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Biomedical subjects

R L Ladda

Publications and source records attributed to R L Ladda.

18 recordsLinked to original sources
PubMed1992

Cutaneous scar at anterior hair line in mother and child with associated frontal bone defect in child.

A large frontal bone defect underlying a "V" shaped scar was noted in a newborn male whose mother had an identical "V" shaped scar at the same location in the anterior hairline. Both had hypertelorism and short palpebral fissures. The mother had no radiographic evidence of skull defect and neither mother nor child had other cutaneous or skeletal anomalies. Cranioplasty was performed on the child using the remaining frontal bones with an excellent cosmetic result. Biopsy performed at operation documented scar tissue extending through the dermis and underlain by thickened dura. Mother and child appear to have a variant form of aplasia cutis congenita, an autosomal dominant trait with wide variation in expression.

Abnormalities, Multiple↗
PubMed1992

The frequency of uniparental disomy in Prader-Willi syndrome. Implications for molecular diagnosis.

BACKGROUND: Prader-Willi syndrome is a genetic disorder characterized by infantile hypotonia, obesity, hypogonadism, and mental retardation, but it is difficult to diagnose clinically in infants and young children. In about two thirds of patients, a cytogenetically visible deletion can be detected in the paternally derived chromosome 15 (15q11q13). Recently, patients with Prader-Willi syndrome have been described who do not have the cytogenetic deletion but instead have two copies of the 15q11q13 region that are inherited from the mother (with none inherited from the father). This unusual form of inheritance is known as maternal uniparental disomy. Using molecular genetic techniques, we sought to determine the frequency of uniparental disomy in Prader-Willi syndrome. METHODS: We performed molecular analyses using DNA markers within 15q11q13 and elsewhere on chromosome 15 in 30 patients with Prader-Willi syndrome who had no cytogenetically visible deletion. We also studied their parents. Three patients with Prader-Willi syndrome who had a cytogenetic deletion served as controls. RESULTS: In 18 of the 30 patients without a cytogenetic deletion (60 percent), we demonstrated the presence of maternal uniparental disomy for chromosome 15 and its association with advanced maternal age. In another eight patients (27 percent), we identified large molecular deletions. The remaining four patients (13 percent) had evidence of normal biparental inheritance for chromosome 15; three of these patients were the only ones in the study who had some atypical clinical features. CONCLUSIONS: In about 20 percent of all cases, Prader-Willi syndrome results from the inheritance of both copies of chromosome 15 from the mother (maternal uniparental disomy). With the combined use of cytogenetic and molecular techniques, the genetic basis of Prader-Willi syndrome can be identified in up to 95 percent of patients.

Adult↗
PubMed1990

Neurologic manifestations in 18q- syndrome.

We report a mother and son with a deletion at 18q22.3. Both have the typical manifestations of the 18q- syndrome. In addition, both have an action tremor which became apparent in childhood. The mother subsequently developed chorea and dysmetria in late adolescence. Magnetic resonance imaging of their brains showed poor myelination of the central white matter tracts with relatively normal myelination of the corpus callosum. We propose that these neurologic findings are most likely due to a failure of expression of the myelin basic protein gene.

Abnormalities, Multiple↗
PubMed1979

Establishment and characterization of a new endometrial cancer cell line (SCRC-1).

A new human endometrial cell line, SCRC-1, has been established from a uterine adenocarcinoma. During a period of 57 weeks in culture, the SCRC-1 cells have been passaged over 100 times. Cultures have an epitheloid morphology, high mitotic activity, and a tendency to form multiple cell layers. The cells are polygonal and are arranged in pavement-like fashion. Most have multiple nucleoli, some are multinucleated, and all have heavily vacuolated cytoplasm. Pretreatment with iododeoxyuridine did not reveal viral markers by cocultivation or immunofluorescence techniques. Karyologic studies indicate that the SCRC11 cell line is essentially diploid with a small subpopulation of tetraploid cells. Over a period of 20 weeks, 1 of 14 athymic nude mice inoculated with SCRC-1 cells developed a tumor which histologically closely resembled the original human tumor. Cells were subsequently propagated from this tumor and the resulting epitheloid-like cell line was designated SCRC-1, Tu 1.

Adenocarcinoma↗
PubMed1979

Decrease in epidermal growth factor receptor levels and production of material enhancing epidermal growth factor binding accompany the temperature-dependent changes from normal to transformed phenotype.

