Pregnancies after ICSI using sperm with abnormal head-tail junction from two brothers: case report

We report ICSI pregnancies in two couples with a history of long standing primary infertility in which the sperm of the male partner were either acephalic or had abnormal head-midpiece attachments. The two couples, in which the men are brothers, underwent ICSI. Sperm were analysed by transmission electron microscopy and immunocytochemistry with an anti-MPM2 monoclonal antibody. The first couple underwent two ICSI cycles, each consisting of the injection of two mature oocytes and the transfer of two embryos. A successful pregnancy occurred after the second transfer and led to the birth to a healthy girl. The second couple underwent three ICSI cycles, each consisting of the injection of 18 oocytes and the transfer of two embryos; the last of these led to a triple ongoing pregnancy which included two identical twins. Caesarean section led to the birth of three fetal-growth restricted children. This case report demonstrates that ongoing pregnancies can be achieved in cases of abnormal development of the head-neck attachment. The genetic origin of this syndrome is generally accepted, but the phenotypic heterogeneity observed by light and electron microscopy among published cases suggests that there are a variety of genetic causes of this syndrome.

Preterm premature rupture of membrane and twin-to-twin transfusion syndrome before 20 weeks: a favourable outcome

We describe a monochorionic twin gestation with a severe twin-to-twin transfusion syndrome associated with a preterm premature rupture of membranes at 20 weeks of gestation in the polyhydramniotic sac. The pregnancy was managed expectantly and outcome was favourable for the 2 neonates. We discuss how these two severe pathologies seem to counteract each other by compensations of their symptoms.

Ultrasonographic evaluation of cervical length in pregnancies complicated by preterm premature rupture of membranes

OBJECTIVE

To evaluate the usefulness of transvaginal ultrasonography in the determination of the risk of preterm delivery and chorioamnionitis in pregnancies affected by preterm premature rupture of membranes preterm premature rupture of membranes.

DESIGN

One hundred and one singleton pregnancies with preterm premature rupture of membranes were included in this prospective study over a 3-year period. Patients underwent cervical length measurement by transvaginal ultrasonography at admission and thereafter, in the absence of chorioamnionitis, were managed expectantly.

RESULTS

The median time interval between admission and delivery (latency period) was 48 h. A cervical length of less than 20 mm was associated with a significant risk of early delivery (mean latency period was 59.44 +/- 159.93 h vs. 240.94 +/- 364.67; P < 0.05). There was no relation between cervical length and occurrence of chorioamnionitis or neonatal sepsis.

CONCLUSIONS

These data suggest that the use of transvaginal ultrasonography for cervical length measurement during preterm premature rupture of membranes may predict an early delivery but cannot anticipate the risk of chorioamnionitis or neonatal sepsis.

Pharmacological aids to locomotor training after spinal injury in the cat

This Topical Review summarizes some of the work we have done mainly in the cat using agonists and antagonists of various neurotransmitter systems injected intravenously or intrathecally to initiate or modulate the expression of hindlimb locomotion after a spinal lesion at T13. The effects of the same drugs are compared in various preparations: complete spinal, partial spinal or intact cats. This has revealed that there can be major differences in these effects. In turn, this suggests that although the locomotor rhythm might normally be triggered and modulated by the activation of a variety of receptors (noradrenaline, serotonin, glutamate), after spinalization there appears to be a predominance of glutamatergic mechanisms. Recent work also suggests that, in the cat, the integrity of the midlumbar segments is crucial for the expression of spinal locomotion. Taken together, this work raises some hope that a targeted pharmacotherapy with better understood drugs and mode and locus of delivery could become a clinical reality.

A high frequency of allelic loss in oral verrucous lesions may explain malignant risk

