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M Dale

Publications and source records attributed to M Dale.

At least 19 recordsLinked to original sources
PubMed2001

Expression, candidate gene, and population studies of the melanocortin 5 receptor.

In mouse the melanocortin 5 receptor is known to regulate sebaceous gland function. To clarify its role in man, we have studied melanocortin 5 receptor expression in skin, and allelic variation at the melanocortin 5 receptor locus in diverse human populations and candidate disease groups. Melanocortin 5 receptor protein and mRNA expression were studied by immunohistochemistry and reverse transcriptase polymerase chain reaction. Melanocortin 5 receptor mRNA was detected in normal skin and cultured keratinocytes but not in cultured fibroblasts or melanocytes. Immunohistochemistry revealed melanocortin 5 receptor immunoreactivity in the epithelium and appendages, including the sebaceous gland, eccrine glands, and apocrine glands, as well as low level expression in the interfollciular epidermis. In order to screen for genetic diversity in the melanocortin 5 receptor that might be useful for allelic association studies we sequenced the entire melanocortin 5 receptor coding region in a range of human populations. One nonsynonymous change (Phe209Leu) and four synonymous changes (Ala81Ala, Asp108Asp, Ser125Ser, and Thr248Thr) were identified. Similar results were found in each of the populations except for the Inuit in which only the Asp108Asp variant was seen. The apparent "global distribution" of melanocortin 5 receptor variants may indicate that they are old in evolutionary terms. Variation of melanocortin 5 receptor was examined in patients with acne (n = 21), hidradenitis supprativa (n = 4), and sebaceous gland lesions comprising sebaceous nevi, adenomas, and hyperplasia (n = 13). No additional mutations were found. In order to determine the functional status of the Phe209Leu change, increase in cAMP in response to stimulation with alpha-melanocyte-stimulating hormone was measured in HEK-293 cells transfected with either wild-type or the Phe209Leu variant. The variant melanocortin 5 receptor was shown to act in a concentration-dependent manner, which did not differ from that of wild type. We have therefore found no evidence of a causative role for melanocortin 5 receptor in sebaceous gland dysfunction, and in the absence of any association between variation at the locus and disease group, the pathophysiologic role of the melanocortin 5 receptor in man requires further study.

Acne Vulgaris↗
PubMed2000

COP I domains required for coatomer integrity, and novel interactions with ARF and ARF-GAP.

We performed a systematic mapping of interaction domains on COP I subunits to gain novel insights into the architecture of coatomer. Using the two-hybrid system, we characterize the domain structure of the alpha-, beta'-, epsilon-COP and beta-, gamma-, delta-, zeta-COP coatomer subcomplexes and identify links between them that contribute to coatomer integrity. Our results demonstrate that the domain organization of the beta-, gamma-, delta-, zeta-COP subcomplex and AP adaptor complexes is related. Through in vivo analysis of alpha-COP truncation mutants, we characterize distinct functional domains on alpha-COP. Its N-terminal WD40 domain is dispensable for yeast cell viability and overall coatomer function, but is required for KKXX-dependent trafficking. The last approximately 170 amino acids of alpha-COP are also non-essential for cell viability, but required for epsilon-COP incorporation into coatomer and maintainance of normal epsilon-COP levels. Further, we demonstrate novel direct interactions of coatomer subunits with regulatory proteins: beta'- and gamma-COP interact with the ARF-GTP-activating protein (GAP) Glo3p, but not Gcs1p, and beta- and epsilon-COP interact with ARF-GTP. Glo3p also interacts with intact coatomer in vitro.

ADP-Ribosylation Factors↗
PubMed1999

Interleukin-1 receptor cluster: gene organization of IL1R2, IL1R1, IL1RL2 (IL-1Rrp2), IL1RL1 (T1/ST2), and IL18R1 (IL-1Rrp) on human chromosome 2q.

The family of interleukin-1 receptor-like genes currently has six known members. We have constructed a contig of 10 overlapping human PAC clones that covers 530 kb and includes five of the six family members. The termini of the contig were mapped to the interval between D2S373 and D2S176 (chromosome 2q12) by radiation hybrid mapping. The contig contains the genes (cen --> tel), in the order given, for the type II interleukin-1 (IL-1) receptor (IL1R2), the type I IL-1 receptor (IL1R1), the IL-1 receptor-related protein 2 (IL1RL2), T1/ST2/fit-1 (IL1RL1), and the IL-1 receptor-related protein 1, which has recently been shown to be a component of the IL-18 receptor (IL18R1). We show that all the genes are transcribed in the same direction, with IL1R2 being transcribed toward the cluster. The only known family member that is absent from the human contig is the IL-1 receptor accessory protein gene (IL1RAP), which maps to 3q28.

