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PubMed1990

[Inversion of uterus].

Inversion of the uterus is a rare condition, basically described in old treatises on obstetrics. On the basis of one recent case, the authors recall details of the diagnosis, treatment and prognosis, while referring to previous older works. The usual description is given of the three anatomical degrees of inversion of the uterus, depending on the extent of invagination of the fundus of the uterus. The aetiology of this event is not always very clear, but faulty manoeuvres at the time of delivery may help to promote its occurrence. Diagnosis is relatively easy, except in cases which are not exteriorized. Treatment relies on reduction of the inversion, which should take place as early as possible, and prevention of a relapse. The prognosis was formerly catastrophic, but has currently been transformed by the progress made in improving intensive care.

Adult↗
PubMedDate not supplied

Stereochemical inversion of haloxyfop in the Fischer 344 rat.

The 2-aryloxypropionate haloxyfop is currently being evaluated for use as a herbicide. This compound is structurally similar to a group of 2-arylpropionates that have been shown previously to undergo stereochemical inversion in a variety of mammalian species. To support the data obtained from a number of toxicity/oncongenicity studies, in which racemic haloxyfop was employed, the stereochemical disposition of this compound was examined in the Fischer 344 rat. After administration of racemic haloxyfop (11 mg/kg, po) to male and female Fischer 344 rats, the day 1-10 urine samples were fortified with D4-haloxyfop (center ring label) and extracted, and the haloxyfop enantiomers were converted to diastereomeric derivatives [(S)-phenylethylamine] and analyzed by gas chromatography-mass spectrometry (GC/MS). Fecal samples for days 1-10 were fortified with D4-haloxyfop, extracted, and purified by reverse phase high-pressure liquid chromatography prior to derivation and GC/MS analysis. In the female rat, 77.3% of the administered dose was recovered in the day 1-10 urine and feces as parent compound. The stereochemistry of the haloxyfop present in these samples was found to be nearly all (R)-enantiomer (greater than 98%). In the male rat, 52.2% of the dose was recovered in the day 1-10 urine and feces as haloxyfop. The stereochemistry of the parent compound present in these samples was similar to the results seen in the female rat [greater than 98% (R)]. These results show that (S)-haloxyfop undergoes rapid and nearly complete inversion to the (R)-enantiomer in the female Fischer 344 rat. The data also suggest a similar stereochemical inversion of haloxyfop in the male Fischer 344 rat.

Animals↗
PubMed1989

[Coronary angiography in patients with U wave inversion during coronary artery spasm].

During ergonovine-induced vasospastic angina, U wave inversion without significant ST segment deviation on the precordial electrocardiograms was documented in four patients. Coronary angiography revealed incomplete spastic obstruction of the left anterior descending artery without delayed filling and runoff in three patients. In the remaining patient, the proximal left anterior descending artery was totally occluded and there were well-developed collaterals from the non-spastic artery. Thus, ergonovine-induced U wave inversion was related to the presence of coronary vasospasm, and angiography demonstrated less severe myocardial ischemia in such patients than in cases with ST segment elevation or depression, which is usually associated with subtotal or total obstruction of a major coronary artery without adequate collaterals. In their clinical courses, two patients had episodes of angina with ST segment elevations or depressions. It was suggested that vasospastic angina with U wave inversion alone is one aspect of a continuous spectrum of vasospastic myocardial ischemia.

Adult↗
PubMed1989

Mechanistic studies of the metabolic chiral inversion of (R)-ibuprofen in humans.

The metabolic chiral inversion of R-(-)-ibuprofen has been studied in human subjects by means of specific deuterium labeling and stereoselective gas chromatography-mass spectrometry methodology. After simultaneous p.o. administration of a mixture of R-(-)-ibuprofen (300 mg) and R-(-)-[3,3,3-2H3]ibuprofen (304 mg) to four adult male volunteers, the enantiomeric composition and deuterium content of the drug in serum, and of the drug and its principal metabolites in urine, were followed over a period of 24 hr. The results of these analyses indicated that: 1) conversion of R-(-)- to S-(+)-ibuprofen takes place with complete retention of deuterium at the beta-methyl (C-3) position; 2) chiral inversion of R-(-)-[2H3]ibuprofen is not subject to a discernible deuterium isotope effect; and 3) replacement of the beta-methyl hydrogen atoms by deuterium has no effect on any of the serum pharmacokinetic parameters for R-(-)- or S-(+)-ibuprofen. These data indicate that the process whereby R-(-)-ibuprofen undergoes metabolic inversion in human subjects does not involve 2,3-dehydroibuprofen as an intermediate, and that the underlying mechanism cannot, therefore, entail a desaturation/reduction sequence.

