Effects of Crop Rotation, Cultivar, and Irrigation and Nitrogen Rate on Verticillium Wilt in Cotton.

A field experiment was conducted under center-pivot irrigation in four wedges, with one wedge in continuous cotton (CC) and three wedges in a rotation (ROT) with 2 years cotton and 1 year in sorghum. Three irrigation rates (base = 1.0B, 1.5B, and 0.5B) were applied during 2007 to 2009 on a susceptible (ST) and partially resistant (PR) cultivar. Nitrogen applied during the season was proportional to irrigation rate. In the ROT wedges, 0.5B, 1.0B, and 1.5B irrigation and nitrogen rates averaged 1, 3, and 9% incidence of wilt, respectively. Disease incidence in the CC wedge averaged 6, 18, and 34% wilt incidence for 0.5B, 1.0B, and 1.5B irrigation and nitrogen rates. In the ROT wedges, the ST cultivar returned $143/ha more than the PR cultivars at the 0.5B irrigation and nitrogen rate whereas, at the 1.0B and 1.5B rates, the PR cultivars averaged $121 and $350/ha more than the ST cultivar. There was no significant irrigation and nitrogen or cultivar effect in the CC wedge on net value; however, trends were similar to the ROT wedge. Overall, ROT returned $285/ha more than CC, PR cultivars returned $123/ha more than the ST cultivar, and 1.0B returned $271 and $296/ha more than 0.5B and 1.5B rates, respectively. Microsclerotia density of V. dahliae averaged 2/cm3 of soil in the ROT wedges and 23/cm3 of soil in the CC wedge. Crop rotation, avoiding excessive irrigation, and using a partially resistant cultivar all reduced incidence of Verticillium wilt and improved net returns.

Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density.

Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log(10) (J2 + 1)/500 cm(3) soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log(10)(J2 + 1)/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18 degrees C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10 degrees C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.

The Scottish Perinatal Neuropathology Study--clinicopathological correlation in stillbirths.

OBJECTIVE: To examine the neuropathology of fetuses dying before birth, to determine the timing of any brain damage seen and to ascertain clinical associations of pre-existing brain damage. DESIGN: Population-based observational study. SETTING: All 22 delivery units within Scotland, 1995-1998. SAMPLE: All stillborn fetuses > or =24 weeks of gestation excluding those with chromosomal abnormality or central nervous system/cardiothoracic malformation. METHODS: Clinical detail was collected on all stillborn fetuses. Requests for postmortem included separate request for detailed neuropathological examination. Stillborn fetuses were classified as full term antepartum (normal growth/growth restricted), preterm antepartum (normal growth/growth restricted), intrapartum (full term/preterm), multiple births and stillborn fetuses following abruptions. Clinicopathological correlation attempted to define the timing of brain insult. Placentas were examined for each case where available. MAIN OUTCOME MEASURES: Presence of established and/or recent brain damage. RESULTS Clinical details were available for 471 stillborn fetuses, and detailed neuropathology was possible in 191 cases. Of these 191, 13 were multiple births, 9 died following abruption, 12 were intrapartum deaths and 157 were antepartum stillborn fetuses (99 preterm and 58 full term). Recent or established brain damage was seen in 66% of the entire cohort. Thirty-five percent of all cases showed well-established hypoxic damage predating the last evidence of fetal life, and this was more common in preterm fetuses (P = 0.015), those fetuses with evidence of recent damage (P < 0.001), in pregnancies complicated by pregnancy-induced hypertension (P = 0.044) and those in whom the placenta was <10th centile (P = 0.002). CONCLUSIONS: Brain damage is commonly seen in stillborn infants, and in around one-third of cases, damage predates the period immediately before death. Factors suggesting suboptimal placental function are associated with such damage. Early identification of placental impairment may lead to improved pregnancy outcome.

The distribution of apolipoprotein E alleles in Scottish perinatal deaths.

