Restoration of spermatogenesis in dibromochloropropane (DBCP)-treated rats by hormone suppression

The exposure of men to the nematocide dibromochloropropane (DBCP) has caused prolonged oligo- and azoospermia, which occasionally reverses spontaneously. We recently demonstrated that in testes of rats treated with a dose of DBCP sufficient to reduce the percentage of tubules producing differentiating germ cells (tubule differentiation index, TDI) to 20%, the tubules lacking differentiating cells contained type A spermatogonia. To determine whether these type A spermatogonia could be stimulated to differentiate, as had been demonstrated previously in other models of toxicant-induced sterility, we suppressed intratesticular testosterone and serum follicle stimulating hormone (FSH) levels with the GnRH agonist Lupron (leuprolide). When the GnRH agonist was given for 10 weeks starting immediately after DBCP exposure, the TDI was maintained at 94%. Even when GnRH-agonist treatment was stopped at week 10, the TDI remained between 65 and 80% 10 weeks later. Late spermatid counts averaged 10 x 10(6) per testis for the GnRH-agonist-treated rats at week 20 compared with 1.7 x 10(6) per testis in rats treated with only DBCP. To determine whether spermatogonial differentiation could be stimulated after the TDI had declined to below 30%, we initiated GnRH-agonist treatment 6 weeks after DBCP exposure. The GnRH treatment increased the TDI to 53% at week 16. These results indicate that, if the same principles apply to humans, suppression of testosterone may be applied to restore spermatogenesis in men rendered azoospermic by DBCP or other reproductive toxicants.     

Reversal of ethanol-induced testosterone suppression in peripubertal male rats by opiate blockade

Teenage drinking is a major problem in the United States, as well as abroad. Besides psychosocial implications, ethanol (EtOH) has detrimental effects on the reproductive system. Clinical problems associated with reduced reproductive hormones include osteoporosis, decreased muscle function, anemia, altered immune function, prostate involution, and decreased reproductive abilities. Education coupled with strategies aimed at preventing these deleterious consequences even in the face of continued EtOH intake is extremely important. We have tested the possibility that naltrexone, a drug currently used in patients to decrease alcohol craving, might also prevent the fall in the male hormone, testosterone, caused by EtOH exposure. Rats aged 35 days old (prepubertal), 45 days old (midpubertal), and 55 days old (late pubertal) were injected (intraperitoneally) with either saline, EtOH, naltrexone, or EtOH plus naltrexone. In the two older age groups, EtOH significantly suppressed testosterone, which was prevented by administration of naltrexone. In the youngest animals, there was no treatment effect presumably due to low basal levels of testosterone. EtOH similarly reduced luteinizing hormone (LH), but this suppression was not prevented by naltrexone. There was no consistent effect of any treatment on hypothalamic concentration of pro-LH releasing hormone (RH) (LHRH), LHRH, or on steady-state levels of LHRH mRNA. We conclude that, as animals progress through puberty, EtOH suppresses LH and testosterone. The testosterone decline can be prevented by opiate blockade with naltrexone, an effect primarily seen at gonadal level. Thus, naltrexone, a drug already used clinically to reduce EtOH intake, also has protective physiological effects on the endocrine system.     

Stereological image analysis of cultured human melanocytes observed by transmission electron microscopy

The aims of the study were to write an image analysis (IA) program allowing the stereological quantification of human epidermal melanocyte melanization at the ultrastructural level and to specify the suitable preparative methods, in keeping with IA limits and stereological principles. Micrographs of cultured human melanocytes obtained in transmission electron microscopy were digitized with a scanner. The key step of the designed IA program is a thresholding based on the gray levels. Hence, gray level histograms (pixel frequency as a function of gray level) of melanocyte images exhibit a peak specific to melanin. The gray level thresholding used consists in isolating the melanin pixels that form profiles on a binary image and in storing the numerical data produced for a given melanocyte profile. These primary data are used to calculate numerous parameters via stereology with melanocyte cytoplasm and melanized melanosome as main reference spaces. The most important stereological parameters obtained are v(mi,cy) (melanin volume per average cell), v(mi,m) (melanin volume per average melanized melanosome), and nm (number of melanized melanosomes per average cell), and their validity is discussed. Melanocytes embedded in situ were abandoned for stereological reasons but pelleted melanocytes were found suitable. Using this computerized tool and stereology, we are able to perform quantitative studies producing varied data even from small cell samples. To our knowledge, this is the first stereological approach for quantifying intracellular melanization. A quantitative comparison of spectrophotometrical results (melanin assay) with stereological results obtained in ultraviolet B-irradiated Caucasian epidermal melanocytes will be performed in order to appraise this method.     