Verrucous carcinoma (VC), a variant of squamous cell carcinoma (SCC), is distinct from SCC in morphology and behavior. The underlying genetic changes involved in the development of VC and its precursor verrucous hyperplasia (VH) are unknown. This study determined whether chromosomal regions frequently lost during the development of SCC are also lost in the VH/VC variant. Twenty-five VH and 17 VC were analyzed for loss of heterozygosity (LOH) at 19 loci on 7 chromosome arms using microsatellite analysis. These data were compared with those from 47 reactive hyperplasias, 92 dysplasias (54 low- and 38 high-grade), and 41 SCCS: The results showed that VC/VH shared many of the losses present in dysplasia/SCC but differed in two aspects. First, VC/VH showed early acquisition of loss, compared with a gradual accumulation of losses from dysplasias to SCC. The LOH pattern of VH was similar to that of high-grade dysplasia and sharply different from reactive hyperplasia. The loss in VH often involved multiple arms (in 60% of VH vs 0% of reactive lesions). Only a marginal elevation of loss was observed at 9p (p = 0.06) and 4q (p = 0.05) from VH to VC because of the high degree of loss already present in VH. Second, a strikingly lower frequency of loss at 17p was noted in VH/VC compared with dysplasia/SCC and may indicate human papillomavirus (HPV) involvement. The finding of high-risk LOH profiles in VH may partly account for the high-progression risk seen for VH and also has potentially important clinical implications. The difficult pathological diagnosis of VH/VC from reactive hyperplasia frequently requires repeated biopsies and results in delay in diagnosis and significantly increased mortality/morbidity. Microsatellite analysis might facilitate this differential diagnosis.

Concurrent and longitudinal links between friendship and peer victimization: implications for befriending interventions

This short-term longitudinal study examined the associations between peer reports of victimization and self-reported friendship among early adolescents. It was carried out to test the view that friendship provides protection against victimization (called the "friendship protection hypothesis"). Data were collected at two points within a school year, separated by 6 months. At Time 1, 170 pupils provided data, and 158 of these did so again at Time 2. Three sets of findings were consistent with the friendship protection hypothesis. First, at Time 1 those early adolescents who had a reciprocated best friend in their home class received significantly fewer peer nominations for victimization than did classmates without a reciprocated best friend. Second, those early adolescents that did not have best friend at either Time 1 or Time 2 showed the highest increase in victimization over the course of the study, whereas those that did have a best friend at both Times 1 and 2 showed the highest falls in victimization. Third, a hierarchical multiple regression analysis indicated that a decrease in conflict and betrayal reported to characterize the participants' best friendship was associated with falls in victimization. The implications of these results for anti-bullying initiatives based on "befriending" principles were discussed.

GABA(A) receptors mediate inhibition of T cell responses

We describe the presence of functional GABA(A) receptors on T cells. GABA inhibited anti-CD3 and antigen-specific T cell proliferation in vitro in a dose-dependent manner that was 1) mimicked by the GABA(A) receptor agonist muscimol (but not the GABA(B) receptor agonist baclofen), 2) blocked by GABA(A) receptor antagonists and a GABA(A) receptor Cl- channel blocker (picrotoxin) and 3) enhanced by pentobarbital. These data suggest that GABA(A) receptors mediate this immune inhibition and that these receptors can be modulated in a similar fashion to their neuronal counterparts. Finally, GABA inhibited DTH responses in vivo. Thus, pharmacological modulation of GABA(A) receptors may provide new approaches to modulate T cell responses in inflammation and autoimmune disease.

[Prenatal diagnosis of fetal goiter revealing iodine utilization defect]

We report on a case of fetal goitrous diagnosed on ultrasonogram done at 31 weeks of gestation. Thyroid maternal function was normal and no therapeutic was responsible. Hormonal test done on cord blood supported diagnosis of prenatal hypothyroidism. The infant was born prematurely at gestation age of 34 without antenatal treatment. He was eutrophic with clinical and biological signs of hypothyroidism and a large goiter. Therapy with thyroxine was instituted on the third day of life. At 9 months, growth and development are normal. Congenital hypothyroidism has an incidence of approximately 1 in every 4000-5000 live births. Rarely fetal goitrous hypothyroidism have been attributed to thyroid hormone dyshormonogenesis. When fetal goiter is diagnosed on ultrasonography, without maternal hypothyroidism or therapeutic and when hypothyroidism is confirmed on fetal blood, this diagnosis must be suspected.

