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.

Incomplete remission with short-term prednisolone treatment in collagenous colitis: a randomized study.

BACKGROUND: Microscopic colitis is a disease of unknown aetiology characterized by chronic watery diarrhoea and diarrhoea can be eliminated by budesonide but frequently recurs when budesonide is stopped. We studied whether prednisolone could induce remission in patients with disabling, chronic diarrhoea due to microscopic colitis. METHODS: A double-blind, randomized (3:1) trial of oral prednisolone 50 mg daily or placebo for 2 weeks. Remission was defined as stool weight < or = 200 g/day or frequency < or = 2/day; effect was defined as > 50% reduction of either stool frequency or weight. Six centres screened 31 consecutive patients and included 11 with collagenous colitis and 1 with lymphocytic colitis. Median duration of diarrhoea was 9 months. Patients had a normal colonoscopy, and no evidence of coeliac disease, bile acid or lactose malabsorption. Patients with gastrointestinal infection, previous gastrointestinal surgery, abnormal biochemical screening or recent treatment with immunosuppressive agents were excluded. RESULTS: Stool weight (grams) declined in 7 of 9 patients given prednisolone and in 1 of 3 receiving placebo; changes in median weight were from 430 to 278 and from 825 to 489, respectively. Stool frequency (per day) declined from 6 to 3 and from 8 to 5. Remission was obtained in 2 and 0, and effect in 5 and 0, respectively (NS; Fisher exact test). CONCLUSIONS: Prednisolone 50 mg daily for 2 weeks induces incomplete remission in patients with chronic diarrhoea due to collagenous colitis.

Sealing of cystic duct with bipolar electrocoagulation.

BACKGROUND: The cystic duct leakage rate is still high. The aim of this study was to evaluate an alternative technique for securing the cystic duct using the Ligasure vessel sealing system. METHODS: Eight pigs were included in this pilot study. We performed a cholecystectomy, using the Ligasure system to sealing the cystic duct and artery. The pigs were killed 8 days after operation, and specimens of the cystic duct and common bile duct were removed for pathologic examination. RESULTS: There were no clinical complications other than two superficial wound infections. The sealing of the cystic duct and artery were both macroscopically and microscopically 100% sufficient. The maximum extension of the coagulative process in the sealed ducts was 0.25 mm on each side of the sealed area. CONCLUSIONS: The Ligasure system seems promising for securing the cystic duct and artery during cholecystectomy. Future studies should evaluate safety with this technique on a larger scale.

Expression of nitric oxide synthases and effects of L-arginine and L-NMMA on nitric oxide production and fluid transport in collagenous colitis.

BACKGROUND AND AIMS: Luminal nitric oxide (NO) is greatly increased in the colon of patients with collagenous and ulcerative colitis. To define the source and consequence of enhanced NO production we have studied expression of NO synthase (NOS) isoforms and nitrotyrosine in mucosal biopsies from these patients. In addition, effects on colonic fluid transfer caused by manipulating the substrate of NOS were studied in patients with collagenous colitis. PATIENTS: Eight patients with collagenous colitis, nine with active ulcerative colitis, and 10 with uninflamed bowel were included. METHODS: Expression of NOS isoforms was quantified by western blotting. Inducible NOS (iNOS) and nitrotyrosine were localised by immunohistochemistry. Modulation of NOS activity by topical N(G)-monomethyl-L-arginine (L-NMMA) or L-arginine was assessed during perfusion of whole colon. Plasma and perfusate nitrite/nitrate (NOx) was measured by Griess' reaction. RESULTS: Both in collagenous and ulcerative colitis, expression of iNOS was 10(2)-10(3) higher (p<0.001) than in uninflamed bowel and localised primarily to the epithelium. Endothelial NOS was evenly expressed in all groups while neuronal NOS was undetectable. Nitrotyrosine was markedly expressed in active ulcerative colitis but rarely detected in collagenous colitis and never in uninflamed bowel. In collagenous colitis, the output of NOx was markedly increased compared with uninflamed bowel (283 (58) v <37 nmol/min; p<0.01) and fluid was net secreted. L-NMMA reduced the output of NOx by 13-66% (95% confidence intervals) and secretion of fluid by 25-109% whereas L-arginine increased the output of NOx by 3-39% and secretion of fluid by 15-93%. CONCLUSIONS: In collagenous colitis, as opposed to ulcerative colitis, upregulation of iNOS occurs in the absence of nitrotyrosine formation and mucosal damage. Excess generation of NO may be the primary cause of diarrhoea in this condition.

