Structural and functional differentiation of follicular and oviductal mouse oocytes visualised with FITC-protein conjugates.

The fluorescence labelling characteristics of mouse oocytes were examined at various stages of periovulatory differentiation using FITC-protein conjugates. The zona pellucida, perivitelline space and plasma membrane underwent visible changes which were developmentally and environmentally related. Following exposure to fluorescein isothiocyanate (FITC)-casein conjugates, the zona pellucida (ZP) of germinal vesicle stage (GV) ovarian oocytes exhibited a bright, amorphous, mesh-like staining pattern (immature type).

Induction of ovulation and oocyte maturation of amphibian (Rana dybowskii) ovarian follicles by protein kinase C activation in vitro.

We previously reported that protein kinase C (PKC) activation induced meiotic maturation (germinal vesicle breakdown, GVBD) of Rana dybowskii follicular oocytes cultured in vitro without hormone treatment. The experiments reported here were carried out to establish whether ovarian follicles ovulated in response to PKC activation during culture. A phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was used for PKC activation.

Effects of human serum on rat cumulus-oocyte complex functions in vitro: oocyte activation and endocrine secretions.

Secretion of hormones and oocyte meiotic events were assessed following in vitro culture of ovulated rat cumulus-oocyte complexes (COCs) in media containing different types of human serum. Both toxic and nontoxic (determined by mouse embryo test) samples of fetal cord or adult female serum were utilized for these experiments. After short-term culture (4.

Kinetics and dynamics of acute rejection after heterotopic heart transplantation.

Right cervical, heterotopic heart transplantation was performed in 18 mongrel dogs. Study design was based on three different groups (n = 3 x 6). Standard immunosuppression consisted of triple drug therapy in all dogs.

The influence of peat extract on the seminiferous epithelium of mouse testes.

Because of the interest in the peat extract as a potential therapeutic agent, its effect on the seminiferous epithelium cells was studied. Adult male mice were intraperitoneally injected with peat extract during 34 days. At intervals equal to the duration of the cycle of the seminiferous epithelium (every 8.

Carcinoma of the breast and heart transplantation: a case report.

A 35-year-old woman underwent heart transplantation in 1986 because of dilated cardiomyopathy that developed after mitral valve replacements in 1971, 1975, and 1982. Additionally, a carcinoma of the left breast was diagnosed in 1984, leading to mastectomy, and in 1985 a local recurrent tumor had to be resected. In 1988 her gallbladder was removed after repeated episodes of biliary colic.

HIV infection after heart transplantation: a case report.

A 38-year-old man received a heart transplant because of dilated cardiomyopathy in 1984, at a time when no HIV screening test was available. Two and a half years after heart transplantation he was found to be HIV seropositive, but as of March 1990 he was still without symptoms of clinical AIDS. Neither the patient nor the organ donor belonged to any of the known risk groups, and a retrospective analysis revealed that presumably cryoprecipitates of clotting factors were the vectors of transmission.

Regulation of nuclear membrane assembly and maintenance during in vitro maturation of mouse oocytes: role of pyruvate and protein synthesis.

In the absence of a suitable energy source, mouse oocytes cultured in vitro resume, but fail to complete, meiotic maturation. However, little is known about the underlying mechanisms leading to this meiotic failure. We utilized pyruvate-deficient medium to test for the role of pyruvate throughout the meiotic maturation process.

Regulation of parthenogenetic activation of metaphase II mouse oocytes by pyruvate.

We report that parthenogenetic activation (pronuclear formation) is induced during in vitro culture of recently ovulated (13-14 hr post-hCG) mouse oocytes in pyruvate deficient medium. Pronuclear formation occurred when oocytes were cultured in medium containing 1/10X (Pyr-) or lower concentrations of pyruvate but failed to occur either in oocytes cultured in the presence of 0.47 mM (1X, Pyr+) or 1/2X pyruvate or in oocytes cultured in the absence of pyruvate but with cumulus cells.

Mediastinitis and mycotic aneurysm of the aorta after orthotopic heart transplantation.

After cardiac transplantation, bacterial mediastinitis is a rare but dangerous early complication. Of the 113 patients who underwent heart or heart-lung transplantation at our hospital from August 1981 to April 1989, 8 developed purulent mediastinitis. Treatment involved surgical débridment, local irrigation, drainage, and high-dose systemic antibiotics.

Comparison of acute rejection in sensitized ("domino") and unsensitized donor hearts following heterotopic transplantation.

Right cervical heart transplantation was performed in 18 mongrel dogs. Three experimental groups (6 dogs in each) were set up. Group I and II dogs received unsensitized donor hearts, while Group III dogs received the potentially sensitized native hearts of Group I and II dogs, following final rejection episodes in those animals.

Antimyosin monoclonal antibodies for early detection of cardiac allograft rejection.

Sixty-eight indium 111-labeled antimyosin Fab-DTPA imaging studies (0.5 mg intravenously with a radioactivity of 65 to 75 MBq) were executed on 37 of 116 patients undergoing heart transplantation to assess diagnostic accuracy and clinical utility. As controls, 21 patients with cardiomyopathy (n = 8), unstable angina (n = 9), and myocardial infarction (n = 4) were selected.

Induction and inhibition of meiotic maturation of amphibian (Rana dybowskii) follicular oocytes by forskolin and cAMP in vitro.

Previous studies have demonstrated that direct or indirect elevation of cAMP levels in cultured amphibian ovarian follicles simultaneously stimulated production of oocyte maturation-inducing steroid (progesterone) by the follicles and inhibited oocyte maturation induced by endogenous or exogenous hormone. The duration of cAMP stimulation influenced arrest and reinitiation of oocyte meiotic maturation in ovarian follicles of Rana dybowskii. Addition of forskolin (adenylate cyclase stimulator) to cultured follicles inhibited both progesterone- and frog pituitary homogenate (FPH)-induced oocyte maturation.

