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K L Pierce

Publications and source records attributed to K L Pierce.

34 records · Page 2Linked to original sources
PubMed1998

Prostaglandin F2 alpha receptors in the human trabecular meshwork.

PURPOSE: Prostaglandin F2 alpha (PGF2 alpha) and analogs, such as latanoprost, are thought to lower intraocular pressure (IOP), primarily by increasing uveoscleral outflow. However, outflow through the trabecular meshwork may be increased as well. The authors hypothesize that any effect on the trabecular meshwork is mediated by prostanoid FP receptors (receptors for prostaglandin F2 alpha) in this tissue. METHODS: To test this hypothesis, tissue sections of the human trabecular meshwork and cultures of human trabecular meshwork cells were examined for the presence of FP receptors using immunofluorescence microscopy with affinity-purified antibodies raised against a glutathione-S-transferase (GST)-FPA receptor fusion protein. The presence of the receptor was confirmed by using reverse transcription-polymerase chain reaction (RT-PCR), functional assays of PGF2 alpha-stimulated inositol phosphate hydrolysis, and intracellular calcium measurements. RESULTS: Positive FPA receptor immunolabeling was observed in sections of the human trabecular meshwork and in cultured human trabecular meshwork cells. In both cases, specific labeling could be blocked by preincubation with a GST-FPA receptor fusion protein. Cross-blocking experiments with other receptor fusion proteins did not block specific labeling in cultured trabecular meshwork cells. PGF2 alpha caused a dose-dependent increase in total inositol phosphate accumulation and intracellular calcium release in human trabecular meshwork cells that was consistent with the presence of FP receptors. Using RT-PCR, message-encoding prostanoid FPA receptors were found in total RNA isolated from human trabecular meshwork cells. CONCLUSIONS: Prostanoid FPA receptors exist in human trabecular meshwork cells, as shown by the presence of mRNA, protein, and functional response to PGF2 alpha. This study indicates that functional FP receptors are present in the human trabecular meshwork and that they may be involved in mediating some of the IOP-lowering effects of PGF2 alpha in the eye.

Animals↗
PubMed1997

Cloning of a carboxyl-terminal isoform of the prostanoid FP receptor.

An FP prostanoid receptor isoform, which appears to arise from alternative mRNA splicing, has been cloned from a mid-cycle ovine large cell corpus luteum library. The isoform, named the FP(B) receptor, is identical to the original isoform, the FP(A), throughout the seven transmembrane domains, but diverges nine amino acids into the carboxyl terminus. In contrast to FP(A), whose carboxyl terminus continues for another 46 amino acids beyond the nine shared residues, the FP(B) terminates after only one amino acid. The FP(A) isoform appears to arise by the failure to utilize a potential splice site, while a 3.2-kilobase pair intron is spliced out from the FP gene to generate the FP(B) isoform mRNA. The two isoforms have indistinguishable radioligand binding properties, but seem to differ in functional coupling to phosphatidylinositol hydrolysis. Thus, in COS-7 cells transiently transfected with either the FP(A) or the FP(B) receptor cDNAs, prostaglandin F(2alpha) stimulates inositol phosphate accumulation to the same absolute maximum, but the basal level of inositol phosphate accumulation is approximately 1.3-fold higher in cells transfected with the FP(B) as compared with cells transfected with the FP(A) isoform. Using the polymerase chain reaction, mRNA encoding the FP(B) isoform was identified in the ovine corpus luteum.

Alternative Splicing↗
PubMed1996

Helical computed tomography at 1.5:1 pitch reconstructed at 15-mm and 7-mm intervals for examination of patients with suspected metastatic disease.

OBJECTIVE: To document the need for overlapped reconstruction when using helical computed tomography (CT) software that reconstructs 10-mm-collimation, 1.5:1-pitch images at 15-mm intervals in follow-up examination of patients with suspected metastatic disease. PATIENTS AND METHODS: Forty consecutive patients with known or suspected metastatic disease were examined with helical CT at 10-mm collimation and 1.5:1 pitch. The studies were examinations of the chest, abdomen and pelvis; the chest and abdomen; or the abdomen and pelvis. Two image sets, one prospectively reconstructed at 15-mm intervals and the other retrospectively reconstructed at 7-mm intervals, were independently reviewed by three radiologists, and the number, size and location of lesions were documented. Differences in interpretation were resolved by consensus. The lesions detected on the two sets of images were classified according to lesion size and location, and the results were analysed by multivariate analysis of variance with repeated measures. RESULTS: Images reconstructed at 7-mm intervals revealed a total of 436 lesions, 127 (41%) more than were revealed by images reconstructed at 15-mm intervals. The number of lesions less than 1 cm in diameter that were visible in the two sets of images was significantly different (p = 0.018). However, there was no significant difference between the two sets of images in terms of lesion location. CONCLUSION: Metastatic lesions may be missed by helical CT at 1.5:1 pitch if overlapped reconstruction is not performed.

