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PubMed1990

Identification of anatomic features of the equine clitoris as potential growth sites for Taylorella equigenitalis.

A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crown-rump length (CRL) to 500-mm CRL (including a mule of 21-mm CRL). In saggital sections of the clitoris of a 480-mm CRL fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of contagious equine metritis. This study indicated excision of the lateral clitoral sinuses was unnecessary for treatment of contagious equine metritis.

Age Factors↗

PubMed1990

Ossification of the human fetal basicranium.

Previous investigations of prenatal development of the human cranium have not identified the sequence of its ossification. The purpose of the present study was to elucidate the pattern of skeletal maturity of the cranial bones in the midsagittal region anterior to the foramen magnum. This study is based upon a radiographic and histochemical investigation of midsagittal tissue blocks of the cranial bases of 73 human fetuses derived from the first half of the prenatal period. A marked regularity in the ossification pattern of the bones in the midsagittal part of the human cranium was observed. Ossification starts in the frontal bone. The sequence in which the next bones ossify is occipital bone, basisphenoid bone, presphenoid bone, and ethmoid bone. The material was divided into 7 maturity stages devised for this analysis. The stages were related to general fetal size (crown-rump length) and to general fetal maturation (composite number of ossified bones in hand and foot). Skeletal development of the median part of the human cranium is not strictly correlated with the size or the stage of general maturation of the fetuses. Knowledge of normal skeletal development is necessary for understanding anomalies of development.

Bone Development↗

PubMed1990

Sonographic estimation of fetal age and weight.

Real-time ultrasound is a very effective tool in the estimation of fetal age and weight. The most accurate fetal age estimates are from crown-rump length measurements in early pregnancy. Late pregnancy age estimates are less accurate, but the use of multiple body measurements provides a composite age estimate generally accurate to within 7 per cent of actual age. Estimates of fetal weight are improved with the use of head, body, and femur measurements, and generally are accurate to within 15 per cent of actual birth weight.

Anthropometry↗

PubMed1990

Early detection of caudal regression syndrome with transvaginal scanning.

High-resolution transvaginal ultrasonography may recognize structures in the first- and early second-trimester fetus. In a patient with pregestational diabetes, caudal regression syndrome in the fetus was diagnosed using transvaginal ultrasonography. At 9 weeks of gestation, a shortening of the crown-rump length and a protuberance of the lower spine suggested caudal regression syndrome. By 17 weeks of gestation, the diagnosis was made with certainty. The transvaginal approach has changed the role of first-trimester ultrasound in the diabetic pregnancy. We suggest that transvaginal ultrasonography be used for purposes of accurate dating and for early detection of diabetic embryopathy, particularly in patients with poor periconceptional glycemic control.

Adult↗

PubMed1990

Real-time ultrasonography for pregnancy diagnosis and estimation of fetal age in farmed red deer.

Twenty-nine farmed red deer hinds two years of age or older were observed during mating in April, and the dates of oestrus and, or, mating were recorded. From May 28 to August 13, at approximately weekly intervals, the deer's uteri and associated structures were examined by rectal ultrasound using a 5 MHz transducer while the deer were held standing in a restraining device. The uterine diameter, amniotic sac diameters, crown-rump length, head length, nose length, chest depth, chest width and placentome base-apex and width were measured for each scan. Quadratic regression equations were computed for each measurement with age, using data from hinds with known mating dates, and the chronological sequence of appearance of a range of uterine and fetal characteristics was recorded. There were significant quadratic regressions. (P less than 0.001) for each of the measurements. The accuracy of pregnancy detection to 117 days after conception was 99.3 per cent and to 132 days after conception 97.4 per cent. The confirmation of non-pregnancy was 96.5 per cent accurate. The regressions of each measurement by age should provide an accurate method for the estimation of fetal age in red deer.

Animals↗

PubMed1989

[Transcervical chorion villous biopsy for prenatal diagnosis in the first trimester. A report of the activity during the first 4 years].

