. Considering the whole group, there were no significant differences in lactate or glycerol concentrations during the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Separation of human spermatozoa with hyaluronic acid induces, and Percoll inhibits, the acrosome reaction.

The effect on the acrosome reaction of human spermatozoa of two widely used sperm separation media, hyaluronic acid (Sperm Select) and Percoll, was studied. Viable and highly motile fractions of human spermatozoa were separated from seminal plasma using self-migration on a Percoll gradient. After translocation of separated spermatozoa from the Percoll solution to a culture medium, serum, Percoll or hyaluronic acid (Sperm Select) was added to aliquots of the spermatozoa containing culture medium. At increasing time intervals, the influx of 45Ca2+ into spermatozoa was measured and the concentration of viable spermatozoa that had undergone the acrosome reaction was analysed using the triple stain technique. Serum was found to be necessary to support sperm motility and viability. Compared to culture medium with serum only, addition of hyaluronic acid induced influx of 45Ca2+ and the acrosome reaction, whilst Percoll inhibited both of these actions. Hyaluronic acid (Sperm Select) added to spermatozoa separated by a 'swim-up' method induced, and the addition of Percoll inhibited, influx of 45Ca2+ when compared to the addition of culture medium with serum only. This study demonstrates that both hyaluronic acid (Sperm Select) and Percoll affect the acrosome reaction and the prerequisite for Ca2+ influx in human spermatozoa. These effects should be taken into consideration when using these media for preparation of spermatozoa for insemination or for fertilization in vitro.

Acrosome↗
PubMed1993

Human sperm motility is affected by plasticizers and diesel particle extracts.

In order to test various drugs and possibly hazardous compounds on living cells in vitro a system with human spermatozoa was employed. A population of human spermatozoa was transferred into a defined medium by a swim-up procedure or by separation on a Percoll gradient. Such a population is rather homogenous with respect to motility characteristics and was found to be useful for this purpose. Different modes of response were recorded, indicating various effect mechanisms. Effects of various phthalates used as plastic softeners in the production of medical equipment, and extracts from diesel particulate material were recorded. All these compounds interfered with sperm motility in a dose-response fashion. Immediate effects of phthalates were modest, but upon prolonged exposure effects became more evident. Sperm motility was more affected by diethyl-hexyl and dibutyl phthalates. Significant effects were noted for the different phthalates with regard both to percent motility and to some of the various qualities of motility, such as velocity, linearity and amplitude of the track. Thus, the pattern of response considering the motion variables was not the same with the different phthalates. With regard to the effects on sperm motion di-n-octyl phthalate seemed to be the least toxic, followed by dibutyl phthalate. The initial effects of diesel particulate extracts were moderate and mainly restricted to percent motile sperm but upon exposure for 18 hr the effects became more pronounced for all the movement variables.

Adult↗
PubMed1993

Isoforms of procarboxypeptidase B, (pancreas-specific protein, PASP) in human serum, pancreatic tissue and juice.

Human Pancreas-Specific Protein (PASP) has been described as a useful serum marker for pancreatic graft rejection and acute pancreatitis. By molecular cloning PASP has recently been identified as procarboxypeptidase B (PCPB). By use of SDS-gel electrophoresis and Western blots, PASP isoforms (proteins interacting with PASP-antiserum) have now been explored in serum and pancreatic tissue and juice. In serum from healthy volunteers, six different isoforms could be visualised. Their MW varied as follows: > 100 K, about 100 K, 45 K, 35-40 K (two bands) about 30 K and 16 K. The 45 K band, corresponding to PASP purified from pancreatic tissue, was always the major band. In pancreatic cytosol and pancreatic juice, the major band corresponded to PASP (45 K) but weak bands were also seen at MW of 40, 30 and 16 K. In serum from 15 patients with acute pancreatitis, PASP was highly increased. Bands corresponding to PASP/PCPB as well as carboxypeptidase B (CPB) were seen simultaneously. During recovery PASP in serum was normalised and the CPB band disappeared. During 12 episodes of pancreatic graft rejection, PASP in serum was also increased but no changes of isoforms in serum were detected. However during these episodes isoforms in pancreatic juice changed dramatically. The band corresponding to PASP disappeared or became much weaker and only bands with lower MW were seen. We have thus observed changes in PASP/PCB serum isoforms during episodes of acute pancreatitis but not at graft rejection episodes although the total increase of PASP in serum was of the same magnitude.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Purification, structure and partial characterization of the major sperm activating protein complex in human serum.

