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Biomedical subjects

R L Ladda

Publications and source records attributed to R L Ladda.

69 records · Page 4Linked to original sources
PubMed1978

Epidermal growth factor potentiates cortisone-induced cleft palate in the mouse.

Epidermal growth factor (EGF) injected into pregnant mice increased the frequency of cleft palate (CP) in cortisone-treated mouse fetuses. EGF alone produced proliferation and thickening of the epithelium of the palatal processes, but CP was not significantly increased over saline injected controls. Cortisone alone produced thinning of the palatal epithelium and caused CP in 61 percent of formed fetuses. The combination of EGF and cortisone treatment induced CP in 100 percent of formed fetuses; epithelial thickening still occurred with the combination treatment. Thus, EGF may be teratogenic under special circumstances. These observations suggest that the relative thickness of the palatal shelf epithelium may not be a critical factor in the fusion of the palatal shelves.

Abnormalities, Drug-Induced↗
PubMed1978

Craniosynostosis associated with limb reduction malformations and cleft lip/palate: a distinct syndrome.

Craniosynostosis associated with short stature, radial and fibular aplasia, and cleft lip and/or palate represents a distinct syndrome. One original case and one previously undiagnosed case from the literature were found to have many distinct features in common, permitting them to be separated from craniosynostosis with radial or fibular aplasia, Robert's syndrome, pseudothalidomide or SC syndrome, and the hypomelia-hypotrichosis-facial hemangioma syndrome. Each had multiple craniofacial abnormalities: dysplastic ears, hypertelorism, strabismus, and malocclusion. Ulnae and humeri were hypoplastic; tibiae were bowed and hypoplastic. Testes were small. Associated mild to moderate mental retardation may be related to early institutionalization.

Abnormalities, Multiple↗
PubMed1977

Chromosomal mosaicism in Down's syndrome: a diagnostic challenge.

In individuals with mosaicism for trisomy 21, phenotype-karyotype correlations are unpredictable. Two patients are described--one with typical features of Down's syndrome and the other with severe mental retardation only. Both had normal karyotypes in their peripheral lymphocytes but high percentages of trisomic cells in skin fibroblasts.

Child↗
PubMed1977

Monozygotic twins concordant for tracheo-esophageal fistula and discordant for the VATER association.

Monozygotic female twins were concordant for tracheo-esophageal fistula (TEF); and one twin also manifested other anomalies in the VATER association, including agenesis of the female reproductive tract. Review of the literature discloses a familial tendency for recurrence of TEF and a high concordance rate in monozygotic twins, indicating a significant genetic influence for the isolated anomaly. In the case of the VATER association, the sporadic occurrence of affected individuals and discordance in twins implicates the effect of non-genetic factors.

Abnormalities, Multiple↗
PubMed1977

Carriers with excessively low factor VIII procoagulant activity (VIII AHF): a study of two unrelated families with mild hemophilia A.

Two unrelated families are described with mild hemophilia A in whom six obligate carriers had unusually low VIII AHF levels. In each family, successive generations of males were affected with hemophilia A as determined by low VIII AHF in the presence of normal VIII AGN and VIII VWF levels. In the first family, two of five obligate carriers had low VIII AHF levels associated with clinical bleeding and one other had a history of bleeding. While receiving oral contraceptives, one of these two carriers was found to have a normal VIII AHF level. In the second family, four cousins below age 10 who were obligate carriers had significantly low VIII AHF levels, while a paternal aunt and paternal grandmother who were also obligate carriers had VIII AHF levels within the normal range. Hemorrhagic diathesis in multiple obligate carriers in these families is not readily explained by the Lyon hypothesis, and suggests that these families may be exmaples of an unusual allelic form of hemophilia A or that they may be transmitting several independent genes affecting VIII AHF levels. Our experience suggests that VIII AHF levels should be determined on all obligate or possible carriers prior to surgery to identify those individuals at risk for postoperative bleeding. Furthermore, it is suggested that hormonal therapy might be effective in the management of carriers with low levels of VIII AHF and clinical bleeding.

Adult↗
PubMed1976

Familial atrial septal defect with prolonged atrioventricular conduction.

This report describes a family with frequent recurrence of congenital heart disease in multiple generations. Eight members had atrial septal defect (ASD) of the fossa ovalis type and seven members had other forms of congenital heart disease. One branch of the pedigree showed a predominance of ASD with prolonged atrioventricular (A-V) conduction and initially suggested an autosomal dominant gene effect. A variety of other forms of congenital heart disease were found in several first degree relatives of those with ASD as well as in more distant relatives. The variability of congenital heart disease in this pedigree is compatible with the polygenic mode of inheritance. Definition of the inheritability of congenital heart disease in a specific family has important consequences in the determination of the recurrence risks for all family members.

Adult↗
PubMed1973

Cytogenetic engineering in vivo: restoration of biologic complement activity to C5-deficient mice by intravenous inoculation of hybrid cells.

Splenic macrophages were identified as at least one source of C5 elaboration in normal mice. Hybrid cells were formed from splenic macrophages from C5-deficient mice and either kidney cells from mice with normal amounts of C5 or chicken erythrocytes. These hybrids elaborated C5 in vitro. C5-Deficient mice inoculated with these hybrid cells developed, in their serum, antigenically active mouse C5, as well as both hemolytic and biologic complement activity. These studies demonstrate the feasibility of genetic "repair" in mammals.

Animals↗
PubMed1970

Introduction of a heterologous nucleus into enucleated cytoplasms of cultured mouse L-cells.

Mouse L-cells exposed to cytochalasin B undergo random nuclear protrusion and, occasionally, total enucleation. The anucleate cell remains viable for several days. Chick erythrocytes were fused to L-cells with inactivated Sendai virus. The resulting hybrids, containing one or more erythrocyte nuclei in addition to the L-cell nucleus, were treated with cytochalasin B. Through the process of random enucleation, the L-cell nucleus was extruded from some hybrid cells while the erythrocyte nucleus was retained in the hybrid. In other experiments, chick erythrocytes were fused directly to enucleated L-cells. The result in both instances is the introduction of an erythrocyte nucleus into L-cell cytoplasm. The erythrocyte nucleus swells and the hybrid cell is capable of incorporating radioactive uridine.

Animals↗