Pharmacological activation and modulation of the central pattern generator for locomotion in the cat

Pharmacological agents have been shown to be capable of inducing a pattern of rhythmic activity recorded in muscle nerves or motoneurons of paralyzed spinal cats that closely resembles the locomotor pattern seen in intact cats. Further work, using intraperitoneal or intrathecal injections, suggests that different neurotransmitters may be involved in various aspects of locomotor control, e.g., initiation and modulation of the pattern. Although precursors, agonists or the neurotransmitters themselves of several systems have been investigated (noradrenergic, dopaminergic, serotonergic, glutamatergic), the noradrenergic system seems the most efficient in triggering locomotion in complete spinal cats, with the alpha-2 agonists (clonidine, tizanidine, oxymetazoline) being more potent than the alpha-1 agonist, methoxamine. Moreover, the potency of the drugs may depend on the time of application after the spinal lesion. In chronic spinal cats capable of spontaneous walking on hindlimbs on the treadmill, all neurotransmitters appear to exert distinct recognizable effects on the locomotor pattern. More recent work also suggests that the effects of drugs may differ significantly depending on the type of spinal lesion. For instance, clonidine further reduces the level of weight support during quadrupedal locomotion of cats with lesions of the ventral-ventrolateral funiculi, possibly due to an interference of clonidine with essential compensatory mechanisms used by these animals to walk. Such considerations as the type of drugs, type of lesions, and the time after the lesion will be important for future studies in spinal cord injured patients.

Congenital rapidly fatal form of nemaline myopathy with fetal hydrops and arthrogryposis. A case report and review

A new lethal case of nemaline myopathy is reported. The diagnosis was made by postmortem muscle biopsy. The child died before his first day of life. This is one of the very rare cases of nemaline myopathy with severe antenatal ultrasonographic signs: fetal hydrops and arthrogryposis. In a review of the literature other cases of the congenital rapidly fatal form are found, some of them with clinical decrease of fetal movements but only few authors report ultrasonographic signs. The diagnostic, histopathogenic, genetic and evolutive aspects of this heterogeneous disorder are analyzed. This congenital nonprogressive myopathy is not as benign as previously thought and may be an etiology of the lethal form of arthrogryposis multiplex congenita. The existence of ultrasonographic antenatal signs seems to be a factor of poor prognosis. In spite of recent genetic discoveries, there is at present no specific antenatal diagnosis. Consequently, muscle biopsy in lethal cases is very important to allow a genetic counselling; however, in utero fetal biopsy has never been performed in such cases.

Effects of intrathecal alpha1- and alpha2-noradrenergic agonists and norepinephrine on locomotion in chronic spinal cats

Noradrenergic drugs, acting on alpha adrenoceptors, have been found to play an important role in the initiation and modulation of locomotor pattern in adult cats after spinal cord transection. There are at least two subtypes of alpha adrenoceptors, alpha1 and alpha2 adrenoceptors. The aim of this study was to investigate the effects of selective alpha1 and alpha2 agonists in the initiation and modulation of locomotion in adult chronic cats in the early and late stages after complete transection at T13. Five cats, chronically implanted with an intrathecal cannula and electromyographic (EMG) electrodes were used in this study. Noradrenergic drugs including alpha2 agonists (clonidine, tizanidine, and oxymetazoline) and an antagonist, yohimbine, one alpha1 agonist (methoxamine), and a blocker, prazosin, as well as norepinephrine were injected intrathecally. EMG activity synchronized to video images of the hindlimbs were recorded before and after each drug injection. The results show differential effects of alpha1 and alpha2 agonists in the initiation of locomotion in early spinal cats (i.e., in the first week or so when there is no spontaneous locomotion) and in the modulation of locomotion and cutaneous reflexes in the late-spinal cats (i.e., when cats have recovered spontaneous locomotion). In early spinal cats, all three alpha2 agonists were found to initiate locomotion, although their action had a different time course. The alpha1 agonist methoxamine induced bouts of nice locomotor activity in three spinal cats some hours after injection but only induced sustained locomotion in one cat in which the effects were blocked by the alpha1 antagonist prazosin. In late spinal cats, although alpha2 agonists markedly increased the cycle duration and flexor muscle burst duration and decreased the weight support or extensor activity (effects blocked by an alpha2 antagonist, yohimbine), alpha1 agonist increased the weight support and primarily the extensor activity of the hindlimbs without markedly changing the timing of the step cycle. Although alpha2 agonists, especially clonidine, markedly reduced the cutaneous excitability and augmented the foot drag, the alpha1 agonist was found to increase the cutaneous reflex excitability. This is in line with previously reported differential effects of activation of the two receptors on motoneuron excitability and reflex transmission. Noradrenaline, the neurotransmitter itself, increased the cycle duration and at the same time retained the cutaneous excitability, thus exerting both alpha1 and alpha2 effects. This work therefore suggests that different subclasses of noradrenergic drugs could be used to more specifically target aspects of locomotor deficits in patients after spinal injury or diseases.