Serum has long been known to enhance sperm motility, and the major factor that mediates this activation has been shown to be a macromolecule complex with a MW of about 250 kD. This macromolecule, named Sperm Activating Protein (SPAP) has now been purified by a four step protocol. Starting with 100 mL of serum 20 to 200 micrograms of purified SPAP was recovered (N = 40). Studies on the identification and structure of SPAP revealed that the macromolecule is formed by an IgG molecule to which an apolipoprotein A-I molecule is bound. Further studies on the structure of the complex was performed by partial proteolytic cleavage of SPAP by pepsin and papain and interaction with poly- and monoclonal antibodies. Based on these results the most plausible structure of SPAP places one molecule of apo A-I between the two arms of the Fab portion of an IgG4 molecule. Human spermatozoa incubated with polyclonal anti-SPAP serum and a second FITC-labelled antiserum showed fluorescence at a distinct band at the lower part of the sperm head, indicating that SPAP acts by direct interaction with the spermatozoa. The SPAP molecule shows a new mechanism mediated by the immunoglobulins, that may be very important for male fecundity.

Apolipoprotein A-I↗
PubMed1992

Isolation of a cDNA encoding a human serum marker for acute pancreatitis. Identification of pancreas-specific protein as pancreatic procarboxypeptidase B.

A human pancreas-specific protein (PASP), previously characterized as a serum marker for acute pancreatitis and pancreatic graft rejection, has been identified as pancreatic procarboxypeptidase B (PCPB). cDNAs encoding PASP/PCPB were isolated from a human pancreas cDNA library using a combination of nucleic acid hybridization screening and immunoscreening with antisera raised against native PASP. The deduced amino acid sequence of PASP/PCPB cDNA predicts the translation of a 416-amino acid preproenzyme with a 15-amino acid signal/leader peptide and a 95-amino acid activation peptide. The proenzyme portion of this protein has 76% identity with rat PCPB and 84% identity with bovine carboxypeptidase B. DNA and RNA blot analyses indicate that human PCPB mRNA (1,400 nucleotides) is transcribed from a single locus in the human genome in a tissue-specific fashion. N-terminal sequencing of native PASP and the specific immunoreactivity of bacterially expressed PASP/PCPB with native PASP antibodies confirm the identification of PASP as human pancreatic PCPB.

Acute Disease↗
PubMed1992

Quantitative estimation of tissue prostate specific antigen, deoxyribonucleic acid ploidy and cytological grade in fine needle aspiration biopsies for prognosis of hormonally treated prostatic carcinoma.

The prognostic value of deoxyribonucleic acid (DNA) flow cytometry, cytological grading and the direct assay of prostate specific antigen (PSA) in the material of fine needle aspirates was studied in 67 consecutive patients with newly detected prostatic carcinoma. All patients were hormonally treated (castration in 27 and luteinizing hormone-releasing hormone agonist or parenteral estrogens in 40). The patients were followed for a minimum of 2 years. PSA was analyzed in the biopsy material by a direct radioimmunoassay and related to the total amount of DNA. In parallel biopsies DNA ploidy using flow cytometry and cytological grade were established. Patients with a geometric mean value of greater than or equal to 0.12 microgram. PSA/microgram. DNA had a progression rate of 7%, compared to 59% for those with less than 0.12 microgram. PSA/microgram. DNA. In Cox multivariate analysis cytology and tissue PSA content were the most important factors in expressing the difference for interval to progression in hormonally treated patients.

Antigens, Neoplasm↗
PubMed1992

Effects of a diet regimen on pituitary and steroid hormones in male ice hockey players.

Serum concentrations of androgens, cortisol, androgen binding proteins, pituitary hormones, together with anthropometric variables and sports performance were studied in two different elite male ice hockey teams. One of the teams (DIF, n = 22) participated in a special dietary program including reduction in fat from approximately 40 per cent of total energy intake (E%) to less than 30 E% and an increase in carbohydrate intake from 45 E% to about 55 E%, while the other (SSK, n = 21) served as a control group and had no special dietary program. The study covered a 7-month period. Basal values of serum testosterone, sex hormone binding globulin (SHBG), non-SHBG-bound testosterone (NST), cortisol, dehydroepiandrosterone sulfate (DHAS) and LH did not differ between the two teams. Serum concentrations of testosterone, SHBG, NST and cortisol increased significantly during the study period in the DIF group and were, with the exception of SHBG, significantly higher than in the SSK group at the end of the study (33.0 vs 26.8 nmol/l, p less than 0.05; 22.5 vs 18.3 nmol/l, p less than 0.05; and 548 vs 464 nmol/l, p less than 0.01). The ratio between NST and cortisol which was used as an index of anabolic/catabolic steroid balance did not change in either group during the study. A significant decrease in the serum concentrations of LH during the observation period was found in the SSK group. The endocrine differences between the teams may be explained by a relative negative energy balance in DIF, together with a reduced fat and increased carbohydrate intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