Complex gangliosides are essential in spermatogenesis of mice: possible roles in the transport of testosterone

Mice, homozygous for disrupted ganglioside GM2/GD2 synthase (EC 2.4. 1.94) gene and lacking all complex gangliosides, do not display any major neurologic abnormalities. Further examination of these mutant mice, however, revealed that the males were sterile and aspermatogenic. In the seminiferous tubules of the mutant mice, a number of multinuclear giant cells and vacuolated Sertoli cells were observed. The levels of testosterone in the serum of these mice were very low, although testosterone production equaled that produced in wild-type mice. Testosterone was found to be accumulated in interstitial Leydig cells, and intratesticularly injected testosterone was poorly drained in seminiferous fluid in the mutant mice. These results suggested that complex gangliosides are essential in the transport of testosterone to the seminiferous tubules and bloodstream from Leydig cells. Our results provide insights into roles of gangliosides in vivo.     

Changes in plasma LH and testosterone levels and semen quality after a single injection of hCG in two dogs with spermatogenic dysfunction

Plasma LH and testosterone (T) levels and semen quality after a single intramuscular injection of 1,000 IU hCG were investigated in a Beagle dog with azoospermia and a Beagle dog with poor semen quality. The plasma LH levels of both dogs did not change after the treatment. Although the plasma T levels of the dog with azoospermia increased temporarily, no sperm were detected in its semen. In the dog with poor semen quality high levels of plasma T were maintained for 2 weeks after hCG treatment and its semen quality was temporarily improved between 3 and 4 weeks after treatment. These findings indicate that the semen quality of dogs with oligozoospermia can be temporarily improved after a single injection of hCG.     

Endocrine and spermatogenic testicular function. 2. Correlations between food protein quality, testosterone level in testes, spermatogenesis and nuclear volume of interstitial cells of Leydig in the adult rat

Proteinase activity was found to be present along the sides of sperm penetration tunnels through the zonae pellucidae of rabbit ova using silver-proteinate staining techniques. This is the first direct confirmation of the generally accepted concept of sperm penetration by proteinase release and digestion of the zona pellucida.     

Suppression of spermatogenesis in man induced by Nal-Glu gonadotropin releasing hormone antagonist and testosterone enanthate (TE) is maintained by TE alone

GnRH antagonists plus testosterone (T) suppress LH and FSH levels and inhibit spermatogenesis to azoospermia or severe oligozoospermia. High-dose T treatment alone has been shown to be an effective male contraceptive (contraceptive efficacy rate of 1.4 per 100 person yr). Combined GnRH antagonist and T induces azoospermia more rapidly and at a higher incidence than T alone; this combination has therefore been proposed as a prototype male contraceptive. However, because GnRH antagonists are expensive to synthesize and difficult to deliver, it would be desirable to rapidly suppress sperm counts to low levels with GnRH antagonist plus T and maintain azoospermia or severe oligozoospermia with T alone. In this study, 15 healthy men (age 21-41 yr) with normal semen analyses were treated with T enanthate (TE) 100 mg im/week plus 10 mg Nal-Glu GnRH antagonist sc daily for 12 weeks to induce azoospermia or severe oligozoospermia. At 12-16 weeks, 10 of 15 subjects had zero sperm counts, and 14 of 15 had sperm counts less than 3 x 10(6)/mL. The 14 who were suppressed on combined treatment were maintained on TE alone (100 mg/week im) for an additional 20 weeks. Thirteen of 14 subjects in the TE alone phase had sperm counts maintained at less than 3 x 10(6)/mL for 20 weeks. Ten remained persistently azoospermic or had sperm concentration of 0.1 x 10(6)/mL once during maintenance. Mean LH and FSH levels in the subjects were suppressed to 0.4+/-0.2 IU/L and 0.5+/-0.2 IU/L in the induction phase, which was maintained in the maintenance phase. The 1 subject who failed to suppress sperm counts during induction had serum LH and FSH reduced to 0.3 and 0.5 IU/L, respectively. The subject who failed to maintenance had LH and FSH suppressed to 1.0 and 0.2 IU/L, respectively, during the induction phase but these rose to 1.6 and 2.1 IU/L, respectively, during maintenance. Failure to suppress or maintain low sperm counts may be related to incomplete suppression of serum LH and FSH levels. We conclude that sperm counts suppressed with GnRH antagonist plus T can be maintained with relatively low dose TE treatment alone. This concept should be explored further in the development of effective, safe, and affordable hormonal male contraceptives.     

