Increased cancellous bone mass accompanies decreased cortical bone mineral density and higher axial deformation in femurs of leptin-deficient obese mice.

Introduction: Leptin is a pleiotropic hormone that regulates food intake and energy homeostasis with enigmatic effects on bone development. It is unclear if leptin promotes or inhibits bone growth. The aim of this study was to characterize the micro-architecture and mechanical competence of femur bones of leptin-deficient mice.

The electrocardiogram on the wrist: a frightening experience to the untrained consumer: a case report.

Background: Smartwatches offering electrocardiogram recordings advertise the benefits of supporting an active and healthy lifestyle. More often, medical professionals are faced with privately acquired electrocardiogram data of undetermined quality recorded by smartwatches. This is boasted by results and suggestions for medical benefits, based on industry-sponsored trials and potentially biased case reports.

Micro-CT data of early physiological cancellous bone formation in the lumbar spine of female C57BL/6 mice.

Micro-CT provides critical data for musculoskeletal research, yielding three-dimensional datasets containing distributions of mineral density. Using high-resolution scans, we quantified changes in the fine architecture of bone in the spine of young mice. This data is made available as a reference to physiological cancellous bone growth.

Normal trabecular vertebral bone is formed via rapid transformation of mineralized spicules: A high-resolution 3D ex-vivo murine study.

At birth, mouse vertebrae have a reticular fine spongy morphology, yet in the adult animal they exhibit elaborate trabecular architectures. Here, we characterize the physiological microstructural transformations in growing young female mice of the widely used C57BL/6 strain. Extensive architectural changes lead to the establishment of mature cancellous bone in the spine.

Nicotine-induced Disturbances of Meiotic Maturation in Cultured Mouse Oocytes: Alterations of Spindle Integrity and Chromosome Alignment.

We investigated whether nicotine exposure in vitro of mouse oocytes affects spindle and chromosome function during meiotic maturation (M-I and M-II). Oocytes in germinal vesicle (GV) stage were cultured in nicotine for 8 h or for 16 h, to assess effects in M-I and in metaphase II (M-II). The latter culture setting used the three protocols: 8 h nicotine then 8 h medium (8N + 8M); 16 h nicotine (16N); 8 h medium then 8 h nicotine (8M + 8N).

Effects of chilling to 0 degrees C on the morphology of meiotic spindles in human metaphase II oocytes.

Objective: To determine the effects of chilling to 0 degrees C on the meiotic spindle of human metaphase II oocytes, as observed by optical sectioning microscopy.

Design: Laboratory study.

Setting: Academic research laboratory in a medical school.

Correlations between two markers of sperm DNA integrity, DNA denaturation and DNA fragmentation, in fertile and infertile men.

Objective: To evaluate two different assays of human sperm DNA integrity, DNA denaturation (DD) and DNA fragmentation (DF), and to correlate these with standard semen parameters.

Design: Prospective, observational study.

Setting: University infertility clinic.

Smoking and reproduction: gene damage to human gametes and embryos.

Assisted conception is a useful methodology for detecting disturbances in clinical outcome, meiotic maturation, and genetic integrity of human gametes. Germinal cells are vulnerable to genetic damage from smoking, but can repair damage during meiosis. In ejaculated spermatozoa, repair capacity declines drastically.

Detection of benzo(a)pyrene diol epoxide-DNA adducts in sperm of men exposed to cigarette smoke.

Objective: To determine whether the adducts formed when benzo(a)pyrene, a diol epoxide derivative, binds covalently to DNA (BPDE-DNA adducts) are detectable in the sperm of men who smoke cigarettes.

Design: Prospective study.

Setting: The Toronto Hospital IVF-ET program.

Detection of benzo[a]pyrene diol epoxide-DNA adducts in embryos from smoking couples: evidence for transmission by spermatozoa.

Tobacco smoking is deleterious to reproduction. Benzo[a]pyrene (B[a]P) is a potent carcinogen in cigarette smoke. Its reactive metabolite induces DNA-adducts, which can cause mutations.

Immunodetection of benzo[a]pyrene adducts in ovarian cells of women exposed to cigarette smoke.

Benzo[a]-pyrene (B[a]P) is a potent mutagen and carcinogen present in cigarettes. We report here on immunodetection and quantification of B[a]P-DNA adducts in granulosa-lutein cells of patients undergoing in-vitro fertilization (IVF) and embryo transfer, who were exposed to cigarette smoke. Follicular fluids (FF) and granulosa-lutein cells were obtained from the same follicular aspirate from 32 women self-reported as active smokers, passive smokers, or non-smokers.

Interovarian differences in levels of cotinine, a major metabolite of nicotine, in women undergoing IVF who are exposed to cigarette smoke.

Purpose: Our purpose was to determine whether there is variation in levels of follicular fluid (FF) cotinine between the two ovaries of women undergoing IVF-ET who are exposed to cigarette smoke.

Methods: In 61 women, there were two to four determinations of FF continine levels for each of two follicles, one from each ovary. For each woman a t test for significant difference between the means of both ovaries was done to test for interovarian variation.

Effects of cigarette smoking and age on the maturation of human oocytes.