Adult↗
PubMed1988

Antagonism of ethanol effects on cerebellar Purkinje neurons by the benzodiazepine inverse agonists Ro 15-4513 and FG 7142: electrophysiological studies.

Ro 15-4513, a benzodiazepine inverse agonist, has been reported to antagonize the ataxic effects of ethanol. The present study investigates the Ro 15-4513 sensitivity of rat cerebellar Purkinje neurons to the depressant effects of locally applied ethanol. Local applications of ethanol by pressure ejection from multibarrel micropipettes caused reversible and dose-dependent depressions of the neuronal firing rates of single cerebellar Purkinje neurons. The ethanol-induced depressions could be antagonized by local applications of Ro 15-4513 applied from another barrel of the same micropipette. This antagonism was not competitive, suggesting that Ro 15-4513 does not interfere directly with the initial step of the ethanol mechanism of action. A beta-carboline inverse agonist, FG 7142, was more efficacious than Ro 15-4513 for antagonizing the ethanol-induced depressions, but appeared to be less potent. Recovery of ethanol-induced depressions of Purkinje neurons firing rates after Ro 15-4513 antagonism was not usually observed for 1 hr or more after the antagonist application. In contrast to ethanol effects, qualitatively similar gamma-aminobutyric acid-induced depressions of these same neurons were not antagonized by the doses of Ro 15-4513 used. We conclude that the electrophysiological depressant effects of ethanol on cerebellar neuronal activity can be antagonized by the benzodiazepine inverse agonists, Ro 15-4513 and FG 7142.

Animals↗
PubMed1988

The inverse problem in electrocardiography: solutions in terms of equivalent sources.

This paper reviews those inverse electrocardiographic solutions that compute the electrical activity of the heart in terms of equivalent sources such as multipoles or multiple dipoles, as opposed to more realistic source formulations such as epicardial potentials. It treats, in succession, inverse solutions in terms of a single fixed-location dipole, a multipole series, moving dipoles, and, finally, multiple fixed-location dipoles. For each category of solution, simulation studies, animal experiments, and work involving human subjects are reviewed. Finally, more recent work that seeks to compute the cardiac activation isochrones, from the time integrals of the torso potentials during the QRS complex of the electrocardiogram, is described. The paper concludes with a discussion on the future of inverse electrocardiographic solutions in terms of equivalent sources.

Animals↗
PubMed1985

[Estimation of location and size of myocardial infarction from body surface potentials using the ECG inverse solution method].

This paper describes a non-invasive mathematical method for estimating the locations and sizes of myocardial infarction using body surface electrocardiographic mappings. The inverse calculation is the theoretical basis of our method of estimation. First, the boundary integral equations were used to relate body surface and epicardial potential distributions. Next, a spherical harmonic expansion was used to solve the equations in order to obtain the epicardial potentials from the body surface potentials. The validity of the method was assessed by animal experiments and the clinical application. Body surface potentials were recorded using a 128 channel electrocardiographic mapping device equipped with a 16 bit microprocessor. In the animal study, the epicardial potentials were recorded by another potential mapping device simultaneously with body surface potential recordings. In the animal study, 60 epicardial electrodes and a freezing unit were mounted on a elastic fabric sack and attached to the heart. After completion of open chest surgery, freezing myocardial injury was incurred by perfusing -50 degrees C acetone-dry ice cryogen into the freezing unit. Twenty minutes after the start of freezing, ST elevations of the body surface and epicardial potentials were simultaneously recorded. An ST subtraction map was compiled as the difference between the maps before and after the myocardial freezing injury. Then, an inverse calculation was applied to the ST subtraction potentials to estimate the epicardial ST elevation. The geometric parameters of each electrode were determined from stereometry using two-dimensional X-ray images. In the clinical study, the body surface potentials of a patient with old myocardial infarction were recorded. The abnormal Q subtraction map was calculated as the difference between the measured and standard potentials of a normal subject. In the inverse calculation, the geometric shape of the heart and the body surface were determined from cross-sectional body images of computed tomography. The location of the infarction was estimated independently using coronary arteriography and left ventriculography. The results obtained were as follows: Experimentally, the estimated epicardial ST elevations correlated well with the measured ones. The area of estimated ST elevation included the portion of the myocardial injury produced by the freezing procedure, although the area estimated was relatively small compared with the actual one. Clinically, the estimated abnormal Q area correlated well with the area of the left anterior descending artery in which severe stenosis was detected by coronary arteriography.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1979

[The inversion of mood (author's transl)].