BACKGROUND: The apolipoprotein E (ApoE) polymorphism has been well studied in the adult human population, in part because the e4 allele is a known risk factor for Alzheimer's disease. Little is known of the distribution of ApoE alleles in newborns, and their association with perinatal brain damage has not been investigated. METHODS: ApoE genotyping was undertaken in a Scottish cohort of perinatal deaths (n = 261), some of whom had prenatal brain damage. The distribution of ApoE alleles in perinatal deaths was compared with that in healthy liveborn infants and in adults in Scotland. RESULTS: ApoE e2 was over-represented in 251 perinatal deaths (13% v 8% in healthy newborns, odds ratio (OR) = 1.63, 95% confidence interval (CI) 1.13 to 2.36 and 13% v 8% in adults, OR = 1.67, 95% CI 1.16 to 2.41), both in liveborn and stillborn perinatal deaths. In contrast, the prevalence of ApoE e4 was raised in healthy liveborn infants (19%) compared with stillbirths (13%, OR = 1.59, 95% CI 1.11 to 2.26) and with adults (15%, OR = 1.35, 95% CI 1.04 to 1.76). However, no correlation was found between ApoE genotype and the presence or absence of perinatal brain damage. CONCLUSIONS: This study shows a shift in ApoE allelic distribution in early life compared with adults. The raised prevalence of ApoE e2 associated with perinatal death suggests that this allele is detrimental to pregnancy outcome, whereas ApoE e4 may be less so. However, ApoE genotype did not appear to influence the vulnerability for perinatal hypoxic/ischaemic brain damage, in agreement with findings in adult brains and in animal models.

Distribution of apolipoprotein E alleles in a Scottish healthy newborn population.

The different alleles of the human apolipoprotein E polymorphism, ApoE epsilon2, epsilon3, epsilon4, have important implications for systemic lipid metabolism, immunological function and for the brain in maintenance and in response to injury. Few studies have focussed on their role in early life. The ApoE alleles and genotypes were ascertained in the cord blood of 371 full-term and normal Scottish newborn infants using PCR methodology. The results were compared to previously published data for Scottish adults in late middle age. There was a marginally significant over-representation of epsilon4 and under-representation of epsilon3 alleles in healthy infants as compared with adults. Inspection of the individual genotypes confirms the over-representation of ApoE 4/4 and 2/4 with a reduction in ApoE 2/3 and 3/3 when compared with Scottish adults. Although these results may have occurred by chance, the ApoE epsilon4 allele may confer an increased risk of premature death.

Short hard palate in prenatal trisomy 21.

OBJECTIVE: The aim of the present study was for the first time to examine on postmortal material the total midpalatal length of the hard palate and the length of its two components (the maxillary and palatine parts) in trisomy 21 fetuses, and to compare the results to normal standards. DESIGN: Material from 31 human fetuses with genetically verified trisomy 21 was studied. The fetuses were derived from legally induced or spontaneous abortions. Palates were, after sectioning, radiographed in lateral projection (Grenz Ray radiographic apparatus). Cephalometric measurements were performed with a digital caliper. Statistically, the length measurements for the two groups were compared, adjusting for crown rump length (CRL) through linear regression. At two specific ages (150 and 170 mm CRL), the length of the palatal components in trisomy 21 was compared to normal standards. RESULTS: For CRL 150 mm and CRL 170 mm it appears that all three palatal lengths, total length, maxillary length, and palatinal length are significantly shorter in fetuses with trisomy 21. CONCLUSION: The main conclusion of our study is that the total palatal length in prenatal trisomy 21 is shorter than normal and that this is due both to a shortness of the maxillary and the palatine components of the hard palate.

Brain damage and axonal injury in a Scottish cohort of neonatal deaths.