Abdominal Neoplasms↗
PubMed1995

Cloning of a receptor for prostaglandin F2 alpha from the ovine corpus luteum.

A complementary DNA clone encoding a functional receptor for prostaglandin F2 alpha (PGF2 alpha) has been isolated from an ovine large luteal cell complementary DNA library (prepared from day 10 mid-luteal phase RNA). This receptor, which has been designated FP, consists of 362 amino acids (M(r) = 40,982) and is a member of the family of G protein-coupled receptors. Radioligand binding studies with membranes prepared from transfected COS cells demonstrated specific 17-[3H]phenyl-trinor-PGF2 alpha binding that was displaced by prostanoids in the order of 17-phenyl-trinor-PGF2 alpha > PGF2 alpha > fluprostenol > PGD2 > PGE2 >> 8-epi PGF2 alpha. Xenopus laevis oocytes injected with RNA encoding the ovine FP receptor responded to 17-phenyl-trinor-PGF2 alpha with increased membrane chloride conductance in calcium-free medium. Northern blot analysis with RNA from day 10 corpus luteum showed a major band of approximately 6.1 kilobases. On day 14, when luteolysis usually starts, the abundance of this 6.1-kilobase band was variable between individual ewes, and on day 16, when luteolysis is underway, the message was uniformly less abundant. This variability appeared to correlate with circulating progesterone. Thus, when the progesterone level was high (days 10 and 14 depending on whether luteolysis had started), the amount of FP receptor message was high, whereas when the progesterone level was low or falling (day 16), the amount of FP receptor message decreased. We have cloned an ovine FP receptor whose expression confers appropriate functional activity in COS cells and Xenopus oocytes. Furthermore, the level of messenger RNA encoding the FP receptor is high in the midluteal phase ovine corpus luteum and decreases during luteolysis.

Amino Acid Sequence↗
PubMed1994

Molecular cloning and expression of human EP3 receptors: evidence of three variants with differing carboxyl termini.

1. The polymerase chain reaction (PCR) was used in combination with plaque hybridization analysis to clone four variants of the EP3 prostaglandin receptor from a human small intestine cDNA library. 2. Three of these variants, i.e. the EP3A, EP3E and EP3D, share the same primary amino acid sequence except for their carboxyl termini, which diverge from one another at the same point, approximately 10 amino acids away from the end of the seventh membrane spanning domain of the receptor. The fourth variant (EP3A1) has a nucleotide coding sequence identical to EP3A but has a completely different 3' untranslated sequence. 3. The carboxyl termini of the three isoforms differ most obviously in length with the EP3A being the longest (41 amino acids) and the EP3E being the shortest (16 amino acids). They also differ in content with the EP3A containing 9 serine and threonines in its carboxyl terminus and the EP3E none. 4. Transient expression in eukaryotic cells showed that the human EP3 receptor variants had similar but not identical radioligand binding properties and differed in their functional coupling to second messenger pathways. Up to 3 pmol mg-1 protein of [3H]-prostaglandin E2 binding could be obtained with more than 95% specific binding. Using a reporter gene assay, as a measure of intracellular cyclic AMP levels, the EP3A coupled more efficiently to the inhibition of adenylyl cyclase than did the EP3E. 5. PCR was used to confirm the presence of mRNAs encoding the four human EP3 receptor variants in tissues of the human small intestine, heart and pancreas. These findings indicate that the EP3 receptor variants identified here are likely to be expressed in tissues. The differences in the carboxyl termini at the protein level, and in the 3' untranslated regions at the mRNA level, could be profound in terms of the regulation and functional coupling of these receptor isoforms.

Adenylyl Cyclases↗
PubMed1994

Teaching daily living skills to children with autism in unsupervised settings through pictorial self-management.

We investigated the efficacy of pictorial self-management to teach daily living skills to 3 low-functioning children with autism. Stimulus and response generalization, stimulus control of self-management materials, and maintenance of behavior change were also assessed. Results showed that children with autism could successfully use pictures to manage their behavior in the absence of a treatment provider, generalize their behavior across settings and tasks, and maintain behaviors at follow-up. In addition, when compared to baseline, all children showed a substantial decrease in stereotypic behaviors. When picture order was manipulated in stimulus control probes, the children followed the new picture sequence, suggesting that the pictures were controlling their behavior. Further, a savings effect was demonstrated, in that 2 subjects reached criterion on second and third behaviors within less than 25% of original training time.

Activities of Daily Living↗
PubMed1994

CT of the chest and abdomen in patients on mechanical pulmonary ventilators: quality of images made at 0.6 vs 1.0 sec.

