Adrenaline and the development of spontaneous hypertension in rats

The effects of chronic alterations in plasma adrenaline levels, on the development of a raised blood pressure in young spontaneously hypertensive (SHR) rats, have been investigated. Bilateral adrenal demedullation (at 4 weeks) significantly reduced plasma adrenaline levels and attenuated the development of hypertension. Pressor responses to phenylephrine (0.3-10 micrograms, i.v.), measured in the pithed animals 11 weeks after demedullation, were unaffected although neurogenic pressor responses were significantly reduced. Subcutaneous implants of procaterol and salbutamol (0.005 and 0.165 mumol/kg, respectively) restored hypertension development in demedullated rats and significantly enhanced neurogenic pressor responses, while responses to i.v. phenylephrine remained unaltered, in the pithed rats. Implants of adrenaline (0.165 and 0.5 mumol/kg, s.c.) also restored hypertension development. However, pressor responses to phenylephrine were reduced and neurogenic responses only slightly enhanced when compared to those obtained in untreated pithed demedullated rats. The pro-hypertensive effect of adrenaline (0.5 mumol/kg, s.c.) was abolished by treatment with the beta 2-adrenoreceptor selective antagonist ICI 118551 (25 mg/kg/day, p.o.). In the subsequently pithed rats, neurogenic pressor responses were slightly reduced when compared to those in animals treated with adrenaline alone. In control demedullated rats, ICI 118551 had no effect on blood pressure nor on the neurogenic and phenylephrine-induced pressor responses. However, in sham-operated animals, ICI 118551 attenuated the development of hypertension and significantly reduced neurogenic pressor responses in the subsequently pithed rats. Responses to phenylephrine remained unaltered. The results support the suggestion that a beta 2-adrenoreceptor-mediated facilitation of sympathetic neurotransmission may be involved in mediating the pro-hypertensive effects of circulating adrenaline in the SHR rat.

Culture factors affecting the success rate of in vitro fertilization and embryo transfer

The development of one-cell mouse zygotes to the blastocyst stage in vitro has been used as a quality control for the media and handling procedures employed for human in vitro fertilization and embryo transfer (IVF/ET). One-cell mouse zygotes were placed in culture in medium containing bovine serum albumin. Aliquots of the same batch of medium containing female patients' homologous serum were used for the fertilization and culture of human oocytes. The following procedures were associated with high rates of mouse embryo development and human pregnancies following IVF/ET: adequate gassing and equilibration of the medium, double-rinsing of pipets and catheters used to handle embryos, use of a HEPES-buffered medium for manipulating embryos in the absence of an atmosphere containing 5% CO2, control of excessive temperature in the vicinity of the embryos, and ET using medium containing 50% patient's serum. The institution of these procedures gave more consistent pregnancy rates. However, there was no obvious association between fertilization and cleavage of human oocytes and the quality of the medium ascertained by the mouse embryo development test. In a continuing trial, we are comparing two culture media (modified Tyrode's and a medium formulated on the composition of human fallopian tube fluid [HTF]) and two culture techniques (culture in medium under oil in petri dishes and in loosely capped tubes). Significantly more mouse zygotes developed in HTF medium compared to Tyrode's medium. In a randomized 2 X 2 factorial trial with human IVF/ET, the highest pregnancy rate occurred when fertilization and culture were carried out in HTF medium under oil, but numbers are not yet sufficient to show any statistical difference between treatments.

The presentation and complications of odontogenic septic shock. Report of a case

Although most odontogenic infections spread locally to adjacent fascial spaces, usually contiguous with the offending odontogenic pathosis, occasionally such an infection can spread rapidly across the midline and appear on the opposite side of the face and neck. Debilitated chronic alcohol abusers who are nutritionally deficient are more likely to develop serious life-threatening infections, either through serious airway involvement as seen in Ludwig's angina or manifest as a gram-negative septicemia with life-threatening shock and even cardiac arrest, than the usual dental patient with cellulitis. Early recognition through a high index of suspicion and vigorous monitoring will pick up the initial manifestation of toxic shock, as noted in this case report.

Epinephrine enhances neurogenic vasoconstriction in the rat perfused kidney

Epinephrine has been implicated in the genesis of some forms of hypertension. We have investigated the effects of epinephrine on vasoconstrictor responses evoked by adrenergic stimuli in the isolated perfused rat kidney. Low concentrations of epinephrine (2.5 - 5 X 10(-9) M) increased the amplitude of vasoconstrictor responses evoked by electrical stimulation of the renal adrenergic nerves. These concentrations of epinephrine had no effect on the basal perfusion pressure of the kidney or on the amplitude of vasoconstrictor responses evoked by exogenous norepinephrine. The potentiating effect of epinephrine persisted after infusion of the amine had ceased. Kidneys that had been perfused with 3H-epinephrine accumulated radioactivity, which could then be released by renal nerve stimulation. Cocaine (3 X 10(-5) M) reduced the renal accumulation of 3H-epinephrine and abolished both the persistent potentiating effect of the amine and the release of radioactivity evoked by subsequent nerve stimulation. The potentiating effect of epinephrine infusion was abolished by the beta 2-selective adrenergic receptor antagonist ICI 118,551 (3 X 10(-8) M), but not by the beta 1-selective adrenergic receptor antagonist atenolol (10(-6) M). These results indicate that concentrations of epinephrine that can be achieved during acute stress can enhance the amplitude of neurogenic vasoconstrictor responses. This effect appears to be mediated via a prejunctional beta 2-adrenergic receptor. The persistent nature of this effect may be due to the neuronal accumulation and subsequent release of epinephrine.