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.

Craniofacial tissues including tooth buds in fetal hypohidrotic ectodermal dysplasia.

OBJECTIVE: Hypohidrotic ectodermal dysplasia (HED) comprises defects in hair, teeth, and sweat glands. Disturbances in other ectodermal tissues have been associated with the condition. Our objective was to examine ectodermal craniofacial structures histologically in a fetus with HED and to compare the findings to similar structures in normal control fetuses. MATERIALS AND METHODS: A male fetus diagnosed with HED was therapeutically aborted in the 15th week of gestation. One male and two female healthy fetuses were used as normal controls. All fetuses were examined with parental consent, and had comparable sizes. Their bone maturation stage in the hand was identical. Tissue blocks from the craniofacial region were excised from all fetuses and prepared for histological analysis (formalin fixed, stained with toluidine blue or Alcian blue). The tissues examined were: tooth buds, skin and skin appendages, oral mucosa including minor salivary glands, major salivary glands, lacrimal glands, and adenohypophysis. RESULTS: Fewer tooth buds, minor salivary glands, and hair follicles were observed in the HED fetus as compared to controls. The structures of the epidermal components in the developing HED organs were loose and disorganised. The adhesion between the ectodermal and mesenchymal organ components in the HED fetus seemed to be disturbed.

Bi-iliac distance and iliac bone position compared to the vertebral column in normal fetal development.

Prenatal standards of bi-iliac width were not found in the literature based on autopsy investigations, nor was the caudo-cranial position of the ilia compared to the vertebral column. The first purpose of the present study was to establish normal standard values for the bi-iliac distance in fetal life, the second to evaluate the level of the iliac bones proportional to the ossified vertebral column. Whole body radiographs in antero-posterior projections from 98 human fetuses (36 female and 44 male fetuses, as well as 18 fetuses on which the sex had not been determined) were analyzed in the study. The fetuses derived from spontaneous or induced abortions and they were radiographed as part of the required autopsy procedure. The crown-rump-length (CRL) of the fetuses varied from 32 to 245 mm. The outer and inner bi-iliac distance was measured from the radiographs with a digital Helios slide caliper. The caudo-cranial position of the iliac bones was evaluated. The present study shows that in normal fetal development there is a continuous linear enlargement of the pelvic region in the transverse and vertical planes. The upper iliac contour stays at the level of the first sacral vertebral body, whereas the lower iliac line moves caudally. Significant differences between male and female fetuses were not found. The value of the present study is that the results can be used as reference standards in prenatal pathology.

Prenatal localization of the dorsal root ganglion in different segments of the normal human vertebral column.

STUDY DESIGN: Vertebral columns from 11 normal human fetuses (10-24 weeks of gestation) derived from spontaneous abortions were examined as part of the legal autopsy procedure including spinal cord analysis. OBJECTIVES: To study the localization of the dorsal root ganglion in the normal fetal spine and to relate the dorsal root ganglion location to the ossification of the vertebral bodies and vertebral arches. SUMMARY OF BACKGROUND DATA: The normal and pathologic ossification pattern of the fetal human spine has been studied. There has been no study addressing the localization of the dorsal root ganglion in normal and pathologic axial development. METHODS: The dorsal root ganglion were studied by using histology (horizontal sections) and morphometric measurement. RESULTS: The study showed: 1) The dorsal root ganglion appeared before ossification of the spine; 2) The dorsal root ganglion had an oval shape in all cases; 3) The longitudinal axis of dorsal root ganglion was directed anterolaterally in the cervical and lumbosacral segments and mainly laterally in the thoracic segment; 4) During development, the dorsal root ganglion changed position according to the body axis; and 5) The para-axial ossification protected the dorsal root ganglion differently in the different axial segments. CONCLUSIONS: The dorsal root ganglion appeared before ossification. The distance from the dorsal root ganglion to the body axis increased during development. In the different segments of the spine, different orientations and different locations of the dorsal root ganglion were observed in relation to osseous spine components. The results can be used as reference data for future studies on the dorsal root ganglion in pathologic spines.

