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J R Carter

Publications and source records attributed to J R Carter.

At least 55 records · Page 3Linked to original sources
PubMed1993

Identification, isolation, and characterization of the structural gene encoding the delta' subunit of Escherichia coli DNA polymerase III holoenzyme.

The gene encoding the delta' subunit of DNA polymerase III holoenzyme, designated holB, was cloned by a strategy in which peptide sequence was used to derive a DNA hybridization probe. The gene maps to 24.95 centisomes of the chromosome. Sequencing of holB revealed a 1,002-bp open reading frame predicted to produce a 36,936-Da protein. The gene has a ribosome-binding site and promoter that are highly similar to the consensus sequences and is flanked by two potential open reading frames. Protein sequence analysis of delta' revealed a high degree of similarity to the dnaX gene products of Escherichia coli and Bacillus subtilis, including one stretch of 10 identical amino acid residues. A lesser degree of similarity to the gene 44 protein of bacteriophage T4 and the 40-kDa protein of the A1 complex (replication factor C) of HeLa cells was seen. The gene, when placed into a tac promoter-based expression plasmid, directed expression of two proteins of similar size. By immunodetection with anti-holoenzyme immunoglobulin G, both proteins are judged to be products of holB.

Amino Acid Sequence↗
PubMed1993

Identification, isolation, and overexpression of the gene encoding the psi subunit of DNA polymerase III holoenzyme.

The gene encoding the psi subunit of DNA polymerase III holoenzyme, holD, was identified and isolated by an approach in which peptide sequence data were used to obtain a DNA hybridization probe. The gene, which maps to 99.3 centisomes, was sequenced and found to be identical to a previously uncharacterized open reading frame that overlaps the 5' end of rimI by 29 bases, contains 411 bp, and is predicted to encode a protein of 15,174 Da. When expressed in a plasmid that also expressed holC, holD directed expression of the psi subunit to about 3% of total soluble protein.

Amino Acid Sequence↗
PubMed1992

Diffuse and localized tenosynovial giant cell tumor and pigmented villonodular synovitis: a clinicopathologic and flow cytometric DNA analysis.

The DNA content and proliferative indexes of seven cases of tenosynovial giant cell tumor of tendon sheath, diffuse type (TGCT-D); 11 cases of tenosynovial giant cell tumor of tendon sheath, localized type (TGCT-L); and seven cases of pigmented villonodular synovitis (PVNS) were analyzed by flow cytometry in an attempt to assess objectively their biologic differences. Three cases of TGCT-D manifested an aneuploid DNA content and four had a diploid DNA pattern. All cases of TGCT-L and PVNS showed a diploid DNA content. The proliferative indexes for TGCT-D were significantly higher than those found in the other two groups. There was no histopathologic feature that correlated with the aneuploid DNA pattern found in two of the three cases of TGCT-D. Only one of the three aneuploid DNA content TGCT-D cases displayed marked cellular pleomorphism with dense fibrous stroma; in that case there was recurrence 4 years after initial excision. Our data further support that TGCT-D, TGCT-L, and PVNS are histopathologically similar but clinically distinct lesions. The high proliferative indexes of TGCT-D may reflect a rapid, uncontrolled growth that may explain its aggressive biologic behavior. The presence of an aneuploid DNA pattern in some cases of TGCT-D in this study, coupled with the reported chromosomal abnormalities and occurrence of malignant transformation in these lesions, clearly supports their neoplastic nature.

Adult↗
PubMed1992

The role of oriT in tra-dependent enhanced recombination between mini-F-lac-oriT and lambda plac5.

Recombination between F42lac and lambda plac5 is typically 20- to 50-fold more efficient than recombination between chromosomal lac and lambda plac5. This enhancement of recombination is recBCD-dependent and requires the expression of genes from the tra regulon of the F factor. Also required is oriT, the origin of F factor conjugational transfer, which must be located in-cis to the cellular copy of lac. In this study we show that enhanced recombination is not supported by an oriT point mutant that reduces oriT function in conjugation. We also present evidence that the activation of oriT for recombination enhancement involves the same strand-specific nick that is required for conjugal DNA transfer. Although it is thought that the role of oriT in recombination enhancement is related to the facilitated entry of RecBCD enzyme into the DNA duplex, we were unable to detect any double-strand breakage at oriT.

Base Sequence↗
PubMed1992

Molecular cloning, sequencing, and overexpression of the structural gene encoding the delta subunit of Escherichia coli DNA polymerase III holoenzyme.

