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Biomedical subjects

R B Goldberg

Publications and source records attributed to R B Goldberg.

At least 19 recordsLinked to original sources
PubMed1992

Deletions and microdeletions of 22q11.2 in velo-cardio-facial syndrome.

Velo-cardio-facial syndrome (VCFS), an autosomal dominant disorder, is characterized by cleft palate, cardiac defects, learning disabilities and a typical facial appearance. Less frequently, VCFS patients have manifestations of the DiGeorge complex (DGC) including hypocalcemia, hypoplastic or absent lymphoid tissue and T-cell deficiency suggesting that these 2 conditions share a common pathogenesis. Here, we report the results of cytogenetic and molecular studies of 15 VCFS patients. High-resolution banding techniques detected an interstitial deletion of 22q11.21-q11.23 in 3 patients. The remaining 12 patients had apparently normal chromosomes. Molecular analysis with probes from the DiGeorge Chromosome Region (DGCR) within 22q11 detected DNA deletions in 14 of 15 patients. In 2 families, deletions were detected in the affected parent as well as the propositus suggesting that the autosomal dominant transmission of VCFS is due to segregation of a deletion. Deletions of the same loci previously shown to be deleted in patients with DGC explains the overlapping phenotype of VCFS and the DGC and supports the hypothesis that the cause of these two disorders is the same.

Chromosome Banding↗
PubMed1992

Regional and cell-specific gene expression patterns during petal development.

We investigated gene expression patterns that occur during tobacco petal development. Two petal mRNA classes were identified that are present at elevated levels relative to other organs. One class is represented equally in the unpigmented tube and pigmented limb regions of the corolla. The other class accumulates preferentially within the limb region. Limb-specific mRNAs accumulate at different times during corolla development, peak in prevalence prior to flower opening, and are localized in either the epidermal cell layers or the mesophyll. The epidermal- and mesophyll-specific mRNAs change abruptly in concentration within a narrow zone of the limb/tube border. Preferential accumulation of at least one limb-specific mRNA occurs within the corolla upper region early in development prior to limb maturation and pigment accumulation. Limb-specific mRNAs also accumulate preferentially within the unpigmented corolla limb region of Nicotiana sylvestris, a diploid progenitor of tobacco. Runoff transcription studies and experiments with chimeric beta-glucuronidase genes showed that petal gene organ, cell, and region specificities are controlled primarily at the transcriptional level. We conclude that during corolla development transcriptional processes act coordinately on limb-specific genes to regulate their regional expression patterns, but act individually on these genes to define their cell specificities.

Color↗
PubMed1992

A mutant lectin gene is rescued from an insertion element that blocks its expression.

The soybean lectin gene Le1 encodes a prevalent seed protein and is highly regulated during the life cycle. The mutant lectin gene allele le1 is not transcribed detectably, contains a 3.5-kb Tgm1 insertion element within its coding region 0.6 kb 3' to the transcription start site, and leads to a lectinless phenotype. To determine whether the Tgm1 element or a secondary mutation was responsible for repressing le1 gene transcription, we eliminated the insertion element by constructing a chimeric lectin gene (le1/Le1) that contained the 5' half of the le1 gene and its promoter region and the 3' half of the wild-type Le1 gene. Transformed tobacco seed containing the le1/Le1 gene produced both lectin mRNA and protein, demonstrating that the mutant lectin gene control region is transcriptionally competent. By contrast, transformed seed containing the le1 gene produced no detectable lectin mRNA. We conclude that the absence of detectable transcription from the le1 gene is due to transcriptional inhibition by the Tgm1 insertion element and that this element acts at a distance to block transcription from an upstream promoter region.

Cloning, Molecular↗
PubMed1992

Sensory function at diagnosis and in early stages of NIDDM in patients detected through screening.