Adrenaline and the development of genetic hypertension

The effects, on the development of a raised blood pressure in spontaneously hypertensive (SHR) rats, of bilateral adrenal demedullation and subcutaneous slow-release implants containing adrenaline, salbutamol and procaterol were studied. Systolic blood pressure (SBP) measurements were made, using an indirect tail-cuff method in groups of male SHR rats aged from three to 14 weeks, which were sham-operated or bilaterally adrenal demedullated under ether anaesthesia at four weeks of age. Bilateral adrenal demedullation attenuated the development of a raised blood pressure, while slow-release implants of adrenaline restored the development of hypertension in adrenal demedullated rats and this effect was abolished by concomitant treatment with the beta 2-adrenoceptor antagonist [C] 118551. Implants of salbutamol and procaterol were also effective in restoring hypertension development in adrenal demedullated rats. It is suggested that adrenaline exerts its pro-hypertensive effects via an action at beta 2-adrenoceptors; possibly those located prejunctionally which are involved in the facilitation of sympathetic neurotransmission.

Beta 2-adrenoceptors mediate adrenaline's facilitation of neurogenic vasoconstriction

Acute bilateral adrenal demedullation significantly reduced pressor responses in pithed spontaneously hypertensive rats. The subsequent infusion of adrenaline (50 ng/min i.v.) significantly enhanced neurogenic pressor responses without affecting those induced by noradrenaline. The adrenaline-induced enhancement of neurogenic pressor responses was unaffected by pretreatment with the beta 1-selective adrenoceptor antagonist atenolol (0.3 mg/kg i.v.), but was completely abolished by pretreatment with the beta 2-selective antagonist ICI 118551 (0.01 mg/kg i.v.). Pressor responses to noradrenaline remained unaltered.

Density of newly synthesized plasma membrane proteins in intracellular membranes II. Biochemical studies

Using two independent methods, incorporation of radioactive amino-acid and quantitative immunoblotting, we have determined that the rate of synthesis of each of the Semliki Forest virus (SFV) proteins in infected baby hamster kidney (BHK) cells is 1.2 X 10(5) copies/cell/min. Given the absolute surface areas of the endoplasmic reticulum and Golgi complex presented in the companion paper (Griffiths, G., G. Warren, P. Quinn , O. Mathieu - Costello , and A. Hoppeler , 1984, J. Cell Biol. 98:2133-2141), and the approximate time spent in these organelles during their passage to the plasma membrane (Green J., G. Griffiths, D. Louvard , P. Quinn , and G. Warren 1981, J. Mol. Biol. 152:663-698), the mean density of each viral protein in these organelles can be calculated to be 90 and 750 molecules/micron 2 membrane, respectively. In contrast, we have determined that the density of total endogenous integral membrane proteins in these organelles is approximately 30,000 molecules/micron 2 so that the spike proteins constitute only 0.28 and 2.3% of total membrane protein in the endoplasmic reticulum and Golgi, respectively. Quantitative immunoblotting was used to give direct estimates of the concentrations of one of the viral membrane protein precursors (E1) in subcellular fractions; these agreed closely with the calculated values. The data are discussed with respect to the sorting of transported proteins from those endogenous to the intracellular membranes.

Density of newly synthesized plasma membrane proteins in intracellular membranes. I. Stereological studies

As the spike proteins of Semliki Forest virus (SFV) pass from their site of synthesis in the endoplasmic reticulum (ER) to the cell surface, they must be concentrated and freed from endogenous proteins. To determine the magnitude of this sorting process we have measured the density of spike proteins in membranes of the intracellular transport pathway. In this first paper, using stereological procedures, we have estimated the surface areas of the ER, Golgi complex, and plasma membrane of infected and mock-infected baby hamster kidney cells. First, we estimated the mean cell volume in absolute units. This was done using a novel in situ method which is described in detail. Infection by SFV was found to have no effect on any of the parameters measured. In the accompanying paper ( Quinn , P., G. Griffiths, and G. Warren, 1984, J. Cell Biol., 2142-2147) these stereological estimates were combined with biochemical estimates of the amount of spike proteins in ER, Golgi complex, and plasma membrane to determine the density in the membranes of these compartments.

Facilitation by beta-adrenoreceptors of stimulation-induced vasoconstriction in pithed spontaneously hypertensive rats

In pithed bilateral adrenal demedullated spontaneously hypertensive rats, slow i.v. infusion of adrenaline (500 ng/min) significantly increased pressor responses to the electrical stimulation of the entire sympathetic outflow, but had little effect on pressor responses induced by bolus injections of noradrenaline. After pretreatment with timolol (1 mg/kg, i.v., 30 min) adrenaline infusion enhanced noradrenaline-induced pressor effects, but not stimulation-induced responses. Salbutamol (50-500 ng/min, i.v.) and procaterol (2.5 ng/min, i.v.) infusions significantly potentiated stimulation-induced pressor effects without affecting noradrenaline-induced responses. Higher rates of salbutamol (5 micrograms/min, i.v.) and procaterol (25 ng/min, i.v.) infusion significantly depressed noradrenaline-induced pressor effects and attenuated those induced by sympathetic nerve stimulation. It is concluded that the potentiation of stimulation-induced pressor responses by adrenaline salbutamol and procaterol, involves a beta-adrenoreceptor mediated facilitation of sympathetic neurotransmission.

