Changes in the bioactivity to immunoreactivity ratio of circulating luteinizing hormone in impotent men treated with testosterone undecanoate

1989 ◽  
Vol 120 (3) ◽  
pp. 284-288 ◽  
Author(s):  
C. Carani ◽  
M. F. Celani ◽  
D. Zini ◽  
A. Baldini ◽  
L. Della Casa ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Serum Levels ◽  
Mean Value ◽  
Serum Concentrations ◽  
Placebo Administration ◽  
In Vitro Bioassay ◽  
Testosterone Undecanoate ◽  
The Mean ◽  
Mouse Leydig Cell

Abstract. Testosterone undecanoate was administered orally (80 mg twice daily) for 30 days to 10 impotent men with mild Leydig cell failure, age 28 to 42 years. Placebo was administered for 30 days both before and at the end of testosterone undecanoate therapy. Serum levels of bioactive LH, immunoreactive LH and testosterone were determined in basal conditions (day zero), 30 days after the first placebo administration, at the 15th and 30th day of testosterone undecanoate therapy, and at the end of the second treatment with placebo (90th day). Bioactive LH was measured by a sensitive and specific in vitro bioassay based on testosterone production by mechanically dispersed mouse Leydig cell preparations. Immunoreactive LH and testosterone were determined by a doubleantibody RIA technique. The results were compared with those obtained in 30 untreated normal young men. In the basal state, serum concentrations of immunoreactive LH were significantly higher in the patients (P< 0.02) than in control subjects, whereas testosterone levels were significantly lower (P< 0.001) in the impotent men. In contrast, bioactive LH levels and the bioactive LH to immunoreactive LH ratios were similar in the two groups. In the patients, at the 15th day of treatment with testosterone undecanoate, serum levels of testosterone and bioactive LH were significantly higher (P< 0.01) than basal values, whereas immunoreactive LH concentrations showed no significant changes. Consequently, the bioactive LH to immunoreactive LH ratios rose significantly (P< 0.01). At the 30th day of treatment with testosterone undecanoate, the mean value of bioactive LH and the mean bioactive LH to immunoreactive LH ratio were significantly higher (P< 0.01) in the patients than in control men, whereas the mean levels of testosterone and immunoreactive LH were similar in the two groups. Neither the first nor the second treatment with placebo changed the hormone values observed in basal conditions. The results support the experimental evidence that androgens may increase the bioactivity of circulating LH.

AN IMPROVED IN VITRO BIOASSAY METHOD FOR MEASURING LUTEINIZING HORMONE (LH) ACTIVITY USING MOUSE LEYDIG CELL PREPARATIONS

1974 ◽  
Vol 77 (4) ◽  
pp. 655-671 ◽  
Author(s):  
M.-P. Van Damme ◽  
D. M. Robertson ◽  
E. Diczfalusy
Keyword(s):  
Luteinizing Hormone ◽  
Leydig Cell ◽  
Marked Reduction ◽  
Improved Method ◽  
In Vitro Bioassay ◽  
Bioassay Method ◽  
Adult Mice ◽  
Assay Design ◽  
Mouse Leydig Cell

ABSTRACT An improved in vitro bioassay method for the measurement of LH activity is presented. The method is based on the assay of testosterone produced by "Leydig cell" preparations from mouse testes in the presence of added gonadotrophin. The method is significantly improved in terms of sensitivity, precision and practicability when compared to the previously described bioassay method employing decapsulated testes from adult mice. The sensitivity of the improved method is 15 μIU for HCG and 50 μIU for HMG. The useful range of the method is 15–260 μIU for HCG and 50–900 μIU for HMG. Using a 3 + 3 point assay design with each dose in quadruplicate, a mean index of precision (λ̅) of 0.044 was obtained in 19 assays. Human FSH, TSH, ACTH, LTH, STH, oxytocin, vasopressin and LHRH preparations did not influence the bioassay method at levels likely to be found in biological samples. A good correlation was found between estimates obtained by the "Leydig cell" method and by the method using decapsulated testes when various HCG and HMG preparations were used. With the proposed method at least 30 samples can be assayed each week by 2 persons, with a marked reduction in cost.

