Comprehensive assessment of cryogenic storage risk and quality management concerns: best practice guidelines for ART labs.

Recent publicized events of cryogenic storage tank failures have created nationwide concern among infertility patients and patients storing embryos and gametes for future use. To assure patient confidence, quality management (QM) plans applied by in vitro fertilization (IVF) laboratories need to include a more comprehensive focus on the cryostorage of reproductive specimens. The purpose of this review is to provide best practice guidelines for the cryogenic storage of sperm, oocytes, embryos, and other reproductive tissues (e.g., testicular and ovarian tissue, cord blood cells, and stem cells) and recommend a strategy of thorough and appropriate quality and risk management procedures aimed to alleviate or minimize the consequences from catastrophic events.

Ultradian sleep-cycle variation of serotonin in the human lateral ventricle.

Serotonin is thought to be intimately involved in the regulation of sleep and waking in humans, though the evidence for such is indirect. Using in vivo microdialysis, the authors show that serotonin in human ventricular CSF covaries with the state of consciousness. They hypothesize that CSF serotonin may be acting in an endocrine-like manner through activation of known leptomeningeal serotonin receptors and possibly participating in modulation of choroidal production of CSF.

Temperature changes in nickel-chromium intracranial depth electrodes during MR scanning.

The authors sought to determine whether there are any heating effects of 1.5-T MR scanning upon nickel-chromium electrodes and to confirm the safety of scanning these electrodes after intracranial surgical implantation in epilepsy patients. Since there was no significant temperature increase of the electrodes tested in their experiments, the authors conclude that nickel-chromium electrodes implanted in the brain are thermally safe for MR scanning.

Early postoperative appearance of radiofrequency lesions on magnetic resonance imaging.

Eleven patients who underwent stereotactic radiofrequency lesions in the central nervous system had magnetic resonance imaging follow-up within 72 hours of surgery to determine the early appearance of their lesions. Eight patients with severe tremor, one with chronic pain, and two with dystonia were analyzed. There were six female patients and five male patients, age 7 to 75 years (mean +/- standard deviation = 42 +/- 21). Magnetic resonance imaging was performed postoperatively at 32 +/- 25 hours (range, 3-72). Postoperative T1-weighted spin echo images demonstrated foci of iso- to hyperintensity surrounded by an edge of hypointensity, and corresponding T2-weighted images showed a lesion with three concentric zones consisting of inner hypointense, middle hyperintense, and outer hypointense zones. Gadolinium increased T1-weighted image lesion visibility, and a ring of enhancement around the zone of hypointensity was observed. Lesions could be seen as early as 3 hours after surgery. The lesions were best shown on gadolinium-enhanced T1-weighted images and on T2-weighted images. The edema surrounding the lesion increased over time, up to the 72 hours studied. These data provide important information on the development of lesion appearance, which may be applied in the development of real-time magnetic resonance imaging monitoring of radiofrequency lesion formation. This technique associated with electrophysiological response and the real-time visualization of the anatomic correlation of the probe may allow for a very precise and selected lesion in the central nervous system for the treatment of functional disorders and brain tumors.

Paired pulse suppression and facilitation in human epileptogenic hippocampal formation.

Paired pulse stimulation has commonly been employed to investigate changes in excitability in epileptic hippocampal tissue employing the in vitro slice preparation. We used paired pulse stimulation in the intact temporal lobe of patients with temporal lobe seizures to compare the excitability of pathways in the epileptogenic hippocampus (located in the temporal lobe in which seizures arise) with those in the non-epileptogenic hippocampus of the contralateral temporal lobe (in the hemisphere to which seizures spread). A total of 20 patients with temporal lobe seizure onsets were studied during chronic depth electrode monitoring for seizure localization. Intracranial in vivo stimulation and recording sites included the hippocampus, entorhinal cortex, subicular cortex and parahippocampal gyrus. A comparison of all hippocampal pathways located in the temporal lobe where seizures typically started (n = 37) with those in temporal lobes contralateral to seizure onset (n = 53) showed significantly greater paired pulse suppression of population post-synaptic potentials on the epileptogenic side (F(1,87) = 6.1, P < 0.01). Similarly, mean paired pulse suppression was significantly greater for epileptogenic perforant path responses than for contralateral perforant path responses (F(1,13) = 7.5, P < 0.01). In contrast, local stimulation activating intrinsic associational pathways of the epileptogenic hippocampus showed decreased paired pulse suppression in comparison to the epileptogenic perforant path. These results may be a functional consequence of the formation of abnormal recurrent inhibitory and recurrent excitatory pathways in the sclerotic hippocampus. Enhanced inhibition may be adaptive in suppressing seizures during interictal periods, while abnormal recurrent excitatory circuits in the presence of enhanced inhibition may drive the hypersynchronization of principal neurons necessary for seizure genesis.