Despite the clinical and medicolegal significance attached to perinatal asphyxia, the neuropathological basis of this condition remains obscure. There are very few studies in the literature which correlate the pathological findings in neonatal brains with detailed epidemiological data, and none which are population based. In a Scotland-wide study of neonatal deaths, 70 brains have been examined. On the basis of glial and macrophage reactions, we previously identified infants with putative antepartum brain damage in this cohort and have related these reactions to signs of birth asphyxia. The present study explores the extent of neuronal/axonal injury in these infants since this is likely to be the basis for neurological deficits in surviving infants. We have also investigated these brains for beta-amyloid precursor protein (betaAPP) positivity to determine whether this is a useful marker of neuronal injury in neonates. Neuronal eosinophilia and karyorrhexes were detected in 43% and 27% of the cohort, respectively; maximally in the subiculum and ventral pons, but often present elsewhere. White matter damage was detected in 24% of cases but without classic cystic lesions of periventricular leucomalacia. betaAPP positivity was present in neuronal soma in 52% of cases and, in axons, in 27% of cases, and was seen from as early as 25-weeks gestation. Axonal bulbs were clearly delineated by betaAPP positivity and were usually located in the cerebral white matter and internal capsule, and infrequently in the brain stem. Although white matter damage and betaAPP axonal positivity were often detected in the same cases (P = 0.034), these features also occurred independently of each other. Both neuronal karyorrhexes and white matter betaAPP positivity were significantly correlated with the features of birth asphyxia, particularly a history of seizures. Immunocytochemistry for both betaAPP and glial fibrillary acidic protein proved useful in detecting neuropathological features which escaped detection on routine examination, particularly in preterm infants. The presence together of recent and older damage in individual brains suggests that there is an ongoing neuronal response to cerebral insults. We find that betaAPP is a useful marker of white matter damage in the neonatal brain. Immunopositivity for betaAPP in these circumstances is not attributable to inflicted or accidental trauma. While birth-related trauma cannot be ruled out, hypoxia/ischaemia is a likely cause in these infants. However, the exact pathogenesis of neuronal/axonal injury in the neonatal brain remains unclear.

The Scottish perinatal neuropathology study: clinicopathological correlation in early neonatal deaths.

BACKGROUND: A proportion of neonatal deaths from asphyxia have been shown to be associated with pre-existing brain injury. OBJECTIVES: (a) To compare the epidemiology of infants displaying signs of birth asphyxia with those not showing signs; (b) to examine the neuropathology and determine if possible the timing of brain insult comparing asphyxiated with non-asphyxiated infants; (c) to compare the clinical features of those born with birth asphyxia with and without pre-labour damage. METHODS: Over a two year period, all 22 Scottish delivery units collected clinical details on early neonatal deaths. Requests for post mortem included separate requests for detailed neuropathological examination of the brain. Infants were classified into two groups: birth asphyxia and non-birth asphyxia. Clinicopathological correlation was used to attempt to define the time of brain insult. RESULTS: Detailed clinical data were available on 137 of 174 early neonatal deaths that met the inclusion criteria. Seventy of 88 parents who had agreed to post mortem examination consented to a detailed examination of additional samples from the brain; in 53 of these cases the infant was born in an asphyxiated condition. All asphyxiated and encephalopathic infants, 38% of mature and 52% of preterm infants with features of birth asphyxia but without encephalopathy, and only one of 12 infants without any signs of birth asphyxia showed damage consistent with onset before the start of labour. CONCLUSIONS: In a large proportion of neonatal deaths, brain injury predates the onset of labour. This is more common in infants born in an asphyxiated condition.

Is there a familial association between obstructive sleep apnoea/hypopnoea and the sudden infant death syndrome?

BACKGROUND: One postulated cause of the sudden infant death syndrome (SIDS) is upper airway obstruction during sleep. Several studies have suggested that SIDS may be more common in families with obstructive sleep apnoea/hypopnoea syndrome (OSAHS), but were limited by uncertainty as to whether the deaths were due to SIDS. We have tested the hypothesis that parents of true SIDS cases have an increased frequency of apnoeas and hypopnoeas during sleep. METHODS: The parents of 269 rigorously determined SIDS cases were invited for single night polysomnography and daytime ventilatory control measurement. RESULTS: Parents of 198 cases were identified but 152 did not respond or declined. Fifty five parents of 34 cases were studied and matched for age, height, and weight to 55 subjects from general practice registers. There was no difference in breathing during sleep between the parents of SIDS cases (median (IQR) 5.9 (3.2, 10.7) apnoeas+hypopnoeas/h) and controls (6.7 (4.0, 12.2) apnoeas+hypopnoeas/h; p = 0.47), but the SIDS parents had lower minimum nocturnal oxygen saturation (median (IQR) 92 (89, 93)%) than controls (92 (90, 94)%; p = 0.048). There were no major differences in control of breathing when awake between SIDS parents and controls. CONCLUSIONS: These results provide no evidence to support an association between SIDS and OSAHS. However, the minor impairment of oxygenation during sleep in SIDS parents requires further study.