It is for a good reason that the colloquium is entitled Affective disorders and not Depression: in reality there is a profound unity between elation and depression and we have to ask ourselves whether there may be inversion of mood in any case of elation and vice-versa. Mood inversion occurs in various conditions: depression sets in a previously elated person, finally overwhelmed by the consequences of his acts; or elation may occur as an over-compensation for the pain of loss. These two situations lead either to a paradoxical content of the patient's talk or to a metapsychological elaboration. Finally, the change may take place without there being a clear psychological formulation. The concomitants of these phenomena, involving the biological amines or the neurotransmitters, must be elucidated. Clinically, there are two types of problem: the problem of the premonitory signs of inversion of mood and the problem of attempting to prevent it.

Adaptation, Psychological↗
PubMed1984

[A case of a well-tolerated spontaneous post partum uterine inversion].

The authors report the unusual case of spontaneous inversion of the uterus that occurred three days after a normal delivery. Clinically this was very well tolerated. There did not seem to be a constriction ring which normally occurs in there cases. The authors were therefore able to wait until it was quite safe to give the patient an anaesthetic. Manual replacement was easy bu inversion recurred immediately. A pack was therefore put inside the uterus, and the uterus closed down satisfactorily on it in the right position. When the pack removed under anaesthesia 48 hours later inversion did not recur.

Adult↗
PubMed1982

The hydrophobic-hydrophilic balance of bile salts. Inverse correlation between reverse-phase high performance liquid chromatographic mobilities and micellar cholesterol-solubilizing capacities.

To examine quantitatively the hydrophobic-hydrophilic properties of bile salts, we determined the reverse-phase high performance liquid chromatographic (HPLC) mobilities of monomeric bile salt solutions and the equilibrium cholesterol-solubilizing capacities of 100 mM micellar solutions. Studies with the common bile salts (ursodeoxycholate, UDC, cholate, C, chenodeoxycholate, CDC, and deoxycholate, DC) demonstrated that HPLC mobility, which correlates with hydrophilicity, was markedly influenced by both position and orientation, in addition to number, of hydroxyl functions, in that mobility decreased in the order UDC > C > CDC > DC. Conjugation of the bile salt was also important, in that the HPLC mobility of the taurine (T)-conjugates was greater than the glycine (G)-conjugates which in turn was greater than that of the free bile salts. Equilibrium micellar cholesterol solubilities were also influenced by bile salt structure and correlated inversely with hydrophilicity, in that solubility decreased in the order DC > CDC > C > UDC with free bile salts > G-conjugates > T conjugates. For each bile salt series, double logarithmic plots of the cholesterol-solubilizing capacities expressed in mole fraction units versus the HPLC retention factors (k') gave linear relationships. Linear regression equations were employed to predict the equilibrium cholesterol-solubilizing capacities of a number of less common bile salts from their HPLC retention factors. Each theoretical value agreed closely with that derived entirely by experiment. A comparison of the HPLC mobilities of the less common bile salts with the more common species revealed that not only were sulfate and oxo substituents more hydrophilic than alpha-oriented hydroxyl functions, but, in the dihydroxy species, a single equatorial hydroxyl function such as in UDC (3alpha,7beta) and in hyodeoxycholate (3alpha,6alpha) was more hydrophilic than two or three hydroxyl functions at 3, 7, and/or 12alpha (axial) positions. These studies taken together suggest that reverse-phase HPLC mobility and equilibrium cholesterol-solubilizing capacities are inverse functions of each other and correlate closely with the hydrophilicity of bile salt molecules. In addition, the evidence here deduced further strengthens our recent deductions based on an evaluation of a number of other physical-chemical properties (Carey, M. C., J-C. Montet, M. C. Phillips, M. J. Armstrong, and N. A. Mazer, 1981. Biochemistry. 20: 3637-3648.) that cholesterol may be solubilized in micellar bile salt solutions by both hydrophobic and hydrophilic association with the external ("hydrophilic") surface of bile salt micelles rather than with the hydrophobic surface of the micelle's interior.-Armstrong, M. J., and M. C. Carey. The hydrophobic-hydrophilic balance of bile salts. Inverse correlation between reverse-phase high performance liquid chromatographic mobilities and micellar cholesterol-solubilizing capacities.

Bile Acids and Salts↗
PubMed1980

Management of acute and subacute puerperal inversion of the uterus.

