Biomedical subjects
Publications and source records attributed to K Benirschke.
Conditions associated with placentomegaly in which the disproportionate placental enlargement is understood include erythroblastosis fetalis, intrauterine infections and chorioangioma. This report suggests that in a pregnancy complicated by a large sacrococcygeal teratoma, placentomegaly results from high-output fetal cardiac failure secondary to the mass acting as an arteriovenous fistula.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Tissue from six human extragonadal teratomas was obtained for cytogenetic study. These included two gluteal lesions in infant females, and one each of thyroid, mediastinal, sacral and gastric teratomas in males. Tissue culture characteristics indicated tumor growth. All tumors, except the mediastinal lesion showed the presumed karyotype of its host, XX or XY. The mediastinal mass was tetraploid XXYY and contained an X chromatin body and double Y bodies. Our data support the concept that extragonadal teratomas in males and females arise mitotically from diploid cells and are more similar to identical twins. No heterosexual (XX) tumors were seen in males which would be expected in parthenogenetic tumors. The sex chromatin positive tumors seen in earlier studies may have resulted from polyploidy. Thus, male and female extragonadal teratomas have a different origin from the postmeiotic ovarian teratomas.
Two cases of holoacardius are presented. Both had a normal 46,XX female karyotype, identical to that of their respective cotwin. Data are presented supporting the concept that the placental vascular anastomoses are the primary agents in the formation of an acardiac. Cytogenetics, epidemiology and other theories of pathogenesis are discussed.
Explore the source record for details and available documents.
A simple pneumoconiosis with lamellar birefringent crystals was observed in animals dying in the San Diego Zoo. We studied 100 autopsies from 11 mammalian and eight avian species. In mammals, mild pulmonary lesions comprised crystal-laden macrophages in alveoli and lymphatics. Interstitial fibrosis was present in 20% of cases. There were no nodules. In birds, dust retention produced large granulomas around tertiary bronchi without fibrosis. Mineralogic analysis using scanning and transmission electron microscopy showed most of the crystals to be silicates. Ninety percent were complex silicates, with aluminum-potassium silicates comprising 70% of the analyzed particles. Electron and x-ray diffraction showed the silicates to be muscovite mica and its hydrothermal degradation product, ie, illite clay. This mica was also present on filtration membranes of atmospheric air samples obtained from the San Diego Zoo. The amount of dust retention was related to the animal's age, anatomic or ecologic variances, and length of stay in the San Diego Zoo. Its semidesert atmosphere is rich in silicates, which are inhaled and deposited in the lungs. Similar mica-induced lesions are found in humans living in this region or the Southwest of the USA. This simple pneumoconiosis is likely to be widespread in human populations living in desert or semidesert climates.
Nineteen pregnant female rhesus monkeys (Macaca mulatta) received 1 mg/day diethylstilbestrol (DES) over three time periods during gestation: day 21 to delivery (group I), day 100 to delivery (group II) and day 130 to delivery (group III). Seven females and five males of a total of 20 offspring are presently alive at 5 1/2 years of age; one female died at 5 years of age. No deaths have been shown to be treatment related. In female offspring, menstruation began at about 2 1/2 years of age, was irregular for approximately one and one-half to two years and then became regular. Vaginal ridging and/or cervical hooding have been observed in seven of the eight DES-exposed females, and three had histologically demonstrable vaginal adenosis. None of the anomalies was related to a specific treatment period, for they appeared in all treatment groups, nor did they occur in the age-matched controls. Furthermore, none of the animals, either treated or control, showed any evidence of adenocarcinoma. Therefore, exposure of Macaca mulatta females to DES in utero appears to be teratogenic, but thus far no carcinogenicity has been observed. Reports in humans indicate that adenocarcinoma is an additional manifestation of prenatal exposure to DES; also, treatment effects appear to be more commonly observed in individuals exposed during the early stages of gestation. From this viewpoint, the rhesus monkey is a potentially valuable model for the study of vaginocervical anomalies and adenosis, but it is premature to consider it a suitable model for the study of adenocarcinoma.
Conjoined twins occur with a frequency of 1/50,000--1/100,000 deliveries. The cephalothoracopagus variety is particularly rare. This paper presents a case report of cephalothoracopagus (Janiceps) twinning, with a detailed pathologic analysis, as well as an historical review and discussion of diagnostic modalities.
We have studied two female newborns with comptomelic dwarfism, XY-gonadal dysgenesis and chromosome anomalies. The preponderance of "females" among the hitherto reported cases of this allegedly autosomal recessive form of lethal drawfism may be due to an increased incidence of an associated XY-gonadal dysgenesis.
Intrauterine fetal demise was suspected in a Douc langur monkey based on measurements of declining urinary estrogen levels. Additional clinical evaluation by fetal cardiac auscultation, ultrasonic instrumentation, radiologic examination, and amniocentesis supported the diagnosis. Blood clotting studies demonstrated deficiency of factors consistent with a diagnosis of consumptive coagulopathy, a syndrome identical to that observed in man following prolonged intrauterine fetal demise.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We encountered two cases of maternal coccidioidomycosis with placental involvement. Altered cell-mediated immunity during pregnancy makes the diagnosis of desseminated coccidioidomycosis difficult by the routine serologic tests; placental examination provides specific information. A high index of suspicion regarding this disease and prompt institution of appropriate therapy are necessary in order to decrease maternal and neonatal mortality.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The karyotypes of three additional species of Edentata are described. The differences in karyotype between Tolypeutes matacus (2n = 38), and other species of armadillo is remarkable. Three species of Euphractini were compared through G- and C-banding patterns. Chaetophractus villosus appears to be much closer to Zaedyus pichiy than suggested by taxonomy. On the other hand, Tamandua tetradactyla and Tamandua longicaudata, two different species of anteater, possess the same karyotypes. The presence of an unusual Y-chromosome in Choloepus hoffmanni may be responsible for the peculiar sex-ratio reported in this species.