Insulin selectively primes Th2 responses and induces regulatory tolerance to insulin in pre-diabetic mice

Little is known about the immunological impact of insulin administration other than it can boost insulin autoantibody levels. In particular, while the subcutaneous administration of a soluble foreign antigen (without adjuvant) is generally only weakly immunogenic in a naive animal, it is unknown what effect the subcutaneous administration of a soluble self-antigen has in animals with established autoimmune responses to the antigen. Addressing these questions in pre-diabetic nonobese diabetic (NOD) mice, we examined the effects of administering insulin, as well as the metabolically inactive B-chain of insulin, on insulin-specific cellular and humoral immune responses. We show that pre-diabetic NOD mice have a spontaneous Th1-biased response against insulin. Administering insulin, or the insulin B-chain, rather than boosting the established Th1 response, primed Th2 cellular and humoral immunity to insulin, shifting the predominant insulin response toward a Th2 phenotype. Despite the presence of a Th1 response against insulin, insulin treated mice failed to mount proliferative T-cell responses following immunization and challenge with insulin, demonstrating that the treatment induced an active form of tolerance to this autoantigen. Thus, the subcutaneous administration of a soluble antigen can engage Th2 responses and induce self-tolerance, even after the establishment of autoreactive Th-1 responses. Such immune deviation and induced regulatory tolerance may contribute to the protective effects of prophylactic insulin therapy, as well as the establishment of a "honeymoon" phase in new-onset insulin-dependent diabetic patients.

Early locomotor training with clonidine in spinal cats

Clonidine, a noradrenergic alpha-2 agonist, can initiate locomotion early after spinalization in cats. Because this effect lasts 4-6 h, we have injected clonidine daily, intraperitoneally or intrathecally, and intensively trained five spinal cats to perform hindlimb walking on a treadmill starting at day 3 and continuing until 10 days posttransection. Each day, clonidine was injected to induce locomotor activity and cats were trained to walk with as much weight support as possible and at different speeds during multiple (1-5) locomotor training sessions, each lasting from 10 to 20 min, until the effects of clonidine wore off. Electromyographic (EMG) activity synchronized to video images of the hindlimbs were recorded before and after each clonidine injection. The results showed, first, a day-to-day change of the locomotor pattern induced by clonidine from the 3rd to the 11th day including an increase in the duration of the step cycle, an increase in the duration of extensor EMG activity, and an increase in total angular excursion of the hip, knee, and ankle joints. Second, after 6-11 days of this regimen, there was an emergence of a coordinated locomotor pattern with weight support of the hindquarters that was visible even before that day's clonidine injection. The results suggested that daily injection of clonidine followed by early and daily interactive locomotor training can enhance the recovery of locomotion in spinal cats.

Plasma fibronectin: predictive factor in gestational hypertension?

Our purpose was to evaluate fibronectin as a marker of endothelial cell injury, and as a test for predicting preeclampsia. A retrospective study was performed from November 1993 to March 1995. Results from 142 women were examined: 108 normal pregnant women and 34 pregnant women with evidence of preeclampsia. The plasma fibronectin concentration was significantly higher in pre-eclamptic gravidas (620 +/- 210 mg/l) than in normotensive gravidae women (390 +/- 130 mg/l). A fibronectin concentration lower than 400 mg/l predicted the non-development of a hypertension with a negative predictive value of 96%. The present findings suggest that fibronectin is rather an exclusion parameter than predictive test for hypertension disorders of pregnancy.