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.

The prenatal cranial base complex and hand in Turner syndrome.

From early childhood, Turner syndrome patients have a flattened cranial base, maxillary retrognathism, and short hands. There are, however, no studies that show when these genotype-determined abnormalities occur prenatally. The purpose of the present study was to measure craniofacial profile and hand radiographs of second trimester foetuses with Turner syndrome and compare the results with similar measurements from normal foetuses. The subjects consisted of 12 Turner syndrome foetuses, gestational age (GA) varying between 15 and 24 weeks, and crown-rump length (CRL) between 108 and 220 mm. The mid-sagittal block of each cranium was analysed as part of the requested brain analysis (pituitary gland analysis). This block and the right hand from seven foetuses were radiographed, and the skeletal maturity of the cranial base complex, i.e. the cranial base and the maxilla, was evaluated from the profile radiographs. Shape and size measurements in the cranial base were performed, and compared with normal values according to cranial maturity and to CRL. The cranial base angle in Turner syndrome was greater and the maxillary prognathism was reduced compared with the normal group. The dimensions in the cranial complex and in the hand showed that the bone lengths and distances in relation to CRL were generally smaller compared with normal foetuses. This investigation showed that the abnormal shape of the cranial base complex and the short hands in Turner syndrome are present prenatally.

Notochordal remnants in human iniencephaly suggest disturbed dorsoventral axis signaling.

Iniencephaly is a central nervous system malformation in which brain and spinal cord are not normally separated at the level of the foramen magnum. The occipital region is fastened to the back of the body at different levels. The purpose of this study of a 16-week human fetus with iniencephaly and holoprosencephaly was to examine the body axis for notochordal remnants in order to determine if an abnormality of dorsoventral axis signaling may be responsible for the development of the iniencephaly abnormality. This aspect of iniencephaly has not been described previously. Radiographic and histochemical investigations were performed. The fetus described here appeared to exhibit an abnormal notochordal course in the upper lumbar, thoracic, and cervical regions. This finding leads us to the hypothesis that iniencephaly might arise because of deviant gene expression in the embryonic period affecting the dorsoventral orientation of the body axis, anatomically indicated by the notochordal malpositions.

Skeletal malformations in fetuses with Meckel syndrome.

In six fetuses with Meckel syndrome (gestational age 16-23 weeks, crown-rump length 130-170 mm) the skeleton was examined as part of the autopsy procedure using whole body radiography and special radiographic techniques. In the upper and lower limbs we found similar types of polydactyly. We noted four types, based on the number and morphology of metacarpals and metatarsals. In the individual fetus there was more often similarity in the pattern of malformation in the two hands or in the two feet than there was between the pattern of malformation seen in the hands and that seen in the feet. Only one foot was normal. Malformations of the cranial base (the basilar part of the occipital bone or the postsphenoid bone) occurred in five cases, and the vertebral bodies in the lumbar region of the spine were malformed (cleft) in three cases. It is proposed that a skeletal analysis be included in the future evaluation of phenotypes in Meckel syndrome.

Pituitary gland and axial skeletal malformations in human fetuses with spina bifida.

