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Biomedical subjects

J B Lessing

Publications and source records attributed to J B Lessing.

At least 235 records · Page 13Linked to original sources
PubMed1985

Relaxinlike bioactivity in pooled human pregnancy serum.

The purpose of this study was to determine whether or not the immunoreactive relaxin contained in human pregnancy serum is biologically active. Relaxin was extracted from pooled serum of women in the third trimester of pregnancy. The extraction also was performed on pooled male serum and pooled serum from women in the follicular phase of the menstrual cycle. The extraction process began with delipidation of the serum followed by extraction of relaxin using 0.1% HCl per 50% acetone. Dialysis then was performed to remove low molecular weight substances (less than 3500 daltons). The partially purified extracts were applied individually to a muscle segment in the in vitro rat uterine horn bioassay for relaxin. The extracts of both male serum and female follicular-phase serum, containing no immunoreactive relaxin, resulted in tetanic contractions of the muscle segment. The extract of pregnancy serum, containing immunoreactive relaxin, produced inhibition of rat uterine horn contractility. This represents the first demonstration of relaxinlike bioactivity in human serum.

Animals↗
PubMed1985

Hyperprolactinemia and associated pituitary prolactinomas.

The association between serum prolactin (PRL) and the presence of pituitary tumors as determined by third generation computed tomography scan was studied in hyperprolactinemic patients. Patient charts from a four-year period were reviewed to identify those patients with elevated PRL (greater than or equal to 25 ng/mL). All patients with hyperprolactinemia underwent computed tomography scan evaluation of the pituitary gland. Hyperprolactinemia was identified in 79 patients, mean PRL 59 +/- 6.1 ng/mL SEM. Pituitary tumors were identified in 35 of these patients, mean PRL 65 +/- 11.9 ng/mL. This level was not significantly different from the level in 43 patients with normal computed tomography scans (52 +/- 5.7 ng/mL). This review found that computed tomography scan identified pituitary tumors in 44% (35 of 79) of patients with hyperprolactinemia. The likelihood of finding a pituitary tumor did not correlate with the level of hyperprolactinemia. Computed tomography scan is indicated for the diagnosis of prolactinomas in all hyperprolactinemic patients regardless of the serum PRL level.

Adenoma↗
PubMed1984

The effect of in vivo progesterone administration on relaxin-inhibited rat uterine contractions.

Progesterone pretreatment in vitro was previously shown to sensitize myometrium to the inhibiting effect of relaxin. The following experiments were performed to control for possible artifacts of the in vitro system and to place these studies on a more physiologic basis. Immature rats were treated with estrogen and either progesterone or vehicle only. Uterine horn segments were isolated and mounted in a muscle bath. After a baseline contraction pattern was established by means of electrical stimulation, porcine relaxin was added to the bath. At all dose levels of relaxin, greater inhibition of contraction amplitude occurred in uterine segments of progesterone-treated animals. Since both progesterone and relaxin are present in the circulation from the time of the missed menses in human pregnancy, this interaction suggests a physiologic synergism in the maintenance of early human pregnancy.

Animals↗
PubMed1984

Stimulation of human sperm cervical mucus penetration in vitro by relaxin.

The effect of relaxin, a peptide hormone present in seminal plasma, on the penetration of cervical mucus by washed human sperm in vitro was studied. Penetration was analyzed by two methods. The total number of sperm per 100 X field at the 10-mm, 20-mm, and 30-mm points along a mucus-filled capillary tube was counted and the farthest distance 100 sperm and 5 sperm/100 X field penetrated the capillary tube was measured. These measurements were made at 30, 60, and 90 minutes. Treating washed sperm with physiologic concentrations of relaxin resulted in significantly increased sperm penetration as compared with sperm treated with albumin or buffer. Replacing seminal plasma to washed sperm resulted in equivalently increased penetration. The findings strongly suggest that relaxin is necessary for proper penetration of cervical mucus by human sperm.

Albumins↗
PubMed1984

The effect of an anti-insulin antiserum on human sperm motility.