Endocrinology of ovarian stimulation for in vitro fertilization

Understanding of the endocrinology of in vitro fertilization has advanced rapidly in the past 5 years. Despite a multitude of ovarian stimulation regimens a particular regimen has not demonstrated a marked superiority. In principle the achievement of high FSH levels during the early follicular phase to recruit a maximum number of follicles with a tolerable degree of asynchrony for final maturation is confined to a limited time span or 'FSH window' of about 3 to 4 days before negative E2 feedback induces below-threshold FSH levels, thereby condemning all subsequent follicles in that cycle to atresia. It appears that one can widen and/or amplify the 'FSH window' too far from gross hyperstimulation resulting in the recruitment of many follicles with an intolerable degree of asynchrony. This may lead to a defective endocrine environment for the oocytes contained within these follicles or an abnormal luteal environment and an increased frequency of fertilization, cleavage and implantation failure. Whichever regimen is used, the stimulation should ideally be sufficient to promote the development of at least 3 follicles beyond 18mm diameter at the time of OPU. This can be expected to result in at least 2 embryos to be available for transfer. Monitoring of follicular response by a combination of E2 and ultrasonic parameters is recommended so that the administration of HCG is given close to the anticipated endogenous rise of LH. This can be achieved by detecting a reduction in the rate of E2 rise (to plateau).(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro fertilization and embryo transfer program, Department of Obstetrics and Gynecology, University of Adelaide at the Queen Elizabeth Hospital, Woodville, South Australia

A review is presented summarizing the in vitro fertilization experience at the University of Adelaide, Australia. Initial attempts utilizing the normal cycle were unsuccessful in obtaining a pregnancy. Since 1982 the overall ongoing pregnancy rate has been 21% per embryo transfer, 16% per laparoscopy, and 12% per treatment cycle. A detailed description of presently utilized methodology is presented.

Culture factors in relation to the success of human in vitro fertilization and embryo transfer

The development of 1-cell mouse zygotes to the blastocyst stage in vitro has been used as a quality control for the media employed for human in vitro fertilization and embryo transfer (IVF-ET). The following procedures were associated with high rates of mouse embryo development and human pregnancies following IVF-ET: adequate gassing and equilibration of the medium, double rinsing of pipettes and catheters used to handle embryos, use of a HEPES-buffered medium for manipulating embryos in the absence of an atmosphere containing 5% CO2, control of excessive temperature in the vicinity of the embryos, and ET using medium containing 50% patient's serum. The institution of these procedures gave more consistent pregnancy rates. However, there was no obvious association between fertilization and cleavage of human oocytes and the quality of the medium ascertained by the mouse embryo development test.

Effect of human seminal plasma and mouse accessory gland extracts on mouse fertilization in vitro

The mouse in vitro fertilization system was used to investigate the effect of human seminal plasma (HSP) on the fertilizing ability of mouse spermatozoa. The addition of HSP to freshly collected mouse epididymal spermatozoa decreased their fertilizing ability to 30%, compared with 85-90% for control spermatozoa not exposed to HSP or for spermatozoa that had been exposed to the capacitating system for 55-145 min (which allowed capacitation to occur before the addition of HSP). Human seminal plasma from a vasectomized donor was more effective in retarding the acquisition of fertilizing ability in mouse spermatozoa than was seminal plasma from non-vasectomized donors. Fluid from the prostate glands and seminal vesicles of mice also reduced the fertilizing ability of freshly collected mouse spermatozoa to 30%.

Use of imported cryopreserved hamster oocytes in the diagnosis of male infertility

Frozen hamster oocytes have been imported from England to Australia to establish a test for human sperm fertilizing capacity based on penetration of zona-free hamster oocytes. When examined under similar conditions used for human in vitro fertilization (IVF), high and consistent rates of penetration by human spermatozoa were obtained which were similar whether the spermatozoa had been stored frozen or freshly collected. The availability of a validated test of the capacity of human spermatozoa to fuse with a receptive vitelline membrane should prove useful in combination with other clinical parameters in the evaluation of male infertility.

The effect of bilateral adrenal demedullation on vascular reactivity and blood pressure in spontaneously hypertensive rats

Bilateral adrenal demedullation of juvenile spontaneously hypertensive rats attenuated, but did not prevent, the development of hypertension. Neither did it affect the subsequent vascular reactivity to phenylephrine though it significantly reduced the vascular effects of sympathetic nerve stimulation. Demedullation of adult spontaneously hypertensive rats did not alter blood pressure, but did attenuate the pressor responses to both alpha-adrenoceptor agonists and sympathetic nerve stimulation. In acutely demedullated adult rats, vascular reactivity to sympathetic nerve stimulation, but not to exogenous amines, could be restored by slow i.v. infusion of adrenaline in a dose-dependent manner. The results support a possible facilitatory role for adrenaline in sympathetic neurotransmitter release, both during the development of genetic hypertension and in vascular responses to sympathetic nerve stimulation.

Validation of indirect systolic blood pressure measurement in ether anaesthetised rats

Systolic blood pressures and plasma catecholamine concentrations were determined in conscious and ether-anaesthetised male spontaneously hypertensive (SHR), Wistar-Kyoto normotensive (WKY/N), Wistar (W) and Sprague-Dawley (SD) rats. When compared to conscious animals, plasma noradrenaline concentrations were significantly higher in all four strains of ether-anaesthetised rats. Only the SHR rats did not show an elevation in plasma adrenaline concentration when anaesthetised with ether. A good correlation was obtained between systolic blood pressures measured indirectly, using a tail-cuff method with two different sensors, in ether-anaesthetised rats and pressures measured directly, via an indwelling carotid catheter, in conscious unrestrained animals. It is concluded that, while ether anaesthesia elevates plasma catecholamine concentrations in rats, the increase in plasma catecholamines has little, if any, effect on indirect systolic blood pressure measurements.

