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Biomedical subjects

S A Wolfe

Publications and source records attributed to S A Wolfe.

At least 19 recordsLinked to original sources
PubMed1992

Tissue-specific binding of testis nuclear proteins to a sequence element within the promoter of the testis-specific histone H1t gene.

The rat histone H1t gene is transcribed only in testis germinal cells. This testis-specific chromosomal protein is first synthesized during spermatogenesis in pachytene spermatocytes and the entire complement of testis histones is replaced during the midspermatid stage of spermiogenesis by positively charged transition nuclear proteins TP1 and TP2. Mobility shift assays conducted using crude nuclear protein extracts from different tissues and an 18-bp DNA sequence element within the H1t promoter as a probe reveal binding only with nuclear proteins from testis. The binding is specifically competed with an excess of the same unlabeled DNA fragment but not with heterologous competitors. A larger oligonucleotide corresponding to the same sequence element plus 18 bp of the adjacent downstream H1/CCAAT element binds nuclear proteins from all tissues tested, but a unique low mobility band is formed only with testis extracts. Protein-DNA crosslinking experiments reveal that two major polypeptides with molecular weights of approximately 13 and 30 kDa bind to the 18-bp H1t promoter sequence element. This strong correlation between the tissue where the H1t gene is transcribed and the presence of testis-specific nuclear proteins that bind to a sequence element within the testis histone H1t promoter supports the possibility that these DNA-binding proteins may participate in formation of an active transcription initiation complex with the testis H1t promoter.

Animals↗
PubMed1992

Temporal correlation between the appearance of testis-specific DNA-binding proteins and the onset of transcription of the testis-specific histone H1t gene.

The histone H1t gene is transcribed only in testis. Northern blot analyses reveal that transcription of the H1t gene occurs first in pachytene primary spermatocytes. Thus, there is a temporal correlation between onset of transcription of the gene and synthesis of histone H1t in primary spermatocytes during spermatogenesis. Previous studies revealed that replacement of most H1t and core histones occurs during the midspermatid stage of spermiogenesis by transition proteins TP1 and TP2. In this paper we extend our study of the specific binding of testis nuclear proteins to a unique sequence element within the H1t promoter. The relatively tight binding is competed with an excess of homologous DNA but not with a mutated element. Testis proteins from prepubertal animals do not bind to the 18-bp promoter element out proteins from enriched populations of primary spermatocytes do bind. Therefore, the temporal correlation between onset of transcription of the H1t gene and the time when the specific H1t promoter-binding proteins are detected in primary spermatocytes suggests that the DNA-binding proteins might be germinal cell-specific transcription factors that participate in formation of an active H1t transcription initiation complex. These studies present the first analysis of binding sites for testis nuclear proteins from primary spermatocytes within the promoter of a gene expressed only during this stage of spermatogenesis.

Animals↗
PubMed1991

Protein-DNA interactions within the rat histone H4t promoter.

The histone H4t gene is actively transcribed in rat testis germinal cells and in several non-testis cell types including cells from liver. This histone H4 gene is expressed most actively in testis premeiotic pachytene spermatocytes, and its expression is down-regulated in postmeiotic early spermatids. The histone H4 gene promoter is functional as demonstrated by finding significant levels of chloramphenicol acetyltransferase (CAT) mRNA in mammalian cells transiently transfected with a histone H4-promoted CAT expression vector compared to cells transfected with an expression vector lacking of the promoter. Examination of the proximal promoter of the histone H4 gene by electrophoretic mobility shift assays indicates that specific protein-DNA interactions occur when pachytene spermatocyte nuclear proteins are mixed with promoter fragments containing regions designated site I and site II, consensus sequence elements essential for regulating transcription of the histone H4 gene. These specific protein-DNA interactions are eliminated by competition with identical DNA fragments, but are not eliminated by competition with nonhomologous DNA fragments. Significant differences are found in mobility shift patterns upon comparison of nuclear proteins from germinal cell populations enriched in pachytene spermatocytes where the gene is actively expressed and early spermatids where the gene is not expressed.

Amino Acid Sequence↗
PubMed1991

Treatment of the particularly fatty neck and the short-interval secondary facelift.

In patients with normal body weight but with large accumulations of submental and cervical fat, good results can be obtained by an extensive subcutaneous dissection, carefully sculpted removal of the excess fat, and relatively limited work on the platysema. For some patients there may be an indication for a secondary facelift involving skin dissection alone within a relatively short interval.

Adipose Tissue↗
PubMed1991

Conservative treatment of genu valgus and varum with medial/lateral heel wedges.

Symptomatic bowlegs and knock-knees are common in the aging person and aging athlete secondary to knee trauma. Diagnosis is made by observation and in mild degrees by a standing alignment x-ray that shows narrowing of the joint surface on the appropriate side. The patients complained of pain on the convexity side of the deformity. Treatment consisted of a simple exercise program, non-steroidal anti-inflammatory drugs and appropriate 1/8-inch wedges on the lateral side of the heel for bowlegs or on the medial side of the heel for knock-knees. The effect of a simple heel wedge formed the basis for conservative treatment of symptomatic knee deformities.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Malar augmentation using autogenous materials.

A variety of methods are available for malar augmentation using autogenous material, and the choice of procedure will depend on the indications presented by each particular case. The ability to produce a smooth natural contour without the need for concern of late problems is a decided advantage to the use of autogenous tissue. We have presented a compendium of available methods, demonstrated clinical examples and described a new technique, which, because of its simplicity, will certainly find further applications. A new method developed by Paul Tessier for malar augmentation is also described.

Humans↗
PubMed1978

The utility of pericranial flaps.

Three cases are presented illustrating various uses of pericranial flaps. In a patient with Apert's syndrome, a large pericranial flap was folded over bone pâté harvested from the upper frontal bone to improve forehead contour. Silicone and acrylic implants had been inserted in 2 other patients, 1 of whom had previously undergone radiation therapy for the correction of cranial defects. Both were lost due to infection. Autogenous bone grafts covered by pericranial flaps healed without difficulty, emphasizing the superiority of autogenous bone grafts over foreign substances in craniofacial reconstruction. Further uses of pericranial flaps are discussed.

Adult↗
PubMed1978

Orbital expansion.

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Exophthalmos↗