Prenatal diagnosis in the first trimester was established in 318 pregnancies at risk by means of transcervical chorion villus sampling (TC-CVS). Criteria for exclusion were discrepancy between the crown-rump length (CRL) and the expected week of gestation, if there was simultaneously insufficient increase in CRL during a week. With the exception of two cases, (0.6%) the specimens of villi obtained were sufficient for diagnostic purposes (mean: 55 mg (8-200 mg]. Twenty-five patients underwent terminations of pregnancy on account of the abnormal findings and one for social reasons. The fetal loss following CVS was seven (2.4%). No serious maternal complications occurred. Vaginal bleeding presumably on account of perforation of the placenta by the catheter was seen in 8.5% (27) of the cases and does not appear to influence the continuing pregnancy. The cytogenic results were all based on the direct prepartion method and also on culture technique and these were successful in 100%. Two false positive results (0.6%) were found in the direct preparation but normal findings were obtained on culture. No false negative results were found. Late complications i.e. preterm delivery (4.6%), perinatal loss (0.7%) and neonatal death (0.7%) did not exceed the expected values. The mean birthweight was within the normal range. It is concluded that transcervical CVS with the Trophocan catheter seems to be a safe and easy way to obtain prenatal diagnosis and this could be offered on the same terms as amniocentesis.

Adolescent↗

PubMed1989

Prenatal skeletal maturation of the human maxilla.

Previous investigations on the prenatal development of the human maxilla have focused mainly on the elevation and fusion of the soft tissue palatal shelves. The bony development has received only sporadic attention. The aim of the present investigation was to analyze and set up bony developmental stages in the human maxilla, as knowledge of normal skeletal developmental course, which has never been elucidated, is the prerequisite to understanding the abnormal course of development. The present study was based on a radiographic and histochemical investigation of maxillae from 104 human embryos and fetuses from the first half of the prenatal period. A marked regularity in the maxillary ossification pattern was observed, and consequently seven maturity stages, Max I-Max VII, were described. The material was divided according to these stages and related to general fetal size (crown-rump length) and to general fetal maturation (composite number of ossified bones in hand and foot). The material available did not justify a description of skeletal development of the maxilla as a function of CRL or CNO.

Humans↗

PubMed1989

[Morphologic characteristics of the vascular network of the dentate nucleus during development].

The development of the blood network of the dentate nucleus was studied on 20 human fetal brains of different crown-rump length (CRL). In the stage of 17 to 20 weeks, the blood network of the dentate nucleus consisted of moderate spiral blood vessels. They anastomosed each other and made irregular elongated polyhedral meshes. From this meshwork, blood vessels of a greater volume arose and extended to the hilum of the nucleus. Between 23 and 25 weeks, a clear segmental vascular pattern was noticed. The capillary network was very dense. Along the outer surface of the nucleus the blood vessels which connected two secondary wrinkles of the gray matter were observed. In all the stages investigated the blood vessels were moderately spiral.

Blood Vessels↗

PubMed1989

Note on differentiation of the epithelium of the small intestine in human embryos.

We studied the development of the human embryonic intestine from the 6th to the 8th week of gestation (embryos with a crown-rump length of 16-25 mm). Semithin sections show that a smooth, simple intestinal lumen, which is often a mere slit, is elsewhere, in the same specimen, distinctly formed and in places is partly occluded by accumulations of cells of a somewhat different character from those of the actual intestinal lining. Whereas the epithelium proper is mainly high and pseudostratified, the cells which secondarily occlude the originally open intestinal lumen are smaller and are more cuboidal to polyhedric in shape. In the electron microscope, the cells of the primitive epithelium appear narrow and columnar, with an ovoid nucleus and a few nucleoli. The cytoplasm contains numerous mitochondria and a gradually developing granular endoplasmic reticulum and Golgi complex. These cells have small, irregular microvilli on their surface, but some have an almost straight surface without any microvilli. They display striking pinocytotic activity and contain a quantity of multivesicular bodies. Their cytoplasm further contains isolated osmiophilic granules and lysosomes and a small amount of glycogen. The accumulation of glycogen is typical of the more mature developmental stages. Cilia are a characteristic finding in embryos with a c-r length of 16-25 mm. There is only one cilium to a cell, but not all the cells have cilia. The cilia are relatively thick and not very long and they almost always grow in the centre of the cell surface. The apical surface of such cells is usually slightly or more deeply concave. Structurally, the ciliated cells closely resemble phylogenetically primitive entodermal collar cells (choanocytes). They are apparently a phylogenetically old type of cells, whose existence could have functional value, which appears for a time during ontogenetic development. The cilia may temporarily play a role in the movement of the intestinal fluid and thus coparticipate in resorption before the musculature of the intestinal wall has been formed.

Cell Differentiation↗

PubMed1978

Peptidergic (VIP) innervation of the esophagus.