Eighteen cases of acute and subacute puerperal inversion were studied to identify important predisposing factors and to assess management and postpartum morbidity. The study patients did not differ from case-matched controls in age, parity, duration of labor, type of delivery, or management of the third stage. The most common signs noted were hemorrhage (94%) and shock (39%). All inversions were recognized immediately and manually replaced within 60 minutes. Shock was treated prior to repositioning in all cases. Calculated blood loss averaged 1775 ml. There was no mortality nor febrile morbidity. The average hospital stay of the study patients and their case-matched controls was 3 days. Immediate recognition of uterine inversion and prompt initiation of therapy will ensure a normal postpartum course.

Acute Disease↗
PubMed1995

[Inverse relationship between fetal growth and arterial pressure in children and adults].

BACKGROUND: Increased prevalence of hypertension, ischaemic heart disease and stroke has been reported in subjects with impaired growth during fetal life and infancy. Blood pressure could mediate this relation. Indeed, reduced growth in fetal life and infancy has been associated with a raised blood pressure in children and adults. However, there is controversy about the relative importance of intrauterine environment and extrauterine adverse environment which can act throughout the life course. We therefore studied the relation between birth weight, which is known to be an indicator of fetal growth, and blood pressure in children and their parents. This association could thus be assessed in childhood before the external environmental influences became important, and in adulthood. METHODS: Seven hundred and fifteen healthy schoolchildren (379 boys) aged 3-12 years from primary schools, and 448 parents (252 women) aged 20-44 years, born at term, without hypertension or diabetes, were studied. Blood pressure and birth weight were measured. Birth weight was taken from the hospital records. Data were analysed by tabulation of means and linear regression and correlation techniques. Mean systolic and diastolic blood pressure were calculated according to birth weight and current weight as fourths of their distributions. RESULTS: There was a significant inverse relation between birth weight and systolic blood pressure both in children and adults. Current weight standardised regression coefficient showed a change of -2.68 mm Hg (95% Cl - 2.0 to 3.26, p = 0.027) for each Kg increase in birth weight in children, and -3.82 mmHg (95% Cl -3.21 to -4.39, p = 0.011) in adults. Within each current body weight group the reduction in mean systolic blood pressure from the lowest to the highest birth weight group was larger in adults (10.4 mmHg) than in children (4.1 mmHg). Adults but not children showed also an inverse relation between birth weight and diastolic blood pressure. Weight standardised regression coefficient was -3.0 mm Hg (95% Cl -2.45 to -3.62, p = 0.036). CONCLUSIONS: Blood pressure in inversely related to birth weight in childhood. This relation becomes stronger in adulthood. Therefore, reduced growth during fetal life may be linked with an increased risk of developing hypertension and cardiovascular disease.

Adult↗
PubMed1994

The natural history of postischemic T-wave inversion: a predictor of poor short-term prognosis?

BACKGROUND: This study followed up the natural history of T-wave inversion and assessed the short-term prognosis associated with the condition. METHODS: Forty patients with acute ischemic syndrome, without infarction, and with postischemic T-wave inversion (group 1) were followed during the persistence (inverted T-wave period) and after the resolution of T-wave inversion (positive T-wave period). Another 40 patients with acute ischemic syndrome, without infarction and with normal T waves (group 2), were also followed. RESULTS: Postischemic inverted T waves showed resolution within 3-21 days of presentation in 31 patients from group 1 on medical treatment alone. Further ischemic events (acute myocardial infarction, acute ischemic syndrome, angina pectoris, silent ischemia), inducible ischemia (during treadmill test), wall-motion abnormalities (demonstrated by echocardiography), all developing in the primarily ischemic myocardial area, were more frequent (P < 0.02) in group 1 patients during the inverted T-wave period compared with those experienced in the positive T-wave period of group 1 patients, and compared with group 2 patients. CONCLUSION: In most patients on medical treatment, postischemic inverted T-waves tended to resolve within 3 weeks. The presence of postischemic inverted T waves appears to be an independent marker of further ischemic events.

Adult↗
PubMed1995

[Complete non-obstetrical uterine inversion].

A rare case of a gynaecologic uterine inversion is reported emphasizing on the exceptional character of the gynecologic uterine inversion and the pathogenic problems which are tackled. Gynaecologic inversion results from a tumor implanted on fundus of the uterus or from the essential atrophy of suspension ligaments of the uterus. Treatment depends on the anatomic type and the stage.

Adult↗
PubMed1994

Lowered motor conduction velocity of the peroneal nerve after inversion trauma.