The relationship between motility and the FITC-BSA binding properties of mouse epididymal spermatozoa

Mouse epididymal spermatozoa exposed to fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) immediately following dilution or after a 2-hour incubation period under fertilization conditions, were assessed by fluorescence microscopy for albumin adsorption. Motile spermatozoa exhibited light fluorescence in the midpiece and tail but not in the head. In contrast the majority of nonmotile spermatozoa displayed a strong and characteristic fluorescence in the post acrosomal region of the sperm head as well as the midpiece. Spermatozoa immobilised by short-term heat stress exhibited fluorescence in the post acrosomal region and midpiece as before but also in the acrosomal cap. The equatorial region failed to fluoresce. The significance of these observations on the involvement of albumin in capacitation is discussed.

Inhibitory influence of uterine secretions on mouse blastocysts decreases at the time of blastocyst activation

Uterine flushings from artificially 'pseudopregnant', pseudopregnant and pregnant mice and those with 'diapausing' embryos were tested for their effect on [3H]uridine incorporation by mouse blastocysts. An inhibitor of [3H]uridine incorporation was detected in the uterine fluid of the mice with diapausing embryos and the activity of the inhibitor was significantly reduced 6.25 h after an injection of oestrogen. This reduction of the inhibitory activity was dependent on the presence of blastocysts in utero, since a similar reduction did not occur in uterine fluids of pseudopregnant mice. The results support the suggestion that 'delayed' implantation in mice is caused by the presence of inhibitors of blastocyst metabolism and that activation, after an increase in oestradiol, is due to an embryo-dependent loss of activity of the inhibitors.

The effect of clomid induced superovulation on human follicular and luteal function for extracorporeal fertilization and embryo transfer

The administration of clomiphene citrate (Clomid) 150 mg/day from days 5-9 of the menstrual cycle to spontaneously ovulatory women in order to induce adequate multiple follicular development followed by timed laparoscopic aspiration of mature oocytes does not appear to impair luteal phase length or the steroid pattern of oestradiol-17 beta (E2) or progesterone (P) production as reflected by their peripheral blood concentrations. In Clomid stimulated cycles where preovular oocyte pickup (OPU) and embryo transfer (ET) occurred but no recognizable pregnancy resulted, the cycle length was 30.0 (s.e.m. = 0.3) days, the follicular phase length was 15.6 (s.e.m. = 0.3) days and the luteal phase length was 14.4 (s.e.m. = 0.3) days, which did not differ from a group of women having spontaneous ovular cycles. Following Clomid stimulation the dominant follicle was similar in size to the pre-ovulatory follicle in spontaneous uniovular cycles, but the second, third, fourth and fifth order follicles were significantly larger (P less than 0.0001). The ultimate test of luteal competence was the successful implantation of 11 concepti in 7 women (4 sets of twins) from 49 laparoscopies (14%) or 33 embryo transfers (21%). Comparisons between conceptual and non-conceptual embryo transfers following identical Clomid regimes showed no difference between plasma E2 concentrations at the time of hCG administration or the start of an endogenous LH rise; follicle volume, follicular fluid E2, P and testosterone concentrations were also not different. However, there was a trend for follicular P to be higher in the non-conceptual group indicating that advanced luteinization may hinder successful implantation. The follicular fluid androstenedione (A4) concentration was significantly lower in the conceptual group and the total androgen concentration (A4 + T) was also lower which was indicative of active aromatase activity in these follicles. It was concluded from this study that there was no indication to give exogenous hormonal support to the luteal phase, provided there was both optimal follicular growth and steroidogenic function following Clomid stimulation and that exogenous hCG was administered very close to the expected rise of LH. This observation was supported by the finding that timing of OPU based on a knowledge of the start of the LH surge was associated with a higher pregnancy rate than when hCG was administered and indicates that the endogenous mid-cycle events may permit superior maturation of the oocyte and/or permit better synchronization of endometrial maturation for implantation.

Dissection of the Golgi complex. II. Density separation of specific Golgi functions in virally infected cells treated with monensin

In the accompanying paper (Griffiths, G., P. Quinn, and G. Warren, 1983, J. Cell Biol., 96:835-850), we suggested that the Golgi stack could be divided into functionally distinct cis, medial, and trans compartments, each comprising one or two adjacent cisternae. These compartments were identified using Baby hamster kidney (BHK) cells infected with Semliki Forest virus (SFV) and treated with monensin. This drug blocked intracellular transport but not synthesis of the viral membrane proteins that were shown to accumulate in the medial cisternae. In consequence, these cisternae bound nucleocapsids. Here we show that this binding markedly increased the density of the medial cisternae and allowed us to separate them from cis and trans Golgi cisternae. A number of criteria were used to show that the intracellular capsid-binding membranes (ICBMs) observed in vivo were the same as those membranes sedimenting to a higher density in sucrose gradients in vitro, and this separation of cisternae was then used to investigate the distribution, within the Golgi stack, of some specific Golgi functions. After labeling for 2.5 min with [3H]palmitate, most of the fatty acid attached to viral membrane proteins was found in the ICBM fraction. Because the viral membrane proteins appear to move from cis to trans, this suggests that fatty acylation occurs in the cis or medial Golgi cisternae. In contrast, the distribution of alpha 1-2-mannosidase, an enzyme involved in trimming high-mannose oligosaccharides, and of galactosyl transferase, which is involved in the construction of complex oligosaccharides, was not affected by monensin treatment. Together with data in the accompanying paper, this would restrict these two Golgi functions to the trans cisternae. Our data strongly support the view that Golgi functions have specific and discrete locations within the Golgi stack.