Comparison of seizure related amino acid release in human epileptic hippocampus versus a chronic, kainate rat model of hippocampal epilepsy.

Recent microdialysis studies of excitatory and inhibitory amino acid release associated with paroxysmal hippocampal activity have found significant increases in the hippocampus of epileptic patients, but minimal or variable increases in animal models. One possible reason for the difference is that the animal models employed in these studies have not adequately reflected the pathophysiology of human epilepsy. The present study sought to verify the amino acid release reported in human epileptic hippocampus and then employs animal studies using a chronic rat model of epilepsy, in which rats exhibit spontaneous seizure activity 3 to 4 months after injection of kainic acid into the hippocampus. In agreement with earlier reports, we found increases in glutamate, aspartate and GABA during seizures in human hippocampus. In addition we found increases in taurine which have not previously been reported. The chronic rat model shows increases in the same amino acids as in the human epileptic hippocampus, both during spontaneous seizures and stimulation evoked after-discharges (ADs). In contrast, minimal increases are elicited by hippocampal stimulation in control (non-kainate injected) animals. These results correlate with the degree of mossy fiber reorganization found in the dentate gyrus of kainate rats or epileptic humans.

Stereotactic investigation of limbic epilepsy using a multimodal image analysis system. Technical note.

A methodology has been developed for stereotactic investigation of limbic epilepsy using an image-analysis system that simultaneously displays different structural and functional images of the brain. The validity and accuracy of this system were established with phantom studies. Surgical planning and electrode implantation are guided by stereotactic magnetic resonance imaging, digital subtraction angiography, and position emission tomography. This methodology provides the spatiotemporal relationship of cerebral structure and function necessary to identify seizure onset and propagation in human limbic system epilepsy.

In vitro capacitation of stallion spermatozoa in calcium-free Tyrode's medium and penetration of zona-free hamster eggs.

Capacitation of stallion spermatozoa in Tyrode's calcium-free (TCF) medium was assessed. Twelve gel-free ejaculates were collected. After removal from the seminal plasma, cells were washed three times with 0.85% saline containing 0.1% bovine serum albumin (BSA) and resuspended in TCF. Both washing and incubation media were adjusted to pH 8 and 300 to 310 mOsm. Final sperm concentration during incubation was 2 x 10(6) cells/ml. The diluted ejaculates were incubated for 2, 4, 6, 8 and 10 h at 37 degrees C in an atmosphere containing 5% CO(2). Acrosomes were stained with naphthol yellow and erythrocin B initially and after each incubation period and evaluated microscopically. Transmission electron microscopy was used to verify whether normal acrosome reaction was occurring or if cells were degenerating. Penetration of zona-free hamster oocytes was evaluated using 10(3) to 10(4) sperm/ml suspension and coincubating eggs for 3.5 to 4 h with sperm. Penetration tests were done for wash and incubation treatments and recorded positive when swollen sperm heads or male pronuclei were present. Incubation time affected acrosome integrity (P<0.001). Incubation for 8 to 10 h significantly improved acrosome reaction (P<0.001) and the percentage of reacted acrosomes increased sharply after 6 h of incubation (P<0.001). None of the washed sperm penetrated zona-free eggs at zero time, but sperm from all incubation treatments penetrated eggs. A peak penetration rate of 29.9% was observed at 8 h (P<0.001). Results indicate that under the conditions used, the requirement for Ca(++) in the medium for the process of capacitation and acrosome reaction can be substituted for by elevated pH.

Hormonal induction of incubation behavior in ovariectomized female turkeys (Meleagris gallopavo).

Two experiments were conducted to evaluate the effect of estradiol benzoate (EB), progesterone (P), ovine prolactin (oPrl), or their combinations on temporal patterns of serum luteinizing hormone (LH) and Prl and on nesting behavior in adult ovariectomized female turkeys. Levels of serum LH were initially reduced (p greater than 0.05) by the steroid treatments, while continuation of treatments induced surges of LH to levels comparable to pretreatment levels. Administration of steroid increased (p less than 0.05) levels of serum Prl, which persisted until termination of treatments. Administration of oPrl had no effect on levels of serum LH but blunted the steroid-induced release of Prl. Neither EB, P, nor oPrl treatments alone nor a combination of EB + P elicited nest occupation. Nest occupation was observed after administration of P only in turkeys pretreated with EB. Administration of oPrl maintained and advanced the P-induced nesting to persistent nesting behavior (incubation behavior). Once persistent nesting behavior was established, hormonal treatments were terminated, yet nesting behavior was maintained and serum samples showed increasing levels of Prl and decreasing levels of LH. It is suggested that incubation behavior in the female turkey is facilitated by the combined action of estradiol, P, and Prl.