OBJECTIVE: We studied whether sensory function abnormalities are present at diagnosis and whether they develop in the early stages of non-insulin-dependent diabetes (NIDDM). RESEARCH DESIGN AND METHODS: Quantitative assessments of vibration sensitivity at the hallux and index fingers, and thermal sensitivity at the hallux were performed at screening (2-h oral glucose tolerance tests) for diabetes in 364 individuals. Twenty-five subjects diagnosed with NIDDM and 25 matched nondiabetic subjects were restudied after an interval of 12-41 mo. RESULTS: When those with NIDDM (n = 41) or impaired glucose tolerance (IGT) (n = 38) were compared with nondiabetic subjects, there were no significant differences in sensory function indices. However, the vibration threshold and HbA1c were related among those found to be hyperglycemic (IGT and NIDDM combined P less than 0.05; NIDDM alone P less than 0.05). Among diabetic subjects, the vibration threshold and interaction term of height and Hba1c were positively related in a multiple regression analysis (P less than 0.01). There were increments in all sensory thresholds in diabetic patients at follow-up (P less than 0.05 for all). Increments were smaller in control subjects. CONCLUSIONS: These data suggest that although sensory function tends to be normal at diagnosis in NIDDM patients, there appears to be a diminution in sensory function as the disease progresses. An interaction between metabolic factors and height may influence sensory function early in the course of NIDDM.

Adult↗
PubMed1991

A review of cancer induction by extremely low frequency electromagnetic fields. Is there a plausible mechanism?

A body of epidemiological evidence suggests an association between residential or occupational exposure to extremely low frequency (ELF) electromagnetic fields (EMF) and an increased incidence of cancer in children and adults. Experimental studies at the whole-animal and cellular level are ambiguous; bioeffects suggestive of a carcinogenic effect have been reported, but a similar volume of negative reports can also be assembled. This literature is critically reviewed based on the hypothesis that the epidemiological results are correct, and asking what plausible mechanism could explain a small increase in the incidence of a range of tumors with a non-specific increased exposure to ELF EMF? We focus on four likely mechanisms: 1) disruption of cell communication, 2) modulation of cell growth via changes in calcium ion flux, 3) activation of specific oncogenic gene sequences, and 4) action as a stress factor operating through disruption of hormonal and immune system tumor control mechanisms. We discuss the implications of epidemiologic and experimental results in the context of hypothetical mechanisms of cancer induction, and suggest experiments likely to help define putative EMF hazards.

Adult↗
PubMed1991

Engineered male sterility in plants.

We constructed two chimaeric ribonuclease genes that are specifically expressed in anthers of tobacco and rapeseed plants. The expression of these genes affects the production of functional and viable pollen yielding plants that are male sterile. This dominant gene for nuclear male sterility should facilitate the production of hybrid seed in various crops.

Brassica↗
PubMed1991

Comparison of the lipid profiles of Cubans and other Hispanics with non-Hispanics.

We compared the plasma lipid profiles of Cuban Americans and other Hispanic-American subgroups with those of non-Hispanics. High-density lipoprotein cholesterol levels were lower and triglyceride levels were higher when Hispanic women were compared with non-Hispanic women, and this pattern was also apparent for men. The lower high-density lipoprotein cholesterol and higher triglyceride levels were consistent for both Cuban and non-Cuban Hispanics. There were higher waist-hip ratios and insulin levels in both Hispanic men and women. When allowances were made for these attributes in covariance analyses, the lipid differences were markedly diminished. These data suggest the lower high-density lipoprotein cholesterol and higher triglyceride levels are consistent across Hispanic subgroups and that this lipid pattern may be attributable at least in part to increased insulin resistance in Hispanics.

Adult↗
PubMed1990

Ocular findings in Treacher Collins syndrome.