Dissection of the Golgi complex. I. Monensin inhibits the transport of viral membrane proteins from medial to trans Golgi cisternae in baby hamster kidney cells infected with Semliki Forest virus

Baby hamster kidney (BHK) cells were infected with Semliki Forest virus (SFV) and, 2 h later, were treated for 4 h with 10 microM monensin. Each of the four to six flattened cisternae in the Golgi stack became swollen and separated from the others. Intracellular transport of the viral membrane proteins was almost completely inhibited, but their synthesis continued and they accumulated in the swollen Golgi cisternae before the monensin block. In consequence, these cisternae bound large numbers of viral nucleocapsids and were easily distinguished from other swollen cisternae such as those after the block. These intracellular capsid-binding membranes (ICBMs) were not stained by cytochemical markers for endoplasmic reticulum (ER) (glucose-6-phosphatase) or trans Golgi cisternae (thiamine pyrophosphatase, acid phosphatase) but were labeled by Ricinus communis agglutinin I (RCA) in thin, frozen sections. Since this lectin labels only Golgi cisternae in the middle and on the trans side of the stack (Griffiths, G., R. Brands, B. Burke, D. Louvard, and G. Warren, 1982, J. Cell Biol., 95:781-792), we conclude that ICBMs are derived from Golgi cisternae in the middle of the stack, which we term medial cisternae. The overall movement of viral membrane proteins appears to be from cis to trans Golgi cisternae (see reference above), so monensin would block movement from medial to the trans cisternae. It also blocked the trimming of the high-mannose oligosaccharides bound to the viral membrane proteins and their conversion to complex oligosaccharides. These functions presumably reside in trans Golgi cisternae. This is supported by data in the accompanying paper, in which we also show that fatty acids are covalently attached to the viral membrane proteins in the cis or medial cisternae. We suggest that the Golgi stack can be divided into three functionally distinct compartments, each comprising one or two cisternae. The viral membrane proteins, after leaving the ER, would all pass in sequence from the cis to the medial to the trans compartment.

Decapacitation factors in semen

Decapacitation factors are components of seminal plasma which modulate the fertilizing ability of spermatozoa. This activity arises from the interaction between cholesterol, phospholipids and a fibronectin-like substance and is delivered via small vesicles in seminal plasma. Its function is to prevent the premature onset of the cascade mechanism known as capacitation and this is achieved through spermatozoal membrane stabilization by maintaining a physiological cholesterol/phospholipid ratio. The study of decapacitation factors may throw light on the aetiology of some forms of hitherto unexplained male infertility and may provide the basis of a specific and reversible method of male contraception.

Preservation of hamster oocytes to assay the fertilizing capacity of human spermatozoa

Between 70 and 80% of zona-intact hamster ova survived freezing after slow cooling (approximately 0.3 degrees C/min) to -80 degrees C in Medium PB1 containing 1.5 or 2.0 M-DMSO before transfer to -196 degrees C. After slow warming (approximately 8 degrees C/min), there was no difference in survival if the DMSO was diluted out by a slow stepwise or a rapid single addition of medium. When slow cooling was terminated at -40 degrees C by direct transfer to -196 degrees C, up to 75% of the ova survived rapid warming (approximately 500 degrees C/min) and rapid dilution if the medium contained 2.0 M-DMSO. The survival rates were calculated on the basis of the number of thawed ova which retained their normal morphological appearance after a 1 h incubation before removal of the zona pellucida with trypsin. All of these ova were penetrated after incubation with mouse spermatozoa, indicating that the freezing procedure per se does not adversely affect the penetration of frozen-thawed hamster ova by heterologous spermatozoa. There was no difference in the penetration rate of human spermatozoa into frozen (34%) or fresh (42%) oocytes when a Hepes-buffered Tyrode solution containing 30 mg BSA/ml and 2.0 M-DMSO was used as the freezing medium. However, fewer ova frozen in Medium PB1 containing 4 mg BSA/ml and 2.0 M-DMSO were penetrated by human spermatozoa (18%) compared with freshly collected ova (38%). Zona-free ova did not survive the freezing procedure as well as zona-intact ova. The survival of hamster oocytes stored at -196 degrees C offers a convenient means of supplying and transporting these ova for the assessment of the fertilizing capacity of human and other heterologous spermatozoa.

Effect of polyamines on fertilization of mouse ova in vitro

After a 1-hour preincubation of epididymal mouse spermatozoa at a concentration of 2 X 10(6)/ml in 0.23 mM spermine, the proportion of F1(C57BL X CBA) mouse ova fertilized after 1 and 2 hours was significantly greater than with untreated spermatozoa. Spermine also significantly increased the proportion of ova fertilized at the sub optimal sperm concentration of 2 X 10(5)/ml. The stimulatory effect was lost when the protein source in the fertilization medium was changed from human serum albumin V (HSA) to HSA crystalline. This provides indirect evidence that albumin is directly involved in the capacitation process and that the crystalline is more potent than the fraction V preparation. At equimolar concentrations, spermidine was partially and putrescine was totally inhibitory to fertilization. Mechanisms whereby spermine may affect metabolic activity or sperm-zona binding are discussed. It is suggested spermine may also be present in ovulatory fluid and therefore could potentially be involved in fertilization in vivo.

Interaction of semen with ova in vitro

Spermine had a beneficial effect on the fertilization of zona-free mouse ova in vitro. A deleterious effect of spermine or seminal plasma on gametes only occurred if normal, untreated BSA was present in the incubation medium. This was due to the activity of spermine oxidase, which could be assayed in the untreated BSA and which was removed by TCA-purification of the BSA. The addition of a spermine oxidase inhibitor, isoniazid, or the use of the TCA-purified BSA preparation allowed the direct effects of spermine or seminal plasma on mammalian fertilization to be assessed. Human seminal plasma retarded the acquisition of fertilizing ability in human spermatozoa and prevented it in mouse spermatozoa. The fertilizing ability of the spermatozoa of both species was unaffected, when spermatozoa were preincubated to achieve capacitation before adding the seminal plasma.