Nerves displaying vasoactive intestinal polypeptide (VIP) immunoreactivity were demonstrated in the esophagus of rats, cats, and pigs. Furthermore, electron microscopy revealed the presence of nerve terminals displaying the features of peptidergic nerves. VIP nerves were abundant within the smooth muscle layer of the lower esophagus of cat and pig. Immunoreactive nerve fibers and nerve cell bodies were found in the plexuses of the esophageal wall. In pig fetuses VIP immunoreactive nerve cell bodies were observed already at crown-rump length of 4 cm. VIP nerves were also observed in human fetal esophagus. For recording of the motor effects of VIP, segments were taken from cat esophagus close to the esophagogastric junction. VIP induced a dose-dependent relaxation upon contraction by carbamylcholine.

Animals↗

PubMed1979

Changes in axonal numbers in developing human trochlear nerve.

Complete axonal counts have been made in the intracranial parts of trochlear nerves from human fetuses of 9.2, 10 and 24 cm crown-rump length. A count was also made in the intraorbital part of the nerve from the 10 cm specimen. Schwann cell nuclei were also counted in typical cross sections, but do not necessarily reflect very accurately the schwann cell contents of the nerves. Axonal numbers conform to the propositions (1) that they do not all grow out at once, (2) do not all survive and (3) that degeneration may occur before or after myelination has begun. It seems inevitable that some loss of Schwann cells occurs in relation to the degeneration of myelinated axons, but there is no evidence for or against such a loss in relation to the degeneration of unmyelinated axons. Overall, however, Schwann cell numbers tend to increase as the number of myelinated axons increases.

Axons↗

PubMed1979

Muscular development of the bladder neck in the human fetus.

We conducted a histologic study of the muscular development of the bladder neck in human fetuses of 5 to 23 cm crown-rump length (CRL) and in neonates in special reference to the middle circular layer of the posterior wall of the bladder neck (posterior circular muscle of the bladder neck) and the deep trigonal muscle. Our attempt was to determine the anatomic relationship between and the origins of the two musculatures. The posterior circular muscle had begun to differentiate in the fetus of 8.3 cm CRL in which the trigonal musculature was indistinguishable. Differentiation of the deep trigonal musculature was evident in the fetus of 17 cm CRL; a complete growth in which the muscle was connected to the posterior circular muscle of the bladder neck was evident only in the largest fetus (23 cm CRL). We conclude that the deep trigonal muscle and the posterior circular muscle of the bladder neck are of different origins.

Gestational Age↗

PubMed1978

Palatal shelf elevation in the Wistar rat fetus.

Palatogenesis in the Wistar rat fetus was studied macroscopically, microscopically, ultrastructurally and experimentally between days 13 and 19. The developmental ages of the fetuses were calculated from the smear age of the litter adjusted for individual variations in crown-rump lengths. Palatal shelf elevation occurs at day 16.4 +/- 0.1. Experimentally induced shelf elevation in freshly delivered fetuses was sluggish at day 14, but by day 16.3 it occurred in less than 1 second. Both shelf elevation and shelf fusion begin anteriorly where the shelves show a marked convexity of their margins, and proceed posteriorly. The extreme posterior part of each shelf (future soft palate) is horizontal from the beginning. The matrix of the shelf mesenchyme (especially in the region of the anterior convexities) shows an increasing accumulation of mucopolysaccharides from day 14 to day 16.3 and becomes increasingly oedematous. The shelf attachment to the main maxillary process is progressively undercut by epithelial invagination, producing a fulcrum for shelf elevation. The maxillary and palatine osteogenic blastemata are present at the base of the shelf prior to elevation and rapidly invade the shelves after the event. The elevated palatal shelves fuse with the nasal septum anteriorly, but posteriorly the palate is not attached to the septum. The posterior septum at first has a free lower edge, but then it develops lateral flanges which fuse with corresponding bulges on the lateral nasal walls. In this way two sphenoethmoidal recesses are formed above the fused flanges, while a common nasal passage is formed above the palate, roofed anteriorly by the septal flanges and posteriorly by the cranial base. The space needed to create (simultaneous with shelf elevation) the common nasal passage is made available by flattening of the tongue and protrusion of its tip out of the oral cavity--this protrusion being facilitated by the sloping bulge of the primary palate and nasal septum. Many existing theories of shelf elevation are inconsistent with these observations. It was concluded that shelf elevation occurs very rapidly at a rather precise developmental stage and that turgor (due to binding of water to mucopolysaccharides) is the intrinsic force which elevates the shelves, a force which at 16.4 days reaches a threshold level enabling the shelves to force their way up and over the intervening tongue.

Animals↗

PubMed1976

Milk protein quantity and quality in low-birthweight infants: I. Metabolic responses and effects on growth.