We examined 14 patients from nine families referred with the diagnosis of Treacher Collins syndrome. We noted seven significant ocular findings including the following: a subnormal horizontal palpebral fissure length and inferomedial displacement of the lateral canthus in primary gaze; further medial displacement (4.0 mm or more) of the lateral canthus with resultant shortening of the horizontal fissure length on forced eyelid closure (fissure narrowing sign); partial-thickness eyelid colobomata localized to the nasal one half to two thirds of the lower eyelids; bilateral absence of the inferior lacrimal puncta; bilateral blepharoptosis; inferior displacement of the palpebral fissures; and regular astigmatism without any consistent orientation of the axis of astigmatism relative to the lower eyelid defects, blepharoptosis, or lateral canthus. The fissure narrowing sign correlates with known anatomic deficiencies in the Treacher Collins syndrome and may prove valuable in confirming the diagnosis in patients who lack certain typical features.

Adolescent↗
PubMed1990

The relation between the plasma lipoprotein pattern and the waist/hip ratio in non-diabetic individuals.

Relations between lipoprotein indices and the waist/hip ratio (WHR) were examined in normoglycemic subjects (124 women and 63 men). Among women, an atherogenic lipoprotein pattern was strongly associated with WHR. The relation was greater than that of the lipoprotein pattern with either the body mass index or the subscapular/triceps ratio, and was independent of these adiposity measures. The association between low-density-lipoprotein cholesterol (LDL-cholesterol) and WHR was much stronger in thinner women than in those more obese (r = 0.64 vs r = 0.22, p = 0.001 for difference). Men had a more atherogenic lipoprotein pattern than women; however, with allowances for WHR the lipoprotein patterns were similar. These findings suggest that: (1) WHR is more strongly related to plasma lipoproteins than other adiposity measures; (2) there is effect modification by the extent of adiposity for the relation between LDL-cholesterol and WHR; and (3) the adipose distribution may be important in explaining lipoprotein differences between men and women.

Abdomen↗
PubMed1990

Correlates of atherosclerosis in coronary arteries of patients undergoing angiographic evaluation.

The correlations between lipid and lipoprotein measurements and other risk factors of coronary artery disease were evaluated in 101 men undergoing coronary angiography. Clinically significant disease was present in 75 patients, whereas 24 had no observable lesions and 2 had minimal lesions. Comparisons of individual lipid and lipoprotein levels were nearly all significantly different between patients with and patients without clinically significant disease; however, no single variable could predict the presence of disease among patients. Logistic regression analysis identified five factors: apolipoprotein A-I, apolipoprotein B, diabetes, age, and family history of heart disease, which account for most of the differences between the two patient groups. These results could have important implications for the evaluation and management of patients suspected of having coronary atherosclerosis.

Age Factors↗
PubMed1990

Spondyloepiphyseal dysplasia congenita: genetic linkage to type II collagen (COL2AI).

Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominantly inherited chondrodysplasia characterized by disproportionate short stature (short trunk), abnormal epiphyses, and flattened vertebral bodies. Manifestations are present at birth. We ascertained a 4-generation family exhibiting the clinical manifestations of the disorder. Previous evidence suggesting defects of type II collagen associated with the SEDC phenotype led us to genotype the family for various COL2A1 gene-associated RFLPs. A total of 17 affected and unaffected members of this family were studied. The family was informative for a recently discovered HinfI RFLP. No recombinants between the marker and the phenotype were found in eight informative meioses. A maximum LOD score of 3.01 was obtained at a recombination fraction of .00. Our results indicate that the SEDC phenotype in this family is caused by mutations in or very close to the COL2A1 locus.

Adult↗
PubMed1989

Genetic control of flower development.

Flowering plants are the most highly evolved and complex organisms within the plant kingdom. The flower consists of several distinct organ systems that are responsible for higher plant reproduction. Cells within specific floral organs differentiate into spores and gametes required by the plant to complete its life cycle. Flower development represents an excellent model for understanding the molecular and physiological processes that control organ differentiation in higher plants. Rapidly emerging gene tagging procedures are facilitating the isolation of genes that control flower morphogenesis.

Cell Differentiation↗