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Biomedical subjects

N Samuel

Publications and source records attributed to N Samuel.

34 records · Page 2Linked to original sources
PubMed1984

The antenatal diagnosis of Potter syndrome (Potter sequence). A lethal and not-so-rare malformation.

Bilateral renal agenesis (BRA) or Potter syndrome is a relatively rare congenital defect in which agenesis of the kidneys is associated with oligohydramnios, pulmonary hypoplasia, characteristic facial features and other abnormalities. The etiology is unknown. While the possibility of autosomal recessive inheritance has been suggested in familial cases, the syndrome most probably develops as a pattern of multiple anomalies derived from one single, mechanical factor. The initiating event of this syndrome is oligohydramnios. This condition in the neonate is incompatible with life. Unfortunately, these infants are often delivered by caesarean section, as it is usually associated with premature delivery, and breech presentation is a frequent finding. Consequently the prenatal diagnosis of BRA is important in order to avoid unnecessary operations. The antepartum diagnosis is possible in most cases by means of ultrasound scanning, and should be made in the second trimester, when therapeutic abortion is still possible. We have reviewed the obstetric course of 10 women who delivered such babies in recent years in our department. In 4 out of 6 cases of premature labor and breech presentation the diagnosis was made predelivery, and caesarean section was avoided.

Abnormalities, Multiple↗
PubMed1984

Infected ectopic pregnancy presenting as unilateral tubo-ovarian abscess.

Ectopic pregnancy may be a dramatic occurrence, such as in the acutely ruptured extrauterine entity, or diagnosis may be delayed in the chronic ectopic gestation. Eight cases of infected ectopic pregnancy simulating tubo-ovarian abscess are reported; the diagnosis may be difficult and misleading. Symptoms and signs include abdominal pain and vaginal bleeding following a period of amenorrhea, usually accompanied by fever. All patients in our series presented with a picture of tubo-ovarian or pelvic abscess; however, the diagnosis of infected ectopic pregnancy was made preoperatively in all due to a positive beta-hCG test. Surgery in our cases included unilateral salpingo-oophorectomy in 7, and salpingectomy in one. Attention was drawn to the fact that, in the case of unilateral tubo-ovarian abscess, infected ectopic pregnancy should be suspected whenever preoperative beta-hCG is positive.

Abscess↗
PubMed1984

Case report. Torsion of pregnant fallopian tube--a rare case.

A case of torsion of the pregnant fallopian tube is presented. Although uncommon, this entity should be considered in the differential diagnosis of abdominal pain in a young female patient. Early surgical intervention is recommended in order to salvage the affected tube by microsurgical techniques.

Adult↗
PubMed1984

Ultrasound diagnosis and management of fetal intestinal obstruction and volvulus in utero.

A case has been described in which the diagnosis of acute intestinal obstruction of the fetal small bowel was made antenatally with the aid of ultrasonography. Cesarean section was done in the 34th week of pregnancy. One hour after birth ileostomy and colostomy were performed after resection of a volvulus in the terminal ileum. Two months later the ileostomy and colostomy were closed, and the baby is doing well. The importance of precise diagnosis of the anomaly in utero is emphasized to avoid unjustified termination of pregnancy.

Adult↗
PubMed1983

Holoacardius: radiologic investigation.

A case of holoacardius is presented from a monozygotic twin pregnancy of 20 weeks, in which the other twin was normal. The classification is reviewed. While the physiology and anatomy of these malformations are known, the etiology remains obscure. Theories of etiology may be divided in two groups: that the primary deficiency is a failure of the parts to develop; and the belief that the acardius is due to an abnormal vascular communication with secondary atrophy of the formed parts. The abnormal twin in the case studied was diagnosed by ultrasound prenatally and investigated radiologically post-mortem.

Abnormalities, Severe Teratoid↗
PubMed1983

Selachian tooth development: II. Immunolocalization of amelogenin polypeptides in epithelium during secretory amelogenesis in Squalus acanthias.

