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Biomedical subjects

G H Sack

Publications and source records attributed to G H Sack.

At least 37 records · Page 2Linked to original sources
PubMed1989

Molecular analysis of the human serum amyloid A (SAA) gene family.

We have assigned the human serum amyloid A (SAA) gene family to a 90 kb region on the short arm of human chromosome 11 (11p) by hybridization of defined genomic fragments of human SAA genes to DNA from rodent-human somatic cell hybrids and to large DNA fragments separated by transverse alternating field gel electrophoresis. We have also characterized SAA probe hybridization patterns in human DNA cleaved with restriction endonucleases Hind III, Pst I, BglII, TaqI, and XbaI and found invariant patterns except for a two-allele restriction fragment length polymorphism (RFLP) with Hind III. These studies show that the SAA gene family comprises at least three members in the haploid human genome and will be useful in identifying variant patterns and establishing linkage between members of the SAA gene family and other markers on chromosome 11.

Chromosome Mapping↗
PubMed1989

Color vision defects in adrenomyeloneuropathy.

The relationship between abnormal color vision and adrenomyeloneuropathy (AMN) was investigated in 27 AMN patients and 31 age-matched controls by using the Farnsworth-Munsell 100 Hue test. Twelve (44%) of 27 patients showed test scores significantly above normal. The axes of bipolarity determined by the testing differed widely between the patients with abnormal scores, compatible with the notion that different alterations in visual pigment genes occur in different AMN kindreds. These observations confirm our earlier impression that the frequency of abnormal color vision is increased in these kindreds, and it supports our contentions that (1) AMN (and its companion, adrenoleukodystrophy) are very closely linked to the visual pigment loci at Xq28 and (2) this proximity might provide the opportunity to observe contiguous gene defects.

Adrenal Gland Diseases↗
PubMed1988

Frequent alterations of visual pigment genes in adrenoleukodystrophy.

Both adrenoleukodystrophy (ALD) and red/green color blindness have been mapped to the distal long arm of the human X chromosome (Xq28). Color-vision defects are frequently associated with ALD, and study of the red and green visual pigment genes in eight ALD kindreds has shown frequent structural changes including deletions and possible intragenic recombinations. Such changes may reflect chromosomal events underlying both ALD and the associated visual defects and should help define both the structural gene responsible for ALD and physical genetic relationships in the Xq28 region.

Adrenoleukodystrophy↗
PubMed1988

Serum amyloid A (SAA) gene variations in familial Mediterranean fever.

Novel structural changes in members of the serum amyloid A (SAA) gene family have been found in four patients of varied ethnic backgrounds with familial Mediterranean fever. Since the genes for these small acute phase proteins are generally well conserved, these observations suggest that alterations of serum amyloid A genes, their protein products and/or their regulation may be responsible for familial Mediterranean fever.

Adult↗
PubMed1987

Thoracolumbosacral laminectomy in achondroplasia: long-term results in 22 patients.

Neurologic problems caused by vertebral stenosis in the thoracolumbosacral (TLS) region are common in achondroplasia. Surgical decompression by means of laminectomy is recommended often, but its long-term results have not been assessed. We reviewed the clinical history of 22 achondroplastic patients who had at least one TLS laminectomy performed before 1981. Symptoms predated the first TLS laminectomy by a mean of 2.3 years (range 0.1-17 years). Preoperatively, 91% of patients had motor function impairment, 86% had sensory dysfunction, 86% had neurogenic claudication, 77% had radicular pain, 59% had symptomatic bladder dysfunction, and 32% had fecal incontinence. Only upper motor neurons were affected in 45%, only lower motor neurons in 27%, and both in 27%. Follow-up after the first TLS laminectomy averaged 8 years. Of the 20 patients who initially improved neurologically, 12 had functional improvement for more than 5 years. However, 11 of these 12 subsequently regressed and 10 had additional laminectomies. Long-term neurologic and functional improvement was associated with both a short duration of symptoms preoperatively and absence of cervical stenosis. Because of hypertrophic scarring, 9 patients developed compression at the site of the initial TLS laminectomy and required re-operation 6.4 years (range 1-11 years) later. We conclude that TLS laminectomy is an effective treatment for spinal stenosis if performed early in the course of the neurologic syndrome. However, some patients have, or later develop, compression adjacent to the myelographic site of stenosis, and some develop hypertrophic scarring at the site of initial decompression. We therefore suggest that the first TLS laminectomy extend (1) 3 levels cephalad to the myelographic block, (2) at least to S2, and (3) laterally at least to the facets.