The optimal quantity and quality of protein for low-birthweight infants is undefined. In this study, 106 well, appropriate-for-gestational age, low-birthweight infants weighing 2,100 gm or less were grouped in three gestational age categories: T1 = 28 to 30 weeks; T2 = 31 to 33 weeks; T3 = 34 to 36 weeks. Each group was assigned randomly to either banked human milk (BM) or to one of four isocaloric formulas varying in quantity and quality of protein but not in mineral content or in fat content: formula 1 = 1.5 gm of protein per 100 ml, 60 parts bovine whey proteins to 40 parts bovine caseins; formula 2 = 3.0 gm of protein per 100 ml, 60:40; formula 3 = 1.5 gm of protein per 100 ml, 18:82; formula 4 = 3.0 gm of protein per 100 ml, 18:82. Caloric intake was 117 kcal/150 ml/kg/day for the formulas. Human milk was fed at 170 ml/kg/day in order to attain a caloric intake approximately equal to that of the formulas. No significant differences were found in the rate of growth in crown-rump length, in femoral length, in head circumference, or in rate of gain in weight from time of regaining birthweight to time of discharge at 2,400 gm. Blood urea nitrogen, urine osmolarity, total serum protein, serum albumin, and serum globulin varied directly with the quantity of protein in the diet: F2, F4 greater than F1, F3 greater than BM. Blood ammonia concentration varied with both quantity and quality of protein in the diet: F2, F3, F4 greater than F1, BM. Metabolic acidosis was more frequent, more severe, and more prolonged in the infants fed the casein-predominant formulas (F3,F4) than in those fed the whey protein-predominant formulas (F1, F2).

Ammonia↗

PubMed1977

[The effect of glucocorticosteroids on sex differentiation in rats].

The influence of two glucocorticoids (hydrocortisone and dexamethasone) on the somatic sex differentiation of female rats was investigated. During the time of sexual differentiation of their foetuses, pregnant rats were given dexamethasone (0.1-0.3 mg/day) or hydrocortisone (20-200 mg). Both compounds interfere with foetal development by virtue of their strong growth-inhibitory activity which manifests itself in reduction of the body weight, the crown-rump length, the length of the genital folds and the genital cord. The inhibition of growth seems to be reversible. Only hydrocortisone acts teratogenically as it causes a shift of the differentiation of the female genital tract into male direction. This virilisation consists of partial stabilisation of the Wolffian ducts, the suppression of mammary nipple development and a male-type differentiation of the urogenital sinus. The relevance of these findings for human beings is briefly discussed.

Animals↗

PubMed1976

Experimental amniocentesis and teratogenesis. 1. Evaluation of the intra-amniotic route of treatment in teratological studies.

Experiments were designed to evaluate the usefulness of the intra-amniotic route of administration of test-substances in teratological studies. Particular attention was given to the differences in fetal parameters of growth and development and the incidence of fetal mortality between treated and untreated offspring which might be induced as a result of the treatment. Amniocentesis on gestational days 14, 15 or 16 produced a high incidence of fetal mortality and a significant reduction in the weights and crown-rump lengths of treated offspring. With increasing gestational age at the time of treatment and by reducing the volume of solvent injected, fetal mortality was decreased.

Amnion↗

PubMed1990

Growth of linear parameters in trisomy 18 fetuses.

Linear growth in fetuses with trisomy 18 has not been systematically described. We studied the relationship between long-bone, crown-rump, and foot length and gestational age in 17 postmortem fetal specimens with this syndrome. Long-bone and crown-rump lengths were compared with normal regression lines and foot length was compared with gestational age determined on the basis of menstrual dates. Correlation between foot length and menstrual dates was weak in trisomy 18. Gestational age predicted by crown-rump length was significantly lower than gestational age by menstrual dates. All long bones were significantly shortened and fell below normal regression lines for gestational age. The fetal femur/foot length ratio was reduced. Thus no endogenous measure of gestational age appears to exist in this aneuploidy, forcing reliance on menstrual dates. The observed pattern of growth alterations will likely preclude the development of a gestational age-dependent biometric screen for the prenatal detection of this syndrome.

Bone and Bones↗

PubMed1991

Measurements of the auricle in the human fetus.

The auricular length, auricular base length and auricular width were measured in 94 human fetuses with crown-rump (CR) lengths ranging from 49 mm (approximately 11 weeks of gestational age) to 250 mm (approximately 31 weeks of gestational age). The three measurement values showed linear increases as the CR length increased, suggesting that they are useful parameters to indicate intrauterine growth. The measurement values also suggested that the mandibular and hyoid derivatives did not grow independently, but did grow with maintaining a certain relationship.

Anthropometry↗