We have determined the distribution of amelogenin polypeptides in an order of elasmobranchs using indirect immunofluorescence with rabbit polyclonal antibodies prepared to purified murine amelogenins. We find that amelogenins are definitely present within the inner enamel epithelium prior to the production of the extracellular matrix component termed "enameloid" (row II developing tooth organs). During subsequent stages of selachian tooth development (row III tooth organs), immunofluorescence staining data indicated localization of amelogenin antigens within epithelium as well as the enameloid extracellular matrix. The results from these immunohistochemical studies suggest that the 16-20 kdalton amelogenins, which are characteristic of murine inner enamel epithelial cells undergoing terminal biochemical differentiation into secretory ameloblasts, may also be regarded as molecular markers for amelogenesis in developing teeth in the spiny dogfish, Squalus acanthias.

Amelogenesis↗
PubMed1983

Selachian tooth development: I. Histogenesis, morphogenesis, and anatomical features in Squalus acanthias.

We have determined the general features of epithelial-mesenchymal interactions during fetal and mature adult stages of odontogenesis in the selachian spiny dogfish, Squalus acanthias. The general features of odontogenesis included the formation of an extended dental lamina, bud, cap, bell, and crown stages as identified and described using serial sections from fetal as well as adult specimens and light microscopy. Fetal and adult lengths, the rostrum-caudal fin distance, were correlated with the number of tooth rows and columns present in each specimen. This positional information and terminology was extremely valuable in attempting to acquire reproducible data for analyses. Whereas a number of histologic features of fetal and adult odontogenesis were comparable to those described in Mammalia, we found a number of epithelial-mesenchymal interaction characteristics unique to elasmobranch tooth development, including the persistence of the dental lamina in the adult stages, the coupling of cervical inner enamel epithelia between sequential stages of tooth formation, and the patterns of odontogenesis in the adult dentition.

Animals↗
PubMed1983

Selachian tooth development: III. Ultrastructural features of secretory amelogenesis in Squalus acanthias.

Ultrastructural features of secretory amelogenesis during selachian tooth development show several similarities to mammalian amelogenesis. However, the following critical differences were noticed: 1) subcellular organelles associated with merocrine-type protein synthesis and secretion were located in both the infranuclear as well as supranuclear regions of the selachian ameloblasts; 2) no evidence for Tomes process formation was found; 3) the basal lamina was not removed during epithelial differentiation into ameloblasts in the selachian model, and the structural features of the basal lamina were significantly altered during amelogenesis in rows III, IV, and VI; and 4) no dentine-enameloid junction was detected. It is suggested that enameloid is an extracellular matrix which is derived from the selachian inner enamel epithelium and appears to be secreted from both the lateral and apical surfaces of ameloblasts.

Amelogenesis↗
PubMed1983

FHR patterns in Potter's Syndrome.

The antenatal diagnosis of POTTER's Syndrome (bilateral renal agenesis) is important in order to avoid delivery by cesarean section of newborns with congenital anomalies incompatible with life. In seven cases of this syndrome delivered at the Hasharon Hospital, a similar FHR pattern was retrospectively observed in pregnancy and labor suggesting that electronic fetal monitoring (EFM) may possibly contribute to the diagnosis of this condition in utero. Nevertheless, it must be emphasized, that similar cardiotocographic alterations may result from umbilical cord and/or placental compression in the presence of severe oligohydramnios. The latter may, concurrent with POTTER's Syndrome, predispose to changes in intraamniotic pressure transmitted to fetal autonomic centers. Thus, these variations in FHR pattern may be of value only if the presence of other signs of POTTER's Syndrome is confirmed by a reliable ultrasound examination. Further observations of antenatal FHR patterns in a large number of cases of this syndrome may establish their value in the antenatal diagnosis of POTTER's Syndrome.

Female↗