OBJECTIVE: Chest and abdominal CT scans using 1.0-sec scan times are often limited by motion in patients who are unable to hold their breath. With our scanner we can obtain images in 0.6 sec (partial scan) that use data from 225 degrees instead of the 360 degrees used for 1.0-sec scans. The purpose of this study was to assess whether the quality of images of the chest and abdomen in patients on mechanical pulmonary ventilators who could not breath-hold could be improved if images were taken using a scan time of 0.6 sec rather than 1.0 sec. MATERIALS AND METHODS: Thirty patients who were being treated with mechanical pulmonary ventilation with indications for chest or abdominal CT or both were scanned with a scan time of 1.0 sec. At the end of the examination, additional 0.6-sec images were taken at three or four levels. Images obtained with these two scan times were filmed at similar levels and windows, and anatomically matched levels were compared. The images were masked and independently evaluated by three radiologists for motion, noise, artifact, and overall image quality. Each parameter was rated using a scale of 1 to 4. Using Kendall's tau correlation, there was no significant difference between the radiologists in the grading of individual parameters or of overall image quality. Therefore, the average of the scores of the three radiologists was used. Statistical analysis was done using repeated measures multivariate analysis of variance. RESULTS: Images obtained in 0.6 sec had significantly less motion (p < .001) but more noise (p < .001) than those obtained in 1.0 sec. We found no statistically significant difference in artifacts between the two scan times. Overall image quality was judged to be significantly better on scans obtained in 0.6 sec than on scans obtained at 1.0 sec (p < .001), in spite of the greater noise on 0.6-sec images. The higher quality of 0.6-sec images was most noticeable for lung window settings. CONCLUSION: Our results indicate that scans taken in 0.6 sec (partial scans) provide better quality images than those obtained in 1.0 sec in patients being treated with mechanical pulmonary ventilation who cannot breath-hold. This technique may be useful not only in this population but in all patients who are unable to cooperate with breath-holding instructions.

Contrast Media↗
PubMed1994

Cloning of a novel human prostaglandin receptor with characteristics of the pharmacologically defined EP2 subtype.

A cDNA that when expressed has the binding and functional characteristics of the pharmacologically defined EP2 prostaglandin (PG) receptor [Cardiovasc. Drug Rev. 11:165-179 (1993)] has been cloned from a human placenta library. This clone, known as Hup-4, encodes a protein of 358 amino acids that has only approximately 30% overall identity with other PG receptors, including mouse and human clones that have been designated as EP2 receptors [J. Biol. Chem. 268:7759-7762 (1993); Biochem. Biophys. Res. Commun. 197:263-270 (1993)]. In COS-7 cells transfected with Hup-4, PGE2 stimulated the formation of cAMP with an EC50 of approximately 50 nM. The EP2-selective agonists AH13205 and butaprost were also active, with EC50 values in the range of 2-6 microM. The order of potency of PGs for competition with binding of [3H]PGE2 to membranes prepared from COS-7 cells transfected with Hup-4 was PGE2 > or = PGE1 > 16,16-dimethyl-PGE2 > or = 11-deoxy-PGE1 > butaprost > AH13205 > 19(R)-OH-PGE2. Natural PGs and analogues that are selective for the FP (PGF2a), DP (PGD2), EP1 (sulprostone), EP3 (MB 28767), and EP4 (1-OH-PGE1) receptors were inactive or competed poorly with the binding of [3H]PGE2 (< 50% displacement of specific binding at 10 microM). Northern blot analysis showed the presence of a Hup-4 message of approximately 3.1 kilobases in mRNA from human lung and placenta. Reverse transcription-polymerase chain reaction studies also indicated that Hup-4 is probably expressed in human uterus and in HL-60 (human promyelocytic leukemia) cells. Our findings suggest that Hup-4 encodes the pharmacologically defined EP2 receptor, whereas the mouse and human cDNAs previously classified as EP2 may represent another EP receptor subtype or the recently defined EP4 subtype [Prostaglandins 47:151-168 (1994)].

Adenylyl Cyclases↗
PubMed1993

Congenital histiocytosis X.

Congenital histiocytosis X involving multiple organs is a rare disease that causes rapid mortality in intrauterine and neonatal life. The diagnosis of histiocytosis X (Letterer-Siwe disease) should be considered in a neonate with vesiculated crusting skin lesions. We present clinical, radiographic and histopathological findings in a neonate with congenital histiocytosis who died of respiratory failure due to diffuse infiltration of lungs with histiocytic cells.

Diagnosis, Differential↗
PubMed1992

Cariostatic and ultraconservative sealed restorations: six-year results.