Normal rat kidney (NRK) cells infected with a temperature-sensitive mutant of Kirsten sarcoma virus (Ts cells) exhibited normal monolayer morphology identical to that observed for uninfected cells (NRK cells) at the nonpermissive temperature, 39 degrees C, but grew as multilayered foci resembling NRK cells transformed by the wild-type virus (KNRK cells) at 32 degrees C, the permissive temperature. NRK cell division was stimulated by epidermal growth factor (EGF), and these cells showed high levels of EGF receptors, as determined by 125I-labeled EGF binding. KNRK cells were unresponsive to EGF and no EGF receptors were detectable. Ts cells also were unresponsive to EGF at both temperatures, but exhibited just detectable EGF binding at 32 degrees C and 10-15% of NRK cell binding at 39 degrees C. Use of EGF added to the culture medium by these cells paralleled the receptor levels. Crossfeeding experiments among NRK, KNRK, and Ts cultures indicated that Ts cells at the permissive temperature and KNRK cells at both temperatures produced a heat-stable substance(s) which stimulated DNA synthesis in NRK cells independent of the presence of serum or of EGF. Conditioned medium from the transformed cultures also significantly enhanced EGF binding to NRK cells. These studies demonstrated a correlation between the transformed phenotype and the receptor levels of a potent cell mitogen, EGF, which was readily reversible in the Ts cultures. In addition, cultures expressing the transformed phenotype produced material that did not compete for the EGF receptor but did enhance EGF binding, in contrast to other reports involving sarcoma virus-transformed cells.

Animals↗
PubMed1979

Quantitation of phosphatidylcholine secretion in lung slices and primary cultures of rat lung cells.

Rat lung slices and isolated rat lung cells were used to study the secretion of phosphatidylcholine by the lung in vitro. The rate of incorporation of [(3)H]choline by lung slices was 20-fold greater than by liver slices and 4-fold greater in lung cells compared to confluent skin fibroblasts. Labeling lung slices or cells with [(3)H]choline for up to 8 hr failed to reveal a significant amount of labeled phosphatidylcholine in the medium of either system compared to the medium from liver slice or fibroblast controls. Labeling of isolated lung cells for up to 24 hr, with or without 10% fetal calf serum, also showed no significant difference in the amount of labeled phosphatidylcholine in the medium compared to control fibroblast cultures. Washing labeled lung slices or cells with a nonlysing concentration of Triton X-100 (0.05%) did not selectively release labeled phosphatidylcholine, indicating that any secreted phosphatidylcholine did not adhere to the surface of the lung slices or cells. Experiments were performed to determine whether the small amount of phosphatidylcholine in the medium and detergent-released phosphatidylcholine was similar to the tissue and cell phosphatidylcholine. The saturated fatty acid composition of the phosphatidylcholine released by Triton X-100 and in the medium (from lung slices) was identical to that of the tissue phosphatidylcholine. In addition, the relative labeling rates of the phospholipids released by Triton X-100 and in the medium (labeled with [(14)C]glycerol) were identical to those of the tissue and cell phospholipids. Based on these results, we conclude that phosphatidylcholine is not secreted by lung slices and lung cells in large amounts compared to controls. The implication of these data is that pulmonary surfactant material may actually not be secreted by the lung in vitro, and perhaps in vivo, in the manner that is currently generally accepted.

Animals↗
PubMed1979

Properties of human epithelioid cells established in vitro by a herpesvirus [IBRV(HMC)] isolated from cytomegalovirus-transformed human cells.

Infectious bovine rhinotracheitis virus [IBRV(HMC)], a double-enveloped herpesvirus, was isolated from human embryo lung fibroblasts transformed by cytomegalovirus (CMV). This agent was identified as an IBRV strain that was antigenically related to human CMV. Inoculation of a primary human kidney cancer cell culture with IBRV(HMC) resulted in persistent infection and subsequent establishment of a cell line [IBRV(HMC)HKC-1]. Virus-related nuclear, cytoplasmic, and cell membrane antigens were detected in these cells in early in vitro passages by anticomplement and indirect immunofluorescence tests. Infectious virus was rescued from one of the cell sublines after temperature-shock treatment at passage 26. Karyotypic analysis confirmed the human origin of the cells. Control uninfected kidney cancer cells survived only six in vitro passages. The established cells grew to more than 100 in vitro passages 1 year after initiation of the experiments and induced an epithelioid cancer of variable morphology that infiltrated nerves and muscles when inoculated sc into athymic nude mice.

Adenocarcinoma↗
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↗