Placental cord insertion visualization with prenatal ultrasonography

Color Doppler and gray scale sonography can be used prenatally to identify the location of the cord insertion into the placenta. The purposes of this paper were to (1) relate sonographic identification of placental cord insertion with placental pathology; (2) evaluate the possibility that a marginal cord insertion may evolve into a velamentous cord insertion; and (3) determine the frequency and factors affecting sonographic visualization of cord insertion. Our results show that the sonographic assessment of cord insertion correlated with the pathologic outcome in 83% (106 of 128) of singleton pregnancies and at least one of the fetuses in 72% (8 of 11) of twin or triplet pregnancies. Although the sensitivity for identification of an abnormal cord insertion was low (42%), the specificity was high (95%). Our data suggest that marginal cord insertion evolved into velamentous cord insertion in one singleton and one twin. Our results showed that cord insertion was visualized in 54% of fetuses scanned in a routine clinical practice. Cord insertion visualization was possible at all gestational ages, although it was more difficult at later gestational ages. In conclusion, this study provides evidence that (1) ultrasonography (either gray scale or color Doppler) is useful in identifying normal, marginal, and velamentous cord insertion; (2) marginal cord insertion may evolve into velamentous cord insertion as pregnancy progresses; (3) in clinical practice the cord insertion site was visualized in just over half of the cases, and (4) prenatal identification of marginal and velamentous cord insertion potentially may be useful for planning obstetrical management.

Locomotor capacities after complete and partial lesions of the spinal cord

This paper first reviews some of the observations made on the locomotor capabilities of several animal species with a special emphasis on cats and including primates and man after complete spinal lesions. We show that animals can perform well-coordinated walking movements of the hindlimbs when they are placed on a treadmill belt and this locomotion is also adaptable to speed and perturbations. Cats with partial spinal lesions of the ventral and ventrolateral parts of the cord can perform voluntary quadrupedal locomotion overground or on the treadmill albeit with deficits in weight support and interlimb coordination. We also show that some drugs such as clonidine (an alpha-2 noradrenergic agonist) can be used to trigger locomotion in early-spinal cats and discuss the effects of various neurotransmitter systems on the expression of the locomotor pattern in both complete and partial spinal cats. It is concluded that a pharmacological approach could be used, in combination with other approaches, such as locomotor training and functional electrical stimulation, to improve locomotor functions after spinal cord injuries in humans.

In vivo MRI of the fetal brain

We report MRI of the brain in 45 fetuses; the findings were confirmed by pathological examination or postnatal neuroradiological studies. MRI necessitates medication to eliminate fetal motion; curare was injected into the umbilical cord, and MRI is therefore limited to cases in which umbilical cord puncture is indicated. T1-weighted images were obtained in axial, sagittal and coronal planes; the last of these were generally as the most useful as regards morphology. We demonstrated cerebral malformations (n = 13), brain haemorrhage (n = 1), a facial angioma (n = 1), a facial mass (n = 1), hydrocephalus (n = 5), unilateral ventricular enlargement (n = 1), atrophy (n = 4), a porencephalic cyst (n = 1) and normal appearances of the brain in 18 cases. Twenty-two of the fetuses were born alive, and the clinical and/or neuroradiological examination confirmed the antenatal findings. The diagnosis was also confirmed in 8 cases in which a neuropathological examination was possible.

Noradrenergic agonists and locomotor training affect locomotor recovery after cord transection in adult cats

In one series of experiments, the effects of noradrenergic, serotonergic, and dopaminergic precursors and agonists on the initiation of locomotion were investigated within the first week after complete spinalization at +13 in five adult cats. In addition, the effects of clonidine and daily locomotor training were investigated during the first week after transection in another cat. The electromyographic (EMG) activity of vastus lateralis (VL) and semitendinosus (St) was recorded bilaterally through percutaneously implanted copper wires in all cats. The movement of the hindlimbs on the treadmill was also simultaneously videorecorded before and after the injection of drugs. Without drug injection, strong and sustained perineal or abdominal stimulation did not induce any prolonged episodes of coordinated stepping on the treadmill during the first week after spinalization. St often had sustained activity, in contrast to VL, in which minimal or no activity was present. Injection of apomorphine (0.3 to 0.5 mg/kg, n = 3), a dopaminergic agonist, or DL-5-HTP (50 mg/kg, n = 2), a serotonergic precursor, failed to induce locomotion at such an early stage after spinalization. In contrast, injection of either L-dopa (50-60 mg/kg, n = 2), a noradrenergic precursor, or clonidine (150 micrograms/kg, n = 2), a noradrenergic agonist, induced locomotion on the treadmill. The animal demonstrated bilateral foot placement on the soles and complete weight support of the hindquarters. The spinal cat could follow the treadmill speed up to 0.80 ms-1. However, these effects disappeared when the NA drugs were tapered off.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term quality of life after kidney transplantation in childhood