Inhibition of sperm motility by anti-relaxin antiserum has been previously reported. This effect may be secondary to a nonspecific effect of immunoglobulins binding to sperm or to a specific inhibition of relaxin activity at the sperm surface. The current investigation demonstrates that an anti-insulin antiserum does not inhibit sperm motility in the same system in which an anti-relaxin antiserum results in inhibition. This supports the hypothesis that the anti-relaxin antiserum effect is specific.

Humans↗
PubMed1984

Effect of prolactin and relaxin on in vitro rat uterine contractions and prolactin interaction with relaxin.

The balance between relaxin and prolactin has been suggested to be significant in the control of uterine activity during pregnancy. The current study was designed to determine the effect of rat prolactin on rat uterine horn segment contractility and its interaction with relaxin. Rat uterine segments mounted on a smooth muscle transducer were treated sequentially with prolactin and relaxin, and stimulated electrically. No stimulatory effect of prolactin was noted. Relaxin-inhibited uterine horn segment activity was not altered by prolactin. The reported stimulatory effect of prolactin may have been a pharmacologic effect of human prolactin on rat uterine horn segments, or may have resulted from contaminants in the preparations used.

Animals↗
PubMed1983

[Relaxin].

Explore the source record for details and available documents.

Humans↗
PubMed1983

Amniotic fluid embolism and disseminated intravascular coagulation complicating hypertonic saline-induced abortion.

Amniotic fluid embolism (AFE) associated with disseminated intravascular clotting (DIC) is usually fatal. Such a combination generally occurs at the term of pregnancy or in the immediate postpartum period. A case of AFE with DIC following a hypertonic-saline-induced abortion, is reported. The patient was in the midtrimester with a live fetus. Prompt recognition and treatment of her condition ensured her complete recovery. Such a case has not, to our knowledge, been previously reported.

Abortion, Induced↗
PubMed1982

Paradoxical hypersecretion of growth hormone in patients with endometrial atypical hyperplasia and carcinoma. Effect of hysterectomy.

Paradoxical hypersecretion of human growth hormone (HGH) followed a glucose load in patients with endometrial cancer and atypical hyperplasia of the endometrium. All patients had normal fasting plasma glucose and serum HGH concentration with a normal glucose tolerance curve. Their urinary estrogen concentrations were within the normal postmenopausal range. 6 months after abdominal total hysterectomy and bilateral oophorectomy, the glucose load was repeated. Following surgery all patients showed a normal suppression of HGH secretion during the hyperglycemic period. These findings suggest the existence of a HGH-releasing factor in the neoplastic and preneoplastic endometrial tissue. This factor might be related to the abnormal HGH responses observed.

Aged↗
PubMedDate not supplied

Excess expression of uterine ribosomal protein genes P2 and S25 during the "implantation window" in the rat.

OBJECTIVE: The present study describes the isolation of "implantation-related" uterine cDNA clones. It further describes their temporal and spatial expression and their identification as the messengers for two ribosomal proteins: RP2 and RS25. METHODS: Libraries of cDNA, representing spayed rats treated with progesterone for 3 consecutive days and with estrogen for either 12 or 36 hours, were screened using homologous and heterologous probes. Two cDNA clones showing differential intensity of the signal were sequenced, the timing of their expression was analyzed by Northern analysis, and their spatial expression was visualized by in situ hybridization. RESULTS: The steady-state level of RP2 mRNA was temporally and spatially controlled by estrogen and progesterone. Whereas estrogen, alone or in combination with progesterone, stimulated this gene, the spatial distribution of the activation was different. Estradiol alone directed RP2 expression to the endometrial-myometrial border, whereas combined treatment increased epithelial staining and directed heavy expression to the stratum vasculare. In normal pregnancy, during the implantation-window period, RP2 was mainly expressed on the mesometrial side, with much less staining on the antimesometrial side. The steady-state levels of the RS25 messenger were elevated by estrogen alone or in combination with progesterone and were confined to the uterine epithelium. RS25 mRNA was evenly distributed throughout the uterine stroma during implantation. CONCLUSION: A developmental pattern of expression of RP2 is reported that corresponds temporally with the primary decidual response but is spatially expressed at the site of the secondary response.