Blotting, Southern↗
PubMed1999

Dual roles of p82, the clam CPEB homolog, in cytoplasmic polyadenylation and translational masking.

In the transcriptionally inert maturing oocyte and early embryo, control of gene expression is largely mediated by regulated changes in translational activity of maternal mRNAs. Some mRNAs are activated in response to poly(A) tail lengthening; in other cases activation results from de-repression of the inactive or masked mRNA. The 3' UTR cis-acting elements that direct these changes are defined, principally in Xenopus and mouse, and the study of their trans-acting binding factors is just beginning to shed light on the mechanism and regulation of cytoplasmic polyadenylation and translational masking. In the marine invertebrate, Spisula solidissima, the timing of activation of three abundant mRNAs (encoding cyclin A and B and the small subunit of ribonucleotide reductase, RR) in fertilized oocytes correlates with their cytoplasmic polyadenylation. However, in vitro, mRNA-specific unmasking occurs in the absence of polyadenylation. In Walker et al. (in this issue) we showed that p82, a protein defined as selectively binding the 3' UTR masking elements, is a homolog of Xenopus CPEB (cytoplasmic polyadenylation element binding protein). In functional studies reported here, the elements that support polyadenylation in clam egg lysates include multiple U-rich CPE-like motifs as well as the nuclear polyadenylation signal AAUAAA. This represents the first detailed analysis of invertebrate cis-acting cytoplasmic polyadenylation signals. Polyadenylation activity correlates with p82 binding in wild-type and CPE-mutant RR 3' UTR RNAs. Moreover, since anti-p82 antibodies specifically neutralize polyadenylation in egg lysates, we conclude that clam p82 is a functional homolog of Xenopus CPEB, and plays a positive role in polyadenylation. Anti-p82 antibodies also result in specific translational activation of masked mRNAs in oocyte lysates, lending support to our original model of clam p82 as a translational repressor. We propose therefore that clam p82/CPEB has dual functions in masking and cytoplasmic polyadenylation.

3' Untranslated Regions↗
PubMed1999

Combined sib-TDT and TDT provide evidence for linkage of the interleukin-1 gene cluster to erosive rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common disease of unknown aetiology which usually causes progressive destruction of the joints. Familial aggregation, twin studies and segregation analyses suggest that there is a genetic component to RA and the HLA-DRB1 locus in the major histocompatibility complex on chromosome 6 has been shown to be linked to, and associated with, RA susceptibility. It is likely that other genes with weaker effects are also involved, which may be difficult to detect using conventional parametric and non-parametric linkage methods. We have implemented the combined sib-TDT and TDT, in addition to parametric and non-parametric linkage methods, to investigate the candidate genes of the interleukin-1 (IL-1) gene cluster on chromosome region 2q13, since IL-1 is an important cytokine in the control of the inflammatory response that is central to RA pathology. Several tightly linked IL-1 cluster markers yielded suggestive evidence for linkage in the combined TDT in those families in which affected siblings did not share two HLA-DRB1 alleles identical by descent. The evidence was significant in those with severe disease, as assessed by the presence of bone erosions. In contrast, there was no evidence of linkage using non-parametric linkage analysis, but parametric analysis revealed weak evidence of linkage when marker-trait disequilibrium was incorporated into the analysis. The data provide preliminary evidence for linkage of genes of the IL-1 cluster to RA and suggest a possible role for this region in severe erosive disease.

Arthritis, Rheumatoid↗
PubMed1997

Effect and mechanisms of the anti-prolactin drug cabergoline on pseudopregnancy in the bitch.

A potent anti-prolactin drug, cabergoline, administered orally for five days, was clinically successful in treating three different clinical manifestations of pseudopregnancy in referred bitches. The clinical conditions treated were categorised as standard pseudopregnant bitches (n = 8), those previously unsuccessfully treated with hormones (n = 10) and those which had behavioural pseudopregnancy following ovariohysterectomy (n = 8). The number of bitches whose owners reported a 'good' response was seven out of eight, six out of 10 and six out of eight, respectively. There were very few side effects in that only one bitch vomited following treatment. The clinical response did not necessarily appear to be related to an alteration in circulating prolactin concentrations, suggesting that the drug may have a direct effect on the tissues as well as in most cases reducing the plasma prolactin concentrations.

Animals↗
PubMed1996

Unmasking mRNA in clam oocytes: role of phosphorylation of a 3' UTR masking element-binding protein at fertilization.