Transplantation is the treatment of choice for children with end-stage renal disease. However, the long-term quality of life and socioprofessional outcome for those with successful transplants have not previously been reported. We studied these factors in patients transplanted when less than 18 years old who currently have greater than or equal to 10 years of graft function. A total of 57 questionnaires were sent out; 57 (100%) responded [24 female and 33 male patients; average (+/- SD) age at tx = 10 +/- 5 years (0.9-17.7); average f/u = 15.6 +/- 3 years (10-26); current age = 26 +/- 5 years (12-38); 26 had greater than 1 transplant]. Of the 57 respondents, 9 are less than 18 (all are in school); 48 are greater than or equal to 18 (7 in school, 37 employed, 4 unemployed); 12 are married, 1 engaged, and 2 divorced; and 9 have children. While in school, 43 (75%) had participated in sports, 37 (65%) in other extracurricular activities; 7 (12%) were A and 33 (58%) B students; 15 (26%) received awards or scholarships. For those working, the range of occupations is broad (average work week = 41 +/- 5 hr). Health-related absence from work has been nonexistent for 93%. Health is rated as good to excellent by 91% and fair by 9%. The future is regarded as hopeful or promising by 80%. Similarly, 89% are satisfied with life in general; 95% said health never or seldom interferes with family life; 95% feel health and drug side effects are of no or minor concern in sexual relationships. Only 3% feel health is a problem in maintaining a sexual relationship (41% are not sexually active). Only 4% stated that health often interferes with social life; 98% meet with friends on a regular basis; 76% are satisfied with personal relationships and 8% dissatisfied; 91% are satisfied with their ability to perform at work or school and 5% dissatisfied. Of note, 32% are dissatisfied with body appearance. Major concerns are short stature and brittle bones. Major suggestions include education/support groups to deal with teasing at school and peer problems. We conclude that transplanted children with long-term graft function have a favorable social and professional outcome. Overall, quality of life seems excellent.

Long-term metabolic function of pancreas transplants and influence of rejection episodes

Pancreas grafts, when not rejected, can sustain an insulin-independent state in type I diabetic recipients for indefinite periods. To what extent the metabolic control achieved approaches that of normal individuals, the relationships between graft endocrine and exocrine function, the effect of reversible rejection episodes on subsequent graft function, and the correlation between the results of serial tests of graft function were determined by studies at 1 month, 1 year, and 2 years in a cohort of 39 recipients (29 females, 10 males; mean age (+/- SD), 33 +/- 5 years; mean duration of diabetes, 22 +/- 6 years) of bladder-drained pancreas transplants performed between November 1984 and December 1988. Fifteen patients received a pancreas transplant alone, 8 a pancreas after a kidney, and 16 a simultaneous pancreas/kidney transplant. Graft endocrine function was tested by a 24-hr metabolic profile of blood glucose levels before meals, at 1 and 2 hr after meals, and during the night (14 values in all), by intravenous and oral blood glucose tolerance tests, and by glycosylated hemoglobin levels (HA1 and HA1c). Graft exocrine function was assessed by urine amylase activity (U/hr). The results of the tests in the recipients were subjected to paired comparisons between timepoints and at each timepoint to the results of the same tests in 55 normal nondiabetic control individuals. The means of the mean 24-hr profile glucose (mg/dl) values were significantly lower (P less than 0.05) at 1 and 2 years posttransplant (116 +/- 27 and 115 +/- 15, respectively) than at 1 month (128 +/- 31) in the recipients, but the mean of the mean values in the normal controls (100 +/- 7) was even lower (P less than 0.05). Mean values of individual timepoints during the profile were significantly lower for 6 of the 14 values in the controls than in the recipients. The mean IVGTT K value of the normal controls (-1.9 +/- 0.4%) was significantly lower than the 1-month and 2-year values of the recipients (-1.5 +/- 0.5% and -1.3 +/- 0.6%, respectively), but the comparison with the 1-year value (-1.6 +/- 0.6%) was not significant. The mean glucose levels at zero minutes and between 120 and 300 min of the OGTTs were significantly lower at both 1 and 2 years than at 1 month in the recipients, and the values in the control group were also significantly lower than in the recipients at 1 month but not at 1 and 2 years.(ABSTRACT TRUNCATED AT 400 WORDS)