The objective of this clinical study was to determine the ability of an ultraconservative, sealed composite resin restoration, without a traditional cavity preparation and without the removal of the carious lesion, to arrest Class I caries. Tooth preparation was limited to placing a bevel in the enamel. These restorations were compared, over 6 years, with (1) ultraconservative, localized, sealed amalgam restorations with no extension for prevention and (2) traditional, unsealed amalgam restorations with the usual extension for prevention outline form. Caries was arrested by the ultraconservative, sealed composite resin restorations for 6 years. Complete sealant retention on the sealed amalgam restorations was somewhat lower than that on the sealed composite resin restorations; conversely, partial sealant retention was higher for the sealed amalgam group. The marginal integrity of the sealed amalgam restorations was significantly superior to that of the unsealed amalgam restorations. The sealant also protected Class I posterior composite resin restorations against wear.

Adolescent↗
PubMed1992

Sealed restorations: 5-year results.

This clinical study determined the feasibility of a sealed resin composite restoration to arrest dental caries using a minimal tooth preparation: a bevel in enamel only without removal of the carious lesion. These ultra-conservative sealed composite restorations placed over caries (CompS/C) were compared with ultra-conservative sealed amalgam restorations (AGS) that had no "extension for prevention". The CompS/C restorations were also compared with the traditional (unsealed) amalgam restorations (AGU) with the "extension for prevention" outline form. Caries progress, as determined by standardized radiographs, revealed that after 5 years caries remained arrested under the CompS/C restorations; the marginal integrity was similar for the CompS/C and the AGS groups, and exhibited highly significant superiority to the AGU restorations (Chi square, P less than = 0.00004). Complete sealant retention over the amalgam restorations (AGS group) was less than over the composite restorations (CompS/C), and conversely, partial sealant retention was higher for the AGS group. Sealants also appeared to protect the posterior composite restorations against wear.

Adolescent↗
PubMed1991

Ultraconservative sealed restorations: three-year results.

The overall objective of this clinical study was to determine the feasibility of using a sealed composite restoration to arrest caries without the removal of the carious lesion and without the traditional cavity preparation. The minimal tooth preparation (a bevel in enamel) usually did not require any anesthetic injection and conserved tooth structure. These ultraconservative sealed composite restorations placed over caries (CompS/C) have been compared with ultraconservative sealed amalgam restorations (AGS) and with the traditional outline form (unsealed) amalgam restorations (AGU). This clinical study has shown that: (1) caries can be arrested by the CompS/C restoration for a period of three years; (2) the marginal integrity of the AGS restorations showed a definite trend toward improvement as compared to the AGU restorations; and (3) complete sealant retention over posterior restorations was similar in both the CompS/C and the AGS groups during the first two years; however, at Year 3 complete sealant retention was 16 percent higher in the CompS/C than in the AGS group.

Adolescent↗
PubMed1991

Sealed restorations: 4-year results.

The overall objective of this clinical study was to determine the feasibility of using a sealed composite restoration to arrest caries. This objective was to be achieved using minimal tooth preparation for Class I lesions, without the traditional Class I cavity preparation and without the removal of the carious lesion. The minimal tooth preparation consisted of no [corrected] removal of the carious lesion, bevel in enamel only, and usually not requiring any anesthetic injection. These ultra-conservative sealed composite restorations placed over caries (CompS/C) were compared with ultra-conservative sealed amalgam restorations (AGS) and with the traditional (unsealed) amalgam restorations (AGU). This study showed that: 1) caries is arrested under the CompS/C restoration for a period of 4 years; 2) sealant retention is similar in both the CompS/C and the AGS groups; 3) the marginal integrity of the AGS restorations is markedly superior to that of the AGU restorations; and 4) sealant appears to prevent wear of posterior composite restorations.

Adolescent↗
PubMed1989

Dentists' professional satisfaction with adolescent dentistry and its association with adolescent dental health behavior.

This study examines dentists' perceptions of behaviors felt to interfere with providing adequate dental care to adolescents. We analyzed gender differences, and whether the dentists' perceptions of adolescent patients were associated with their professional satisfaction. A stratified random sample of 227 graduates (males = 180, females = 47) from a Southern dental school were asked to complete a questionnaire assessing professional satisfaction. Based on Kruskall-Wallis analysis of variance tests, female dentists expressed generally higher levels of satisfaction than males with adolescent dentistry, diagnosis and treatment planning, patient education, preventive procedures, and the adolescent dentistry curricula during dental school. Male dentists felt that the male adolescents' failure to keep appointments, communication problems, seeking dental care only in emergency situations, and resentment of authority interfered more with their providing adequate dental care than did female dentists. Male dentists also felt that the female patients' menstrual period, communication problems, low tolerance of pain, seeking dental care only in emergency situations, and resentment toward authority were more significant problems than did the female dentists. Communication problems with both male and female adolescents were more strongly correlated with the dentists' satisfaction with adolescent dentistry than any other variable.

Adolescent↗