During meiotic maturation or after fertilization of invertebrate and vertebrate oocytes, many of the quiescent stored mRNAs are recruited into polysomes. In the clam, Spisula solidissima, such masked messages include the abundant mRNAs encoding cyclin A and the small subunit of ribonucleotide reductase. We have previously shown that mRNA-specific unmasking of these two messages can be achieved in vitro, in oocyte cell-free extracts, by the addition of antisense RNAs corresponding to a fairly short (130-140 nucleotides) segment in their cognate 3' untranslated regions. We postulated that the antisense RNAs prevented the binding of a masking repressor protein (Standart et al., 1990). Here we report UV-crosslinking and gel retardation studies which show that the masking portions of the translationally regulated mRNAs bind an oocyte protein of 82 kDa (p82), which is phosphorylated after fertilization. This modification was accompanied by altered RNP complex formation in gel retardation assays. These changes presumably reflect the activation of translation of the masked mRNAs. The role of p82 phosphorylation in maternal mRNA unmasking was assessed in a novel in vitro activation system developed from clam oocytes, based upon the natural rise in pH which accompanies fertilization. Concomitant with mRNA unmasking, several kinases, including cdc2 and MAP kinases were activated in this system, as was p82 phosphorylation. Inhibitors of serine/threonine kinases, including 6-DMAP, staurosporine, and H7 inhibited p82 phosphorylation, whereas inhibitors of tyrosine kinases, protein kinase C, cAMP-dependent protein kinase, and p70s6k did not prevent this modification. A specific inhibitor of cdc2 kinase, p27Kip1, prevented p82 phosphorylation and translational activation, strongly suggesting that p82 modification is required for unmasking.

Amino Acid Sequence↗
PubMed1993

Regulated polyadenylation of clam maternal mRNAs in vitro.

During meiotic maturation of Spisula oocytes, maternal mRNAs undergo changes in translation and in the length of their poly(A) tails. In general, those mRNAs that are translationally activated, i.e., unmasked, become polyadenylated, while deactivated mRNAs lose their poly(A) tails. The activated class of mRNAs encode ribonucleotide reductase, cyclins A and B and histone H3, while the proteins that stop being made include tubulin and actin. Previously, we demonstrated that mRNA-specific unmasking can be brought about in vitro by preventing the interaction of protein(s) with central portions of the 3' noncoding regions (masking regions) of ribonucleotide reductase and cyclin A mRNAs. In this report, we show that clam egg extracts are capable of sequence-specific polyadenylation of added RNAs since the 3' untranslated regions (UTRs) of ribonucleotide reductase and histone H3 mRNAs are polyadenylated, while that of actin mRNA is not. In contrast, oocyte extracts, as in vivo, are essentially devoid of polyadenylation activity. We present an initial characterisation of the cis-acting sequences in the 3' UTR of ribonucleotide reductase mRNA required for polyadenylation. The results suggest that the sequences for cytoplasmic polyadenylation are more complex and extensive than those determined in vertebrates and that they may partly overlap with the masking regions.

Animals↗
PubMed1991

Carpal orientation from computed reference axes.

Carpal instability is usually diagnosed by abnormal two-plane radiographic angles. These angles are often unreliable. A method that eliminates interpretation of overlapping shadows and uses all of the carpal geometry should improve clinical diagnoses. The digital data from computed tomography scans can be manipulated to describe the carpal orientation in the normal wrist. The digital data from the computed tomography scans of twenty-two normal wrists were used to compute distances with and without directions between the volumetric centroids of the carpal bones. An expansion technique also extracted from the computed tomography data an orthogonal set of vectors, the principal axes. The first principal axis describes the longest dimension of each bone. The average angle produced by the first principal axes of the scaphoid and lunate was 23.6 degrees, scaphoid and capitate was 73.2 degrees, and the capitate and the lunate was 93.5 degrees. These computations represent new carpal axes and intercarpal angles that are not related to the commonly measured two-plane radiographic angles. They should prove helpful in the study of kinematics and pathomechanics in the wrist joint.

Carpal Bones↗
PubMed1991

Computed analyses of the pathomechanics of scaphoid waist nonunions.