Change of karyoskeleton during mammalian spermatogenesis: expression pattern of nuclear lamin C2 and its regulation

The photophysical and photochemical properties of porphyrins were profoundly changed upon addition of rhodamine 123. The Soret band of the porphyrins shifted to higher wavelengths, the fluorescence yield of the porphyrins decreased with unaltered decay rates, and their triplet state was quenched. These observations indicate a strong interaction between porphyrins and rhodamine 123 and formation of 1:1 nonfluorescent complexes, of which the binding constants were determined. Illumination of a porphyrin in the presence of rhodamine 123 resulted in the formation of a porphyrin radical cation, which could be detected with ESR spectroscopy. Quenching of the triplet state of the porphyrins by rhodamine 123 resulted in a decreased singlet oxygen yield and a decrease of the photooxidation of histidine, methionine, tyrosine, and tryptophan. However, the oxidation of thiol compounds was increased and the stoichiometry of the reaction between cysteine and oxygen changed from 2 to 3.8 mol cysteine/ mol oxygen. These results show that the presence of rhodamine 123 converted the for porphyrins prevalent energy transfer (type II) reaction to an electron transfer (type I) reaction.     

Polypeptide pattern of human breast epithelial cells following human chorionic gonadotropin (hCG) treatment

Numerous attempts have made to describe the particular protein pattern of malignant cells by using high resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The placental hormone human chorionic gonadotropin (hCG) inhibits tumor initiation and progression in experimental animals and has an inhibitory effect on the proliferation of human breast epithelial cells (HBEC) in vitro. The inhibitory effect on the immortalized HBEC MCF-10F is accompanied by the immunocytochemical expression of inhibin alpha and beta subunits by treated cells. With the purpose of clarifying the molecular mechanisms involved in this effect, the pattern of protein synthesis and mRNA were studied by 2-D PAGE in the immortalized HBEC MCF-10F cells treated in vitro 1001U for 24 h. The effect of hCG treatment on the synthesis of MCF-10F cells was monitored by labeling both control and treated cells with [S35]methionine and separation by 2-D PAGE. At least 11 proteins were preferentially synthesized and five specific polypeptides were decreased in hCG treated cells in comparison with controls. The hCG induced at least four new mRNAs which encoded protein in the molecular mass range of 24-72 kDa. It also increased the expression of at least six mRNAs and reduced the expression of least four mRNAs in comparison with control cells. The hCG-treated cells actively synthesized a 33-kDa polypeptide which was not present in control cells. The nature of this hCG-inducible 33 kDa protein elucidated by immunoprecipating [S35]methionine-labeled proteins with antisera directed against rat inhibin subunit alpha and beta b.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-related decrease of plasma testosterone in SAMP8 mice: replacement improves age-related impairment of learning and memory