To analyze the effect of inversion trauma on peroneal nerve function, motor conduction velocity was measured in 22 patients. In the injured leg, 4-8 d post trauma motor nerve conduction velocity in the knee-caput fibulae segment of the superficial peroneal nerve was significantly smaller when compared with the contralateral leg and the control group. Five weeks post trauma these values were normal again. For three segments of the deep peroneal nerve, the motor conduction velocity was significantly reduced, 4-8 d post trauma, when compared with the control group. In the caput-ankle and knee-ankle segment, motor conduction velocity was still significantly lowered 5 wk post trauma. Lowered amplitudes of the Compound Motor Action Potentials of the extensor digitorum brevis muscle were found 4-8 d post trauma. No correlation was found between motor nerve conduction velocities and subjective clinical tests (anterior drawer sign and (manually performed) talar tilt test). The results of this study support the hypothesis that inversion trauma is frequently accompanied by lesions of the peroneal nerve. Motor conduction velocity measurements can be a valuable tool in assessing more objectively functional instability of the ankle joint induced by inversion trauma.

Adolescent↗
PubMedDate not supplied

Metabolic chiral inversion of stiripentol in the rat. I. Mechanistic studies.

To study enantioselective aspects of the disposition of stiripentol (STP), a chiral allylic alcohol undergoing development as an antiepileptic drug, a stereoselective synthesis was developed and the configuration of the two enantiomers determined to be (R)-(+) and (S)-(-). Following a single oral dose (300 mg kg-1) of the individual enantiomers to adult male Sprague-Dawley rats, it was found that (R)-STP was transformed extensively to its antipode, whereas little inversion was detected when (S)-STP was administered. Studies on the mechanism of this apparently unidirectional chiral inversion revealed that the phenomenon was dependent on the presence of the side-chain C==C double bond, because the enantiomers of the corresponding saturated alcohol (D2602) did not interconvert in vivo. Experiments with analogs of STP labeled with deuterium or oxygen-18 at the chiral center showed that, whereas the deuterium was retained in vivo, partial loss of the 18O occurred from both enantiomers of the drug. Pretreatment of rats with pentachlorophenol (40 mumol kg-1 i.p.), an inhibitor of sulfation (and possibly other conjugation reactions), led to a marked decrease in the rate of conversion of (R)-STP to its antipode, suggesting that the chiral inversion phenomenon may be mediated, at least in part, by an enantioselective conjugation process.

Administration, Oral↗
PubMedDate not supplied

Metabolic chiral inversion of stiripentol in the rat. II. Influence of route of administration.

As described in the accompanying study, it was found that when the S enantiomer of stiripentol [(S)-STP] was given orally to rats, blood specimens contained only (S)-STP, whereas following administration of an equivalent dose of (R)-STP, both R and S forms of the drug were detected in the systemic circulation. In the present study, we investigated the influence of route of administration on this apparently unidirectional chiral inversion of (R)-STP in the rat. When (R)-STP was given either intravenously (60 mg kg-1) or intraperitoneally (300 mg kg-1), the inversion phenomenon was not observed, indicating that the process must take place presystemically. Following oral administration of either enantiomer of STP, it was found that the drug present at various points along the gastrointestinal tract became progressively enriched in molecules of R configuration, such that the free STP in cecum, large intestine, and feces consisted largely of the R enantiomer, regardless of the configuration of the administered drug. In a parallel in vitro study, it was demonstrated that STP undergoes acid-catalyzed racemization, the rate of which is appreciable at the pH value of the rat stomach (pH approximately 4). On the basis of these observations, it is proposed that the apparent metabolic chiral inversion of (R)-STP results from the combination of at least two factors: 1) partial acid-catalyzed racemization in gastric acid (that affects both enantiomers equally), and 2) enantioselectivity in one or more of the processes involved in the absorption, first pass metabolism or biliary excretion of STP, such that the S isomer appears selectively in the systemic circulation, whereas the R enantiomer is eliminated preferentially in the feces.

Administration, Oral↗
PubMed1994

In flight verification of the inversion illusion.

Pilots' sensations of orientation while pushing over (bunting) are inconsistent. We flew 13 aircrew or naive subjects individually in a Hawk or Hunter jet training aircraft. With sun visor down and eyes closed, each was asked to report what the aircraft was doing. After unaccelerated level flight for 30 s, the aircraft was accelerated in level flight from 200 to 250 kts at +0.15 to +0.25 Gx, and gently pulled into a stable 250-kt, 3000 ft/min climb. After 30 s, it was pushed to -1 G during 3 s. Minus 1 G was then held for a further 3 s. Of 30 maneuvers, 14 produced sensations of inversion in 9 of 13 subjects. Two subjects reported feet-up rotation to the inverted; one felt a rotation of indeterminate direction; five felt sudden inversion. This illusion was experienced by 3/3 naive non-pilots, 6/8 pilots, and 0/2 test pilots. We conclude that the "inversion illusion" exists, and that the postulated sensation of backward rotation is often not perceived.

Acceleration↗