The computed tomography scans of both the injured and the normal wrists of nine patients with a scaphoid nonunion of 5 to 120 months' duration were used to create three-dimensional computer models. When the computer images of the normal and the contralateral fractured scaphoids were superimposed, it was possible to calculate the volume of bone that was lost as a result of the injury and its failure to heal, as well as the angular relationship of the fracture components to one another. The amount of the scaphoid bone that was lost varied from 6% to 15% of bone volume and did not show a linear correlation with the duration of the nonunion. The configuration of the missing bone was consistent and exhibited a prismatic shape whose base is quadrilateral and faces palmarly. The proximal scaphoid fracture component is extended, radially deviated, and supinated in relation to its distal fracture component. The consistent fracture deformity and the configuration of the bony defect in the scaphoid waist nonunions should be helpful in the understanding and treatment of the condition.

Adult↗
PubMed1990

Maternal mRNA from clam oocytes can be specifically unmasked in vitro by antisense RNA complementary to the 3'-untranslated region.

Clam oocytes display a striking difference in the pattern of protein synthesis on fertilization, which is maintained when cell-free extracts are assayed in the rabbit reticulocyte lysate. The mRNAs encoding ribonucleotide reductase and cyclin A (the major masked messages in the oocyte extracts) can be translationally activated by gel filtration in 0.5 M KCl, presumably by removal of repressor protein(s). When synthetic RNAs corresponding to different segments of ribonucleotide reductase and cyclin A mRNAs were added to oocyte extracts in 0.5 M KCl in a "competitive unmasking" assay, specific and complete unmasking of these mRNAs occurred on addition of antisense 3'-noncoding transcripts. The unmasking region in ribonucleotide reductase mRNA maps to a region of 134 nucleotides centered one-third of the way down the 3'-noncoding region.

Animals↗
PubMed1988

Mathematical analysis of computed carpal models.

The computed carpal models from digital computed tomography (CT) data obtained in this study compare favorably to natural anatomy. A new application of algebraic analysis of this data provides mathematical markers from which to calculate the position and orientation of each carpal bone. When the origin of the spatial coordinates of a carpal bone is transferred to the centroid of the bone, the data can be treated as three-dimensional pattern vectors describing its surface. It is then possible to calculate vectors that are the principal axes of the geometry. These axes provided references that were used to calculate position and orientation of the carpal bones in three wrist specimens. Comparisons of volumes, surface areas, and sizes and proportions of five computed images of each carpal bone from two of these wrists demonstrate the reliability of the technique. The analysis of CT scans of ceramics with known boundaries allows an estimation of its accuracy. The technique is well suited to the future study of normal wrist kinematics and pathological conditions.

Carpal Bones↗
PubMed1986

Scaphoid orientation and location from computed, three-dimensional carpal models.

Subtle subluxations within the carpus are often difficult to diagnose. Carpal orientation and location can now be quantified by mathematical analysis of computed, three-dimensional models produced from serial CT scans. The technique and its application in the analysis of scaphoid subluxation are described.

Biomechanical Phenomena↗
PubMed1985

An unusual computed tomography appearance of nasopharyngeal carcinoma: a case report.

The computed tomography findings of an unusual case of nasopharyngeal carcinoma are presented. Typical features of nasopharyngeal carcinoma from clinical, pathologic, and radiologic aspects are discussed. Atypical features of this case are presented, consisting of extensive muscular infiltration and lack of destruction of contiguous bony structures.

Adult↗
PubMed1981

A quantitative determination for the detection of immunoglobulin (IgG) on the surface of platelets.

A sensitive method for the quantitation of IgG on platelets had not been demonstrated until 1975, when Dixon, Rosse, and Ebbert described a quantitative antiglobulin consumption test useful in detecting platelet associated IgG (N Engl J Med 292:230, 1975). A modification of that technique has rendered the assay reproducible and removed the need for daily repetition of a standard IgG titration curve for quantitation. This modification utilizes 1-ethyl-3-3(dimethylaminopropyl)carbodiimide HCl (ECDI) (Sigma, E-7750), in place of chromic chloride, as a coupling agent for attaching IgG (Miles 64-145) to sheep cells (SRC), used as indicator cells. The ECDI consistently couples IgG to SRC and does not subject the SRC to sporadic spontaneous lysis, as does chromic chloride. This modification permits the detection of IgG on platelets (Direct Test), or in sera (Indirect Test) by incubation of a washed platelet pool with sera in vitro, and testing as in the Direct Test. Normal values of 0.01-1.56 and 0.14-1.6 femtograms (F) per platelet have been obtained for the Direct and Indirect Tests, respectively. In six cases of suspected ITP, values ranged 12.0-221.0 F and 2.9-37.6 F for the Direct and Indirect Tests, respectively. In conclusion, in disease states or other abnormal situations, quantities of IgG can be detected that are not usually present on the platelets of normal subjects.

Blood Platelets↗
PubMed1978

Terminal care.

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Fear↗