Achondroplasia↗
PubMed1987

Linkage of adrenoleukodystrophy to a polymorphic DNA probe.

Linkage studies between X-linked adrenoleukodystrophy and a cloned deoxyribonucleic acid fragment (St14), which detects polymorphisms in the distal end of the long arm of the X chromosome (Xq27-28), have shown no recombination in six families. The lod score for these data (and another kindred reported earlier is 13.766 at recombination fraction (theta) = 0.0. These data permit assignment of adrenoleukodystrophy carrier status in family members at risk, supplementing the chemical measurement of very-long-chain fatty acids.

Adrenoleukodystrophy↗
PubMed1985

Linear skin atrophy, scarring alopecia, anonychia, and tongue lesion: a "new" syndrome?

One of a pair of female monozygotic twins showed skin atrophy with linear alternation of depressed scarlike areas and intervening ridges of normal or nearly normal skin. She was born with friable skin and a vesicular-bullous eruption which was followed by gradual scabbing. Hypohidrosis in the affected areas, heat intolerance, and febrile convulsions were noted in infancy and childhood. No new skin lesions developed, and the existing ones, the sweating disturbance, and the heat intolerance gradually improved with time. Scarring alopecia, congenital absence of three toenails, and a scarlike lesion of the tongue were also present. Their absence in the other twin supports the view that 1) these manifestations all are part of the same syndrome, and 2) this syndrome is nongenetic. Histologically, there were no diagnostic or consistent findings, but the number of skin appendages was diminished, and the elastic fibers were reduced in number and size in one biopsy. The calculated probability for the twins being monozygotic was 0.9998. This family was also remarkable for the presence of alopecia areata in three successive generations with only one instance of apparent nonpenetrance. We conclude that this may represent a previously undescribed syndrome of congenital fragility of connective tissue which predisposed to damage of the elastica, possibly caused by an early inflammatory phase.

Alopecia Areata↗
PubMed1984

Arthrogryposis multiplex congenita occurring with maternal multiple sclerosis.

All children of a mother with multiple sclerosis (MS) had increasing grades of congenital joint contractures without demonstrable neuromuscular disease. Two had talipes equinovarus, one had congenital hip subluxation, and the youngest had arthrogryposis multiplex congenita. Maternal MS may be causally related to the development of congenital joint contractures.

Adolescent↗
PubMed1984

Autosomal dominant inheritance of hereditary canine spinal muscular atrophy.

Hereditary canine spinal muscular atrophy ( HCSMA ) is a motor neuron disease in Brittany spaniels. Three phenotypes are recognized (accelerated, intermediate, and chronic) and are distinguished on the basis of rate of progression and age at onset. Breeding studies within a kindred of more than 125 dogs (Brittany spaniel and beagle-Brittany outcrosses ) have established an autosomal dominant inheritance for HCSMA . Pups homozygous for the trait have accelerated disease whereas heterozygous dogs have intermediate or chronic disease. The reason for the two phenotypes in heterozygotes is under study. HCSMA provides a unique opportunity to study the genetic and pathophysiological mechanisms of a motor neuron disease, and findings may have broad relevance to investigations of autosomal dominant degenerative disorders of the central nervous system.

Animals↗
PubMed1980

Plaque formation and purification of BK virus in cultured human urinary cells.

Primary human urinary cells support growth and plaque formation by papovavirus BK, permitting plaque purification of the virus. After plaquing, the virus forms uniform plaques and its DNA has a homogeneous restriction enzyme fragment profile. Support of BK replication as well as morphological and cultural characteristics suggest an epithelial origin for the cells.

BK Virus↗