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Biomedical subjects

D N Foster

Publications and source records attributed to D N Foster.

At least 73 records · Page 4Linked to original sources
PubMed1991

Cloning and sequence analysis of the common alpha-subunit complementary deoxyribonucleic acid of turkey pituitary glycoprotein hormones.

Two cDNA clones of nearly full length that encode the turkey pituitary common alpha-subunit glycoprotein hormone have been isolated from a pituitary cDNA library and their nucleotide sequences have been determined. The longer alpha-subunit clone was 777 bp in length. It contained 88 bp of the 5'-untranslated region (UTR), an open reading frame of 360 bp (that encodes the turkey alpha-subunit 24 amino acid leader polypeptide fragment and 96 amino acid apoprotein), and a 312-bp 3'-UTR followed by a 17-bp poly A tract. When the nucleotide sequence of the turkey alpha-subunit was compared with the sequence of the chicken alpha-subunit clone, the coding region was greater than 98% homologous, but was only 69 to 76% homologous when compared with mammalian alpha-subunit sequences. Northern blot analysis showed an approximate 800 bp processed transcript that hybridized to the labeled turkey alpha-subunit cDNA. There was a greater than fourfold up-regulation of the steady-state levels of turkey alpha-subunit transcription when intact cultured pituitaries were treated with chicken gonadotropin-releasing hormone I.

Amino Acid Sequence↗
PubMed1991

Back pain and the exercise prescription.

Rationale for the use of exercise in the treatment and prevention of LBP and injury has been discussed. Current knowledge supports the use of individualized exercise programs that emphasize the restoration and maintenance of adequate lumbar-spinal function. When indicated, aerobic exercises to develop overall fitness and prevent deconditioning should be included in the exercise prescription. Several commonly used exercises for strengthening the lumbar extensor muscles have been reviewed. Lumbar extension exercises that stabilize the pelvis, provide a means for progressively increasing the resistance, and allow the exerciser to move through a full range of lumbar movement appear to offer the greatest benefit to the patient with LBP.

Back Pain↗
PubMed1990

Nucleotide sequence of the complementary DNA for turkey growth hormone.

Near-full length complementary DNA (cDNA) clones encoding turkey growth hormone (GH) have been isolated from a pituitary library. The longer of the two turkey GH cDNA clones that were sequenced is 803 base pairs (bp) in length and contains 41 nucleotides of the 5'-untranslated region (UTR), an open reading frame of 648 bp that encodes a 25 amino acid leader polypeptide segment as well as a 191 amino acid mature turkey GH protein, and a 3'-UTR that is 92 bp long followed by a 22 bp poly A tract. Comparison of the turkey GH nucleotide sequence to that of other avian GH clones shows the coding region to be greater than 93% homologous while the homology to mammalian GH sequences is between 68 and 78%. Northern blot analysis showed an approximate 800 bp turkey GH processed mRNA transcript that hybridized to the turkey GH cDNA probe. A large up-regulation of turkey GH transcription occurred when intact cultured pituitaries were treated with 1 nM human growth hormone releasing hormone but only modest changes were observed when cultures were treated with thyroid releasing hormone or somatostatin.

Amino Acid Sequence↗
PubMed1990

The 5'-flanking region of the mouse vascular smooth muscle alpha-actin gene contains evolutionarily conserved sequence motifs within a functional promoter.

The 5'-flanking, 5'-untranslated, and amino-terminal protein coding regions of the single-copy 13-kilobase mouse vascular smooth muscle (VSM) alpha-actin gene have been cloned and sequenced. Respectively, there is 73 and 89% homology from the start of transcription (+1) to a point 206 base pairs upstream when comparing mouse to chicken and mouse to human VSM alpha-actin 5'-flanking region sequences. Two proximal 16-base pair motifs containing putative cis-acting regulatory elements having the configuration CC(A/T)6GG were found to be 100% conserved and present in the same position upstream from the transcription start site in all three species. A third more distal CC(A/T)6GG-like motif was 100% conserved between only the mouse and human genes whereas a fourth motif was unique to the mouse gene. The two upstream motifs may be important in controlling VSM alpha-actin gene transcription in mammals. Cell transfection assays using hGH reporter gene fusion plasmids showed that all four CC(A/T)6GG elements were required for tissue-specific, core promoter activity and were able to direct hGH expression in both mouse BC3H1 myogenic cells and early-passage rabbit aortic smooth muscle cells. The core promoter was not active in mouse fibroblasts suggesting that the region between -372 and -143 may mediate tissue-restrictive expression of the VSM alpha-actin gene. A putative "cell density responsive element" may be located between -1074 and -372 since fusion plasmids containing this portion of the VSM alpha-actin 5'-flanking region were significantly more active in promoting hGH expression in inducible, density-activated BC3H1 myoblasts compared to aortic smooth muscle cells which are largely constitutive for VSM alpha-actin expression.