The purpose of the present study was to describe the pituitary gland and axial skeleton, including the sella turcica, in human fetuses with spina bifida. Ten fetuses with gestational ages (GA) 15 1/2-28 weeks were investigated radiographically (Faxitron X-ray apparatus) and immunohistochemically. Four of the fetuses have been described previously. The study showed that nine fetuses had minor or no skeletal abnormalities in the vertebral bodies of the spine, and one fetus had severely malformed vertebral bodies. In all cases the sella turcica and the pituitary gland were malformed. Adenopituitary tissue was in all cases located in both the sella turcica and the pharyngeal submucosa. The most severe sella turcica/pituitary gland malformation was seen in the fetus with the malformed spine. The connection between the prenatally registered sella turcica/pituitary gland malformation and the endocrinological status of children with spina bifida should be emphasized in future studies.

Hand development in trisomy 21.

The purpose of the present study was to evaluate hand size and maturity in fetuses with trisomy 21 (Down syndrome). Twenty-five fetuses, crown-rump length (CRL) 55-222 mm, foot length (FL) 8-42 mm, were included in the study. After whole-body radiography (Hewlett Packard Faxitron), special radiographs of the hand and foot were taken. Hand length was measured as the length of the third finger from the distal tip of the distal phalanx to the proximal tip of the metacarpal bone, the digital-metacarpal length (DML). The lengths of the proximal phalangeal bone (PPL) and the metacarpal bone (MCL) of the third finger were also measured. The DML, PPL, and MCL values of each fetus were related to CRL and FL. The individual hand bones were evaluated with regard to time of appearance on radiographs, sequence in comparison with the normal sequence of appearance, and morphology. The hand length is normal during the first half of the fetal period, whereas the length of individual bones in the third finger is reduced. The normal sequence of ossification, with the middle phalanx of the fifth finger last to ossify, also occurred in Down syndrome; however, this bone appeared later in Down syndrome. In four of the fetuses it did not appear.

Pituitary gland and sella turcica in human trisomy 18 fetuses.

The purpose of this study was to elucidate the phenotypic conditions in the sella turcica/pituitary gland complex in human trisomy 18 fetuses. Fourteen human fetuses with gestational ages from 12 to 39 weeks were included in the study. Normal fetuses at corresponding ages were used as controls. Whole body and special radiographic examination was undertaken before the midsagittal cranial base block, including the pituitary gland, was excised and analyzed histologically and immunohistochemically (keratin wide spectrum [KWS], thyroid-stimulating hormone [TSH], and neurophysin [Nph]). In all trisomy 18 fetuses, TSH-positive adenopituitary tissue was present in the sella and in greater or lesser amounts pharyngeally. The neurohypophysis was Nph-positive and located normally in the sella turcica. The adenohypophyseal tissue reacted either KWS-faint or KWS-negative, whereas KWS-positive reaction occurs in normal fetuses. This circumstance might suggest an altered cytoskeletal structure of the surface ectoderm in the pituitary placode in trisomy 18. The sella turcica was malformed in all the fetuses. Very broad craniopharyngeal canals were observed in some of the fetuses. Because endocrine disorders occur in many congenital malformations, it is essential in future studies to chart the sella turcica/pituitary gland region systematically in different genotypes.

Pituitary gland and sella turcica in human trisomy 21 fetuses related to axial skeletal development.

The purpose of the present investigation was to study the sella turcica/pituitary gland region in trisomy 21 fetuses and to relate the findings in the region to the ossification pattern in the axial skeleton formed by the cranial base and spine. Material from 22 human fetuses with trisomy 21, CRL 80 mm to CRL 190 mm, corresponding to gestational ages from 14 to 21 weeks, was examined and compared with material from gestation-matched normal controls. After radiography, tissue blocks from the cranial base, including the pituitary gland, were examined and compared with those of normal fetuses. Four different types of sella turcica/ pituitary gland morphology were observed. Thirteen fetuses (Type I) were morphologically normal. Minor abnormalities occurred in the sella turcica and pituitary gland (adenopituitary gland tissue pharyngeally) in six fetuses (Types II and III). There was agreement between the histologically recorded deviations in the sella turcica and the radiographic observations of the basisphenoid bone. In three cases (Type IV) out of 22, more pronounced structural abnormalities occurred in the sella turcica, and radiographically the basisphenoid bone appeared cleft. All sella turcica changes observed in trisomy 21 were situated anteriorly in the base of the sella. In all cases the basilar part of the occipital bone was normal. Minor changes in the sella turcica region were mainly accompanied by cervical vertebral abnormalities, while the most severe abnormalities occurred in association with malformations in the lumbar vertebrae. There was no association between sella turcica malformations and the absence or presence of the nasal bone.