Polyethylene glycol-induced attachment of human spermatozoa to zona-free rat ova in vitro

When human spermatozoa are incubated with zona-free ova in the presence of polyethylene glycol (PEG), the spermatozoa attach to the ova. Although the binding occurs when bovine serum albumin (BSA) is omitted from the incubation medium, the spermatozoa are better maintained and bind in higher numbers in the presence of both PEG and BSA. No spermatozoa bind to zona-intact ova or to zona-free ova in the absence of PEG. The number of spermatozoa bound to ova is dependent on the concentration of PEG (optimum between 10 and 15% w/v), time of incubation (increases linearly) and concentration of spermatozoa (increases linearly).

Development of preimplantation mouse embryos in vivo and in vitro

The culture conditions for the development in vitro of (C57BL/6 x CBA) F2 hybrid two-cell embryos to the blastocyst stage have been optimized. Commercially available pre-sterile disposable plastic culture dishes supported more reliable development than re-usable washed glass tubes. The presence of an oil layer reduced the variability in development. An average of 85% of blastocysts developed from hybrid two-cell embryos cultured in drops of Whitten's medium under oil in plastic culture dishes in an atmosphere of 5% O2: 5% CO2: 90% N2. The time taken for the total cell number to double in embryos developing in vivo was 10 h, and in cultured embryos 17 h. Embryos cultured in vitro from the two-cell stage to blastocyst stage were retarded by 18-24 h in comparison with those remaining in vivo. Day-4 blastocysts in vivo contained 25-70 cells (mean 50) with 7-28 (mean 16) of these in the inner cell mass. Cultured blastocysts contained 19-73 cells (mean 44) with 8-34 (mean 19) of these in the inner cell mass. In the uterine environment, inner-cell-mass blastomeres divided at a faster rate than trophectoderm blastomeres and it is suggested that a long cell cycle is associated with terminal differentiation. Although cultured blastocysts and inner cell masses contained the same number of cells as blastocysts and inner cell masses in vivo, the rate of cell division in cultured inner cell masses was markedly reduced.

Habituation of visual attention in infants with minor physical anomalies

Human and geometric forms were presented to 12-month-old male infants to determine if those with a large number of minor physical anomalies would show different habituation than infants with a small number. Results from a procedure using human forms in a random order failed to yield differences, but differences in dishabituation did appear when geometric forms were presented in a standard habituation procedure, and in response decrement when subgroups were created to test for differences in infant state as a function of task demands. Slower response decrement found in high-anomaly infants tested in a low task-demand condition was consistent with Lewis's findings in infants with various forms of brain pathology.

Species variation in arterial-myocardial sensitivity to verapamil

The changes in tension with increasing calcium concentration were examined in papillary muscles isolated from cats, rabbits, and rats, and in isolated rat atria. Similar curves were determined for cat femoral artery and lower descending aorta from rabbits and rats. In all tissues, the concentration of verapamil (KB) was determined which achieved a calcium dose ratio of 2. Rat myocardium was the most (KB = 3.38 +/- 0.18 X 10(-6) mol . litre-1) and rabbit the lest (KB = 1.18 +/- 0.01 X 10(-5) mol . litre-1) sensitive to verapamil. Cat tissue was intermediate; rat atria and ventricle were similar. By contrast, arterial sensitivity was always greater with arterial-myocardial sensitivity ratios varying from 175 +/- 7 in the cat to 1073 +/- 97 in the rabbit. This technique is a formal evaluation of the arterial-myocardial sensitivity of calcium entry blockers and may permit prediction of the myocardial and vasodilator properties of novel compounds.

Interaction of uterine flushings with mouse blastocysts in vitro as assessed by the incorporation of [3H]uridine

Culture of mouse blastocysts in medium supplemented with uterine flushings from mice at random stages of the oestrous cycle resulted in a depression of [3H]uridine incorporation. This depression was maintained for up to 12 h, but by 24 h of culture, inhibition of uterine incorporation was no longer apparent. The loss of inhibition wa due to a change in the activity of the flushings and not to a change in the ability of blastocysts to respond to the inhibitory influence. The inhibition of [3H]uridine incorporation was maintained for at least 24 h when blastocysts were transferred every 6 h to fresh uterine flushings.

Cellular mechanisms of impaired adrenergic responsiveness in neonatal dogs

The myocardial responsiveness of conscious, instrumental dogs to exogenously administered isoproterenol and norepinephrine was investigated in neonatal, 6-wk-old, and adult animals. Comparable base-line values for peak left ventricular derivative of pressure with respect to time were observed in all age categories. However, when compared with adult responses, the sympathomimetic amine-induced increases in neonatal left ventricular dP/dt were significantly blunted at each concentration of adrenergic agonist examined, whereas the 6-wk-old puppies displayed an intermediate inotropic response. To investigate the cellular mechanisms of this blunted neonatal response, we correlated physiologic and biochemical measurements of the myocardial responses to catecholamines in each age category. When compared with adult myocardial membrane preparations, neonatal cardiac membranes were characterized in vitro by an increased density of beta-adrenergic binding sites, comparable affinity for adrenergic agonists and antagonists, and an enhanced coupling of adenylate cyclase activation to receptor occupancy. Simultaneous changes in either the serum catecholamine concentration or the membrane content of other intrinsic proteins failed to account for the observed neonatal increase in beta-adrenergic receptor density. These findings are most consistent with a compensatory mechanism of the cardiac cell membrane, whereby an inherent depression in the adrenergic responsiveness of the immature myocardium appears to induce the increase in receptor density and activation of adenylate cyclase.