Effects of estrogen and progesterone on serum prolactin and luteinizing hormone levels in ovariectomized turkeys (Meleagris gallopavo).

Serum prolactin (PRL) and luteinizing hormone (LH) levels from mature female turkeys were determined following ovariectomy and daily subcutaneous injections for 4 or 9 days of 0.002-2.0 mg/kg estradiol benzoate (EB), 0.05-2.0 mg/kg progesterone (P), or their combinations. Serum PRL levels were increased (P less than 0.05) at the onset of sexual maturity in intact controls, but not in ovariectomized turkeys. Injection of 0.02 mg/kg EB into ovariectomized turkeys resulted in elevated (P less than 0.05) serum PRL levels after 8 treatment days. Higher doses failed to elicit a response of greater magnitude. EB at doses of 0.02-2.0 mg/kg reduced LH levels while 0.002 mg/kg EB increased LH levels above (P less than 0.05) those of ovariectomized controls. The 1.0-mg/kg P dose increased (P less than 0.05) serum PRL within 24-48 hr of administration while the 0.05-, 0.5-, or 2.0-mg/kg P doses failed to elicit a response. When P was injected in doses of 0.5-2.0 mg/kg, LH levels were decreased in a dose-response manner. The injection of EB combined with P had a variable effect on serum PRL levels. The 0.5- or 1.0-mg/kg dose of P facilitated (advanced in time) the rise in serum PRL level induced by 0.02 mg/kg of EB. In contrast, the positive feedback effect of 0.2 mg/kg of EB was blocked when administered with 0.5 mg/kg of P. Serum LH levels were dramatically decreased by all steroid combinations used. These results indicate that daily injections of EB and/or P in ovariectomized turkeys have a variable effect on serum PRL and LH levels depending upon the dose, the duration of treatment, or the ratio between EB and P.

Reinitiation of ovulatory cycles in incubating female turkeys by an inhibitor of serotonin synthesis, P-chlorophenylalanine.

Nest deprivation of incubating turkeys caused a decrease in serum prolactin (Prl) levels from 1184.5 +/- 116.4 ng/ml to 896.8 +/- 83.0 ng/ml 1 day after initiation of deprivation, with a further decline to 156.5 +/- 111.7 ng/ml at the end of the 22-day experimental period. Serum luteinizing hormone (LH), progesterone and estradiol levels following nest deprivation were similar to those in birds allowed to incubate (controls). Oral administration of p-chlorophenylalanine (PCPA, 50 mg/kg) to incubating turkeys for 3 consecutive days reduced nesting frequency (P less than 0.05) on the 4th day after initiation of treatment and the nesting virtually ceased by the 9th day. Pretreatment Prl was 1655 +/- 210 ng/ml and declined (P less than 0.05) after PCPA administration to a low of 28.6 +/- 2.8 ng/ml. In addition, PCPA caused a sustained rise in serum LH peaking (5.59 +/- 1.09 ng/ml) 3 days after treatment initiation. Contrary to nest deprivation, serum levels of progesterone and estradiol increased (P less than 0.05) as a consequence of PCPA treatment. Seven of 8 PCPA-treated birds later came into lay when their Prl levels and nesting frequency increased again. The results suggest a role for serotonin (5-HT) in incubation behavior, and Prl and LH secretion in turkeys.

Inhibitory influence of catecholamines on prolactin release in the turkey (Meleagris gallopavo).

The involvement of catecholamines (CAs) in the control of prolactin (PRL) secretion was investigated in female turkeys. The birds were treated with DL-alpha-methyltyrosine methyl ester HCl (alpha-MT; 10, 100, or 200 mg/kg), diethyldithiocarbamate (DDC; 200 or 400 mg/kg), or phentolamine (5, 10, and 20 mg/kg), all antiadrenergic drugs. Reduction in central CAs by alpha-MT or DDC, or blockade of adrenergic receptors by phentolamine resulted in elevated serum PRL levels in a dose-dependent manner. Prior administration of the adrenergic stimulant clonidine (15, 150, or 1500 micrograms/kg) attenuated the elevated PRL response to phentolamine (20 mg/kg). These results are consistent with the view that the release of PRL in the turkey may be under the inhibitory influence of an adrenergic system.

Correlation between MRI-based stereotactic thalamic deep brain stimulation electrode placement, macroelectrode stimulation and clinical response to tremor control.