REDUCTION OF ANDROSTENEDIONE BY SKIN IN VITRO AND SERUM LEVELS OF GONADOTROPHINS AND ANDROGENS IN MEN WITH HYPOSPADIAS

1979 ◽  
Vol 82 (3) ◽  
pp. 395-401 ◽  
Author(s):  
JAN SVENSSON ◽  
PETER ENEROTH ◽  
JAN-ÅKE GUSTAFSSON ◽  
MARTIN RITZÉN ◽  
ÅKE STENBERG
Keyword(s):  
Reductase Activity ◽  
Serum Levels ◽  
Serum Concentrations ◽  
Scrotal Skin ◽  
Upper Arm ◽  
Control Subjects ◽  
The Mean ◽  
And Control ◽  
Mean Concentration

The reduction of 4-[1,2-3H]androstene-3,17-dione (androstenedione) in vitro by scrotal skin was measured in samples from nine men (16–34 years old) with hypospadias and from ten male control subjects. The reduction of androstenedione was also studied in axillary and upper arm skin of seven control subjects. Androstenedione was reduced to material with chromatographic characteristics of 5α-androstane-3,17-dione and to 3α- and 3β-hydroxy-5α-androstan-17-one. No difference in 5α-reductase activity (defined as the sum of these three metabolites formed) was found in scrotal skin from hypospadic and control men. The mean concentration of 5α-dihydrotestosterone in serum from men with hypospadias was lower than that in serum from control subjects (P< 0·01). The mean ratio of the serum concentrations of testosterone and 5α-dihydrotestosterone was higher in hypospadic men than in control subjects (P< 0·05). No differences between the two groups were found in the mean serum concentrations of LH, FSH, prolactin, dehydroepiandrosterone, androstenedione, testosterone or testosterone-binding globulin.

Human serum LH inhibitor(s): behaviour and contribution to in vitro bioassay of LH using dispersed mouse Leydig cells

1989 ◽  
Vol 121 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Ying-Qing Ding ◽  
Ilpo Huhtaniemi
Keyword(s):  
Human Serum ◽  
Leydig Cell ◽  
Binding Studies ◽  
In Vitro Bioassay ◽  
Lh Receptor ◽  
Testosterone Production ◽  
Free Serum ◽  
Source Of Error ◽  
Mouse Leydig Cell

Abstract. The present study aimed at investigating the nature and causes of non-parallelism in testosterone responses to serial dilutions of peripheral serum and standard LH preparations in the mouse Leydig cell in vitro bioassay of LH. Immunoadsorption with monoclonal antibody to the β-subunit of LH was used to obtain LH-free serum; the procedure removed more than 98% of the immunoassayable LH. When a constant amount of the LH-free serum was added to standard dilutions, the bioassay dose-response curves to serum dilutions and standards became parallel, i.e. the well-known source of error of this assay system was eliminated. When standard curves prepared in medium and LH-free serum (final concentration 10%) were compared, no effect of the serum was found on basal cAMP and testosterone production. However, the LH-stimulated testosterone and cAMP production were suppressed by serum by a rather constant factor of 40%. Mild heating (60°C, 15 min) or treatment with dextran-coated charcoal, but not ether extraction, was able to eliminate the inhibitory activity of the LH-free serum. Binding studies demonstrated that [125I]hCG interaction with mouse Leydig cell homogenates was inhibited by LH-free serum in a fashion indicative of reduced LH receptor number, but not of reduced binding affinity. In conclusion, these data show that human serum contains LH inhibitor(s) which affect the LH-receptor interaction and LH stimulated testosterone production in mouse Leydig cell in vitro. The effect is marked in serum concentration over 1.5% and it shows only minor variation between individual sera. This source of error can be effectively removed from the LH in vitro bioassay by using LH-free serum for preparation of dilutions of LH standards.

scholarly journals Shear bond strength evaluation of bonded molar tubes on fluorotic molars

2012 ◽  
Vol 83 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Erika L. Silva-Benítez ◽  
Veronica Zavala-Alonso ◽  
Gabriel A. Martinez-Castanon ◽  
Juan P. Loyola-Rodriguez ◽  
Nuria Patiño-Marin ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dental Fluorosis ◽  
In Vitro Study ◽  
Mean Value ◽  
Fixed Appliance ◽  
Adhesive Remnant Index ◽  
The Mean ◽  
Electronic Microscope

Abstract Objective: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. Materials and Methods: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. Results: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. Conclusions: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.

scholarly journals Biological and physicochemical stability of ceftazidime and aminophylline on glucose parenteral solution