Fertilization of pronase-treated mouse ova in vitro

In order to obtain consistently a large number of zona-free mouse ova for studies of sperm-egg interactions, a study was made of the relative effectiveness of removing the zona pellucida from ova by mechanical or enzymatic treatments. Ova exposed to pronase before mechanical removal of the zona pellucida in medium devoid of pronase had similar fertilization rates in vitro compared with ova mechanically denuded in the absence of pronase. Ova with pronase-weakened zonae were easier to denude and survived the mechanical manipulations better than the ova denuded by vigorous aspiration in narrow-bore pipettes. However, exposure to pronase did significantly lower the incidence of polyspermy in the naked ova, indicating that some of the enzyme may have diffused across the perivitelline space and damaged sperm-binding sites on the vitelline plasma membrane. The enzyme treatment also reduced the fertilization rate of zona-intact ova.

Properties of mouse inner cell masses isolated by Immunosurgery, exposure to the calcium ionophore A23187 or low osmolarity

Mouse inner cell masses remained intact when exposed to extreme osmotic stress (distilled water) for short periods, but the trophectoderm was lysed in one-third of blastocysts. However, these inner cell masses were not viable as they could not fluoresce after incubation in fluorescence diacetate nor continue development in vitro. It was concluded that cells of the inner cell mass are not more tolerant of osmotic stresses than those of the trophectoderm. Inner cell masses were isolated from only 50% of blastocysts when exposed to the calcium ionophore A23187. Some lysing trophectoderm cells are probably able to restore their normal calcium levels after transfer to fresh culture medium allowing normal blastocyst-like development in vitro. Further evidence which suggests that not all trophectoderm cells are removed after incubation in ionophore is that these inner cell masses produced more trophoblast-like outgrowths in vitro and were able to induce the decidual cell reaction in vivo more often than their immunosurgically isolated counterpart. Immunosurgically isolated inner cell masses were viable as they fluoresced brightly after incubation in fluorescein diacetate and developed normally in vitro. There was little or no contamination of these inner cell masses with trophectoderm cells as they formed considerably smaller outgrowths than control blastocysts and were rarely able to induce the decidual cell reaction in vivo. Trophoblast-like giant cells were found less frequently from inner cell masses isolated from 142-h, post-HCG blastocysts and cultured in vitro, than from 118-h, post-HCG blastocysts. These results are discussed in relation to a current theory on the time of inner cell mass determination which states that apparently differentiated inner cell mass cells may reverse their direction of development in response to altered environmental conditions.

Physostigmine-atropine solution fails to reverse diazepam sedation

Patients undergoing dental extraction under intravenous diazepam sedation were studied to determine whether physostigmine, a cholinesterase inhibitor, reverses diazepam-induced sedation. A modified Bender-Gestalt Dot Test was used to measure psychomotor function. Patient self-assessment of recovery and a surgeon's independent assessment of recovery were scored on a 0 to 10 measured scale before and after administration of either a physostigmine-atropine mixture (nine patients) or saline (12 patients). The physostigmine-atropine mixture did not significantly speed recovery or improve psychomotor function when compared with normal saline. The results indicate that, in contradiction to previous case report, the analeptic effect of physostigmine may be specific for anticholinergic drugs.

Failure of human spermatozoa to penetrate zona free mouse and rat ova in vitro

When incubated for 8 to 26 hours with zona-free mouse or rat ova, human spermatozoa failed to attach to or penetrate any of the ova. The ova were capable of being fertilized since both intra- and inter-species penetration of spermatozoa and formation of pronuclei occurred between rat and mouse gametes. When mouse spermatozoa were incubated for three to eight hours with rat ova, a high proportion of the ova were penetrated, formation of pronuclei occurred and in 9 out of 36 ova incubated for 40 hours after insemination, regular cleavage and formation of morphologically normal 2-cell embryos occurred. Human spermatozoa retained their morphological integrity and motility only when the culture medium contained purified bovine serum albumin (3 mg/ml) or human serum (5% v/v) and not when unpurified BSA from several different commercial sources was used as a protein source. In this latter medium, the ova of both rats and mice degenerated after 8-hour incubation in the presence of human spermatozoa but not when human spermatozoa were absent or in the presence of either rat or mouse spermatozoa. Electron microscopy indicated that the human spermatozoa incubated for eight hours in medium containing purified BSA had undergone an acrosome reaction. These spermatozoa also attached to and penetrated human oocytes which had been matured in vitro.

Isolation of inner cell masses from mouse blastocysts by immunosurgery or exposure to the calcium ionophore A23187

Two techniques have been evaluated for their use in routinely isolating inner cell masses from mouse blastocysts by destroying the trophectoderm. The most efficient method of immunosurgery was a 15-min incubation in a 1:50 dilution of rabbit anti-mouse spleen antiserum followed by a 30--60-min incubation in guinea pig complement (1:10). Alternatively, inner cell masses were isolated by incubating blastocysts in 10(-5) M calcium ionophore A23187 in medium devoid of calcium and magnesium ions. Inner cell masses re-exposed to immunosurgery or the ionophore were less susceptible to lysis than the trophectoderm had been. The presence of the zona pellucida reduced trophectoderm lysis by immunosurgery in antiserum dilutions greater than 1:100, but had no effect when in the presence of ionophore. Inner cell masses were consistently isolated from expanded blastocysts which had been collected 78 h after ovulation and cultured in vitro for 24 h before exposure to ionophore or immunosurgery, whereas blastocysts which had developed for the full 102 h in vivo were frequently unaffected.