We investigated whether cigarette smoking, measured by follicular fluid concentrations of cotinine (a major metabolite of nicotine), affects the maturity of oocytes from women undergoing in-vitro fertilization (IVF) and embryo transfer. In 234 women, follicular fluid samples were assessed for cotinine and their 2020 oocytes were assessed for maturity stage. Data on individual proportions of oocytes which were mature (OM) and were fertilized (OF) were analysed by regression in relation to age and follicular fluid cotinine.

Immunodetection of cotinine protein in granulosa-lutein cells of women exposed to cigarette smoke.

Objective: To detect immunoreactivity to cotinine protein, a major metabolite of nicotine, in granulosa-lutein cells from patients exposed to cigarette smoke, as measured by levels of cotinine in follicular fluid (FF) samples.

Design: Controlled immunocytochemical study.

Setting: Hospital IVF-ET program treating infertile patients.

Cotinine, a major metabolite of nicotine, is detectable in follicular fluids of passive smokers in in vitro fertilization therapy.

Objective: To assess cotinine, a metabolite of nicotine, in follicular fluids (FF) of women who smoke either actively or passively or not all.

Design: Controlled clinical study.

Setting: Infertile patients in a hospital IVF-ET program.

Cigarette smoking may affect meiotic maturation of human oocytes.

There is a strong association between cigarette smoking and reduced fecundity, reduced fertility, and early mean age of menopause, suggesting that smoking may impair oocyte function and viability. We analysed the effect of smoking on meiotic maturation of oocytes. A total of 156 women undergoing in-vitro fertilization therapy, classified as non-smokers (n = 102), passive smokers (n = 21), light smokers (< 15 cigarettes/day; n = 19), and heavy smokers (> or = 15 cigarettes/day, n = 14), participated in this study.

Cadmium accumulation in follicular fluid of women in in vitro fertilization-embryo transfer is higher in smokers.

Objective: To assess cadmium, a heavy metal in cigarette tobacco, in follicular fluid (FF) of women in IVF-ET, who smoke.

Design: Controlled clinical study.

Setting: Infertile patients in a hospital IVF-ET program.

Chromosome status of untransferred (spare) embryos and probability of pregnancy after in-vitro fertilisation.

Many spontaneous abortions are associated with chromosomal abnormality of the fetus. In in-vitro fertilisation (IVF) the chromosome status of untransferred ("spare") embryos and subsequent fate (pregnancy or not) of the transferred sibling embryos might be related. Since the spare and transferred embryos of a patient's cycle genetically are full siblings, the inherited chromosomal abnormalities in spare embryos have a 50% probability of also appearing in transferred embryos.

Cytogenetics of human oocytes, zygotes, and embryos after in vitro fertilization.

Chromosome errors, inherited or arising de novo during gametogenesis and transmitted at fertilization to the conceptus, may be a major cause of embryonic mortality. The in vitro fertilization and embryo transfer (IVF/ET) procedure provides extra material--oocytes, zygotes, and embryos--to investigate the contribution of chromosomal abnormality to implantation failure. This paper reviews the results of cytogenetic studies on such material.

Evidence for maternal predisposition to chromosome aneuploidy in multiple oocytes of some in vitro fertilization patients.

Objectives: To assess the rate of chromosome aneuploidy (e.g., extra or missing chromosomes) in oocytes remaining unfertilized in our in vitro fertilization (IVF) program.

The effect of cryopreservation on the development of S- and G2-phase mouse embryos.

The survival rate and development of four-cell-stage mouse embryos frozen and thawed in S phase versus G2 phase was compared. Significantly more G2-phase than S-phase embryos survived freezing and thawing. In both groups, disruption of the zona pellucida, fusion of blastomeres, and dispersion of chromosomes were occasionally observed after thawing.

Non-poisson distribution of sperm from grandfathers in zona-free hamster ova.

Earlier reports indicated that sperm from 25% of patients from infertile couples, but not from normal or fertile donors, show deviations from the theoretical Poisson distribution of the number of sperm penetrating zona-free hamster ova. Using semen samples from 15 grandfathers (aged 60 to 84 years) and 24 young fathers (aged 25 to 36 years), this study analyzed whether age also has an effect on the distribution. It was found that the overall fit to the Poisson distribution of the samples from grandfathers was very poor; in contrast, the samples from young fathers fit well.

Abnormalities of sperm chromosome condensation in the cytoplasm of immature human oocytes.

This study analysed data from 27 couples in an IVF-ET programme. The maternal age range was 28-43 years. Statistical analyses on 182 oocytes showed no maternal age effect on the number of oocytes, their stage of maturation or their fertilization rate.

Confirmation of an abnormal (non-Poisson) distribution of sperm from some infertile men in the hamster-ovum test.

The present study was carried out to investigate an earlier report that stated that some men of infertile couples (patients), but not normal donors, have an abnormal (non-Poison) distribution of penetrating sperm among ova in the hamster-ovum test. Semen samples from 60 men, 24 proven fathers and 36 patients, were analyzed for agreement with the theoretical Poisson distribution (PD). Most of the fathers (23 of 24) fit PD well, but 10 of the patients did not.

Sperm from some infertile men may consist of several populations.

In the hamster ovum penetration (HOP) test, when ova have equal penetrability and sperm have equal penetrating ability, the distribution of zona-free hamster ova classified by number of penetrating human sperm is expected to follow the Poisson distribution (PD). This study reports tests for PD in HOP tests on 9 infertile patients and 11 normal controls. The data, presented in detail, show the expected PD in the control group.