Amino Acid Sequence↗
PubMedDate not supplied

Probability of sperm detection in nonobstructive azoospermic men undergoing testicular sperm extraction procedures unrelated to clinical parameters.

The study was conducted to evaluate the significance of preoperative clinical parameters for detection of mature testicular sperm cells in nonobstructive azoospermic men. Sixty-five consecutive men with nonobstructive azoospermia underwent testicular sperm extraction procedures. Testicular samples were analyzed histologically with patterns classified as mature spermatogenesis (normal or partial), arrest of spermatogenesis, and Sertoli cell only. Testicular sperm cells were isolated for use in an IVF/ICSI program. Histologic patterns and detection rate of sperm cells were correlated to clinical characteristics. Mature sperm cells were found in all levels of serum FSH. The men were divided into 3 groups based on their clinical characteristics (serum FSH level and testicular size). The distribution of the different testicular histologic patterns, as well as detection rate of sperm cells, was similar in all groups. No correlation was found between serum levels of FSH, LH, prolactin, or testosterone and sperm presence. None of these parameters, nor the testicular size and consistency, can serve as predictive variables of the histological pattern or the presence of mature sperm cells in the testicular biopsies in cases of nonobstructive azoospermia. Until an effective predictive tool is available, a trial of sperm retrieval is recommended for all azoospermic men independent of their clinical characteristics.

Adult↗
PubMedDate not supplied

The expression of mannose-ligand receptor is correlated with sperm morphology.

The objective of the present study was to evaluate the association between the expression of sperm mannose-ligand receptors and sperm morphology. Sperm samples were obtained from 45 men, 30 fertile sperm donors and 15 infertile men. Sperm concentration, motility and morphology were evaluated and then incubated with control medium (Ham's F-10 + 1% HSA) for 4 h. Expression of mannose-ligand receptors was evaluated by mannosylated-BSA-FITC (subdivided into 3 patterns: I, for uncapacitated sperm; II, for capacitated; and III, for acrosome-reacted sperm). The mean (+/- SE) frequencies of sperm cells of the total sperm population that expressed patterns I, II, and III were 88 +/- 2.1%, 7 +/- 1.6%, and 5 +/- 0.8%, respectively, for fertile men, and 90 +/- 2.1%, 7 +/- 1.3%, and 3 +/- 0.5%, respectively, for infertile men. The rate of pattern III expression of mannose-ligand receptors was significantly higher in the fertile group compared to the infertile patients (p <.01). A poor but significant correlation was observed between the rate of pattern III and the percentage of normal-forms sperm cell in the ejaculate (r =.35, p =.018). Fertile sperm samples express more advanced patterns of mannose-ligand receptors compared to infertile men. This phenomenon is related to the morphology of human sperm cell in the ejaculate more than to any other basic sperm characteristics.

Humans↗
PubMedDate not supplied

Improvement in the cervical mucus penetration test by using standard sperm control.

The objective of the present experiments was to establish an acceptable standard for the cervical mucus penetration test (CMPT) by determining the minimal progressive motile spermatozoa concentration (PMSC) that will yield the highest score for proven fertile donor sperm specimens. For this purpose, fresh and frozen-thawed samples were used. Semen was obtained from 29 fertile donors and different PMSC (8, 10, and 14 x 10(6)/mL) were prepared for each sample. The same mucus specimen was used for testing each sperm sample in the three different dilutions. No difference in the scoring of the CMPT between the fresh vs. frozen-thawed groups was found. When PMSC of 14 x 10(6)/mL was used, almost all specimens scored the highest rank. The present study revealed that only semen samples with a minimal PMSC of 14 x 10(6)/mL cells can be used in the CMPT. The information that the freeze-thaw process does not affect the CMPT results supports the concept of cryopreservation of pooled fertile donor specimens in aliquots with adequate concentration of progressive motile spermatozoa for later use as a CMPT control.

Cervix Mucus↗