Corticosterone increases with aging but pregnenolone, dehydroepiandrosterone, and testosterone decrease. The marked decrease in hormones that occurs with aging may contribute to the age-related deficit in learning and memory. Administration of these hormones after training was found to improve long-term memory processing in normal young mice. SAMP8 (P8) mice show an age-related loss of learning and memory for a variety of tasks whereas age-matched control mice of the closely related SAMR1 (R1) strain do not. In this study, we found an age-related decrease in serum testosterone levels of 71% between P8 mice 4 and 12 months of age, but only a 26% decrease between R1 mice of the same ages. The difference between the P8 mice was significant (p < 0.01) and the difference between the R1 mice was not. The decrease in testosterone in 12-month-old P8 mice was not accompanied by gross morphological change in the testes. A SC testosterone implant, sufficient to increase plasma testosterone levels to 414 +/- 25 ng/dl, alleviated impaired learning and memory of a foot shock avoidance task in P8 mice. Castration of 4-month-old P8 mice did not produce a deterioration in learning and memory, indicating that low levels of testosterone per se are not responsible for the impairment seen in 12-month-old P8 mice. This suggests that impaired cognitive functioning of the older P8 mice was due to an interaction of aging and reduced testosterone levels.     

Comparative studies of the aromatization of testosterone and epitestosterone by human placental aromatase

The aromatization of epitestosterone (17 alpha-hydroxy-4-androsten-3-one) and testosterone by lyophilized human placental microsomes was studied. Upon incubation of epitestosterone, 12% was converted to 17 alpha-estradiol, 15% to 19-keto-epitestosterone (17 alpha-hydroxy-4-oxo-4-androsten-19-al), 10% to 19-hydroxyepitestosterone (17 alpha, 19-dihydroxy-4-androsten-3-one), and about 10% to several unidentified products. A similar incubation with testosterone resulted in 60% conversion to 17 beta-estradiol; 30% was unchanged. At increasing substrate concentrations (0.1-50 microM), the aromatization rate of epitestosterone increased gradually and did not reach a plateau, whereas aromatization rate of testosterone plateaued at about 3 microM. The presence of either testosterone or 17 beta-estradiol in concentrations 0.1-10 times the concentration of epitestosterone inhibited the aromatization of epitestosterone by about 70%, while the aromatization of testosterone was not inhibited by either epitestosterone or 17 alpha-estradiol. Lyophilization of fresh microsomes or storage of the lyophilized microsomes at -20 C greatly reduced the aromatizing activity upon epitestosterone but not upon testosterone. These results suggest that the aromatizing system for epitestosterone is different from that for testosterone.     

Effect of vindesine sulfate on the radiation-induced alterations in mouse spermatogenesis: a flow cytometric evaluation

The effect of 0.05 mg/kg body weight of vindesine sulfate was studied on the radiation-induced changes in mouse spermatogenesis at 1, 2, 7, 14, 21, 28, 35 and 70 days post-irradiation. Vindesine administration before exposure to 0, 0.5, 1, 2 and 3 Gy gamma-irradiation resulted in an increase in the radiation-induced perturbations of mouse spermatogenesis at various post-exposure time periods studied. A significant reduction in testicular weight was observed in both DDW + irradiated and VDS + irradiated groups at various post-irradiation time periods, depending on the exposure dose. Vindesine pretreatment resulted in an enhanced killing of spermatogonial cells at day 2 post-exposure at all the exposure doses, except 3 Gy when compared to DDW + irradiated controls. Consequently, the tetraploid (4C) population declined significantly by day 14 post-irradiation followed by a severe depletion in round spermatids (1C) by day 21 post-irradiation. The dose-response relationship for 4C and 1C populations was linear-quadratic at days 14 and 21, respectively. A significant elevation was observed in HC population from days 1 to 21 depending on the exposure dose. The germ cell ratios, viz. 4C:2C, 4C:S-phase, 1C:2C and 1C:4C, showed a significant decline in the VDS + irradiated group when compared to the DDW + irradiated group at various time periods, depending on the exposure dose.     

