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Biomedical subjects

D Lev

Publications and source records attributed to D Lev.

At least 37 records · Page 2Linked to original sources
PubMed2001

LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development.

In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass accrual during growth. Mutations in LRP5 cause the autosomal recessive disorder osteoporosis-pseudoglioma syndrome (OPPG). We find that OPPG carriers have reduced bone mass when compared to age- and gender-matched controls. We demonstrate LRP5 expression by osteoblasts in situ and show that LRP5 can transduce Wnt signaling in vitro via the canonical pathway. We further show that a mutant-secreted form of LRP5 can reduce bone thickness in mouse calvarial explant cultures. These data indicate that Wnt-mediated signaling via LRP5 affects bone accrual during growth and is important for the establishment of peak bone mass.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Clinical manifestations in a cohort of 41 Rothmund-Thomson syndrome patients.

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis characterized by a poikilodermatous rash starting in infancy, small stature, skeletal abnormalities, juvenile cataracts, and predisposition to specific cancers. We have identified a contemporary cohort of 41 patients to better define the clinical profile, diagnostic criteria, and management of patients with RTS. Patients with the diagnosis of RTS were ascertained by referrals from dermatology, ophthalmology, genetics, and oncology or from direct contact with the patient's family. Medical information was obtained from interviews with physicians, patients, and their parents and a review of medical records. The age range at ascertainment was 9 months to 42 years (28 males and 13 females; M:F, 2:1). All subjects displayed a characteristic rash. Thirteen subjects had osteosarcoma (OS) (32%), eight had radial defects (20%), seven had gastrointestinal findings (17%), two had cataracts (6%), and one had skin cancer (2%). Twenty-two of 28 patients without OS were less than 15 years old and thus remain at significant risk for this tumor. This case-series study reveals a clinical profile of RTS that includes a higher prevalence of OS and fewer cataracts, compared with historical reports. These differences may reflect either allelic or genetic heterogeneity. This study documents the frequency of clinical anomalies in a contemporary cohort of RTS patients and revises guidelines for diagnosis and management of RTS.

Adolescent↗
PubMed2001

Neuronal sodium-channel alpha1-subunit mutations in generalized epilepsy with febrile seizures plus.

Generalized epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome characterized by the presence of febrile and afebrile seizures. The first gene, GEFS1, was mapped to chromosome 19q and was identified as the sodium-channel beta1-subunit, SCN1B. A second locus on chromosome 2q, GEFS2, was recently identified as the sodium-channel alpha1-subunit, SCN1A. Single-stranded conformation analysis (SSCA) of SCN1A was performed in 53 unrelated index cases to estimate the frequency of mutations in patients with GEFS+. No mutations were found in 17 isolated cases of GEFS+. Three novel SCN1A mutations-D188V, V1353L, and I1656M-were found in 36 familial cases; of the remaining 33 families, 3 had mutations in SCN1B. On the basis of SSCA, the combined frequency of SCN1A and SCN1B mutations in familial cases of GEFS+ was found to be 17%.

Amino Acid Sequence↗
PubMed2001

The fetal cerebellar vermis: normal development as shown by transvaginal ultrasound.

OBJECTIVE: To determine the normal appearance and development of the fetal cerebellar vermis using mid-sagittal planes obtained by transvaginal sonography. SUBJECTS AND METHODS: A total of 101 fetuses were evaluated by transvaginal sonography between 21 and 39 weeks of gestation. The mid-sagittal antero-posterior and cranio-caudal vermian diameters, circumference and surface area were measured and calculated. Nomograms were produced. RESULTS: The vermis was observed in 96% of the cases and all the measurements were performed in 92%. The vermis grows in a linear fashion throughout pregnancy. The growth pattern correlates well with gestational age, biparietal diameter, head circumference and transverse cerebellar diameter. CONCLUSION: Transvaginal sonography is a valuable tool in the study of the fetal vermis during the second half of pregnancy. Knowledge of its normal appearance may help identify developmental anomalies and enable accurate prenatal counseling.

Cerebellum↗
PubMed2001

Dramatic improvement in mitochondrial cardiomyopathy following treatment with idebenone.

Idebenone, a synthetic analogue of coenzyme Q10, has been shown to improve cardiac function in patients with Friedreich ataxia and a deficiency of respiratory chain complexes I-III. We describe a woman with severe combined right and left heart failure due to a mitochondrial cardiomyopathy. The patient underwent an endomyocardial biopsy as part of an evaluation for cardiac transplantation. It showed severely decreased respiratory complex activities dependent on CoQ, pointing to CoQ depletion. Following idebenone treatment there was a dramatic improvement in her clinical status with resolution of the heart failure.