In this study we compared the position of the electronically active contact of the thalamic (Vim) deep brain stimulation (DBS) electrode to the stereotactic location of its tip. Fifteen patients with either Parkinson's disease (PD) or essential tremor (ET) underwent stereotactic, MRI-based placement of the Medtronic quadripolar DBS electrode. An overall improvement of 69% was achieved in the tremor scores during a period of 1-13 months after implantation of the DBS electrode. Eleven patients with ET showed 70% clinical improvement of tremor, compared to a 58% response observed in the 4 patients with PD. The electrode tip center was 11.2 +/- 1.54 mm lateral to the third ventricular wall, 5.38 +/- 1.02 mm anterior to the posterior commissure and 2.9 +/- 3.57 mm inferior to the level of AC-PC line. The most significant deviation from the planned stereotactic target was observed in the Z-coordinate. In our group of patients, stimulation settings favored the contacts closer to the AC-PC line, correcting the electrode tip position to 0.80 +/- 2.84 mm (p < 0.001) inferior to the level of the AC-PC line. In our experience, thalamic DBS offers a reversible and adjustable 'lesion' to compensate for the anatomic variabilities encountered in the positioning of the DBS electrode tip.

Effect of ambient temperature on serum prolactin and luteinizing hormone levels during the reproductive life cycle of the female turkey (Meleagris gallopavo).

An ambient temperature of 30 degrees C compared to 18 degrees C accelerated the increase in serum prolactin (Prl) level induced by photostimulation of female turkeys. The contribution of reproductive stage and nesting behavior to this serum Prl elevation was assessed by housing adult female turkeys in individual wire cages while allowing other females free access to nests on the floor. Birds of both groups were exposed to 10 degrees C, 24 degrees C or 30 degrees C beginning 4 wk prior to photostimulation and continuing throughout the reproductive phase. Lapsed time between the onset of photostimulation and onset of sexual maturity, and between the onset of sexual maturity and onset of incubation behavior was shorter in birds housed at 30 degrees C with access to nests than in corresponding birds housed at 24 degrees C and 10 degrees C. The increases in serum Prl associated with sexual maturity or incubation behavior occurred at a greater rate in the birds maintained at 30 degrees C. Cage-reared birds had the same lapsed time between onset of photostimulation and onset of sexual maturity and the same sustained low Prl level regardless of ambient temperature exposure. All groups exhibited similar luteinizing hormone profiles. These findings indicate that the accelerated increase in Prl under elevated temperature in floor-reared turkeys is related to accelerated development of reproductive function, and not the direct effect of ambient temperature on mechanisms controlling Prl.

Accuracy of MR-guided stereotactic electrode implantation. 1. Preimplantation correlation with the Talairach system.

The accuracy of stereotactic electrode implantation using MR guidance and a computerized imaging system was compared to the conventional Talairach system, using ventriculography and a stereotactic atlas. A combined methodology of two stereotactic approaches was used, with a modified Leksell and a Todd-Wells frame. The coordinates of temporo-limbic structures and the length of the AC-PC line were measured prior to implantation in 10 epileptic patients undergoing the combined procedure. Relative differences in single and three-dimensional values were obtained for 68 targets within the temporal lobe. Lengths of AC-PC lines were measured in 9 patients. Statistical differences were found for all temporal coordinates, but the AC-PC line did not differ significantly.

Hypothalamic and serum factors influence on prolactin and luteinizing hormone release by the pituitary gland of the young turkey (Meleagris gallopavo).

Intravenous administration of 1.0 or 3.0 eq hypothalamic extract (HE) to 8-week-old male and 7-week-old female turkeys, respectively, induced an increase in circulating prolactin (PRL) levels but had no effect on circulating luteinizing hormone (LH) levels. The incubation of dissociated anterior pituitary cells from 13-week-old female turkeys with HE induced a dose-related increase in PRL release; however, only the highest dose of HE induced an increase in LH release. Coincubation of a hypothalamic fragment with anterior pituitary cells from 9-week-old females induced a release of both PRL and LH. Dissociated pituitary cells from 11-week-old females initially incubated for 3 hr in medium containing charcoal-treated (stripped) turkey serum yielded a larger release of PRL and LH in the presence of HE than did cells initially incubated with turkey serum or no serum. Luteinizing hormone-releasing hormone (LHRH) induction of LH release was greatest from cells initially incubated with stripped serum for 3 or 24 hr. The LHRH-induced LH release was completely blocked in cells initially incubated for 24 hr with turkey serum. The initial incubation of cells for 24 hr with stripped serum yielded a larger release of PRL and LH in response to HE than did cells initially incubated with serum. The hypothalamus of the young turkey contains substantial PRL-releasing activity as well as LH-releasing activity. The ability of the releasing factors to stimulate pituitary hormone release is influenced by factors present in the blood of the young turkey. This is especially evident in the LHRH-induced LH release where serum factors inhibited the release.