Foetal and placental growth in the mouse after pre-implantation development in vitro under oxygen concentrations of 5 and 20%

Blastocysts which developed from two-cell mouse embryos in culture tubes containing an atmosphere with 20% oxygen had approximately 20% fewer blastomeres than blastocysts which developed under an oxygen concentration of 5%. When these smaller blastocysts were transferred to the uteri of pseudopregnant foster mothers, the foetuses developing were as viable as those developing from blastocysts cultured under 5% oxygen, indicating their ability to regulate for a lower blastomere number by at least day 17 of development. The transfer operation itself had no adverse effect on foetal or placental growth. However, culture of blastocysts in vitro did depress foetal though not placental growth, suggesting that the inner cell mass is more susceptible than the trophectoderm to culture in vitro. Foetal but not placental growth was lower following the transfer of blastocysts to a day-3 rather than a day-4 uterus. Four cases of placental fusion were found. In one case, the foetuses were contained within the same embryonic sac and may have been twins.

Odontogenic myxoma. Surgical management and an ultrastructural study

Odontogenic myxoma is a tumor of primitive mesenchyme, probably derived from the dental apparatus. Surgical management of this benign but locally aggressive tumor is either by curettage or en bloc resection. Two cases of odontogenic myxoma of the mandible are reported. In one case, en bloc resection. Two cases of odontogenic myxoma of the mandible are reported. In one case, en block resection with immediate reconstruction was undertaken. In the second case, the neoplasm was thoroughly curetted. The first case was studied by electron microscopy. Six ultrastructural studies of seven odontogenic myxomas have been previously reported. The ultrastructural features of odontogenic epithelium that may be present in myxomas of the jaws have been examined by electron microscopy once before. Our observations are in agreement with those of other workers who suggest that the connective tissue cell is the proliferating component of the tumor and is very similar to a fibroblast but has enough ultrastructural and functional features to deserve the term myxoblast. The majority of the tumor cells are metabolically active and secretory and there is adequate evidence that the tumor matrix consists of large amounts of mucopolysaccharides. It is reasonable, therefore, to conclude that myxoblasts secrete the mucoid matrix that is so characteristic of odontogenic myxomas. Unlike normal or neoplastic fibroblasts, the myxoblasts are not engaged in abundant synthesis of banded collagen throughout the entire lesion.

Newborn minor physical anomalies and prediction of infant behavior

The relationship between a newborn score of minor physical anomalies (MPAs) and behavior at ages 1 and 2 was examined. From an initial screening population of 933, 63 high anomaly and 78 low anomaly infants were followed until age 2 by examiners blind for the newborn anomaly score. High anomaly infants were more likely to be temperamentally difficult as rated by parent interview and direct observation. A subgroup of six infants who were considered irritable at both ages 1 and 2 were all from the high anomaly group. However, there was little agreement between behavioral ratings across situations and over time, and there were no significant predictors of behavior problems at age 2 based on any newborn or 1-year measure. These results indicate that the newborn anomaly score by itself is unlikely to prove clinically useful in predicting preschool behavior problems for an unselected population. The usefulness of this measure for other, "high-risk," populations remains to be explored.

Measurement of multiple simultaneous small dimensions and study of arterial pressure-dimension relations in conscious animals

This paper describes the development of several important modifications that were incorporated into the ultrasonic, transit-time dimension system in order to obtain multiple simultaneous, instantaneous, and continuous measurements of the external dimensions of the aorta and its major branches in conscious, unrestrained animals. At operation a pair of small piezoelectric crystals was sutured to arterial adventitia, and a miniature pressure gauge was implanted in the vessel at the same cross-sectional plane. After recovery from surgery, wall motion was not altered appreciably and scarring was minimal. This technique allows long-term monitoring of aortic pressure-dimension relations and is applicable for small (fetal and neonatal) as well as large (adult dogs and sheep) animals. When vessel wall thickness is measured, stress-radius analysis can be performed so as to compute vascular elastic stiffness as a function of stress. Moreover, the suitability for radiotelemetry of the pressure and dimension signals measured with this technique enables the study of these parameters in unrestrained animals, e.g., during spontaneous severe exercise.

The effect of oxygen on the development of preimplantation mouse embryos in vitro

The optimal oxygen tension for development of preimplantation mouse embryos to the blastocyst stage in vitro was found to be between 2.5% and 5%. One- and two-cell embryos had a more sharply defined range of oxygen tension capable of supporting development than 8-cell and morula stages. At all stages of development, more embryos developed to the blastocyst stage under 5% O2 compared to the numbers of developing under higher oxygen tensions (20% and 40% O2). The blastocysts developing under 20% O2 had fewer blastomeres than those which developed under 5% O2. As the time required for development to the blastocyst stage in vitro increased, there were fewer blastomeres present at the blastocyst stage. These results indicate that the cleaving mouse embryo has an optimal oxygen requirement in vitro of about 5%. At higher oxygen tensions, fewer embryos develop to the blastocyst stage and in those which do develop, there are fewer cell divisions. If a gradient of oxygen tension exists across the blastomeres from the outside of the embryo to its centre, the blastomeres might be using this gradient to obtain imformation about their location within the embryo and respond accordingly. Thus blastomeres on the outside at a higher oxygen tension would divide at a slower rate and form trophectoderm whereas those on the inside at a lower oxygen tension would divide more rapidly and contribute to the inner cell mass.