Actins↗
PubMed1990

Pneumoscrotum following endoscopic sphincterotomy.

Perforation is an infrequent complication of endoscopic sphincterotomy. We report here a man who developed a pneumoscrotum following a retroperitoneal perforation of the duodenum after endoscopic sphincterotomy. The mechanism of this unusual complication is discussed.

Air↗
PubMed1990

Comparison of omeprazole and cimetidine in reflux oesophagitis: symptomatic, endoscopic, and histological evaluations.

Symptomatic patients with endoscopically verified reflux oesophagitis were randomised to a double blind trial in which they received either omeprazole (20 mg once daily) or cimetidine (400 mg four times daily) for four, and if necessary, eight weeks. In an 'intention to treat' analysis, oesophagitis was found to have healed after four weeks in 77 of 137 (56%) in the omeprazole group and in 34 of 133 (26%) in the cimetidine group (p less than 0.001). By eight weeks these values were 71% and 35% respectively; p less than 0.001. Histological assessments were available for 73% of the patients. At entry, 63% (66 of 104) in the omeprazole group and 60% (56 of 94) in the cimetidine group (ns) had abnormal histology. After the study, the proportions of patients who initially had had abnormal histology but who then progressed to normal were 67% (44 of 66: omeprazole) and 48% (27 of 56: cimetidine) respectively (p less than 0.001). All patients had reflux symptoms at entry. After four weeks, 46% in the omeprazole group and 22% (p less than 0.001) in the cimetidine group were asymptomatic. Diary cards completed for the first two weeks showed that patients treated with omeprazole experienced fewer reflux symptoms by day and night and used fewer antacids. Omeprazole, 20 mg once a day for four to eight weeks, healed a greater proportion of patients with reflux oesophagitis than cimetidine, 1.6 g per day, assessed endoscopically and histologically, and relieved more patients' symptoms.

Cimetidine↗
PubMed1990

Type I protein S deficiency and skin necrosis.

A kindred with Type I protein S deficiency is described in which the index case developed skin necrosis during induction of oral anticoagulant therapy for deep venous thrombosis. Two other family members with protein S deficiency have been detected, and demonstrate the clinical variability of this condition.

Acenocoumarol↗
PubMed1990

Isolation and characterization of Salmonella from broiler carcasses or parts.

A study was conducted to determine and characterize Salmonella contamination on ready-to-cook broilers or parts in the Columbus, OH, metropolitan area. Ten to twelve samples per store were examined, using a whole-carcass rinse method. The Salmonella cultures isolated were tested for resistance to a series of nine drugs and, subsequently, were sent to the National Veterinary Services Laboratory at Ames, IA for serotype identification. Cultures identified as Salmonella were also examined for the presence of plasmids. Salmonella was isolated from one or more samples obtained from 11 of the 12 stores, and from 43% of the 142 samples examined. The serotypes isolated most often were Salmonella hadar, Salmonella heidelberg, and Salmonella johannesburg. Of the 55 cultures tested for drug resistance, 32.7% were sensitive to all nine drugs. The most-common patterns of drug resistance were triple sulfa (41.8% of the cultures) and tetracycline (34.5% of the cultures). Plasmids were found in 41.7% of the 36 cultures analyzed. The results of the present study indicate that the probability is high that carcasses from retail stores will have at least a few drug-resistant Salmonella cells.

Animals↗
PubMed1989

Identification of a highly abundant cDNA isolated from senescent WI-38 cells.