2012 ◽  
Vol 48 (4) ◽  
pp. 691-698
Author(s):  
Carolina Alves dos Santos ◽  
Laura Oliveira-Nascimento ◽  
Marcos Camargo Knirsch ◽  
Marco Antônio Stephano ◽  
Adalberto Pessoa Júnior ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Performance ◽  
Inhibitory Concentration ◽  
Serum Levels ◽  
High Loss ◽  
Physicochemical Stability ◽  
Physicochemical Evaluation ◽  
The Mean ◽  
The Stability

Ceftazidime is a broad spectrum antibiotic administered mainly by the parenteral route, and it is especially effective against Pseudomonas aeruginosa. The period of time in which serum levels exceed the Minimum Inhibitory Concentration (MIC) is an important pharmacodynamic parameter for its efficacy. One of the forms to extend this period is to administer the antibiotic by continuous infusion, after prior dilution in a Parenteral Solution (PS). The present work assessed the stability of ceftazidime in 5% glucose PS for 24 hours, combined or not with aminophylline, through High Performance Liquid Chromatography (HPLC). The physicochemical evaluation was accompanied by in vitro antimicrobial activity compared MIC test in the 24-hour period. Escherichia coli and Pseudomonas aeruginosa were the microorganisms chosen for the MIC comparison. The HPLC analysis confirmed ceftazidime and aminophylline individual stability on PS, while the MIC values were slightly higher than the mean described in the literature. When both drugs were associated in the same PS, the ceftazidime concentration by HPLC decreased 25% after 24 hours. Not only did the MIC values show high loss of antibiotic activity within the same period, but also altered MIC values immediately after the preparation, which was not detected by HPLC. Our results indicate that this drug combination is not compatible, even if used right away, and that PS might not be the best vehicle for ceftazidime, emphasizing the importance of the MIC evaluation for drug interactions.

Varying dose–response characteristics of different immunoassays and an in-vitro bioassay for FSH are responsible for changing ratios of biologically active to immunologically active FSH

1990 ◽  
Vol 127 (3) ◽  
pp. 523-532 ◽  
Author(s):  
F. Jockenhövel ◽  
S. A. Khan ◽  
E. Nieschlag
Keyword(s):  
Sertoli Cell ◽  
Dose Response ◽  
Serum Levels ◽  
Biologically Active ◽  
Testicular Function ◽  
In Vitro Bioassay ◽  
Great Caution ◽  
Response Characteristics ◽  
Infertile Men

ABSTRACT Serum FSH levels in fertile and infertile men were determined by applying the Sertoli cell in-vitro bioassay and six different immunoassays. Bioassay and immunoassay estimates were significantly correlated (r ranging from 0·78 to 0·86; P<0·01). On average, all immunoassays measured lower FSH concentrations in samples with low FSH levels and higher FSH concentrations in those with high FSH levels compared with the bioassay. Ratios of bioactivity to immunoreactivity (B/I) were highest in fertile men and lowest in men with severe disturbances of testicular function. Depending on which immunoassay was used these differences were either significant or only marginal. Dose–response characteristics for WHO FSH standard preparation 78/549, used in the bioassay as well as in the immunoassays, were different between immunoassays and the bioassay, suggesting that decreasing B/I ratios with increasing FSH serum levels were method-related and reflected different slopes of the dose–response characteristics of the assays, rather than being true changes in the molecular composition of FSH. The present investigation underlines the necessity of choosing the immunoassay used for comparison with the bioassay carefully and of validating the system in regard to parallelism between dose–response characteristics. B/I ratios must be interpreted with great caution and previous studies which report changing B/I ratios in various endocrine situations may have to be reevaluated. Journal of Endocrinology (1990) 127, 523–532

Estrogen induces secretary proteins in transformed mouse Leydig cell in vivo, but not in vitro

1984 ◽  
Vol 124 (1) ◽  
pp. 277-282 ◽  
Author(s):  
Bunzo Sato ◽  
Yasuko Nishizawa ◽  
Makoto Nakao ◽  
Keizo Noma ◽  
Susumu Kishimoto ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Mouse Leydig Cell

scholarly journals Antagonism at combined effects of chemical fertilizers and carbamate insecticides on the rice-field N2-fixing cyanobacterium Cylindrospermum sp. in vitro