Infection with Ureaplasma urealyticum: is there a specific clinical and radiological course in the preterm infant?

BACKGROUND: Despite having mild early respiratory disease, many preterm babies develop chronic lung disease (CLD). Intrauterine infection with Ureaplasma urealyticum has been associated with preterm labour and CLD. OBJECTIVE: To test the hypothesis that infection with U urealyticum results in a specific clinical and radiological picture in the first 10 days of life. METHODS: Retrospective study of 60 ventilated babies < 30 weeks gestation, who had tracheal secretions tested for U urealyticum. Placental histology was reviewed by a paediatric pathologist for signs of chorioamnionitis. Chest radiographs were independently reviewed by two paediatric radiologists according to previously agreed criteria. All reviewers were blinded to the infection status of the babies. RESULTS: Twenty five babies were U urealyticum positive. These were more likely to experience chorioamnionitis (p = 0.004), premature rupture of membranes (p = 0.01), and spontaneous vaginal delivery (p = 0.09). U urealyticum positive babies had fewer signs of respiratory distress syndrome on early chest radiographs (p = 0.038), and they could be weaned from their ventilation settings (fraction of inspired oxygen (FIO(2)) and mean airway pressure) more quickly in the first few days. Subsequently U urealyticum positive babies deteriorated clinically and radiologically. More often they required ventilation to be restarted (p = 0.051), a higher proportion being ventilated on day 10 (p = 0.027) with higher FIO(2) (p = 0.001) and mean airway pressure (p = 0.002). Their chest radiographs showed more emphysematous changes as early as day 5 (p = 0.045), with a pronounced difference by day 10 (p = 0.009). CONCLUSIONS: Preterm ventilated babies with U urealyticum in their tracheal secretions have a different clinical and radiological course, with less acute lung disease but early onset of CLD, compared with those with negative cultures.

The prenatal development of the human cerebellar field in Down syndrome.

OBJECTIVES: To describe the development of the osseous field enclosing the cerebellum and part of the brain stem (the neuro-osteological cerebellar field) in Down syndrome, and compare the development with normal developmental standard of the field. DESIGN: Radiographic, cephalometric and histologic examination of 58 legally or spontaneously aborted Down syndrome prenatal human fetuses; crown-rump length of 80-255 mm and approximate gestational age from 13 to 26 weeks. RESULTS: The growth of the Down syndrome cerebellar field is smaller in the sagittal and vertical directions than in normal fetuses. CONCLUSION: In the present study the pathological development of the cerebellar field was described in a genotypic sample. In combining normal and pathological development of neural and osseous tissues a better understanding of the genotype/phenotype interactions is attainable and fields of common gene expression maybe defined.

A histological and radiological investigation of the nasal bone in fetuses with Down syndrome.

OBJECTIVES: Previous studies of nasal bone development in Down syndrome have used radiographs or ultrasound for the detection of nasal bone length or nasal bone absence. The aim of this study was to investigate the presence and size of the nasal bones in postmortem Down syndrome fetuses by means of radiographs and histological examination. METHODS: Thirty-three aborted human fetuses (gestational age 14-25 weeks) with Down syndrome were included. A mid-sagittal tissue block was excised from the skull base to the foramen magnum and along the lateral aspect of the spine. Radiographs of the tissue block were taken in lateral, frontal and axial projections. The length of the nasal bone was measured. The tissue blocks were cut in serial sections and stained. The crown-rump length (CRL), foot length (FL) and number of ossified bones in the hand and foot (CNO) were recorded. RESULTS: A total of 8/33 fetuses had bilateral nasal bone absence and two had unilateral absence. In fetuses with radiographically diagnosed nasal bone absence, no nasal bone could be found histologically. The majority of the Down syndrome fetuses had CRL, FL and CNO values within the range of those for normal age-matched fetuses. Nasal bone length was normal or reduced. CONCLUSIONS: Absence of the nasal bone was registered by postmortem examination in one-third of fetuses with Down syndrome. In some fetuses this could be a result of delayed maturation associated with Down syndrome. The phenotypic differences in nasal bone appearance may reflect genotypic differences in the Down syndrome group.