The influence of thyrotropin releasing hormone on in vivo prolactin release and in vitro prolactin, luteinizing hormone, and growth hormone release from dispersed pituitary cells of the young turkey (Meleagris gallopavo).

Intravenous administration of 0.025, 0.25, or 2.5 micrograms/kg thyrotropin releasing hormone (TRH) to 4-week-old female turkeys induced a dose-dependent increase (P = 0.004) in serum prolactin (PRL) 15 min post-treatment. Dispersed anterior pituitary cell cultures were utilized to determine the effect of TRH on cellular release of PRL, luteinizing hormone (LH), and growth hormone (GH). In the first experiment, cells from 13-week-old male turkeys were initially incubated for 24 hr in Medium 199 (M-199) plus 10% turkey serum and then placed in M-199 plus 10(-10) to 10(-4) M TRH for 5 hr. Incubation with TRH produced no change in PRL release from that of spontaneous release (P = 0.854). However, 10(-5) and 10(-4) M TRH induced LH release (P less than 0.0001). The TRH-induced GH response was parabolic (P less than 0.0001), with the maximal release at 10(-8) M. The second experiment, utilizing pituitary cells from 7-week-old females, studied these responses on 3, 5, and 7 days of monolayer incubation. TRH failed to induce a PRL release in all tests (P greater than 0.162), although hypothalamic extract induced a large release (P less than 0.0001) of PRL each time. Both 10(-6) and 10(-4) M TRH induced a LH release on Day 3 while only 10(-4) M did so on Day 5, and none of the doses elicited a release on Day 7. The parabolic GH response generally persisted in all tests.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of acute or repeated immobilization on plasma prolactin levels in the turkey (Meleagris gallopavo).

Three experiments were conducted to evaluate the effect of immobilization on plasma prolactin (PRL) levels in the immature turkey. Acute immobilization for 120 min resulted in elevated PRL levels (P less than 0.05) starting 15 min after the onset of immobilization. Release from immobilization caused PRL levels to return to those of the nonimmobilized controls by 120-180 min following replacement of the turkeys in cages. Repeated immobilization for 3 or 5 consecutive days diminished PRL response (P less than 0.05) to subsequent immobilization. It is suggested that the PRL controlling mechanism(s) of the young turkey is both susceptible and able to habituate to changes induced by immobilization stress.

The significance of elevated progesterone at the time of administration of human chorionic gonadotropin may be related to luteal support.

PURPOSE: Our purpose was to determine if the progesterone concentration on the day of HCG administration is associated with the establishment of pregnancy in IVF patients. METHODS: Concentrations of progesterone on the day of hCG were examined retrospectively in 293 patients with ovarian hyperstimulation induced by GnRH agonist with hMG and/or FSH. Patients were grouped based on progesterone concentration: < 0.9, 0.9 to < 1.2, 1.2 to < 1.5, and > or = 1.5 ng/ml. Oocytes recovered, fertilization rate, and pregnancy rate were compared among groups. RESULTS: Patients with a higher concentration of progesterone had increased concentrations of estradiol and greater numbers of oocytes retrieved. No differences were found for fertilization rate, polyploid fertilization, or pregnancy rate. It was noted that there was an association between the type of luteal support and the effect of high preovulatory progesterone on pregnancy rate. CONCLUSIONS: These data suggest that oocytes and embryos derived from patients with high preovulatory progesterone are not of a reduced quality. The association of high progesterone concentrations with a reduced rate of pregnancy varied with the type of luteal support.

Multimodality imaging of brain structures for stereotactic surgery.

An image analysis system was developed for stereotactic neurosurgery that allows the simultaneous display of brain images from different imaging devices obtained in different orientations. The system is based on a stereotactic frame and a microcomputer and features an easy user interface together with point registration and region of interest analysis in three-dimensional space. A dynamic multi-image environment allows for simultaneous display of magnetic resonance, computed tomography, digital subtraction angiography, and positron emission tomography images in multiple windows, adjusted for common coordinates with reference to stereotactic frame fiducial markers. Linkages between images allow information interchange between different modalities and different views: Points and regions defined in one image can be transferred to others, and cursor coordinates in one image can be calculated and dynamically projected in other images. Phantom studies show that the system distortions are minor and that the system is suitable for clinical use. The system provides exceptional advantages over previous imaging procedures for stereotactic surgery.