A cDNA library was constructed from poly(A)+ RNA derived from late passage WI-38 cells and differentially screened with cDNA probes from early and late passage cells. From a number of clones which exhibited differences in intensity of hybridization to the early or late passage probes, one was chosen for further analysis because of its large increase in hybridization to the late passage probe. This clone accounted for approximately 1% of the recombinants in the library. The partial cDNA clone shows complete sequence homology to elongation factor I alpha (EF-I alpha). Northern analysis of poly(A)+ RNA from cells at various population doublings suggested that a 2.2-kb transcript, homologous to EF-I alpha accumulates as cells near the end of their replicative life span (phase III). When early and late passage cells were reexposed to serum after serum starvation, this transcript decreased in abundance. Additionally, a lower molecular weight transcript (1.6 kb) was detected 18 h following serum stimulation in early passage cells and 9 h after stimulation in late passage cells.

Base Sequence↗
PubMed1989

Increase in abundance of a transcript hybridizing to elongation factor I alpha during cellular senescence and quiescence.

We have isolated a senescence-specific clone (pSEN) from a cDNA library constructed from late passage WI-38 human diploid fibroblast that accounts for approximately 1% of the recombinants. Nucleotide sequence analysis of the partial cDNA clone has led to the identification of pSEN as elongation factor I alpha. Northern analysis of poly(A)+ RNA from various intermediate population doubling levels shows that a 2.2 kb transcript hybridizes to pSEN but is expressed prior to PDL-40 at very low levels. This transcript begins to accumulate at PDL-40 and is induced approximately 50-fold just prior to senescence. Furthermore, this transcript was shown to be specific to Go of the cell cycle whereas a second, lower molecular weight transcript (1.6 kb) was observed during S phase (Giordano and Foster, unpublished data). The 2.2 kb transcript is also detected in neonatal foreskin cells but very little increase in abundance is observed between early and late passage cells. Sucrose gradient fractionation of RNA from late passage WI-38 cells suggests that the lower molecular weight transcript is associated with the polysome fraction while the 2.2 kb transcript sediments with the nonpolysomal fraction. Thus, the possibility exists that the 1.6 kb transcript is derived from the 2.2 kb transcript.

Aging↗
PubMed1989

Influence of selection for increased body weight on the incidence of leiomyomas and leiomyosarcomas in Japanese quail.

Leiomyomas and leiomyosarcomas were observed in adult laying hens from lines of Japanese quail selected solely (HW) or partly (HW-HP; HW-LP) for increased 4-wk BW and the corresponding randombred control (R1). No neoplasms were observed in a line (LW) selected for decreased 4-wk BW based on observations in one generation. Line R1 served as the base population for Lines HW and LW and was maintained without conscious selection for any trait, Lines HW-HP and HW-LP were sublines of Line HW in which the males were selected for increased 4-wk BW and the females were selected for high or low levels of plasma total phosphorus, respectively. Hens of all lines were necropsied after completing a 120-day production period. A high incidence of neoplasms were found in the dorsal and ventral ligaments of the oviduct in the immediate vicinity of the magnum, and the incidence was much greater in the lines selected for increased growth than in Line R1. These results suggest that selection for increased BW in Lines HW, HW-HP, and HW-LP has resulted in genetic changes that are conducive to neoplastic growth. Based on the results of one generation, it appears that selection for decreased 4-wk BW reduced incidence of neoplasms.

Animals↗
PubMed1988

Induction of fibronectin gene transcription and mRNA is a primary response to growth-factor stimulation of AKR-2B cells.

A cDNA library, prepared from poly(A)+ RNA isolated from quiescent AKR-2B cells 4 hr after stimulation with epidermal growth factor in the presence of cycloheximide, was screened to identify RNA transcripts whose abundance is specifically increased as a primary response to growth stimulation. Approximately 40% of the inducible clones detected by this procedure corresponded to either cytoskeletal beta- or gamma-actin genes. One nonactin clone, designated c99, was found to be derived from an 8.5-kilobase RNA whose abundance began to increase as early as 30 min after stimulation. DNA sequencing established the identity of this RNA as fibronectin. Several additional mitogens were then tested and found to efficiently induce fibronectin mRNA. These included fetal calf serum, platelet-derived growth factor, and transforming growth factor type beta. For at least one inducer, fetal calf serum, the increase in mRNA was preceded by an increase in fibronectin gene transcription. This increase was rapid, reaching maximal levels within 10 min, and was accompanied by near-coordinate increases in both c-fos and beta-actin transcription. These results indicate that fibronectin is a member of a class of "early-response" genes, typified by c-fos and including beta-actin, whose rapid expression may be important in mediating cellular responses to peptide growth factors.