Pharmacokinetics of testosterone in hypogonadal men after transdermal delivery: influence of dose

To assess the pharmacokinetics of testosterone after application of one, two, or three testosterone transdermal delivery systems to hypogonadal patients, 12 hypogonadal men (mean age 46.6 +/- 10.5 years) were enrolled in an open-label, randomized, crossover study. Each application period comprised 4 days: a 2-day washout period with no exogenous testosterone therapy followed by 2 days of therapy with one, two, or three transdermal systems applied daily to the patient's back. On day 4 of each period, serial blood samples were collected for determination of total and non-sex hormone binding globulin (non-SHBG) bound serum testosterone concentrations. Serum concentrations of testosterone were determined using validated radioimmunoassay methods. Residual testosterone analysis of used transdermal systems was used to estimate testosterone delivery through the skin. In general, serum concentrations of testosterone rose in accordance with an increase in dose. Using a strict bioequivalence approach to dose proportionality, the increases in area under the concentration-time curve (AUC) and morning concentrations were proportional to the increase in dose from two to three transdermal systems, but somewhat less than proportional with an increase from one to two transdermal systems. Results from the non-SHBG bound serum testosterone concentrations closely paralleled those of total serum testosterone. Use of three transdermal systems yielded serum concentrations of testosterone that tended to be above the upper limit of the normal range. The AUC and cumulative release of testosterone were linearly related to the number of applied systems. If necessary, the standard recommended dose of two testosterone transdermal delivery systems can be modified to accommodate interindividual differences in testosterone requirements of hypogonadal men.     

Expression after suppression: A motivational explanation of postsuppressional rebound.

Five studies examined the effect of expressing a construct after suppressing it on subsequent accessibility. Suppression of color terms (Studies 1, 2, and 5) and of stereotypes (Studies 3 and 4) were examined. Both expression alone and suppression alone enhanced the construct's accessibility relative to the no-suppression/no-expression condition, demonstrating activation by recent construct use and postsuppressional rebound, respectively. However, introducing expression after suppression reduced accessibility relative to both the suppression alone and the expression alone conditions. These results are explained within a motivational theory of rebound, according to which suppressing a construct induces a need to use it, and subsequent expression satisfies this need, thereby instigating an inhibition of the accessibility of need-related constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Different expression pattern of cytokine receptors by human osteosarcoma cell lines

Cytokine receptor expression in human osteosarcoma cell lines (U2-OS, Saos-2, MG-63) was analyzed by flow cytometry to identify receptors which may interact with osteosarcoma cell growth and that should not be used in a clinical setting. U2-OS, Saos-2, MG-63 and bone marrow stromal cells, that were used as normal controls, constitutively express the FAS and SCFR surface molecules. GM-CSFR is expressed only by U2-OS and Saos-2 cell lines, that are phenotypically less differentiated than MG-63. Different gp130 clones were express ed only by Saos-2 and MG-63 cell lines. IL-2Rgamma,IL-7R and 4-1BB were expressed only by Saos-2 cell line. These data add new evidence of receptors that may be activated by autocrine or paracrine cytokines that could induce osteosarcoma cell growth.     

PMS after 40: persistence of a stress-related symptom pattern

BACKGROUND AND OBJECTIVE: Various yellow light lasers have been used over the past decade in an attempt to eradicate facial telangiectasia. Based on their power output, spot size, and pulsing characteristics, these lasers belong to one of two categories that exist at either end of a spectrum--high power, short pulse, and large spot size, or low power, long exposure, and small spot size. The copper bromide laser clearly belongs in the latter group, but with higher available power than most other lasers in this group, it exists further along the spectrum toward the region in which the laser parameters might be considered closer to theoretical ideals for treating certain cutaneous vascular pathologies. The objective of this study was to ascertain the role and efficacy of the copper bromide laser on treatment of a variety of facial telangiectasia. STUDY DESIGN/MATERIALS AND METHODS: A total of 570 patients with facial telangiectasia of different diameters and on different regions of the face were treated with the copper bromide laser one or more times and followed up over 5 years. RESULTS: More than 75% clearance was achieved in 70% patients, 50-75% clearance in 17.4% patients, and < 50% clearance in 12.6% patients. Poor results were correlated with anatomical location on the nasal alae and nasal tip and also with vessel size. Very small (< 100 microns) and very large (> 300 microns) vessels did not respond as well as vessels in the 100-300-micron diameter group. Very large vessels responded better to a combination of sclerotherapy and laser treatment. There were no reported long-term adverse effects. CONCLUSION: The copper bromide laser is a safe and effective modality for the treatment of the majority of facial telangiectasia. It is less suited to treating very small vessel lesions such as diffuse erythema, and conversely very large vessels as well as those of the nasal alae. These latter two groups respond better and more permanently to combined sclerotherapy and laser treatment.     