Using an oligonucleotide hybridization probe, we have mapped the structural gene for the delta subunit of Escherichia coli DNA polymerase III holoenzyme to 14.6 centisomes of the chromosome. This gene, designated holA, was cloned and sequenced. The sequence of holA matches precisely four amino acid sequences obtained for the amino terminus of delta and three internal tryptic peptides. A holA-overproducing plasmid that directs the expression of delta up to 4% of the soluble protein was constructed. Sequence analysis of holA revealed a 1,029-bp open reading frame that encodes a protein with a predicted molecular mass of 38,703 Da. holA may reside downstream of rlpB in an operon, perhaps representing yet another link between structural genes for the DNA polymerase III holoenzyme and proteins involved in membrane biogenesis. These and other features are discussed in terms of genetic regulation of delta-subunit synthesis.

Amino Acid Sequence↗
PubMed1991

traY and traI are required for oriT-dependent enhanced recombination between lac-containing plasmids and lambda plac5.

Recombination between F42lac and lambda plac5 is typically 20- to 50-fold more efficient than recombination between chromosomal lac and lambda plac5. This enhancement of recombination requires trans-acting factors located in the promoter-distal and promoter-proximal regions of the main traY-to-traI (traZ) operon. By testing the ability of deletion mutants of tra to support enhanced recombination, we have identified traY as the only product has been ruled out. We also report that traI is the only gene from the promoter-distal end of the traY to traI operon that is required for recombination enhancement. Of the two proposed domains of traI, we conclude that the oriT-nicking activity is essential, whereas the helicase activity is largely dispensable. The possibility of a third traI activity is also discussed.

Bacterial Proteins↗
PubMed1990

Early-onset primary osteoarthritis and mild chondrodysplasia. Radiographic and pathologic studies with an analysis of cartilage proteoglycans.

Three generations of a nonconsanguineous family with premature onset of primary (idiopathic) osteoarthritis (OA) were studied for clues to the etiopathogenesis of their disorder. Articular symptoms began in their second and third decades of life and involved multiple joints, both typical and atypical for primary OA. Radiographs of the majority of involved peripheral joints showed abnormalities typical of primary OA. Evidence of chondrodysplasia was found in the spines. Pathologic examination of femoral heads obtained at total hip arthroplasty from 3 affected family members showed moderate to severe OA. Articular cartilage proteoglycans from these specimens were evaluated for aggregatability with hyaluronic acid, levels of chondroitin sulfate and keratan sulfate, and core protein structure. The results from each patient's specimen differed from the results of the other specimens. We conclude that this family's disorder, primary OA associated with a mild chondrodysplasia, was a late-onset overlap form of an epiphyseal dysplasia, that a defect common to hyaline articular and physeal cartilage was primary, and that a single structural proteoglycan abnormality was not likely to be the underlying cause.

Cartilage↗
PubMed1990

Unusual presentations of genital tract tuberculosis.

Three cases of genital tract tuberculosis (GTB) are described. This disease is uncommon in developed countries. Patients may present with infertility, non-specific menstrual disturbance, pain or abdominal distention. The genital tract is usually infected by hematogenous spread from a distant focus, with the fallopian tubes most commonly involved. Diagnosis is often made retrospectively, and once confirmed medical management is the mainstay of treatment. Future fertility is doubtful in these patients.

Adult↗
PubMed1990

Bone metastasis from gynecologic carcinomas: a clinicopathologic study.

Between 1948 and 1984, autopsies were performed on 305 patients with primary carcinomas of the cervix, endometrium, ovaries, fallopian tubes, vulva, and vagina. Skeletal metastases were detected premortem and at autopsy in 49 cases (16.1%): cervix, 20 (40.8%); endometrium, 17 (34.7%); ovary, 7 (14.3%); vulva, 4 (8.2%); fallopian tube, 1 (2%). There were no cases of osseous metastasis from vaginal carcinoma. The incidence and sites of metastasis from these gynecologic carcinomas were correlated with their clinical and histopathologic classifications. This clinicopathologic study, based on autopsy data, demonstrates that osseous metastases are not uncommon, are significantly greater than clinically appreciated, and correlate with advanced anatomic stage and histopathologic type and grade.

Autopsy↗
PubMed1990

Primary neoplasms of the thoracic and lumbar spine. An analysis of 29 consecutive cases.