Induction and inhibition of amphibian (Rana pipiens) oocyte maturation by protease inhibitor (TPCK).

We report for the first time that oocyte nuclear and cytoplasmic maturation are triggered in vitro in non-hormone-treated amphibian (Rana pipiens) ovarian follicles following transient exposure to synthetic chymotrypsin inhibitor N alpha-tosyl-L-phenylalanine-chloromethyl ketone (TPCK). The mechanism of action of TPCK in regulating oocyte maturation was investigated and compared to that induced by progesterone or pituitary hormone. Follicular oocytes failed to mature following continuous exposure to the same doses of TPCK in the presence or absence of progesterone.

Alterations in the cell cycle characteristics of granulosa cells during the periovulatory period: evidence of ovarian and oviductal influences.

Granulosa cells at different stages of differentiation were collected from ovarian follicles and oviducts during the periovulatory period, and their nuclear DNA content was monitored by flow cytometry to establish their cell cycle characteristics (G0 + G1, S, G2 + M). The proportion of cells in the three phases of the cell cycle varied in characteristics patterns depending upon the time they were collected, before or following ovulation. Granulosa (cumulus) cells recovered from ovulated oocytes were mitotically inactive as shown by the large proportion of cells with a 2C amount of DNA and the absence of cells in S phase.

Studies on the Mechanism of Action of Estradiol in Regulating Follicular Progesterone Levels: Effects on cAMP Mediated Events and 3β-Hydroxysteroid Dehydrogenase: (ovarian steroidogenesis/cAMP, 3β-hydroxysteroid dehydrogenase/progesterone/estradiol regulation/Rana pipiens).

Previous studies demonstrated that estradiol interferes with pituitary-induced progesterone production and oocyte maturation in cultured amphibian (Rana pipiens) ovarian follicles. To elucidate the mode of action of estradiol in modulating follicular progesterone accumulation we have examined its effects on cAMP-induced progesterone production and enzymatic conversion of pregnenolone to progesterone by 3β-hydroxysteroid dehydrogenase (3β-HSD). Follicular cAMP levels were manipulated with forskolin (an adenylate cyclase activator), isobutyl methyl xanthine (IBMX-phosphodiesterase inhibitor) and exogenously added cAMP.

Role of protein kinase C activation in oocyte maturation and steroidogenesis in ovarian follicles of Rana pipiens: studies with phorbol 12-myristate 13-acetate.

In ovarian follicles of Rana pipiens, frog pituitary homogenates (FPH) elevate intrafollicular progesterone levels which in turn is thought to induce meiotic resumption in the prophase I arrested oocytes. Calcium plays a role in FPH and steroid-provoked responses in the somatic and gametic components of the follicle, presumably via effects exerted at the plasma membrane of their respective target cells. Many membrane active hormones which utilize Ca2+ in their intracellular transduction also provoke membrane phosphoinositide hydrolysis yielding inositol triphosphate (IP3) and diacyl glycerol (DAG), an activator of the CA2+-dependent protein kinase C (PKC).

Sources of calcium and the involvement of calmodulin during steroidogenesis and oocyte maturation in follicles of Rana pipiens.

In the amphibian ovarian follicle, progesterone production is thought to induce maturation of the enclosed oocyte. Intracellular mechanisms regulating these events in the somatic and germ cells are incompletely understood. However, calcium appears to play a role in the production and action of progesterone.

Cholesterol mediation of progesterone production and oocyte maturation in cultured amphibian (Rana pipiens) ovarian follicles.

Treatment of isolated amphibian ovarian follicles with frog pituitary homogenate (FPH) increases follicular progesterone levels, which, in turn, initiate oocyte maturation. Recent studies have demonstrated that follicular progesterone production requires concomitant protein synthesis at some stage preceding pregnenolone formation. Experiments were carried out to determine whether cholesterol metabolism plays a role in mediating these biochemical and physiological processes.

Calcium effects on progesterone accumulation and oocyte maturation in cultured follicles of Rana pipiens.

Pituitary homogenates (FPH) provoke a cascade of responses in the amphibian ovarian follicle, culminating in progesterone biosynthesis and oocyte maturation (GVBD). Calcium may play an important role as an intracellular second messenger in regulating these physiological responses. Experiments were carried out on cultured, isolated follicles of Rana pipiens to assess the effects of varying extracellular calcium on follicular progesterone accumulation and oocyte maturation.

Role of cAMP in modulating intrafollicular progesterone levels and oocyte maturation in amphibians (Rana pipiens).

The role of cAMP in regulating follicular progesterone levels and oocyte maturation was investigated following in vitro culture of amphibian (Rana pipiens) ovarian follicles. Intrafollicular levels of cAMP were manipulated with the use of a stimulator of cAMP synthesis (forskolin) or by exogenous addition of cAMP alone or either of these in combination with an inhibitor of cAMP catabolism (3-isobutyl-1-methyl xanthine, IBMX). Follicular progesterone content was determined by RIA and oocyte maturation was assessed cytologically.

Protein synthesis and steroidogenesis in amphibian (Rana pipiens) ovarian follicles: studies on the conversion of pregnenolone to progesterone.

Previous experiments demonstrated that protein synthesis was involved in frog pituitary homogenate (FPH)-induced follicular progesterone production. In this study the metabolic conversion of pregnenolone to progesterone, and involvement of protein synthesis in this specific step of the progesterone synthetic pathway, was investigated in vitro cultured ovarian follicles of Rana pipiens. Fully grown follicles were incubated with frog pituitary homogenates or exogenous pregnenolone and progesterone content of follicle extracts and medium were measured by radioimmunoassay.