Coronary endothelial dysfunction after Kawasaki disease: evaluation by intracoronary injection of acetylcholine

1. Caffeine (Cf) enhances the DNA cleavage induced by tert-butylhydroperoxide (tB-OOH) in U937 cells via a mechanism involving Ca2+-dependent mitochondrial formation of DNA-damaging species (Guidarelli et al., 1997b). Nitric oxide (NO) is not involved in this process since U937 cells do not express the constitutive nitric oxide synthase (cNOS). 2. Treatment with the NO donors S-nitroso-N-acetyl-penicillamine (SNAP, 10 microM), or S-nitrosoglutathione (GSNO, 300 microM), however, potentiated the DNA strand scission induced by 200 microM tB-OOH. The DNA lesions generated by tB-OOH alone, or combined with SNAP, were repaired with superimposable kinetics and were insensitive to anti-oxidants and peroxynitrite scavengers but suppressed by iron chelators. 3. SNAP or GSNO did not cause mitochondrial Ca2+ accumulation but their enhancing effects on the tB-OOH-induced DNA strand scission were prevented by ruthenium red, an inhibitor of the calcium uniporter of mitochondria. Furthermore, the enhancing effects of both SNAP and GSNO were identical to and not additive with those promoted by the Ca2+-mobilizing agents Cf or ATP. 4. The SNAP- or GSNO-mediated enhancement of the tB-OOH-induced DNA cleavage was abolished by the respiratory chain inhibitors rotenone and myxothiazol and was not apparent in respiration-deficient cells. 5. It is concluded that, in cells which do not express the enzyme cNOS, exogenous NO enhances the accumulation of DNA single strand breaks induced by tB-OOH via a mechanism involving inhibition of complex III.     

Depression and memory impairment: A meta-analysis of the association, its pattern, and specificity.

The existing evidence paints an unclear picture of whether an association exists between depression and memory impairment. The purpose of this investigation was to determine whether depression is associated with memory impairment, whether moderator variables determine the extent of this association, and whether any obtained association is unique to depression. Meta-analytic techniques were used to synthesize data from 99 studies on recall and 48 studies on recognition in clinically depressed and nondepressed samples. Associations between memory impairment and other psychiatric disorders (e.g., schizophrenia, dementia) were also examined. A significant, stable association between depression and memory impairment was revealed. Further analyses indicated, however, that it is likely that depression is linked to particular aspects of memory, the linkage is found in particular subsets of depressed individuals, and memory impairment is not unique to depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulation of newborn-like hemoglobin synthesis in adult rats by recombinant human erythropoietin and suppression by aspirin

A study was carried out to determine whether recombinant human erythropoietin can induce newborn-like hemoglobin synthesis in adult rats. A fixed dose of recombinant erythropoietin was administered each time intravenously in each rat for altogether 5 weeks. Blood samples drawn at 7-day intervals were analyzed by DEAE-cellulose chromatography. Hematological parameters like red blood cell counts, hematocrit values and reticulocyte counts were evaluated and compared. A significant changing pattern for certain hemoglobin components in red cells of erythropoietin-treated rats was measured compared to their baseline values. However, aspirin (a prostaglandin synthesis inhibitor) intake along with recombinant erythropoietin administration totally abolished the reversion of hemoglobin proportions toward newborn values, but not the increase in hemoglobin synthesis. These data reveal that concurrent prostaglandin synthesis is needed for reversing hemoglobin proportions in adult rats, but not for hemoglobin synthesis per se.