Primary osseous neoplasms of the thoracic and lumbar spine are uncommon lesions. Between 1965 and 1982, of 1971 patients with musculoskeletal neoplasms, only 29 (1.5%) had primary osseous tumors in these locations. There were eight children and 21 adults. Back pain was the most common complaint in 25 patients (86%), and neurologic symptoms or deficits were present in 16 patients (55%). All lesions were visible on routine spine roentgenograms, while computed tomography and myelography demonstrated spinal canal encroachment and extradural spinal cord compression in 19 patients (66%). The histologic diagnoses included 11 benign and 18 malignant lesions. Benign lesions occurred predominantly in children and malignant tumors in adults. Treatment was individualized, based on the histologic diagnoses. Twenty-two patients had surgical resection of their lesions. Laminectomy without stabilization and arthrodesis resulted in late instability and neurologic deterioration in three of seven patients (43%) with malignant lesions. Resection and decompression combined with arthrodesis did not predispose to late instability. Twenty-one patients were followed for a mean of 4.1 years (range, two to 14 years). Eight patients died from malignant disease between one month and seven years after diagnosis.

Adolescent↗
PubMed1990

Late-onset tibia vara (Blount's disease). Current concepts.

Idiopathic tibia vara or Blount's disease can be classified into three age-onset groups: (1) infantile, less than three years; (2) juvenile, four to ten years; and (3) adolescent, 11 years or older. The latter two groups comprise late-onset tibia vara, which is much less common than the infantile-onset form. In a comparison of eight juvenile-onset patients (13 knees) and seven adolescent-onset patients (nine knees), there were essentially no significant clinical, roentgenographic, or physeal-histopathologic differences. Both groups had severe obesity, mild to moderate varus deformities, and less-pronounced roentgenographic characteristics. Histopathologic analyses of the entire physis from the proximal tibia in five cases (seven knees) were essentially identical in patients with the infantile form as well as in those with slipped-capital femoral epiphyses, suggesting a common etiology. Recurrence of deformity after surgical correction occurred frequently in the juvenile onset males but not in juvenile onset females or the adolescent onset group. Incomplete correction of the varus deformity occurred more frequently in the latter group. The etiology for tibia vara appears to involve varus stress growth suppression, and disruption of endochondral ossification. The major differences between the three groups is due to the age at clinical onset, the amount of remaining growth, and the magnitude of the medial compression forces across the medial aspect of the knee.

Adolescent↗
PubMed1989

The use of radioisotope scans in the evaluation of primary lymphoma of bone.

Primary lymphoma of bone is a rare lesion comprising less than 5% of all malignant primary bone tumors. Because of this rarity, the diagnosis of this lesion based on clinical findings and standard radiographic evaluations is extremely difficult and may not be entertained until after a biopsy has been performed. We retrospectively reviewed the cases of 22 consecutive patients with a diagnosis of primary lymphoma of bone (appendicular and axial skeleton) who along with standard radiographic evaluations had a technetium 99 bone scan performed as part of the preoperative staging process. A characteristic pattern demonstrating an increased uptake of intense tracer concentration peripherally and a relatively cold central area was seen consistently in all cases. This uptake pattern is then reversed with use of a gallium 67 scan. Because of the ambiguity of plain radiographs in the evaluation of adult bone lesions, radioisotope bone scans should be used as a diagnostic aid in an attempt to obtain as much information as possible about the biologic behavior of the bony lesion prior to any surgical intervention.

Adolescent↗
PubMed1988

Osteogenic sarcoma. Malignant fibrous histiocytoma subtype.

A distinctly different entity from the now well-delineated malignant fibrous histiocytoma (MFH) of bone is the MFH histopathologic subtype of osteogenic sarcoma. Although uncommon, recently the authors have encountered six cases of this neoplasm, in each of which the soft tissue component was devoid of bone elements and was microscopically indistinguishable from MFH of bone or soft tissue. Neoplastic osteoid and woven bone were present in the osseous component of each tumor, however. Radiologically, the lesions generally were osteoblastic but focally osteolytic with features typical of osteogenic sarcoma. Pain was the most common presenting symptom. There was no age or sex predilection. Immunocytochemical staining showed strong positivity with alpha-1-antichymotrypsin within malignant bizarre giant cells and occasional neoplastic osteoblasts in five cases. The biological behavior followed a very aggressive course. Four of the six patients developed pulmonary metastases 6 to 12 months after initial surgery; one patient presented initially with pulmonary metastases. Adequate tumor sampling as well as optimal correlation with clinical and radiographic information are required to distinguish the MFH subtype of osteogenic sarcoma from MFH of bone, both being high-grade neoplasms, however.

Adolescent↗