2014 ◽  
Vol 7 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Rabindra N. Padhy ◽  
Nabakishore Nayak ◽  
Shakti Rath
Keyword(s):  
Mean Value ◽  
Chemical Fertilizers ◽  
Carbamate Insecticides ◽  
Growth Inhibitory ◽  
Progressive Growth ◽  
The Mean ◽  
Growth Promoting ◽  
Reduced Toxicity ◽  
Ppm Level

Abstract Effects of chemical fertilizers (urea, super phosphate and potash) on toxicities of two carbamate insecticides, carbaryl and carbofuran, individually to the N2-fixing cyanobacterium, Cylindrospermum sp. were studied in vitro at partially lethal levels (below highest permissive concentrations) of each insecticide. The average number of vegetative cells between two polar heterocysts was 16.3 in control cultures, while the mean value of filament length increased in the presence of chemical fertilizers, individually. Urea at the 10 ppm level was growth stimulatory and at the 50 ppm level it was growth inhibitory in control cultures, while at 100 ppm it was antagonistic, i.e. toxicity-enhancing along with carbaryl, individually to the cyanobacterium, antagonism was recorded. Urea at 50 ppm had toxicity reducing effect with carbaryl or carbofuran. At 100 and 250 ppm carbofuran levels, 50 ppm urea only had a progressive growth enhancing effect, which was marked well at 250 ppm carbofuran level, a situation of synergism. Super phosphate at the 10 ppm level only was growth promoting in control cultures, but it was antagonistic at its higher levels (50 and 100 ppm) along with both insecticides, individually. Potash (100, 200, 300 and 400 ppm) reduced toxicity due to carbaryl 20 and carbofuran 250 ppm levels, but potash was antagonistic at the other insecticide levels. The data clearly showed that the chemical fertilizers used were antagonistic with both the insecticides during toxicity to Cylindrospermum sp.

scholarly journals Dental implant location via surface scanner: a pilot study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Miao Zhou ◽  
Hui Zhou ◽  
Shu-yi Li ◽  
Yuan-ming Geng
Keyword(s):  
Dental Implant ◽  
Clinical Investigation ◽  
Mean Value ◽  
Angular Deviation ◽  
Surface Scanning ◽  
Anatomic Structure ◽  
Vertical Deviation ◽  
Significant Difference ◽  
The Mean

Abstract Purpose Implant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro. Material and methods A total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad). Results In IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements. Conclusions Dental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.

scholarly journals Serum levels of insulin-like factor 3, anti-Müllerian hormone, inhibin B, and testosterone during pubertal transition in healthy boys: a longitudinal pilot study

Reproduction ◽  
2014 ◽  
Vol 147 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Marie Lindhardt Johansen ◽  
Ravinder Anand-Ivell ◽  
Annette Mouritsen ◽  
Casper P Hagen ◽  
Mikkel G Mieritz ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Cell Function ◽  
Serum Levels ◽  
Reproductive Hormones ◽  
Inhibin B ◽  
Testicular Volume ◽  
Serum Concentrations ◽  
Pubertal Onset ◽  
Additional Information ◽  
And Function

Insulin-like factor 3 (INSL3) is a promising marker of Leydig cell function with potentially high clinical relevance. Limited data of INSL3 levels in relation to other reproductive hormones in healthy pubertal boys exist. In this study, we aimed to evaluate longitudinal serum changes in INSL3 compared with LH, FSH, testosterone, inhibin B, and anti-Müllerian hormone (AMH) during puberty in healthy boys. Ten boys were included from the longitudinal part of the COPENHAGEN Puberty Study. Pubertal evaluation, including testicular volume, was performed and blood samples were drawn every 6 months for 5 years. Serum concentrations of testosterone were determined by a newly developed LC–MS/MS method, and serum concentrations of INSL3, AMH, inhibin B, FSH, and LH respectively were determined by validated immunoassays. The results showed that serum INSL3 levels increased progressively with increasing age, pubertal onset, and testicular volume. In six of the ten boys, LH increased before the first observed increase in INSL3. In the remaining four boys, the increase in LH and INSL3 was observed at the same examination. The increases in serum concentrations of LH, testosterone, and INSL3 were not parallel or in ordered succession and varied interindividually. We demonstrated that INSL3 concentrations were tightly associated with pubertal onset and increasing testicular volume. However, the pubertal increases in LH, INSL3, and testosterone concentrations were not entirely parallel, suggesting that INSL3 and testosterone may be regulated differently. Thus, we speculate that INSL3 provides additional information on Leydig cell differentiation and function during puberty compared with traditional markers of testicular function.

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