Adult↗
PubMed2001

Behavioral phenotypes of genetic syndromes: a reference guide for psychiatrists.

OBJECTIVE: To review the literature on behavioral phenotypes of genetic syndromes, displaying the data as a reference guide for everyday practice. METHOD: A computerized search was performed for articles published in the past 10 years, and selected papers were surveyed. RESULTS: The behavioral phenotypes of 11 major genetic syndromes were reviewed including the following topics: genetic etiology, genetic counseling, physical features, medical problems, cognitive and behavioral profile, and psychopathology. The speculated correlation between the identified gene and the pathophysiology of the cognitive and behavioral features is discussed. CONCLUSIONS: Updated knowledge of behavioral phenotypes will help psychiatrists identify these conditions, refer the patient and his/her family for genetic diagnosis and counseling, make specific treatment recommendations, and contribute to research and syndrome delineation.

Child↗
PubMed2001

Febrile convulsions, ataxia, developmental delay, and obesity: a new syndrome?

We describe the association of recurrent complicated febrile convulsions, developmental delay, ataxia, and obesity in three unrelated girls. The three girls, aged 3 to 4 years, were all born to healthy, nonconsanguineous parents and have normal siblings. Their birth weight was appropriate for gestational age. They are not dysmorphic and have normal head circumference. Development is delayed; they all walked with an ataxic gait after the age of 2 years and started speaking at 3 years. Their growth charts are remarkably alike: they initially had a normal growth curve and around 24 months of age started to gain weight excessively. They all continue to suffer from complicated febrile seizures, which started before 12 months of age, and are resistant to prophylactic anticonvulsants. Metabolic evaluation is normal. They have normal magnetic resonance images and electroencephalograms. Fragile X and Prader-Willi syndromes were ruled out. We suggest that this is a new mental retardation syndrome that should be considered in children with recurrent febrile convulsions, developmental delay, and obesity. In a recent study, mutations in the beta4 calcium channel were identified in the mutant epileptic mouse that presents with epilepsy, mental retardation, and ataxia. We hypothesize that a calcium channel gene may be involved in this syndrome.

Child, Preschool↗
PubMed2001

[Malignant humoral hypercalcemia associated with angiotropic large B cell lymphoma].

Angiotropic large B cell lymphoma (angiotropic LCL) or intravascular large cell lymphoma (IVLCL) was diagnosed by liver and bone marrow biopsies and immunohistochemical studies in a 52 year old Caucasian male. IVLCL is a very rare disease characterized by widespread intravascular proliferation of lymphoma cells. Although it most commonly affects the central nervous system or skin and occasionally bone marrow, angiotropic LCL may be present without evidence of localized disease, as seen initially in our patient. To date, only a few cases of intravascular malignant lymphomatosis associated with parathyroid hormone related protein (PTH-rP) induced humoral hypercalcemia have been published. Our extraordinary case was diagnosed mainly by liver biopsy. The neoplastic lymphoid cells stained diffusely and strongly positive with CD-20 (Pan B) and were negative for CD-3 (Pan T) immunostain. The most significant, initial clinical finding was severe, unexplained hypercalcemia (until 18.6 mg/dl). Plasma PTH-rP showed a ten-fold increase at 8 pmol/L (normal value less than 0.8 pmol/L). Very unusual cytogenic abnormalities were found. The patient received the massive third generation combination chemotherapy comprising of Methotrexate, Doxorubicine, Cyclophosphamide, Vincristine, Prednisone and Bleomycin and developed, complete although temporary, clinical, humoral and cytogenetic remission.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Molecular cytogenetic studies in three patients with partial trisomy 2p, including CGH from paraffin-embedded tissue.