Novel SOX9 expression during human pancreas development correlates to abnormalities in Campomelic dysplasia.

Haploinsufficiency of SOX9, which encodes a homeodomain transcription factor, results in Campomelic dysplasia. Classical features of this disorder (e.g. skeletal dysplasia and 46,XY sex reversal) are in concordance with SOX9 expression profiles during human embryonic development. We report the robust expression of SOX9 throughout the pancreas during human embryogenesis, at levels of detection equivalent to the developing skeleton and testis. In the early foetal period, SOX9 expression declines and, in particular, is not apparent within the pancreatic islets. In keeping with this profile, examination of three cases with Campomelic dysplasia revealed abnormal pancreatic morphology. Epithelial cells were less densely packed within the mesenchymal stroma and islets less clearly formed with variable expression of hormone and beta cell markers. Taken together, these data indicate a novel potential role for SOX9 in pancreas development during human embryogenesis and early foetal life.

Symmetrical upper limb peromelia and lower limb phocomelia associated with a de novo apparently balanced reciprocal translocation: 46,XX,t(2; 12)(p25.1;q24.1).

We report a female fetus of 20 weeks gestation with severe symmetrical deformity affecting all four limbs. These deformities were unusual in that there was upper limb peromelia and lower limb phocomelia. No additional major malformations were identified on postmortem examination. In particular there was no evidence of splenogonadal fusion or micrognathia and hypoglossia. The limb malformations in this case are associated with a de novo apparently balanced reciprocal translocation 46,XX,t(2;12)(p25.1;q24.1). The cytogenetic features of Roberts-SC phocomelia syndrome were not detected. Unfortunately, the fibroblast line died and no FISH or DNA analysis could be carried out. In spite of this, the case is presented as it may be useful to other researchers in the selection of candidate genes for mendelian forms of peromelia and phocomelia.

p75NGFR immunoreactivity in normal prenatal human dorsal root ganglia.

The purpose of the present study was to examine immunohistochemically the expression of the low-affinity p75 nerve growth factor receptor in the dorsal root ganglia from 12 human fetuses (gestational ages, 10-24 weeks) located in three different spinal segments (cervical, thoracic, and lumbosacral), using a monoclonal mouse-antihuman low-affinity p75 nerve growth factor receptor antibody. The low-affinity p75 nerve growth factor receptor immunoreactivity was present within the dorsal root ganglia and the surrounding nerve fibers in all spinal segments at the different gestational ages examined. From 10 weeks of gestation, three different types of neuronal staining were observed: dorsal root ganglia neurons without low-affinity p75 nerve growth factor receptor immunoreactivity (classified as type I neurons), neurons displaying weak low-affinity p75 nerve growth factor receptor immunoreactivity (classified as type II neurons), and neurons manifesting intense low-affinity p75 nerve growth factor receptor immunoreactivity (classified as type III neurons). The distribution of the three types of neurons in the dorsal root ganglia was identical in the three spinal segments and did not change between 10 and 24 weeks of gestation. This study provides the first demonstration of the low-affinity p75 nerve growth factor receptor immunoreactivity in the dorsal root ganglia from human fetuses at different gestational ages.

Histological investigation of the palatine bone in prenatal trisomy 21.