Cervical ribs in fetuses with Ullrich-Turner syndrome.

The purpose of this study was to analyze the cervical skeleton in fetuses with Ullrich-Turner syndrome (45,X) in a search for skeletal characteristics in the neck region affected by hygroma. In connection with requested autopsies, 9 second trimester human fetuses were investigated radiographically by whole-body and special radiography of the spine. The presence of unilateral or bilateral cervical ribs was a constant finding which seems applicable as a phenotypic characteristic of Ullrich-Turner syndrome. This study may also be important in the diagnosis of newborn infants with Ullrich-Turner syndrome.

The association between prenatal sella turcica morphology and notochordal remnants in the dorsum sellae.

The purpose of this study was to describe the location and morphology of notochordal remnants in the cranial base in normal and pathological conditions and to relate these findings to the morphological appearance of the sella turcica. Serially cut sagittal sections of paraffin-embedded sella turcica tissue blocks from 88 normal and pathological fetuses, 13 to 24 weeks of gestation, were examined. Twenty-seven specimens out of 88 had visible notochordal remnants in the cranial base, and these constituted the material available for this study. A straight notochordal course is always seen in normal sella turcica morphology, and a non-straight notochordal course is always seen in malformed sella turcica. Among the fetuses diagnosed at autopsy as "normal fetuses," both normal and pathological findings in the sella turcica regions were observed. The pathological findings were always found in the spontaneously aborted fetuses (five cases). Among the fetuses diagnosed at autopsy as "pathological fetuses," both normal and pathological findings were also observed in the sella region. Our conclusion is that the morphological appearance of the notochordal remnants in the dorsum sellae is associated with the morphology of the sella turcica. These structures ought to be analyzed on larger materials of both normal and pathological fetuses. One of the more obvious perspectives opened up by the present study is the probable disclosure of malformations in spontaneously aborted fetuses without external malformations.

Pattern of malformations in the axial skeleton in human trisomy 13 fetuses.

The purpose of this study was to analyse the development of the axial skeleton in human trisomy 13 fetuses and to define which fields in the axial skeleton are affected in this condition. We investigated nine human fetuses with trisomy 13 and gestational ages of 14-19 weeks. Whole body radiographs and radiographs of midsagittal tissue blocks of the cranial base and the spine were studied. In the youngest fetus, 14 w GA, no malformations were observed. In eight fetuses, 17-19 weeks GA, malformations occurred in the lumbosacral spine. In four fetuses additional malformations were observed in the thoracic spine. The study showed that there was a correspondence between the extent of malformation in the lumbosacral spine and the thoracic spine. When mild malformation occurred in the lumbosacral region, no malformation was observed in the thoracic region, whereas malformation was observed in the thoracic region when there was extensive malformation in the lumbosacral region. Malformations did not occur in the cervical spine or the basilar part of the occipital bone, but the postsphenoidal part of the sphenoid bone was small and irregular in the six cases where it could be examined. In seven fetuses there was malformation or agenesis of the nasal bone. This pattern of axial skeletal malformations in trisomy 13 fetuses was not described previously. Comparisons are made with previous studies of the fetal axial skeleton in trisomy 18 and trisomy 21, where the pattern of malformations was different. We reiterate our recommendation that axial skeletal radiography should be part of the postmortem examination of fetuses with suspected or verified chromosome abnormalities.