We report on three cases of partial trisomy 2p in which the identification and exact localization of the duplicated chromosome segment was possible only by application of molecular cytogenetic techniques. These included fluorescence in situ hybridization by use of wcp2, N-myc, and subtelomeric 2p probes and comparative genomic hybridization with DNA isolated from blood samples, frozen fetal tendon, and formalin fixed, paraffin-embedded fetal lung tissue. Two of the cases concerned fetuses of gestational week 20 and 24 with duplication of nonoverlapping terminal (2pter-->p24) and more proximal (2p25-->p23) segments and with distinctly different phenotypes. The third case was due to a de novo inverted duplication of 2p25-->p23, with loss of the subtelomeric region of 2p. This 53-month-old girl was a Bloom syndrome carrier. The patient had prenatal growth failure, borderline microcephaly, dilated lateral horns of the cerebral ventricles, transient cortical blindness, myopia, muscle hypotonia, and dilatation of the left renal collecting system. Dermal cysts were found on the glabella, the soles of both feet, and the vocal cord, causing respiratory embarrassment. Previously reported cases of pure trisomy 2p are reviewed, in an attempt to correlate clinical findings to overlapping regions in 2p. These cases illustrate the effectiveness of molecular cytogenetic methods in resolving subtle chromosomal aberrations in order to coordinate more accurately a chromosome regionspecific phenotype.

Abortion, Induced↗
PubMed2000

Gastrointestinal autonomic nerve (GAN) tumor of the rectum.

Gastrointestinal autonomic nerve (GAN) tumor is a relatively newly defined member of the gastrointestinal stromal tumor family, which is a rare group of mesenchymal neoplasms originating in the bowel wall throughout the entire gastrointestinal tract. A thorough search of the literature revealed only one brief mention of this tumor arising in the rectum. We present a full description of such a tumor and summarize the clinical characteristics, therapeutic measures used, biological behavior, and outcome of this unique case.

Autonomic Nervous System Diseases↗
PubMed2000

Neurologic presentations of mitochondrial disorders.

This article describes the neurologic presentations of children with mitochondrial disorders. The charts of 42 children with highly suspect mitochondrial disorders were reviewed. Thirty-seven children were diagnosed as having definite mitochondrial disorders based on a suggestive clinical presentation and at least one accepted criteria, while in five patients the diagnosis remained probable. All patients had nervous system involvement, but it was the presenting symptom in 28 of 42. Eighteen children had normal intelligence and 24 had mental retardation or developmental delay at the onset of their disease. Twenty-five patients had either an acute regression or a progressive encephalopathy. The most frequent neurologic manifestations were abnormal tone, seizures, extrapyramidal movements, and autonomic dysfunction. The eyes were involved in 11 children. Nerve deafness was found in seven patients. Myopathy was found in only six patients. In conclusion, a complex neurologic picture, especially with other organ involvement, warrants a full mitochondrial evaluation.

Brain Diseases, Metabolic, Inborn↗
PubMed2000

Familial mitochondrial intestinal pseudo-obstruction and neurogenic bladder.

Intestinal dysmotility and neurogenic bladder have been described as part of two autosomal-recessive mitochondrial disorders assumed to be due to a defect in communication between the nuclear and mitochondrial genomes: myoneurogastrointestinal encephalopathy (MNGIE) and diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (Wolfram syndrome). Partial cytochrome c oxidase deficiency has been described in both. We describe three Ashkenazi Jewish siblings with progressive intestinal dysmotility, neurogenic bladder, and autonomic manifestations but no central nervous system involvement. Cytochrome c oxidase deficiency was demonstrated in peripheral and multiple intestinal muscle biopsies. Mitochondrial DNA analysis of an intestinal biopsy of patient 1 showed heteroplasmy consisting of a normal 16.5-kb band and an approximately 28-kb band, suggestive of a duplication. Mitochondrial DNA analysis of a muscle biopsy of patient 2 showed multiple deletions, mainly 10- and 11-kb bands. We suggest that this unique combination of intestinal pseudo-obstruction and neurogenic bladder could comprise a new autosomal-recessive mitochondrial disorder.

Adolescent↗
PubMed1999

Pulmonary agenesis, microphthalmia, and diaphragmatic defect (PMD): new syndrome or association?

We present the prenatal diagnosis of a 22-week-gestation fetus with unilateral pulmonary agenesis, diaphragmatic hernia, microphthalmia, pulmonary vessel agenesis, and intrauterine growth retardation. The "association" of pulmonary agenesis, diaphragmatic defect, and microphthalmia was described previously in two patients but the resemblance was not noted by the authors. While each case differs slightly in some of the associated anomalies, it is evident that the mainstay of diagnosis is similar to the case presented here and that this represents a new syndrome or association.

Abnormalities, Multiple↗
PubMed1999

[The "wandering spleen" syndrome].

We describe a 26-year-old woman with thrombocytopenia discovered during gestation. On admission for evaluation of abdominal pain, torsion of an ectopic spleen was found. The spleen was removed and the thrombocytopenia resolved.

Abdominal Pain↗