OBJECTIVE: The purpose of the present study was to investigate the horizontal part of the palatine bone in palates from human fetuses with trisomy 21 to improve the phenotypic classification of the genotypic anomaly. METHODS: Material from 23 human trisomy 21 fetuses was included in the study. The crown rump lengths of the fetuses ranged from 80 mm to 190 mm, corresponding to about 12 to 21 weeks of gestational age. The material was examined histologically. RESULTS AND CONCLUSIONS: Histological examination demonstrated four different palatal phenotypes on the basis of the development of the horizontal part of the palatine bone: type I, palatine bone complete; type II, the mesial region of the horizontal part of the palatine bone is lacking; type III, complete absence of the horizontal part of the palatine bone; and type IV, auxiliary bones in the region of the transpalatine suture. This finding shows that different types of malformations may occur in the horizontal part of the palatine bone in human trisomy 21 fetuses.

Hepatoblastoma presenting with lung metastases: treatment results of the first cooperative, prospective study of the International Society of Paediatric Oncology on childhood liver tumors.

BACKGROUND: The prognosis of children who are affected by hepatoblastoma (HB) that presents with lung metastases has always been considered very poor. In light of the overall improvement in the survival of HB patients since the introduction of cisplatin (CDDP) in the therapeutic armament of this tumor, the question has been raised whether patients with metastatic HB also would benefit from this drug. The purpose of the current study was to address this issue by analyzing the treatment outcome of those patients presenting with metastases who entered into the first HB study on childhood liver tumors conducted by the International Society of Paediatric Oncology (SIOPEL 1). METHODS: SIOPEL 1 was a prospective, international, multicentric, single-arm study based on preoperative chemotherapy that was open to patient registration from January 1990 to February 1994. After undergoing a biopsy, patients received four courses of CDDP (80 mg/m(2) in a 24-hour, continuous infusion) on Day 1 followed by doxorubicin (60 mg/m(2) in a 48-hour, continuous infusion) on Days 2 and 3 (PLADO). Surgery was performed after four courses of PLADO and was followed by two more courses. Untreated children age < 16 years with biopsy-proven HB were eligible for the study. Metastatic spread was assessed by chest X-ray and, where available, lung computed tomography scan. RESULTS: Thirty-one of 154 children that entered into the trial presented with metastases. Eight children presently are alive with no evidence of disease (NED) after being treated with protocol therapy only (median follow-up, 60 months); nine children are alive with NED after having failed PLADO and having been rescued with alternative therapies (median follow-up, 80 months). The 5-year overall and event free survival rates for these children were 57% (95% confidence interval, 39-75%) and 28% (95% confidence interval, 12-44%), respectively. Persistent lung disease was the main reason for PLADO failure (17 of 23 patients; 74%). CONCLUSIONS: The SIOPEL 1 therapeutic strategy seems to cure 25% of the HB patients who present with metastases. However, further chemotherapy and the use of thoracotomies still can save significant numbers of these children.

Prenatal malformed lumbar vertebral corpora in trisomies 21, 18, and 13, evaluated radiographically and histologically.

The aim of the present study was to compare, both radiographically and histologically, malformed vertebral lumbar corpora in trisomies 21, 18 and 13 with earlier reported normal corporal development in the axial lumbar region. Axial skeletons of human fetuses (GA 15-22 wk) derived from therapeutically induced abortion were investigated in connection with requested autopsy. The number of lumbar vertebral corpora examined for each genotype was as follows: 20 from trisomy 21, 10 from trisomy 18, and 10 from trisomy 13. After radiography in frontal, lateral and axial projections, the individual vertebral corpora were decalcified and horizontally embedded in paraffin. The blocks were serially sectioned and stained with toluidine blue and alcian blue/van Gieson. The radiographic characteristics of the vertebral corpora varied from an almost normal appearance of the corporal bone to complete clefting of the bony corpora. Histological examination showed accumulations of cartilage centrally, in some cases associated with amorphous material. Pronounced metachromatic differences were observed in the cartilaginous ground substance. The study showed identical phenotypic characteristics in the corpora from trisomy 21, trisomy 18, and trisomy 13. It is characteristic of all three genotypes that there are central anomalies, corresponding to the location of the notochord in normal corpora, and marked regional differences in metachromasia in the ground substance of the cartilage.