Actins↗
PubMed1988

Effects of kanamycin administration to poultry on the interspecies transmission of drug-resistant Salmonella.

Three experiments were conducted to assess the relationship between antibiotic administration to poultry and the transmission of drug-resistant Salmonella through a simulated food chain. Poults were inoculated per os with either multiply drug-resistant Escherichia coli and drug-sensitive S. typhimurium or with multiply drug-resistant S. typhimurium. One-half of the poults inoculated with drug-sensitive S. typhimurium and all poults given drug-resistant S. typhimurium received kanamycin in their drinking water. Liver tissue from these poults was incorporated into diets fed to rats, half of which were treated with kanamycin. Antibiotic administration to the poults was associated with a significantly (P less than .05) higher frequency of transmission of drug-resistant S. typhimurium to the rats through the simulated food chain. S. typhimurium was isolated only from rats treated with kanamycin. The highest frequency of isolation of drug-resistant S. typhimurium from rats (40%) was observed in kanamycin-treated rats fed a diet containing liver from kanamycin-treated poults. Results of this experiment indicate that antibiotic administration can increase the frequency of transmission of drug-resistant Salmonella through the food chain.

Ampicillin Resistance↗
PubMed1983

Structure and expression of mouse VL30 genes.

DNA sequencing and blot hybridization analyses have been used to study the structure of a mouse VL30 gene and the molecular nature of VL30-related RNA which is induced upon the stimulation of cultured AKR mouse embryo cells with defined peptide growth factors. An integrated mouse VL30 gene was found to contain identical 601-base-pair long terminal repeats (LTRs) which were themselves terminated in short inverted repeats. The entire VL30 gene was flanked by a 4-base-pair direct repeat of cellular DNA. Thus, VL30 genes are structurally analogous to integrated forms of retrovirus proviruses and certain other classes of mobile genetic elements. The LTR sequence was found to contain putative promoter and polyadenylation signals and generally exhibited little sequence homology to murine leukemia virus proviral LTRs. Certain short regions of sequence conservation, however, were evident, including the inverted terminal repeat, LTR-adjacent regions corresponding to origins of murine leukemia virus proviral DNA synthesis, and a 36-base-pair direct repeat bearing homology to the 72-base-pair direct repeat (enhancer sequence) of the murine leukemia virus-related Moloney sarcoma virus. Upon mitogenic stimulation of quiescent cells with epidermal growth factor and insulin, a major 5.5-kilobase VL30-specific RNA complementary to both LTR and non-LTR sequences was rapidly induced. We conclude that a complete VL30 gene(s) is highly regulated by peptide growth factor binding to specific membrane receptors in these cells.

Animals↗
PubMed1982

Polyadenylylated RNA complementary to a mouse retrovirus-like multigene family is rapidly and specifically induced by epidermal growth factor stimulation of quiescent cells.

Complementary DNA probes prepared from total polysomal poly(A)+RNA populations were used to identify clones of mouse DNA containing sequences whose expression is specifically enhanced after epidermal growth factor (EGF) stimulation of quiescent mouse embryo cells in culture. Three such clones were isolated and used to study changes in the levels of clone-specific poly(A)+RNA in the polysomes of cells after mitogenic stimulation by EGF. RNA complementary to sequences present in these clones increased approximately equal to 10-fold as a fraction of the total poly(A)+RNA by 6 hr after stimulation. All three clones were found by hybridization criteria to contain sequences related to the class of mouse retrovirus or transposon-like elements termed VL30. These VL30-related sequences were further found to be complementary to EGF-inducible poly(A)+RNAs and enhanced expression was detectable as early as 1 hr after EGF stimulation. In contrast, nine additional clones, including an AKR-type murine leukemia provirus DNA clone, contained no detectable VL30 sequence elements and were complementary to poly(A)+RNA species whose relative concentration was essentially constant in quiescent and EGF-stimulated cells. Therefore, VL30 sequence elements appear distinct in that they encompass members whose expression is specifically regulated in response to a defined peptide growth factor.

Animals↗